Dissertations / Theses on the topic 'Digestione acida'

I rifiuti prodotti dall'estrazione petrolifera si presentano come incrostazioni o fanghi oleosi e viscosi, che si formano all'interno delle tubazioni e dei condotti nelle riserve petrolifere, soprattutto in prossimità di angoli e gomiti. Il loro contenuto radioattivo è di origine naturale ed è composto principalmente da Ra-226. A causa dell'elevata quantità di materiale che supera i valori limite di 10 Bq/g, i NORM (Naturally Occurring Radioactive Materials) rappresentano un notevole problema di rifiuto per l'industria petrolifera. In questo elaborato si descrivono le proprietà dei materiali NORM ed il metodo della riduzione del volume di incrostazione oleosa. Inoltre si sviluppa il metodo di digestione acida, analizzando i rifiuti NORM. Lo scopo delle attività di laboratorio è quello di cercare di ridurre la quantità dei rifiuti prodotti dall'estrazione di petrolio, concentrando la radioattività in un'unica fase. Una prova è stata svolta sul campione tal quale, mentre l'altra è stata eseguita sottoponendo il campione ad un pre-trattamento termico. Infine sono stati descritti alcuni metodi di smaltimento relativi ai rifiuti NORM.

Several biological abnormalities exist between the ruminant and nonruminant small intestine and influences carbohydrate assimilation. Two experiments were conducted to identify potential mechanisms to improve carbohydrate utilization in cattle. Experiment 1 evaluated the effects of duodenal starch infusions with casein or glutamic acid on post-ruminal carbohydrase activities. Experiment 2 evaluated the effects of dietary fructose on visceral organ development and expression of nutrient transporters and digestive enzymes involved in carbohydrate assimilation. In experiment 1, the results suggest that small intestinal starch digestion may be improved in cattle with increased small intestinal flow of casein through increases in post-ruminal carbohydrase activities. In experiment 2, dietary fructose supply influenced nutrient utilization, visceral organ growth, and digestive enzyme mRNA expression and activity in neonatal calves.

Digestion of titaniferous slag (Sorelslag) with sulphuric acid was studied in an effort to optimise the process and develop a better understanding of its chemistry.
Thermodynamic analysis of the digestion reaction was performed using the program F*A*C*T. A laboratory reactor was built to simulate the operation of an industrial slag digestion reactor. Microstructure examinations of digestion samples revealed the main phases present.
Statistically designed experiments using the Box-Behnken technique were performed in the laboratory to correlate the responses (digestion yield, maximum temperature, solidification time, degree of Ti$ sb2$O$ sb3$ oxidation, sulphuric acid loss in the gas, active acid/titanium ratio and cake height) to the four experimental variables (particle size of the slag, acid concentration, acid/slag weight ratio and baking time).
Model equations successfully tested were obtained for each response. The analysis of the figures obtained from those equations revealed the relative importance of the variables evaluated. In complement to these experimental results the qualitative mass and heat balances were calculated.

An investigation was carried out to study whether long-chain fatty acids (LCFAs) have an effect on digestion of waste sludge under anaerobic conditions. Four different kinds of LCFAs were used in this study. The 18 carbon series with 0, 1, 2 and 3 double bonds were studied to evaluate the degree of saturation on fatty acid degradation. Due to their molecular structure, unsaturated LCFAs are more soluble than saturated LCFAs. Oleic, linoleic, linolenic acid with an ascending number of double bonds were tested as representatives for three different degrees of saturation. In addition, stearic acid, a saturated fatty acid was also tested. LCFAs were added to sewage sludge at concentrations ranging from 5% to 20% on a weight basis and the pH, solids reduction and COD reduction were determined. The results suggested that in addition to degrading in the digesters, all unsaturated acids contributed additional solids removal, compared to the control group. In contrast, stearic acid did not affect the solids removal. The COD reduction was similar to solids reduction in that additional COD was destroyed when unsaturated LCFAs were added to the sludge. The mechanism for additional solids reduction is not known.
Master of Science

Acidogenic codigestion of fats, oils, and greases (FOG) was studied at 37"C using suspended sludge digesters operated as sequencing batch reactors (SBRs). Volatile fatty acid (VFA) production was found to increase with larger FOG loading rates, although this increase was insignificant compared the theoretical VFA production from FOG addition. Long chain fatty acids (LCFAs) were found to have accumulated in the reactor vessel in semi-solid balls that were primarily composed of saturated LCFAs. Adding high FOG loadings to an APD not acclimated to LCFAs allowed for a mass balance calculation and resulted in near complete saturation of unsaturated LCFAs and significant accumulation of LCFA material in the digester, which was found to be mostly 16:0, 18:0, and 18:1. While 18:2 and 18:3 LCFAs were nearly completely removed, 18:0 and 14:0 LCFAs were produced, most likely from the degradation of 18:2 and 18:3 LCFAs. The APD pH was found to have a significant impact on the amount of accumulated LCFA material present, with higher pH levels resulting in less accumulated material. Two-phase codigestion of FOG was also studied using an APD followed by gas-phase (GPD) digesters. The two-phase systems were compared by FOG addition to the APD versus GPD. FOG addition to the APD resulted in 88% destruction of LCFAs, whereas FOG addition to the GPD resulted in 95% destruction of LCFAs. Accumulated LCFAs in the APD receiving FOG were composed mostly of stearic acid (18:0). The low pH of the APD is likely the cause of LCFA accumulation due to saturation of unsaturated LCFAs.
Master of Science

Los aceites ácidos son co-productos que derivan del proceso de refinación de los aceites para consumo humano (oleínas; aceites ácidos de refinación química y ácidos grasos destilados de refinación física). Se caracterizan por presentar un perfil en ácidos grasos (AG) similar al de los aceites crudos de los que derivan, pero se diferencian en su estructura molecular, ya que tienen un alto contenido en ácidos grasos libres (AGL), lo que puede afectar a su valor nutricional. El objetivo de la presente tesis es profundizar en el estudio de los procesos de digestión y absorción de la grasa en pollos de carne y determinar cómo se ven afectados por el nivel de saturación y nivel de AGL de la dieta y edad de los pollos. El primer ensayo (Capítulo 3) se llevó a cabo con el fin de evaluar el efecto del grado de saturación de la dieta y edad del pollo (14 d y 35 d) sobre los procesos de digestión y absorción de la grasa. Para ello se utilizaron dietas con un 6% de aceite crudo de soja y aceite crudo de palma. El segundo ensayo (Capítulos 4 y 5) se llevó a cabo para estudiar el efecto del nivel de AGL y grado de saturación de la dieta, así como también de la edad (14 d y 37 d) sobre los procesos de digestión y absorción de la grasa. Se utilizaron ocho dietas experimentales con dos grados de saturación (derivados del aceite de soja como fuente insaturada y del aceite de palma como fuente saturada) y cuatro niveles de acidez (5%, 15%, 35% y 50%). Para ello, se combinaron dos aceites crudos y dos co-productos ricos en AGL (oleínas). En ambos estudios se determinó la digestibilidad de los AG y el contenido en fracciones lipídicas a lo largo del tracto gastrointestinal (TGI; molleja, duodeno, yeyuno e íleon) y excreta. Los resultados demuestran que el yeyuno es el principal lugar de absorción de los AG y que la absorción está más afectada por la edad, grado de saturación y nivel de AGL de la dieta que la hidrólisis. La mayor utilización de las dietas insaturadas se confirmó tanto en pollos jóvenes como adultos y se relacionó con una mayor capacidad de absorción de los AG saturados a nivel del íleon. La mejora en la utilización de la grasa en pollos adultos se relacionó con una mayor absorción de los AG a nivel de yeyuno. Los resultados también evidencian que los pollos adultos (37 d) se vieron menos afectados por el nivel de AGL en la dieta que los pollos jóvenes (14 d), debido a que en los primeros la absorción de los AG a nivel de yeyuno fue más eficiente. Otro hallazgo interesante es que el aceite crudo de soja podría ser parcialmente reemplazado por el aceite ácido de soja de refinación química , cómo grasa alternativa, siempre y cuando no se supere el 15% y 35% de AGL en dietas de inicio y crecimiento-acabado, respectivamente. Por otro lado, no se observaron diferencias destacables entre los resultados obtenidos con dietas saturadas con 50% y 5% de AGL, lo que lleva a sugerir que el aceite ácido de palma (ácidos grasos destilados de refinación física de palma) podría reemplazar el aceite crudo de palma en dietas de crecimiento-acabado, al menos cuando no se supera el 50% de AGL de la dieta, sin que se produzcan repercusiones negativas sobre la utilización de la grasa de la dieta.
Acid oils, fat by-products from the edible oil refining industry, are rich in free fatty acids (FFA), have similar fatty acid (FA) composition to their respective crude oils, but different molecular structures, which can affect their nutritional value. The aim of the present thesis is to study in depth the digestion and absorption of fat in broiler chickens, and determine how the age of the chickens, the saturation degree and the FFA level of dietary fat affect these processes in order to raise recommendations on the use of oils with certain percentages of FFA in the diets with no negative repercussions on fat utilization. The first trial (Chapter 3) was conducted in order to study the effect of the dietary fat saturation degree and age (14 d and 35 d) on the fat digestion and absorption processes. For this purpose the dietary use of crude soybean oil and crude palm oil was studied. The second trial (Chapters 4 and 5) was conducted to assess the effect of the dietary FFA level, fat saturation degree and age (14 d and 37 d) on fat digestion and absorption processes. Two crude oils and two fat by-products from the edible oil refining industry rich in FFA were used in order to produce eight dietary treatments with two different saturation degrees (soybean oil products as unsaturated fat source, and palm oil products as saturated fat source), and four levels of dietary FFA (5%, 15%, 35%, and 50%). In both trials the FA digestibility and lipid class composition were determined along the gastrointestinal tract (GIT; gizzard, duodenum, jejunum, and ileum), and excreta. The results evinced that the absorption process mainly takes place in the jejunum, and is more affected than the hydrolysis process is by the saturation degree and free fatty acid level of dietary fat, as well as by the age of the chicken. The greater utilization of unsaturated diets irrespective of the age was confirmed, which was mainly due to the higher contribution of the ileum, especially to saturated FA absorption. The improvement on fat utilization in adult broiler chickens was due to an increase in the contribution of the jejunum to FA absorption. The results also evinced that adult broiler chickens (37 d) were less affected by the dietary FFA level than young broiler chickens (14 d) were due to a more efficient FA absorption at the jejunum level. Another interesting finding is that crude soybean oil could be partially replaced by acid soybean oil from chemical refining, being a good alternative fat source to be used in broiler chicken diets at least when the dietary FFA level does not exceed 15% and 35% in starter and grower-finisher diets, respectively. On the other hand, the saturated diet with 50% dietary FFA level did not differ from the saturated diet with the lowest dietary FFA level (5%), suggesting that acid palm oil (palm fatty acid distillate) could replace crude palm oil in grower-finisher diets, at least when the FFA level does not exceed 50% with no negative repercussions on fat utilization compared to the use of crude palm oil. Regardless of the age, it was concluded that the FA profile of dietary fat has a bigger impact on fat utilization than the level of dietary FFA.

Two different sludge pretreatments were investigated in an attempt to improve the management and performance of processes for the co-digestion of biosolids with fats, oils, and grease (FOG). The mechanisms of long chain fatty acids (LCFA) degradation in thermal hydrolysis pretreatment and the influence of pH on LCFA degradation in two-phase co-digestion systems were studied. LCFA thermal hydrolysis was investigated at different temperatures (90-250 °C) and reaction times (30 minutes and 8 hours). Approximately 1% of saturated fatty acids were degraded to shorter chain fatty acids at 140 and 160 °C (8-hr thermal hydrolysis). Only 1% or less of unsaturated fatty acids were degraded from 90 to 160 °C (8-hr thermal hydrolysis). Little degradation (< 1%) of both saturated and unsaturated LCFAs was observed at a 30-min reaction time. Both groups of LCFAs were stable up to 250 °C (30-min hydrolysis). The use of chemical-thermal treatments was also investigated. Only unsaturated LCFAs, C18:1 and C18:2, were degraded when thermally hydrolyzed with hydrogen peroxide coupled with activated carbon or copper sulfate. Semi-continuous, acid-phase digesters (APDs) under different pH conditions were studied in order to understand the effects of pH on FOG degradation. Increases in soluble chemical oxygen demand (SCOD) were observed in all APDs. However, the APDs with pH adjustment appeared to perform better than the controls in terms of solubilizing organic compounds. Approximately 38% and 29% of total COD (TCOD) was solubilized, and maximum volatile fatty acid (VFA) concentrations of 10,700 and 7,500 mg/L TCOD were achieved at pH 6 and 7, respectively; It is useful to note that the feed sludge had a VFA concentration of 2,700 mg/L COD. Higher pH (6.0-7.0) showed less accumulation of LCFA materials and more soluble LCFAs in the APDs. This indicates that the lower pH in the APDs was most likely the cause of precipitation and accumulation of LCFAs due to saturation of unsaturated LCFAs.
Master of Science

A series of lab-scaled digestion studies including conventional mesophilic anaerobic digestion(MAD), thermophilic anaerobic digestion (TAD) at a range of treatment temperatures, and mesophilic high solids digestion of thermally pretreated wastewater sludge (THD) were carried out. Enhanced digestion performance in terms of solids destruction and methane generation by THD relative to MAD was achieved, and was largely attributable to the solubilization and subsequent biodegradation of energy-rich substrates within blended primary and secondary sludge. TAD was observed to underperform MAD, especially at elevated temperatures as methanogenic inhibition resulted in the accumulation of headspace hydrogen, thus resulting in poor removal of volatile fatty acids. The thermodynamics of fatty acid metabolism was favorable at each digestion temperature, thus it was concluded that microbial inhibition was the controlling factor in poor thermophilic performance. Inhibition by free unionized ammonia (NH₃) was characterized for THD and MAD biomass. Acetic acid degradation was equally affected over a range of NH₃ concentrations; however, methane generation by THD was less sensitive to ammonia inhibition, thus suggesting that methanogenesis by THD was less dependent on the NH₃-sensitive process of aceticlastic methanogenesis. Total ammonia nitrogen (TAN) and bicarbonate alkalinity were stoichiometrically produced from proteinaceous material during thermal hydrolytic pretreatment and subsequent high solids anaerobic digestion. Combined effects of TAN and high pH resulted in NH₃-inhibition during THD. Kinetic evaluations suggested that a growth rate reduction of approximately 65% was associated with in-situ NH₃ concentrations of the THD reactor. NH₃-inhibition was apparently responsible for a shift in dominant methanogenic community of the aceticlastic Methanosarcina barkeri in MAD to the hydrogenotrophic Methanoculleus bourgensis in THD. A similar shift in methanogenic community was observed between low temperature thermophilic digestion at 47°C, where the dominant order was Methanosarcinales, to high temperature thermophilic digestion at 59°C where the dominant order was Methanobacteriales. These findings support a process-driven pathway shift from aceticlastic to non-aceticlastic methanogenesis between 180 and 290 mg/L NH₃-N. Such a threshold is supported by previous literature related to ammonia tolerance of pure cultures of methanogens and has significant implications for the kinetic design of advanced anaerobic digestion processes.
Ph. D.

Two studies were conducted to evaluate the effects of diet on phosphorus (P) digestion in dairy cattle. The objective of the first study was to evaluate the effects of forage and non-fiber carbohydrate (NFC) content on total P (TP) and inositol phosphates-P (IPs-P) digestion. Samples of feed, duodenal digesta and feces from a previously conducted study were analyzed for TP and IPs-P. In this study, eight lactating Holstein cows were fed diets containing either 60 or 35% forage and either 30 or 40% NFC in a 2 × 2 factorial with replicated 4 × 4 Latin square design. Dietary TP content (% DM) was 0.35, 0.36, 0.36, 0.36 and dietary IPs-P content (%DM) was 0.08, 0.13, 0.06, 0.11 for diets with forage: NFC ratio 35:30, 35:40, 60:30, and 60:40, respectively. Increasing dietary forage content decreased IPs-P and TP intake, fecal TP excretion, and total tract IPs-P digestibility (72.4 vs. 61.4%). Fecal IPs-P excretion tended to decrease as increasing forage content. Duodenal IPs-P and TP flow and apparent TP digestibility were unaffected by forage content. Increasing dietary NFC content increased IPs-P and TP intake, duodenal IPs-P flow, fecal IPs-P excretion, total tract IPs-P digestibility (61.4 vs. 72.4%), and apparent TP digestibility (32.8 vs. 41.6%). Dietary forage and NFC content affected IPs-P and TP digestion. The second study was to evaluate the effects of increasing dietary beet pulp (BP) content to replace high moisture corn (HMC) on ruminal and post-ruminal digestion of TP and IPs-P. Eight lactating Holstein cows were fed diets containing 0, 6.1, 12.1 or 24.3% BP in a replicated 4 × 4 Latin square design. Samples of rumen contents, duodenal digesta, and feces from this previously conducted study were analyzed for TP and IPs-P content. Linear and quadratic effects of BP content were analyzed using Proc Mixed of SAS. Dietary TP and IPs-P content were reduced linearly with increasing BP (0.59, 0.58, 0.57, 0.56% TP and 0.15, 0.14, 0.13, 0.11% IPs-P). Intake, ruminal content, and rumen pool size of TP decreased with increasing BP content. Digestion of TP and duodenal flow and fecal excretion of IPs-P and TP were not affected. With increasing dietary BP content, IPs-P intake was reduced, ruminal IPs-P pool size was reduced, and rumen turnover time (h) of IPs-P was increased. Apparent ruminal IPs-P digestibility (36.5, 31.8, 24.6, 13.6 %) and apparent total tract IPs-P digestibility (85.3, 82.7, 82.1, 79.1%) decreased linearly with increasing BP. Fecal excretion of IPs-P averaged 5.2 g/d. Replacing HMC with BP reduced digestion of IPs-P. The majority of IPs-P disappearance occurred post-ruminally. In conclusion, dietary BP, forage, and NFC content affected IPs-P digestion in dairy cows.
Master of Science

Organosilicon compounds, which are heavily utilized in personal care products, are typically present, sometimes in high concentrations in the influent of wastewater treatment facilities. During anaerobic sludge digestion, these compounds volatilize and enter the methane gas recovery stream. As the methane is combusted for energy cogeneration, these compounds become oxidized to microcrystalline silicon dioxide and cause damage and potential failure of expensive infrastructure. Adsorption and other catchment methods are typically utilized for removal of these volatilized compounds in order to mitigate their entrance into methane combustion systems. This research investigated the effect of phased anaerobic digestion, specifically acid-gas digestion, on the behavior of the volatilization of these organosilicon compounds, particularly octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) as these are the most abundant volatile silicone compounds present in sludge. A bench scale acid reactor anaerobic digester was operated at varying solids retention times and temperatures in order to quantify biogas effects generated in the downstream gas reactor, which was operated at a constant mesophilic conditions. Results of the research indicated that the addition of an acid reactor did not cause a change in behavior of the D4 and D5 siloxane volatilization in the downstream gas reactor. However, it was observed that hydrogen sulfide gas was decreased in the gas reactor when an acid reactor was utilized, which could permit decreased corrosivity of biogas recovery. Cumulative volatile solids reduction and gas reactor methane yield data did not indicate an enhancement due to utilization of acid-gas digestion.
Master of Science

Doctor of Philosophy
Department of Animal Sciences and Industry
Evan C. Titgemeyer
Previous data suggest that greater amounts of postruminal protein increase small intestinal starch digestion in cattle. Duodenally and ileally cannulated steers were used in 5 studies to measure responses in small intestinal starch digestion to amino acids (AA) or casein. Flows of starch to the ileum from the diet were small. Small intestinal starch digestibility was 34.0% when raw cornstarch was continuously infused into the duodenum. Infusion of casein linearly increased (P ≤ 0.05) small intestinal starch digestibility, and small intestinal starch digestion adapted to infusion of casein in 6 d. Ethanol-soluble starch and unpolymerized glucose flowing to the ileum increased linearly (P ≤ 0.05) with increasing infusion of casein. Plasma cholecystokinin was not affected by casein infusion, but circulating levels of glucose increased linearly (P ≤ 0.05). In another study, 5 steers were fed a low-starch diet and provided continuous duodenal infusion of raw cornstarch in combination with AA or casein in order to measure response of small intestinal starch digestion. Duodenal infusion of casein increased (P ≤ 0.05) small intestinal starch digestion. When a mixture of AA with a profile similar to casein (CASAA) was infused, small intestinal starch digestion was similar (P = 0.30) to casein infusion. Infusion of only non-essential AA tended to increase (P = 0.14) small intestinal starch digestion relative to control; however, infusion of essential AA alone did not affect (P = 0.84) small intestinal starch digestion. Additionally, infusion of casein or essential AA increased ileal flows of ethanol-soluble starch, but non-essential AA alone were not different than the negative control. Duodenal infusion of Glu increased (P ≤ 0.05) small intestinal starch digestion, whereas a mixture of Phe, Trp, and Met (PTM) did not. Neither Glu nor PTM increased ileal flow of ethanol-soluble starch, but Glu and PTM provided together tended (P = 0.07) to increase ileal flows of ethanol-soluble starch. Our data suggest that Glu alone can increase small intestinal starch digestion in cattle similar to casein, but increases in small intestinal starch digestion in response to Glu are not associated with an increase in ileal flows of ethanol-soluble starch.

Els residus carnis, o subproductes animals, són interessants per al procés de digestió
anaeròbia i producció de biogàs, donat el seu elevat potencial energètic i l'actual marc legislatiu que prima la producció d'energia renovable. Tot i així, l'elevat contingut en lípids i proteïnes d'aquests residus pot limitar el seu tractament en introduir fenòmens d'inhibició, dels quals el més important és el produït pels àcids grassos de cadena llarga (AGCL), resultants de la hidròlisi dels lípids. L'objectiu de la present tesis és aprofundir en el coneixement d'aquest procés d'inhibició, en la capacitat d'adaptació dels microorganismes i en la recuperació o prevenció dels fenòmens d'inhibició. En una primera aproximació a la problemàtica, es caracteritzen residus orgànics d'escorxador, s'estudia la seva biodegradabilitat anaeròbia amb diferents relacions lípids/proteïnes i es realitzen assaigs discontinus seqüencials incrementant la concentració de substrat mitjançant pulsos consecutius. Es comprova que la hidròlisi i acidogènesi de proteïnes és molt ràpida i que la degradació dels lípids i AGCL limita la velocitat global del procés. Malgrat aquesta limitació, el sistema es recupera després dels pulsos aplicats, tot augmentant la taxa màxima de producció de metà. Per tal d'estudiar el fenòmen de recuperació, s'estudien i desenvolupen diferents estratègies en reactors sotmesos a processos d'inhibició per AGCL. L'increment dels ratis biomassa/AGCL o l'adició d'additius com la bentonita, per tal de reduir la biodisponibilitat o l'adsorció dels AGCL sobre la biomassa activa, es mostren com estratègies funcionals d'utilitat en l'operació de plantes industrials. Els resultats obtinguts reforcen la hipòtesi de que la inhibició és deguda a adsorció d'AGCL sobre la membrana cel·lular i que la recuperació es pot mesurar mitjançant un augment de l'activitat dels microorganismes. Per tal de dilucidar sobre la natura del augment de l'activitat en els processos de recuperació es caracteritza la inhibició-recuperació mitjançant tres tècniques: 1) estudi de les activitats dels microorganismes a diferents substrats 2) utilització de tècniques de biologia molecular per caracteritzar les poblacions, i 3) desenvolupant expressions cinètiques del procés d'inhibició, basades en l'adsorció, en el marc del model matemàtic ADM1 de la International Water Association. Mitjançant aquestes metodologies es comprova que els fenòmens d'inhibició i adaptació es poden explicar mitjançant un creixement poblacional específic i la inclusió dels fenòmens físic d'adsorció en el procés d'inhibició metabòlica. Finalment, s'avalua de forma més detallada el procés d'adsorció-inhibició mitjançant la determinació de les isotermes d'adsorció i monitoritzant mitjançant assaigs amb biomassa granular i tècniques de microscòpia de fluorescència. Aquesta caracterització ha permès obtenir estratègies de prevenció de la inhibició per AGCL, mitjançant competència amb adsorbents sintètics, i concloure que l'àcid palmític és el limitant en el procés de -oxidació
dels AGCL. Els resultats obtinguts constitueixen una base per al millor coneixement de les possibilitats de tractament anaerobi del residus carnis i dels processos d'inhibició per AGCL i adaptació de la biomassa. El procés físic d'adsorció ha estat directament relacionat amb el fenòmen d'inhibició metabòlica, obtenint-se una descripció matemàtica del mateix. Els resultats han permès plantejar estratègies operacionals, sent una eina a disposició d'operadors de plantes de biogàs per optimitzar la producció d'energia d'aquests residus >mitjançant la seva digestió anaeròbia.
Los residuos cárnicos, o subproductos animales, son interesantes para el proceso de digestión anaerobia y producción de biogás, dado su elevado potencial energético y el actual marco legal que prima la producción de energía renovable. A pesar de esto, el elevado contenido en lípidos y proteínas puede limitar su tratamiento, al introducir fenómenos de inhibición, de los cuales el más importante es el producido por ácidos grasos de cadena larga (AGCL), resultado de la hidrólisis de los lípidos. El objetivo de la presente tesis es profundizar en el conocimiento de este proceso de inhibición, en la capacidad de adaptación de los microorganismos t en la recuperación de sistemas inhibidos. En una primera aproximación a la problemática, se caracterizan los residuos orgánicos de matadero, se estudia su biodegradabilidad anaerobia con diferentes relaciones lípido/proteína y se realizan ensayos discontinuos secuenciales incrementando la concentración de substrato mediante pulsos consecutivos. Se comprueba que la hidrólisis y acidogénesis de las proteínas es muy rápido y que la degradación de lípidos y AGCL limita la velocidad global del proceso. A pesar de esta limitación, el sistema se recupera después de los pulsos aplicados aumentando la tasa máxima de producción de metano. A fin de estudiar el fenómeno de recuperación, se estudian y desarrollan diferentes estrategias en reactores inhibidos por AGCL. El incremento de los ratios biomasa/AGCL o la adición de aditivos como la bentonita, a fin de reducir la biodisponibilidad o la adsorción de los AGCL sobre la biomasa activa, se muestran estrategias funcionales de utilidad en la operación de plantas industriales. Los resultados obtenidos refuerzan la hipótesis de que la inhibición es debida a adsorción de AGCL sobre la membrana celular y que la recuperación se puede medir mediante un aumento de la actividad de los microorganismos. A fin de dilucidar sobre la naturaleza del aumento de la actividad en los procesos de recuperación se caracteriza la inhibición mediante tres técnicas: 1) estudio de las actividades de los microorganismos a diferentes substratos, 2) utilización de técnicas de biología molecular para caracterizar las poblaciones, y 3) desarrollando expresiones cinéticas del proceso de inhibición, basado en la adsorbió, en el marco del modelo ADM1 de la International Water Association. Mediante estas metodologías se comprueba que los fenómenos de inhibición y adaptación se pueden explicar mediante un crecimiento poblacional específico y la inclusión de la adsorción en el proceso de inhibición metabólica. Finalmente, se evalúa de forma detallada el proceso de adsorción-inhibición mediante la determinación de las isotermas de adsorción y monitorizando estos procesos mediante ensayos discontinuos con biomasa granular y técnicas de microscopia de fluorescencia. Esta caracterización ha permitido obtener estrategias de prevención de la inhibición por AGCL, mediante competencia con adsorbentes sintéticos, y concluir que el ácido palmítico es el limitante en el proceso de mutante -oxidación de los AGCL. Los resultados obtenidos constituyen una base para el mejor conocimiento de las posibilidades de tratamiento anaerobio de residuos cárnicos y de los procesos de inhibición por AGCL y adaptación de la biomasa. El proceso físico de adsorción se ha relacionado directamente con el fenómeno de inhibición metabólica, obteniéndose una descripción matemática del mismo. Los resultados han permitido plantear estrategias operacionales, siendo una herramienta a disposición de operadores de plantas de biogás para optimizar la producción de energía de estos residuos mediante su digestión anaerobia.
Slaughterhouse wastes are interesting for the anaerobic digestion process regarding its high biogas production potential and because the current legal scenario promotes renewable energy production. The high lipid and protein content of those residues limit its treatment due to inhibitory processes, in particular the inhibition caused by long chain fatty acids (LCFA). The objective of the present disertation is to obtain a deeper insight on the LCFA inhibition process, the microorganism adaptation ability and the prevention/recovery of inhibitory phenomena. In a preliminary approach, organic wastes generated in slaughterhouses are characterized, by studying the anaerobic biodegradability of waste mixtures containing diferents lipid/proteins concentrations. Anaerobic batch tests are performed at increasing substrate concentrations by sequential pulse feeding. From those experiments, the fast hydrolysis-acidogenesis of proteins is verified, being the lipids and LCFA degradation the main limiting step of the overall anaerobic process. Despite this limitation, the system is able to recover up to a higher methane production rate after each applied pulse. In order to elucidate on the mechanisms of the recovery process, several strategies to recover LCFA inhibited reactors are tested. The increase of the biomass/LCFA ratio and the adition of bentonite to reduce the biodisponibility or the adsorption of LCFA over microbial cell walls, are found to be effective approaches in the operation of fullscale biogas plants. The obtained results reinforce the hypothesis of the adsorptive nature of the LCFA inhibition, and that the recovery process can be followed as an increase in the microbial activity. The nature of the reported microbial activity improvement after subsequent sytem inhibition is characterized by three different techniques: 1) the study of specific microbial activities on different model substrates, 2) the application of molecular biology tools to monitor the microbial population structure and, 3) the development of kinetic expressions of the LCFA inhibition phenomena, based on the adsorption process, within the framework of ADM1 model of the International Water Association. The combined analysis of those confirmed that inhibition and adaptation phenomena are explained by a specific microbial growth, including adsorption in the metabolic LCFA inhibition process. The adsorption-inhibition process is evaluated in detail by determining LCFA adsorption isotherms on granular sludge, LCFA toxicity test, and fluorescence microscopy techniques. This multidisciplinary approach results in the definition of an inhibition preventing strategy based on the introduction of competitive adsorbents, and on stating the importance of
palmitate during ß-oxidation of LCFA. This study contributes to the understanding of slaughterhouse wastes anaerobic treatment, the LCFA inhibition process, and the biomass adaptation phenomena. The physical adsorption process has been directly related with the LCFA metabolic inhibition, and a new mathematical kinetic expression is proposed. New strategies guiding the operation of anaerobic reactors are suggested in order to obtain high renewable energy yields from slaughterhouse wastes digestion.

The purpose of this research was to investigate the relationship between the oxidation-reduction potential (ORP) measurement and volatile fatty acid (VFA) production in the acid-phase anaerobic digestion process under different conditions of temperature and residence time. Two identical anaerobic digesters were operated while VFAs, SCOD, VSS, alkalinity, ORP and pH were measured. In digester 1, VFA production of 5,556 mg/L was generated with an ORP of -315 mv at a 10 day SRT; while 5,400 mg/L of VFA with an ORP of -389 mv was recorded in digester 2. The SRT was adjusted at 5, 8, 10, 12 and 15 days and the optimum SRT was 10 days in both digesters. The results of this study indicate there were no tight relationship between VFA production and ORP values, thus ORP by itself is not a good predictor of the amount of VFAs generated. However, ORP combined with temperature had good linear relationship with VFA production. An ORP range of -315 to -390 mv was desirable for maximizing VFA production in both anaerobic digesters. Different temperatures (14, 29 and 37 ℃) were trialed and the results indicate that the conditions at 29 ℃ and 37 ℃ were not significantly different in terms of VFA production, however, less VFAs were generated at the lowest temperature of 14 ℃.

The aim of this work was to quantify the utilisation by rats and pigs of microbial amino acids synthesised in their gastrointestinal tracts. The method which was developed is based on the oral administration of isotopes in non-amino acid form (15NH4Cl or 14C-polyglucose) and the measurement of the incorporation of these isotopes into the amino acids of the body protein of the animal. Since animals cannot incorporate 15N or 14C into certain of the essential amino acids, labelling of such amino acids is only possible via microbial amino acid synthesis and absorption. To calculate the amount of amino acid absorbed the total amount of labelled amino acid (or total radioactivity in the amino acid) in the body was divided by the enrichment (or specific radioactivity, SRA) of that amino acid in microbial protein. It was shown that germ-free rats fed 15NH4Cl were not able to incorporate inorganic 15N into lysine. Conventional rats, however, showed 15N-incorporation in body lysins. When rats fed 15NH4Cl were prevented from coprophagy they did not incorporate 15N in their body lysine. It was concluded that the utilisation of microbial amino acids in rats occurs exclusively via coprophagy. The estimated absorption of microbial lysine by the conventional rats was 21 mg/kg.75 per day. The direct (non-coprophagic) uptake of microbial amino acids in pigs was also measured. Pigs (prevented from coprophagy) were offered a low-protein diet containing 15NH4Cl and 14C-polyglucose. At the end of the experiment the 15N-enrichment of body lysine and the 14C SRA of lysine, histidine, tyrosine, phenylalanine, valine, isoleucine and acids of the microbial fractions of ileal and caecal digesta were also measured.

Ce travail porte sur l'étude biologique (survie, croissance, condition, conversion, histo-cyto enzymologie digestive) de l'anguille Anguilla Anguilla en élevage. Après avoir montré la possibilité d'alimenter des anguilles avec du foie de bœuf, l'auteur a mis au point une méthode de conservation, par ensilage acide, de déchets protéiques d'abattoirs et de pêcheries. Cet aliment ensile a été incorporé (40%) dans la nourriture. Sa composition, sa longévité et sa digestibilité (nutriments et énergie) ont été testées sur des anguilles et des truites. Les performances de survie, de croissance et de conversion ont été comparées à celles de l'aliment commercial. Ses effets sur l'anatomo-physiologie de l'appareil digestif ont été suivis à l'échelle histologique, cytologique et enzymologique (api-zym). Les résultats obtenus démontrent la faisabilité de l'utilisation d'un aliment partiellement ensile, à partir de déchets protéiques valorisables, à des fins d'anguilliculture.

Environmentally sound treatment of by-products in a value-adding process is an ongoing challenge in animal agriculture. Thermophilic anaerobic digestion of wastes originating from agricultural production and animal processing represents a potential waste treatment technology to address environmental concerns such as odor emissions and removal of pathogenic microorganisms, while at the same time producing renewable energy (biogas) as a by-product. However, thermophilic digestion is subject to inhibition by ammonia and long chain fatty acids (LCFA), both of which are prevalent in manure and animal processing wastewater. Several swine manure collection methods under development separate the urine from the feces, which creates the opportunity to operate a digester on feces only, greatly reducing the ammonia load to the digester. One objective of this study was to determine whether operation on feces only would yield significant performance improvements for a thermophilic anaerobic digester operating on swine waste. Effluent from a continuously stirred tank reactor (CSTR) was used as the inoculum for batch tests in which the substrate contained three different concentrations of urine (urine-free, as-excreted urine:feces ratio and double the as-excreted urine:feces ratio). Inocula were acclimated to these same urine:feces ratios to determine methane production. Results show that both urine-free and as-excreted substrates were not inhibitory to anaerobic inocula. Anaerobic microorganisms can be readily acclimated to substrate with double the as-excreted urine concentration, which contained TKN concentrations up to 7.20 g-N liter-1. The sludge collected from the dissolved air flotation (DAF) wastewater treatment process in swine processing facilities is an example of a high-lipid substrate containing potentially inhibitory levels of LCFA. A second objective of this study was to determine the fundamental performance parameters for thermophilic anaerobic digestion of DAF sludge. Testing in a semi-continuous stirred tank reactor and in batch reactors was conducted to determine substrate degradation rates and biogas yield. Stable operation could not be achieved using pure DAF sludge as a substrate, possibly due to inhibition by long chain fatty acids or to nutrient deficiencies. However, a 1:1 ratio (w/w, dry basis) of DAF sludge and swine manure (feces only), resulted in stable and productive digester operation. In the semi-continuous stirred reactor at 54.5ï°C, a hydraulic residence time of 10 days, and an organic loading rate of 4.68 gVS/day/L, the methane production rate was 2.19 L/L/day and the specific methane production rate was 0.47 L/gVS (fed). Maximum specific methanogenic activity (SMA) in batch testing was 0.15 mmolesCH4 hr-1 gVS-1 at a manure/DAF substrate concentration of 6.9 gVS liter-1. Higher substrate concentrations cause an initial lag in methane production, possibly due to long chain fatty acid or nitrogen inhibition.

Volatile fatty acids (VFAs) are important building blocks for the chemical industry. These acids can be produced through environmentally friendly processes from a variety of wastes, such as food waste, sludge and cow manure, through anaerobic digestion (AD). The main objective of this thesis was to investigate which operating parameters (e.g. pH, retention time, mix of substrate etc.) are optimal for producing VFAs as efficiently as possible, through AD batch processes. The highest VFA concentration was reached at pH 10 and at day 11 when food waste and sludge were used as substrate to a value of 15.4 g/L, corresponding to 0.77 g VFAs/ g of VSfed. Highest VFA concentration where cow manure was used as substrate was reached on day 10 and with a value of about 10 g/L corresponding to 0.51 g VFAs/ g VSfed.
Flyktiga fettsyror (VFAs) är en viktig byggsten inom den globala kemiindustrin. Dessa fettsyror kan produceras med hjälp av miljövänliga processer där en mängd olika sorters avfall, som t.ex. matavfall, avloppsslam och koavföring kan fungera som substrat, genom anaerobisk rötning. Det huvudsakliga målet med den här kandidatuppsatsen var att utreda vilka de optimala driftförhållanden var för särskilt utvalda driftparametrar (t.ex. pH, retentionstid, mix av substrat etc.) för att producera flyktiga fettsyror så effektivt som möjligt, genom anaerobisk rötning. Högst koncentration av VFAs nåddes vid pH 10 på dag 11 när matavfall och avloppsslam användes tillsammans som substrat till ett värde på 15 g/L, vilket motsvarar en avkastning på 0.77 g VFAs / g VSin. Högst VFAs-koncentration när koavföring användes som substrat nåddes på dag 10 med ett värde på 10 g/L, motsvarande en avkastning på 0.51 g VFA/ g VSin.

Dissertation for the Master degree in Biotechnology
The main goal of the present work was to study the production of volatile fatty acids (VFAs) from cheese whey powder (CWP) by employing a packed bed bioreactor (PPBR) for the anaerobic acidogenesis. First experiments were performed in 100-mL Pyrex bottles to study the acidogenesis trends, namely: lactose consumption, VFAs and biogas production and composition. These tests were done with freely suspended-cells (control experiment) and with immobilized cells using granular activated carbon (AC) and ceramic cube Vukopor S10 supports. The utilized inoculum – an acidogenic mix consortium- belongs to an analogous CWP digestion process in which a different culture system is being studied. Therefore, the incubations conditions were the same as for that culture system: 20 g/L of CWP (corresponding to 15 g/L lactose), 37ºC and pH 6. The observed trend consisted on lactose consumption, lactic acid formation (as an intermediate product) and from this VFAs production. The best yield was obtained when Vukopor was used (87% against 30% for AC); after 9 days the VFAs was (g/L): acetic (1.6), propionic (2.4); butyric (6.6) acids. The mentioned preliminary studies allowed selecting the operational hydraulic retention time(HRT) for the bioreactors. Two recirculate 1-liter PBBR one filled with Vukopor and other with AC were developed. CWP concentration, pH and temperature were the same as in the microcosm experiment. Both were operated in batch and continuous. In first batch performed in PBBR-Vuko it was achieved 6 g/L of propionic. However a loss of capability of producing it was observed during continuous operation. It was ascribed to a wash-out of related strains. With PBBR-Vuko were tested two different hydraulic retention times (HRT), 9 and 6 days, instead for PBBR-AC only HRT of 9 days. The yields for PBBRVuko were the same as at the microcosms scale, 80% for both HRT. On the other hand, the yield for PBBR-AC was 20%, this is a confirmation that AC was not the proper support even at a 1-L scale. Additionally to immobilization study, it was also set up a bioreactor with freely suspended cells. In this last mentioned bioreactor when a HRT of 6 days was set up it was observed a decrease in the VFAs yield to 44%. From this, it was concluded that the immobilization is an advantage for the VFAs production.

The objective of this study is to illustrate that phase separation improves the efficiency of an anaerobic system which digests semi-solid organic wastes. Organic fraction of municipal solid waste (OFMSW) was the semi-solid organic waste investigated. In the first part of the study, the optimum operational conditions for acidified reactor were determined by considering the volatile solid (VS) reductions and average acidification percentages at the end of two experimental sets conducted. Organic loading rate (OLR) of 15 g VS/L.day, pH value of 5.5 and hydraulic retention time (HRT) of 2 days were determined to be the optimum operational conditions for the acidification step. Maximum total volatile fatty acid and average acidification percentage were determined as 12405 mg as HAc/L and 28%, respectively in the reactor operated at optimum conditions. In the second part, an acidification reactor was operated at the optimum conditions determined in the first part. The effluents taken from this reactor as well as the waste stock used to feed this reactor were used as substrate in the biochemical methane potential (BMP) test. The results of BMP test revealed that the reactors fed by acidified samples indicated higher total chemical oxygen demand (tCOD) removals (39%), VS reductions (67%) and cumulative gas productions (265 mL). The result of this study indicated that the separation of the reactors could lead efficiency enhancement in the systems providing that effective control was achieved on acidified reactors.

Pancreatic cancer (PC) is the fourth leading cause of cancer death in Western societies. Despite significant progress in understanding the molecular pathology of PC and its precursor lesion: pancreatic intraepithelial neoplasia (PanIN), there remain no molecules with proven clinical utility. Affymetrix Genechipfi oligonucleotide microarrays were used to interrogate mRNA expression of PC and normal pancreas to identify molecular pathways dysregulated in PC. Analysis of these data identified altered expression of numerous components of the S100 Calcium Binding Protein Family, Retinoic Acid signalling pathway and the HOX transcriptional network in PC compared to normal pancreas. These pathways were assessed using immunohistochemistry (IHC) and in-situ hybridisation (ISH) in a cohort of patients with PC. Increased protein expression, of S100A2, S100A6 and S100P was observed in 43%, 60% and 48% of PC respectively. Expression of S100A2 was associated with a poor outcome (p = 0.009), whilst increased expression of S100A6 (p = 0.0008) and S100P (p = 0.0005) were associated with an improved outcome. Additionally, S100A2 expression was identified as an independent marker of outcome in resected tumours. Aberrant expression of retinoic acid signalling components was demonstrated in PC cell lines using semi-quantitative RT-PCR. ISH demonstrated expression of Retinoic Acid Induced 3 (RAI3), an orphan G protein coupled receptor normally expressed in the fetal lung, in 68% of PC, and this co-segregated with an improved overall survival (p = 0.026).Ectopic protein expression of HOXB2, a transcription factor normally expressed in the developing hindbrain and modulated by retinoic acid, was observed in 15% of early PanIN lesions and 38% of PC specimens. Expression of HOXB2 was associated with non-resectable tumours and was an independent predictor of poor survival in resected tumours. Suppression of HOXB2 protein expression using small interfering RNA, resulted in epithelioid trans-differentiation in the Panc-1 PC cell line, however no alteration in proliferation rates were observed compared to controls. This thesis has shown that transcript profiling and tissue validation has identified potential markers of early diagnosis and outcome in PC. Furthermore, pathways and molecules previously thought to be associated with normal human development have been implicated to play a role in the development and progression of PC. Further analyses of these markers will determine any potential role in future diagnostic and therapeutic strategies.

In recent years, there has been a growing interest in feeding phytogenic products to poultry for their growth and health benefits. The objective of this experiment was to determine the effects of a phytogenic feed additive on turkey poult performance and digestive physiology over a 6-week brooding period. In total, 864 male Hybrid Converter turkey poults were obtained from a local commercial hatchery on day-of-hatch and placed into floor pens with clean pine shavings. The treatments were randomly assigned including an industry-type corn-soybean meal positive control (PC), a similar diet with a 1.5% reduction in crude protein and key amino acids (NC), or the NC with the addition of Digestarom® (PFA) included at a rate of 1 g/kg. Body weight gain (BWG), feed intake (FI), feed efficiency (FE), and mortality were recorded throughout the experiment. On day 14 poults fed the PFA had significantly higher BWG compared to the PC and NC fed birds. By day 42 birds fed the PC and PFA diets had significantly higher BWG compared to the NC, and the PC had significantly higher FE compared to the NC and PFA fed birds. No differences in FI or mortality were observed throughout the experiment. There were no significant differences in AMEn, crude protein digestibility, or nutrient transporter or pancreatic enzyme mRNA expression among treatments. However, aminopeptidase activity tended to be lower in the ileum of poults fed the PC or PFA diets compared to the NC, suggesting that the PFA may be improving protein utilization.
Master of Science

This work involves the combination of chelation and microwave extraction as a technique for extracting adsorbed metals in soil. It has been termed in this work, Chelate Assisted Microwave Extraction (CAME). Unlike other extraction methods, CAME is able to differentiate between anthropological and geological trace metals. The method has been applied to major sample matrices included three types of soils (Bertie Sandy Loam, Davidson Silty Clay, and Davidson Clayey Loam) as well as sea sand, alumina, and iron oxide. In order to investigate the effects of sorptive coatings on metal concentrations, a sample set was first treated with humic acids, which represented organic coated materials. Afterwards, copper (II) solutions were spiked to both untreated and treated matrices and the efficiencies of recoveries were studied. Metal determinations were performed by Inductively Coupled Plasma-Atomic Emission Spectrophotometry (ICP-AES). Initial studies of control (untreated soil) and long-term Cu amended (spiked) Bertie Sandy Loam (BSL) indicated that extraction efficiencies were method dependent. Ethylenediaminetetraacetic acid (EDTA) was a primary chelating agent used for method comparisons. Extracting solutions having a pH range from 7.8 to 10.1 did not affect the EDTA-microwave method, but the increase in pH enhanced Cu removal by the EDTA-shaking extraction method which was a conventional chelation using a mechanical shaker. With the EDTA-microwave method, complete extraction was achieved in a short period of time (20 minutes). Compared to the EDTA-shaking method using two sandy soils, the EDTA-microwave method proved to be more efficient in extracting sorbed metals in soils (5.9 vs. 4.6 µg/g for the control BSL and 37.5 vs. 27.8 µg/g for the amended BSL. FT-IR and C13 NMR were used to characterize extracted and commercially available humic acids. The latter was employed to prepare the humate coated materials. Iron oxide containing materials such as Davidson Silty Clay (DSC), Davidson Clayey Loam (DCL), and iron oxide (Fe2O3), showed extremely high adsorption capabilities for humic acids, while sea sand, Bertie Sandy Loam, and alumina (Al₂O₃) provided lower adsorption capabilities for humic acids. Two sets of uncoated and humate coated materials were used for Cu spiking procedures using 0.001 M Cu (II) at pH 5.3 for 24 hour-equilibration. Three original soils and alumina showed high adsorption capabilities for Cu (II). The presence of coated humate helped increase Cu adsorption capabilities of these soils, but diminished the ability of alumina to react with Cu (II) ions. For HA-uncoated matrices, iron oxide had a higher Cu adsorption capability than sea sand but less than real soils. Humate coating improved Cu adsorption capabilities of not only real soils but iron oxide and sea sand as well. Lastly, the developed method named Chelate Assisted Microwave Extraction (CAME) was further examined and optimized. Several samples were investigated for extraction efficiencies. A two-step extraction, applying 120 W for 5 min followed by 60 W for 10 min, was efficient in removing sorbed metals from different matrices regardless of sorptive oxide and organic components. Concentrations of chelating agents slightly affected percent metal removal; however, there was no significant difference in results obtained using EDTA or diethylenetriaminepentaacetic acid (DTPA). Recoveries of spiked metals (Cu and Cd) ranged from 96 to 107%. Using the untreated (control) Davidson Silty Clay and Bertie Sandy Loam, the comparison of other chelating solutions were made. Clearly, CAME was promising and proved to be a good alternative to classical shaking method for extracting adsorbed metals from soils.
Ph. D.

Anaerobic digestion is a biochemical process that transforms diverse categories of biomass feedstock to renewable energy, in the form of methane, and contributes to resources conservation and greenhouse gases emission mitigation. Lipid-rich waste and wastewaters have a high energy potential, however efficient methane recovery with conventional anaerobic digestion technology is not easy to achieve because of a wide assortment of operational problems mainly related to the accumulation of long chain fatty acids (LCFA), products of lipids hydrolysis, in the system. The objective of the present dissertation is to test and to evaluate new methodologies and strategies to improve the anaerobic digestion of high-strength lipid waste. In a preliminary approach, the suitability and the attractiveness of high-strength lipid wastes and slaughterhouse wastes for biogas production was confirmed, suffice to control the applied organic load. The obtained results reinforced the existing knowledge describing the flotation and wash-out of substrate/biomass and the inhibition phenomena affecting the microbial population, as the main process drawbacks. The results of studies submitting anaerobic reactors to increasing concentrations of lipids/LCFA underlined the importance of the adsorption of LCFA onto the microbial cell membrane as limiting factor, guiding further research to found new technical approaches in order to control the biomass-LCFA adsorption dynamics. The use of inorganic adsorbents to capture LCFA prior to the anaerobic digestion process or the application of sequential low-energy ultrasonic pulses in order to control the adsorption-desorption kinetics were tested with interesting results. However, the effectiveness of these strategies was limited by the proportion of inorganic adsorbent/LCFA and the cumulative damaging effect of ultrasonic treatment over biomass, respectively. Further studies are thus required to optimize the efficiency and the applicability of these strategies. Efficient conversion of complex high-strength lipid waste to methane was proved to be possible in a novel reactor system configuration combining saponification pre-treatment and digested solids recirculation to the anaerobic digestion process, to increase solids retention time. A start-up step consisting on pulse-feeding cycles of the fatty waste prior to the semi-continuous process promoted an adapted microbial community for LCFA mineralization. The feasibility of this system configuration for solid slaughterhouse fatty waste was evidenced at lab scale reactors, reaching organic matter removal efficiencies higher than 90%. The comparison of this configuration with systems without saponification or without digested solids recirculation confirmed the synergistic effect of both strategies. The use of high throughput sequencing approach (454-pyrosequencing) to characterize the evolution of the biodiversity and the phylogenetic structure of the microbial community during the operation of the tested configurations concluded that a selection of a defined functional acidogenic population (ß-oxidizers) was induced by substrate pretreatment. Contrary, the solids recirculation resulted in an enrichment of the methanogenic biodiversity, mainly of hydrogenotrophic archaea. Based on the satisfactory results obtained with the strategies studied in the present dissertation, it is expected that lipid-rich waste valorization will be a real alternative to increase renewable energy production through anaerobic digestion process.

Fats, oil and grease (FOG) are generated in large amounts by cooking and food processing. Anaerobic co-digestion with municipal sewage sludge has proven to be one of best alternatives for FOG disposal due to its high potential for biogas production. However, excessive addition of long chain fatty acid, the major content of FOG, has been reported to have inhibitory effects on the anaerobic digestion process and to cause operational challenges. In this study, high purity long chain fatty acids (LCFAs) including linoleic acid, oleic acid, and a mixture of oleic acid and stearic acid were added to laboratory completed mixed anaerobic digesters. The performance of the digesters in terms of solids destruction, COD degradation, LCFAs accumulation and gas production was investigated. After reaching steady state, a large amount of palmitic acid was found in the reactors with oleic acid addition and mixture of stearic and oleic acid addition. In the meantime, no palmitic acid increase was observed in reactors where linoleic acid was added. A better solids and COD reduction and a higher biogas production were observed in reactors with higher LCFAs addition. For reactors with the same dosage of LCFAs addition, linoleic acid addition resulted in the greatest improvement in digester performance; the mixture of stearic acid and oleic acid achieved the least increase in biogas production and solids and COD reduction. A high concentration of both palmitic and stearic acid in the reactors with oleic acid addition and with 20% mixed acid addition was observed. In contrast, linoleic acid and 30% mixed acid addition did not lead to a greater palmitic or stearic acid concentrations. Up to 30% of pure linoleic acid, oleic acid and mixed acid addition are able to enhance the performance of anaerobic digesters. It is recommended that the dosage of oleic acid be below 30% to avoid LCFAs accumulation and to increase reactor stability.
Master of Science

Anaerobic co-digestion of municipal sludge and food wastes high in chemical oxygen demand (COD) has been an area of interest for waste water treatment facilities looking to increase methane production, and at the same time, dispose of the wastes and increase the revenue. However, addition of food wastes containing fats, oils and grease (FOG) to the conventional anaerobic digestion process can be difficult and pose challenges to utilities. Incorporating these wastes into the treatment plants can potentially inhibit the digestion process. In this study four lab-scale, anaerobic digesters were operated under mesophilic conditions and fed municipal sludge. One of them served as the control, while the other three digesters were fed with different volumetric loadings of juice processing waste, cheese processing waste (whey), dissolved air flotation waste (DAF) from a food processor, and grease trap waste (GTW), in addition to the municipal sludge. The impact of these high strength wastes (HSWs) on digester performance was analyzed for a total period of 150 days. Among the parameters analyzed were pH, total and soluble COD (tCOD and sCOD), Total and Total Volatile Solids (TS and TVS), Total Ammonia Nitrogen (TAN), Total Kjeldahl Nitrogen (TKN), Volatile Fatty Acids (VFA), Long Chain Fatty Acids (LCFA), and alkalinity. Biogas was collected and analyzed for methane content. The dewatering characteristics of digested sludge were also studied. Volatile organic sulfur compounds were analyzed on the dewatered sludge in order to monitor odors. This study showed that different high strength wastes have different impacts on digester performance. HSWs have the ability to degrade along with municipal sludge and to increase biogas production. However, anaerobic digestion can be inhibited by the presence of FOG, and addition of these wastes might not always be cost effective. Careful selection of these wastes is necessary to ensure stable digester operation, while bringing about increases in gas production. Utilities need to be cautious before adding any high strength wastes to their digesters.
Master of Science

Dal 2008, sono evidenti che i benefici del selenio nell'organismo dipendono dalla forma in cui è ingerito, stabilendo che quella organica è migliore dell'inorganica. L’introduzione di selenio raccomandato a livello internazionale è di 55-70 μg/giorno e la sua specie chimica efficace dal punto di vista biologico è la seleniometionina. Infatti, si può affermare che il selenio in forma inorganica possieda una bassa bioattività rispetto al selenio legato agli aminoacidi (Se-metionina e Se-cisteina) di maggiore bioattività. Nell’ambito dei prodotti lievitati da forno, uno dei fattori che desta maggior interesse è l’effetto esercitato dal processo tecnologico (che include fermentazione e cottura) sull’aumento della biodisponibilità dei composti antiossidanti e nutrizionali. In particolare, attraverso il processo fermentativo, è possibile aumentare sia l’azione degli enzimi digestivi sul substrato alimentare, che la stabilità del selenio inorganico e organico presente modificandone le caratteristiche chimiche e fisiche (es. organicazione). Nello specifico, i processi fermentativi che caratterizzano gli impasti acidi (basati sulle interazioni metaboliche tra batteri lattici e lieviti) sono stati riconosciuti efficaci per modificare la composizione delle micro e macromolecole responsabili del miglioramento non solo delle caratteristiche qualitative ma anche di quelle nutrizionali, come il selenio. Lo scopo della mia tesi era lo sviluppo di un prodotto funzionale a base di cereali arricchito con selenio bioattivo tramite un processo di natura biotecnologica di tipo fermentativo. L’aggiunta di selenio alla farina attraverso un impasto acido arricchito favorisce la sua organicazione da parte dei batteri lattici presenti che trasformano parte del selenio additivato (SeIV) in forme organiche come SeMet e MeSeCys e in parte in altri frammenti organici non rilevati dall’analisi. D’altra parte la quantità di selenio inorganico rilevato nei digeriti di piadina ottenuta con impasto acido è risultata essere drasticamente ridotta. Dalla mia sperimentazione ho ottenuto molteplici indicazioni che riguardano la possibilità di produrre un alimento fermentato a base di cereali ed a elevato contenuto di selenio bioattivo. Dal punto di vista applicativo questo sperimentazione costituisce una base sia per la comprensione del ruolo dei processi fermentativi nella generazione di alimenti o ingredienti funzionali ma anche per l’individuazione di nuovi microrganismi probiotici con potenziali attività antiossidante ricchi di selenio bioattivo.

We initially studied the treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron as the electron donor. The results demonstrate that this electron donor can serve as the sole exogenous slow-release electron donor to drive sulfate reduction over 400 operational days at short HRTs (1-3 days). The synthetic acid rock drainage contained high heavy metal concentrations (up to 50 mg/L of copper) and pH values ranging from 3.0 to 7.0. Treatment of this acid rock drainage efficiently removed Cu, Cd and Pb (>99.7%) and increased pH to circumneutral values (7.3-7.7). Elemental analysis indicated that formation of insoluble metal sulfides was responsible for the effective metal removal in the zero valent iron columns. In the second study, three inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H₂SO₄ and Cu²⁺ during the experimental period of 4 months. Algae biomass promoted 80% of sulfate removal (12.7 mg SO₄²⁻ d-1), enabling near complete Cu removal (>99.5 %), and alkalinity generation, raising the effluent pH to 6.5. In the algae amended columns Cu²⁺ was precipitated with biogenic H2S produced by sulfate reduction. Whole cell algae and lipid extracted algae biomasses were both shown to be effective e-donors in driving sulfate reduction of ARD, thus enabling the precipitation and removal of Cu²⁺. The precipitate retained in the columns was composed mostly of insoluble copper sulfide formed from the biogenic sulfide, as shown by sequential extraction and X-ray diffraction. In the third study, several pretreatments, i.e., thermal, chemical, sonication and combinations thereof, that enhance anaerobic biodegradability of Chlorella protothecoides biomass were evaluated. The results demonstrate that anaerobic digestion of pretreated Chlorella protothecoides biomass generates energy-rich methane and recovers nitrogen nutrients. Sonication of algal biomass under optimized conditions provided a significant increase in the methane yield (327 mL STP CH₄ g⁻¹ VS) compared to untreated algae (146 mL STP CH₄ g⁻¹ VS), as demonstrated in anaerobic digestion experiments incubated for 41 days. In contrast, thermal pretreatment provided only a moderate increase of the methane yield and alkaline treatment led to a decrease of the methane yield compared to the untreated algal biomass. Additionally, sonication treatment provided a 4.1-fold increase in the release of ammonia nitrogen during anaerobic digestion of the algal biomass. In the fourth study, the nutrient recovery and biogas generation from the anaerobic digestion of waste biomass from algal biofuel production was investigated. Anaerobic digestion of whole cell and lipid extracted Chlorella sorokiniana-1412 released 48.1 and 61.5% of the total algal nitrogen as NH₄⁺-N, and 87.7 and 93.6% of the total algal P as soluble P, respectively. The biochemical methane potential, quantified through the methane yield of whole cell algae and lipid extracted algae, was 0.298 and 0.253 L methane/g algal volatile solids, respectively. The conversion of lipid extracted algae and whole cell algae biomasses to methane was very similar (38 and 41% on a COD basis, respectively), indicating that the energy yield was not significantly lowered by extraction of the lipid fraction (which accounted for 9% of algal dry weight). Sonication improved the access of hydrolytic enzymes to algal biopolymers, compensating in part for the energy lost due to lipid extraction. The above results demonstrate that algal waste from the biodiesel industry has the potential to be recycled through anaerobic digestion into valuable nutrients and energy. These studies indicate that zero valent iron and algae biomass are promising reactive materials for the treatment of acid rock drainage in sulfate-reducing permeable reactive barrier systems. Additionally, to promote algae cultivation for the biodiesel industry, the anaerobic digestion of algae residues can generate nutrients and energy, making algae cultivation more fiscally attractive.

The process of natural gas extraction through hydraulic fracturing produces large quantities of fluid containing naturally-occurring salt, radionuclides, and heavy metals which form residual solids during storage and treatment. The purpose of this research was to characterize the residual solids from hydraulic fracturing operations in the Marcellus Shale to predict the leaching behavior of select elements in disposal environments. Samples collected for this research were: (1) drilling mud, (2) treated sludge from the chemical treatment of process waters, (3) solids from the gravity settling of produced water, and (4) sludge solidified prior to disposal in a municipal landfill. These samples were subjected to various digestion techniques to determine the composition and leaching potential for elements of concern. Strong acid digestions were performed to determine the total environmentally available composition, whereas weak acid digestions were used to predict the leaching potential of these solids under various environmental conditions. The extraction fluids for the leaching experiments included weak acetic acid, acid rain, reagent water, and synthetic landfill leachate. Solids were agitated in a standard tumbling apparatus to simulate worst-case conditions based on ASTM and EPA recommendations. Results from EPA's Toxicity Characteristic Leaching Procedure (TCLP) were used to determine if solids were considered hazardous based on the metal leaching potential. The results from strong and weak acid digestions were compared to better understand the types and quantity of materials that have the potential to leach from the samples. This research may be used to develop best management practices for hydraulic fracturing residual solids.
Master of Science

Master of Science
Department of Animal Sciences and Industry
Michael D. Tokach
A total of 5,212 nursery pigs were used in 11 experiments to evaluate amino acids in nursery pig diets. Experiments 1 and 2 were conducted to determine whether the Lys level fed during one phase of the nursery influenced the response to Lys during subsequent phases. Experiment 1 tested a wide range of dietary Lys in 2 phases and reported that pigs fed high Lys during each period had increased growth performance; however, compensatory growth occurred for the pigs previously fed low Lys diets, resulting in no impact on overall ADG or final BW. Experiment 2 tested a narrow range of dietary Lys in 3 phases and found that marginally deficient diets can be fed in the early nursery phases without influencing final BW or the response to Lys levels in subsequent phases. Both experiments demonstrate that the low dietary Lys levels used in each can be fed in the early nursery phases with no negative impact on overall nursery growth rate provided that adequate levels are fed thereafter. Experiments 3 to 6 were conducted to determine the standardized ileal digestible (SID) Lys requirement of nursery pigs from 7- to 14-kg. Data from all experiments were combined and break-point and quadratic broken-line analysis was used to determine the estimated SID Lys requirement. The SID Lys requirement for optimal growth was at least 1.30% for ADG and 1.37% for G:F, or at least 3.86 and 4.19 g SID Lys/Mcal ME, respectively. Experiments 7 to 11 were conducted to evaluate the effect of replacing specialty protein sources with crystalline AA and AA requirements for 7- to 12-kg pigs. Experiment 7 demonstrated that crystalline AA can be used to replace fish meal in diets with no negative effects on growth performance. Experiment 8 demonstrated that L-Trp, L-Val, and a source of non-essential AA were needed in low-CP, AA-fortified nursery diets to achieve maximum growth performance, whereas the addition of L-Ile was not required. Experiment 9 indicated that feeding greater than 7.35% total Lys:CP decreased growth performance and Exp. 10 indicated that a SID Val:Lys ratio of 65% was sufficient for optimal growth of early nursery pigs. Implementing the results from the previous experiments, Exp. 11 determined that crystalline AA in nursery pigs diets can replace high amounts of fish meal, meat and bone meal, and poultry meal when balanced for minimum AA ratios and maximum Lys:CP with no negative effect on growth performance.

Thesis (Ph. D.)--University of Kentucky, 2005.
Title from document title page (viewed on August 17, 2005). Document formatted into pages; contains: xii, 144 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 127-143).

In most of the analytical and environmental laboratories today inductively coupled plasma (ICP) is a method of choice for analysis of trace metal elements present in coal and coal combustion products. This method requires use of liquid samples, so all coal and coal combustion products must be digested prior to analysis by ICP. Traditionally an open-air hot-plate acid digestion method published as ASTM D6357-04 was used to extract all trace metal elements into solution. Recent development of microwave systems designed for digestions under extreme acidic conditions and high temperatures and pressures shifted focus toward more rapid and precise microwave-assisted digestion of samples. A number of papers have been published involving research efforts toward development of quantitatively satisfying digestion methods. However, there is still no published ASTM or EPA method for microwave-assisted digestion of coal and coal combustion products. The goal of this research is compare the recoveries obtained by using hot plate method with results obtained by microwave-assisted digestion, as well as to attempt to optimize method conditions for latter.

The purpose of this research was to characterize the residual solids produced from hydraulic fracturing operations in the Marcellus Shale region. Four field samples were evaluated: drilling mud, treated sludge from the chemical treatment of process water, solids from the gravity settling of produced water, and sludge solidified prior to disposal in a municipal landfill. Cement kiln dust (CKD), used for solidification, was also considered in this study. All samples were subjected to a variety of laboratory techniques to determine their elemental composition and the potential for the elements to leach from the landfill. Strong acid digestion using a 3:1 combination of nitric acid to hydrochloric acid in a microwave with closed vessels was used to determine overall elemental composition. Leaching experiments were performed with de-ionized water and acetic acid (0.57%, pH 2.88) in an attempt to respectively evaluate the effects of weak and strong fluids that might be encountered by the residuals in landfill environments. Elements were analyzed by means of ICP-MS revealing the increased tendency for alkali metals, alkaline earth metals and halogens to leach. Leachablility was further increased for metals when exposed to acidic conditions.
Master of Science

Orientador: Luciano Hauschild
Coorientador: Ines Andretta
Banca: Edney Pereira da Silva
Banca: Charles Kiefer
Resumo: Numerosos estudos estão sendo publicados para avaliar os efeitos do consumo de lisina sobre o desempenho de frangos de corte, no entanto, tais estudos diferem em seus resultados, principalmente devido à variabilidade existente nas condições experimentais. Uma meta-análise foi realizada para conduzir a informação disponível neste campo de pesquisa e estudar a resposta de lisina em dietas para frangos de corte. Os dados de diferentes níveis de lisina 104 experimentos dose-resposta oriundos de 66.726 frangos de corte foram utilizados neste banco de dados. Codificações foram usadas com critérios de agrupamento qualitativo e como moderador nas variáveis analisadas. O banco de dados foi dividido em quatro grupos: machos em fase inicial (de 1 a 21 dias de idade); machos em fase de crescimento (22-42 dias de idade); fêmeas em fase inicial (de 1 a 21 dias de idade); e fêmeas em fase de crescimento (22-42 dias de idade). Análises gráficas foram usadas para explorar a base de dados, ao passo que equações foram utilizadas para estudar o estudo das respostas das variáveis dependentes em cada grupo anteriormente descrito. Essas equações foram geradas através de análises sequenciais usando modelos de efeitos fixos e de efeitos aleatórios. Menores variâncias foram observados em modelos equipados usando dados de frangos de corte machos, comparando com os dados de fêmeas. A utilização de componentes aleatórios permitiu que os modelos explicassem a variabilidade na base de dados e reduzir a variação de 67% em média para machos e fêmeas nos períodos: inicial e crescimento, em comparação com o modelo de efeito fixo. O ganho de peso médio diário foi maximizado num...
Abstract: Numerous publications are being published evaluating the effects of lysine intake on broiler performance, however, showing differing results mainly due to the variability in the experimental conditions. A meta-analysis was conducted to address the available information in this research field and study the response of lysine in diets for broilers. Data of 104 dose-response experiments testing different dietary lysine levels for 66.726 broilers were used in this database. Codifications were used with qualitative grouping criteria and as moderating variables in the analysis. The database was subdivided into four groups, which were: males in initial phase (from 1 to 21 days of old); males in growth phase (from 22 to 42 days of old); females in initial phase (from 1 to 21 days of old); and females in growth phase (from 22 to 42 days of old). Graphical analyses were used to explore the database, whereas equations were used to study study the response of dependent variables in each group previously described. These equations were generated through sequential analysis using fixed-effects and random-effects models. Lower variance responses were observed in models fitted using data of male broilers comparing to the female treatments. Using random components allowed the models to account for the variability in the database and to reduce the variance by 67% in average for males and females in initial and growing comparing to the fixed-effect model. Average Daily Gain was maximized at dietary digestible lysine intake of 0,526 and 1,364 grams day-1 for males in the initial and growth phases ...
Mestre

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Numerosos estudos estão sendo publicados para avaliar os efeitos do consumo de lisina sobre o desempenho de frangos de corte, no entanto, tais estudos diferem em seus resultados, principalmente devido à variabilidade existente nas condições experimentais. Uma meta-análise foi realizada para conduzir a informação disponível neste campo de pesquisa e estudar a resposta de lisina em dietas para frangos de corte. Os dados de diferentes níveis de lisina 104 experimentos dose-resposta oriundos de 66.726 frangos de corte foram utilizados neste banco de dados. Codificações foram usadas com critérios de agrupamento qualitativo e como moderador nas variáveis analisadas. O banco de dados foi dividido em quatro grupos: machos em fase inicial (de 1 a 21 dias de idade); machos em fase de crescimento (22-42 dias de idade); fêmeas em fase inicial (de 1 a 21 dias de idade); e fêmeas em fase de crescimento (22-42 dias de idade). Análises gráficas foram usadas para explorar a base de dados, ao passo que equações foram utilizadas para estudar o estudo das respostas das variáveis dependentes em cada grupo anteriormente descrito. Essas equações foram geradas através de análises sequenciais usando modelos de efeitos fixos e de efeitos aleatórios. Menores variâncias foram observados em modelos equipados usando dados de frangos de corte machos, comparando com os dados de fêmeas. A utilização de componentes aleatórios permitiu que os modelos explicassem a variabilidade na base de dados e reduzir a variação de 67% em média para machos e fêmeas nos períodos: inicial e crescimento, em comparação com o modelo de efeito fixo. O ganho de peso médio diário foi maximizado num...
Numerous publications are being published evaluating the effects of lysine intake on broiler performance, however, showing differing results mainly due to the variability in the experimental conditions. A meta-analysis was conducted to address the available information in this research field and study the response of lysine in diets for broilers. Data of 104 dose-response experiments testing different dietary lysine levels for 66.726 broilers were used in this database. Codifications were used with qualitative grouping criteria and as moderating variables in the analysis. The database was subdivided into four groups, which were: males in initial phase (from 1 to 21 days of old); males in growth phase (from 22 to 42 days of old); females in initial phase (from 1 to 21 days of old); and females in growth phase (from 22 to 42 days of old). Graphical analyses were used to explore the database, whereas equations were used to study study the response of dependent variables in each group previously described. These equations were generated through sequential analysis using fixed-effects and random-effects models. Lower variance responses were observed in models fitted using data of male broilers comparing to the female treatments. Using random components allowed the models to account for the variability in the database and to reduce the variance by 67% in average for males and females in initial and growing comparing to the fixed-effect model. Average Daily Gain was maximized at dietary digestible lysine intake of 0,526 and 1,364 grams day-1 for males in the initial and growth phases ...

Obiettivo della presente ricerca è stato la valutazione dell’utilizzo degli scarti derivanti dal processo di vinificazione come substrato per la digestione anerobica finalizzata alla produzione di VFA (“Volatile Fatty Acids”). I VFA sono acidi grassi a corta catena, convenzionalmente fino a 6 atomi di carbonio, che possono essere utilizzati industrialmente nell’ambito della “Carboxilation Platfrorm” per produrre energia, prodotti chimici, o biomateriali. La sperimentazione si è articolata in due fasi principali: 1) Produzione di VFA in processi batch alimentati con vinacce e fecce come substrato; 2) Recupero dei VFA prodotti dall’effluente anaerobico (digestato) mediante processi di adsorbimento con resine a scambio anionico. Nella prima fase sono stati studiati i profili di concentrazione dei principali VFA nel brodo di fermentazione al variare della tipologia di substrato (vinacce e fecce, bianche e rosse) e della temperatura di incubazione (35 °C e 55 °C). La condizione ottimale rilevata per la produzione di VFA è stata la digestione anaerobica di vinacce rosse disidratate e defenolizzate alla temperatura di 35 °C (mesofilia), che ha permesso di raggiungere una concentrazione di VFA totali nel digestato di circa 30 g/L in 16 giorni di monitoraggio. Nella seconda fase è stato analizzato il processo di estrazione in fase solida (Solid Phase Extraction, SPE) con resine a scambio anionico per il recupero dei VFA dal digestato di vinacce rosse. Sono state messe a confronto le prestazioni di quattro diverse resine a scambio anionico: Sepra SAX, Sepra SAX-ZT, Sepra NH2, Amberlyst A21. I parametri operativi ottimali per l’adsorbimento sono risultati essere condizioni di pH acido pari al valore naturale delle soluzioni indicate sopra (~2.5) e tempo di contatto di 2 ore. Tra le quattro resine quella che ha fornito i migliori risultati è stata la Amberlyst A21, una resina polimerica a scambio anionico debolmente basica il cui gruppo funzionale caratteristico è un’ammina terziaria. Infine è stato valutato il processo di desorbimento dei VFA adsorbiti dalla resina con tre diverse soluzioni desorbenti: acqua demineralizzata, etanolo (EtOH) ed acqua basificata con NaOH (1 mol/L). I risultati migliori sono stati conseguiti nel caso dell’EtOH, ottenendo un recupero finale del 9,1% dei VFA inizialmente presenti nel digestato di vinacce rosse incubate in termofilia.

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia
The composition of lipid and fatty acids in fish has been widely studied by several authors, showing the well-being associated with the consumption of polyunsaturated fatty acids ω-3. Seafood is a healthy food because contains high quality protein with all essential amino acids, and especially because is very rich in polyunsaturated fatty acids. In this work we studied the farmed salmon, with the aim of analyzing the bioaccessibility of ω-3 fatty acids. To this end, we used an in vitro digestion model. Before testing, it was determined the lipid content and total fatty acid composition. Subsequently, we analyzed the bioaccessibility using TLC. It was found that the fat content of the salmon was 14%. It was found that an excellent source of polyunsaturated fatty acid ω-3, which are more than 60% EPA and DHA. In bioaccessible fraction, it was found that there are essentially polyunsaturated fatty acids for absorption. Salmon is a good source of polyunsaturated fatty acids ω-3, provides high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and is therefore considered very important and beneficial, from a physiological and nutrition health.