Academic literature on the topic 'Isomaltulosa'

In vitro experiments have indicated prebiotic activity of isomaltulose, which stimulates the growth of probiotics and the production of short chain fatty acids (SCFAs). However, the absence of in vivo trials undermines these results. This study aims to investigate the effect of isomaltulose on composition and functionality of gut microbiota in rats. Twelve Sprague–Dawley rats were divided into two groups: the IsoMTL group was given free access to water containing 10% isomaltulose (w/w), and the control group was treated with normal water for five weeks. Moreover, 16S rRNA sequencing showed that ingestion of isomaltulose increased the abundances of beneficial microbiota, such as Faecalibacterium and Phascolarctobacterium, and decreased levels of pathogens, including Shuttleworthia. Bacterial functional prediction showed that isomaltulose affected gut microbial functionalities, including secondary bile acid biosynthesis. Targeted metabolomics demonstrated that isomaltulose supplementation enhanced cholic acid concentration, and reduced levels of lithocholic acid, deoxycholic acid, dehydrocholic acid, and hyodeoxycholic acid. Moreover, the concentrations of propionate and butyrate were elevated in the rats administered with isomaltulose. This work suggests that isomaltulose modulates gut microbiota and the production of SCFAs and secondary bile acids in rats, which provides a scientific basis on the use of isomaltulose as a prebiotic.

The impact of slow digestible sources of dietary carbohydrate in reducing the risk of developing obesity and related metabolic disorders is unclear. The aim of the present study was to compare the postprandial metabolic response to the ingestion of sucrose v. isomaltulose. We hypothesised that the reduced digestion and absorption rate of isomaltulose would result in lower glycaemic and insulinaemic responses when compared with the ingestion of sucrose, leading to greater postprandial fat oxidation rates. In a randomised, single-blind, cross-over study, ten overweight subjects ingested two different carbohydrate drinks (sucrose and isomaltulose, 75 g carbohydrate equivalents) following an overnight fast (08.40 hours) and with a standardised meal (12.30 hours, 25 % of total energy content was provided as either a sucrose or isomaltulose drink). Blood samples were taken before ingestion and every 30 min thereafter for a period of 3 h, substrate use was assessed by indirect calorimetry and breath samples were collected. Ingestion of carbohydrates with a mixed meal resulted in a lower peak glucose and insulin response and a lower change in area under the curve (ΔAUC) following isomaltulose when compared with sucrose. Together with the lower glucose and insulin responses, postprandial fat oxidation rates were higher (14 %) with isomaltulose when compared with sucrose when ingested with a mixed meal (P = 0·02). The attenuated rise in glucose and insulin concentrations following isomaltulose results in reduced inhibition of postprandial fat oxidation. The metabolic response to isomaltulose co-ingestion suggests that this may represent an effective nutritional strategy to counteract overweight-induced metabolic disturbances.

: Cane molasses is one of the main by-products of sugar refineries, which is rich in sucrose. In this work, low-cost cane molasses was introduced as an alternative substrate for isomaltulose production. Using the engineered Yarrowia lipolytica, the isomaltulose production reached the highest (102.6 g L−1) at flask level with pretreated cane molasses of 350 g L−1 and corn steep liquor of 1.0 g L−1. During fed-batch fermentation, the maximal isomaltulose concentration (161.2 g L−1) was achieved with 0.96 g g−1 yield within 80 h. Simultaneously, monosaccharides were completely depleted, harvesting the high isomaltulose purity (97.4%) and high lipid level (12.2 g L−1). Additionally, the lipids comprised of 94.29% C16 and C18 fatty acids, were proved suitable for biodiesel production. Therefore, the bioprocess employed using cane molasses in this study was low-cost and eco-friendly for high-purity isomaltulose production, coupling with valuable lipids.

Isomaltulose is a noncariogenic reducing disaccharide and also a structural isomer of sucrose and is used by the food industry as a sucrose replacement. It is obtained through enzymatic conversion of microbial sucrose isomerase. An Erwinia sp. D12 strain is capable of converting sucrose into isomaltulose. The experimental design technique was used to study the influence of immobilization parameters on converting sucrose into isomaltulose in a batch process using shaken Erlenmeyer flasks. We assessed the effect of gelatin and transglutaminase addition on increasing the reticulation of granules of Erwinia sp. D12 cells immobilized in alginate. Independent parameters, sodium alginate concentration, cell mass concentration, CaCl2 concentration, gelatin concentration, and transglutaminase concentration had all a significant effect (P<0.05) on isomaltulose production. Erwinia sp. D12 cells immobilized in 3.0% (w/v) sodium alginate, 47.0% (w/v) cell mass, 0.3 molL-1 CaCl2, 1.7% (w/v) gelatin and 0.15% (w/v) transglutaminase presented sucrose conversion into isomaltulose, of around 50–60% in seven consecutive batches.

Isomaltulose, also known as palatinose, is produced by sucrose isomerase and has been highlighted as a sugar substitute due to a number of advantageous properties. For the massive production of isomaltulose, high resistance to sucrose and stability of sucrose isomerase as well as sucrose conversion yields would be critical factors. We describe a series of screening procedures to isolate the mutant strain of Serratia sp. possessing enhanced isomaltulose production with improved stability. The new Serratia sp. isolated from a series of screening procedures allowed us to produce isomaltulose from 60% sucrose solution, with over 90% conversion yield. Moreover, when this strain was immobilized in calcium alginate beads and placed in a medium containing 60% sucrose, it showed over 70% sucrose conversion yields for 30 cycles of repeated-batch reactions. Thus, improved conversion activity and stability of the newly isolated Serratia sp. strain in the present study would be highly valuable for industries related to isomaltulose production.

Isomaltulose is mainly produced from sucrose by microbial fermentation, when the utilization of sucrose contributes a high production cost. To achieve a low-cost isomaltulose production, soy molasses was introduced as an alternative substrate. Firstly, α-galactosidase gene from Rhizomucor miehei was expressed in Yarrowia lipolytica, which then showed a galactosidase activity of 121.6 U/mL. Under the effects of the recombinant α-galactosidase, most of the raffinose-family oligosaccharides in soy molasses were hydrolyzed into sucrose. Then the soy molasses hydrolysate with high sucrose content (22.04%, w/w) was supplemented into the medium, with an isomaltulose production of 209.4 g/L, and the yield of 0.95 g/g. Finally, by virtue of the bioremoval process using Pichia stipitis, sugar byproducts in broth were transformed into ethanol at the end of fermentation, thus resulting in high isomaltulose purity (97.8%). The bioprocess employed in this study provides a novel strategy for low-cost and efficient isomaltulose production from soybean molasses.

Isomaltulose is a low glycemic and insulinemic carbohydrate available as a constituent of sports drinks. However, it remains unclear whether thermoregulatory responses (sweating and cutaneous vasodilation) after isomaltulose drink ingestion differ from those of sucrose and water during exercise in a hot environment. Ten young healthy males consumed 10% sucrose, 10% isomaltulose, or water drinks. Thirty-five minutes after ingestion, they cycled for fifteen minutes at 75% peak oxygen uptake in a hot environment (30 °C, 40% relative humidity). Sucrose ingestion induced greater blood glucose concentration and insulin secretion at the pre-exercise state, compared with isomaltulose and/or water trials, with no differences during exercise in blood glucose. Change in plasma volume did not differ between the three trials throughout the experiment, but both sucrose and isomaltulose ingestions similarly increased plasma osmolality, as compared with water (main beverage effect, p = 0.040)—a key response that potentially delays the onset of heat loss responses. However, core temperature thresholds and slopes for heat loss responses were not different between the trials during exercise. These results suggest that ingestion of isomaltulose beverages induces low glycemic and insulinemic states before exercise but does not alter thermoregulatory responses during exercise in a hot environment, compared with sucrose or water.

Hyperglycemia is linked to impaired arterial endothelial function (EF), an early sign of cardiovascular disease. We compared the efficacy of low-glycemic index isomaltulose (Palatinose™) with that of sucrose in modulating EF, as assessed by flow-mediated dilation (FMD). In this double-blinded cross-over study, 80 overweight mildly hypertensive subjects were randomized to receive 50 g of either isomaltulose or sucrose. On two non-consecutive days, brachial artery ultrasound FMD scans were obtained prior to and hourly (T0–T3) after carbohydrate load. Blood was drawn immediately after scanning. Glucose and insulin levels were analyzed. Overall, the FMD decrease was attenuated by isomaltulose compared to sucrose (ΔFMD = −0.003% and −0.151%; p > 0.05 for the interaction treatment x period). At T2, FMD was significantly higher after isomaltulose administration compared to that after sucrose administration (FMD = 5.9 ± 2.9% and 5.4 ± 2.6%, p = 0.047). Pearson correlations between FMD and blood glucose showed a trend for a negative association at T0 and T2 independently of the carbohydrate (r-range = −0.20 to −0.23, p < 0.1). Sub-analysis suggested a lower FMD in insulin-resistant (IR) compared to insulin-sensitive subjects. Isomaltulose attenuated the postprandial decline of FMD, particularly in IR persons. These data support the potential of isomaltulose to preserve the endothelial function postprandially and consequently play a favorable role in cardiovascular health.

ABSTRACT Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35°C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50°C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35°C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the V max was 638 U mg−1, and the K cat/Km was 1.79 × 104 M−1 s−1, compared to a Km of 76.0 mM, a V max of 423 U mg−1, and a K cat/Km of 0.62 × 104 M−1 s−1 for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose.

Cada vez es más habitual la demanda de alimentos que no provoquen ciertos efectos indeseables relacionados, por ejemplo con el consumo de azúcar, como pueden ser el desarrollo de caries o la diabetes. Junto a esto, el hecho de que la población sepa apreciar los continuos avances en la mejora de la calidad organoléptica y su contenido nutricional, lleva a la industria agroalimentaria al desarrollo de nuevos productos que satisfagan todas las expectativas del consumidor. La existencia en el mercado de nuevos carbohidratos funcionales que pueden sustituir la sacarosa permite desarrollar y/o reformular productos que cumplan dichas expectativas. La deshidratación osmótica tradicional o por vía húmeda (DOH) es una técnica ampliamente extendida en el procesado de frutas y verduras debido a la elevada calidad de los productos obtenidos. Sin embargo, existen una serie de desventajas relacionadas con el manejo de grandes volúmenes de las disoluciones, que deberían ser tenidas en cuenta. La deshidratación osmótica por vía seca (DOS) podría ser una alternativa, ya que el volumen de la disolución generada es considerablemente menor y además, ésta es más rica en compuestos aromáticos e hidrosolubles (vitaminas y minerales) que provienen de la propia fruta. El trabajo realizado en la siguiente tesis docotral ha consistido en la optimización del proceso de formulación de un producto untable de fresa mediante deshidratación osmótica sustituyendo además, parcial o totalmente, la sacarosa por otros azúcares más saludables. Para ello se estudió la influencia de diferentes variables de proceso (tipo de azúcar, tipo de deshidratación osmótica, % de pectina, % de ácido cítrico) sobre la cinética de transferencia de materia y, sobre diferentes parámetros relacionados con la calidad funcionalidad (antocianinas y actividad antioxidante) y sensorial (color, textura, reología y perfil aromático) en los untables de fresa formulados. Los resultados obtenidos permiten afirmar que la cinética de transferencia de materia es mayor cuando la concentración del medio envolvente es variable, siendo ligeramente superior en los procesos de deshidratación por vía húmeda que en los de vía seca.
Peinado Pardo, I. (2011). Estudio de utilización de isomaltulosa en el desarrollo de productos untables de fresa de bajo indice glicémico [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11671
Palancia

[EN] The current tendency by consumers towards healthier products, which also offer a functional added value as a high content in vitamins and antioxidants, has made the development of new products one of the priorities of the food industry. In this sense, the development of spreadable products from fruits or vegetables and healthier sucrose replacers such as fructose and isomaltulose, with a low glycemic index, represent an attractive alternative to boost the sector of products processed from fruit and vegetables. Furthermore, isomaltulose does not produce tooth decay, so the interest in the development of these products would still be greater. Moreover, the processing of fruits and vegetables for marmalades for example, involves subjecting the product to a long cooking time, in order to obtain the typical characteristics of the product and increase its stability. In this research work, the production of tomato spreadable products by means of dry osmotic dehydration consisting of directly covering the food with the osmotic agent in solid state is proposed. This method presents the environmental advantage, compared to the conventional osmotic dehydration process, of not requiring the use of an external osmotic solution which must be managed as a waste. Additionnaly a solution riched in native bioactive compounds is generated by the output of the liquid phase of the food during the process. This solution could be incorporated to the final product in order to enhance its functional properties. In this research work, the influence of the osmotic dehydration method (wet and dry methods), the formulation (% sucrose replacing by isomaltulose and/or fructose , % pectin , % citric acid, potassium sorbate (ppm) and heat treatment time on the physicochemical (rheological, mechanical and optical among others) and antioxidants properties of different spreadable tomato products of 20 and 50 Brix was studied. Finally, and based on the results obtained, the formulation of a spreadable tomato product of 50 Brix was optimized. The obtained results allow to conclude that it is possible to obtain spreadable tomato products with low glycemic index and high functional profile by means of dry osmotic dehydration. The optimization of the process variables, based on maximizing the antioxidant content, reaching a colour as close as possible to the fresh tomato and an appropriate texture, concludes that the optimal process variables are: 50 % of isomaltulose, 2.5 % of pectin, 0.5 % of citric acid, 253.4 ppm of potassium sorbate and 7.6 minutes at 90 °C, in order to obtain a 50 Brix spreadable tomato product by means of dry osmotic dehydration.
[ES] La actual tendencia por parte de los consumidores hacia productos más saludables, que además ofrezcan un valor funcional añadido, como un elevado contenido en vitaminas y compuestos antioxidantes, ha hecho que el desarrollo de nuevos productos en esta dirección, sea uno de los objetivos prioritarios para la industria alimentaria. En este sentido, la elaboración de productos untables a base de frutas u hortalizas y azúcares más saludables que la sacarosa como la fructosa y la isomaltulosa, de bajo índice glicémico, representaría una atractiva alternativa para dinamizar el sector de productos procesados a partir de frutas y hortalizas. Además, la isomaltulosa no produce caries dental, por lo que aún sería mayor su interés, en la elaboración de estos productos. Por otra parte, el procesado de frutas y hortalizas para obtener mermeladas por ejemplo, conlleva el someter al producto a largos tiempos de cocción, con el fin de obtener las características típicas del producto y aumentar su estabilidad. En este trabajo, se plantea la producción de untables de tomate por deshidratación osmótica por vía seca consistente en cubrir el alimento con el agente osmótico en estado sólido. Este método presenta la ventaja mediambiental, frente a la deshidratación osmótica convencional por vía húmeda, de no requerir el uso de una disolución osmótica externa evitando, por tanto, la gestión de la misma como residuo del proceso. En cambio, sí se genera una disolución rica en compuestos bioactivos por salida de la fase líquida del alimento durante el proceso, la cual se incorpora al producto final con el incremento del valor funcional del mismo. En el presente trabajo se ha estudiado la influencia del método de deshidratación osmótica (vía húmeda o seca), de la formulación (% de sustitución de sacarosa por isomaltulosa y/o fructosa, % de pectina, % de ácido cítrico, sorbato potásico (ppm), y del tiempo de tratamiento térmico sobre las propiedades físico-químicas (reológicas, mecánicas y ópticas, entre otras) y antioxidantes de diferentes productos untables de tomate de 20 y 50 ºBrix. Por último y en base a los resultados obtenidos, se ha optimizado la formulación de un producto untable de tomate de 50 ºBrix. Los resultados obtenidos permiten afirmar que es posible la elaboración de un producto untable de tomate de bajo índice glicémico y un alto valor funcional, mediante el método de deshidratación osmótica por vía seca. La optimización de las variables de proceso, en base a maximizar su contenido en antioxidantes, conseguir un color lo más parecido posible al tomate fresco y una textura adecuada, indica que las condiciones de proceso más adecuadas para obtener un producto untable de tomate de 50 ºBrix por deshidratación osmótica por vía seca son: 50 % de isomaltulosa, 2,5 % de pectina, 0,5 % de ácido cítrico, 253,4 ppm de sorbato potásico y 7,6 minutos a 90 ºC.
[CAT] L'actual tendència per part dels consumidors cap a productes més saludables, que a més ofereixin un valor funcional afegit, com un elevat contingut en vitamines i compostos antioxidants, ha fet que el desenvolupament de nous productes en aquesta direcció, sigui un dels objectius prioritaris en la indústria alimentària. En aquest sentit, l'elaboració de productes untables de fruites o hortalisses i sucres més saludables que la sacarosa, com la fructosa i la isomaltulosa, de baix índex glicèmic, representaria una atractiva alternativa per dinamitzar el sector de productes processats a partir de fruites i hortalisses. A més, la isomaltulosa no produeix càries dental, de manera que encara seria major el seu interès, en l'elaboració d'aquests productes. D'altra banda, el processat de fruites i hortalisses per obtenir melmelades per exemple, comporta sotmetre al producte a llargs temps de cocció, per tal d'obtenir les característiques típiques del producte i augmentar la seva estabilitat. En aquest treball, es planteja la producció d'untables de tomaca per deshidratació osmòtica per via seca, consistent en cobrir l'aliment amb l'agent osmòtic en estat sòlid. Aquest mètode presenta l'avantatge mediambiental, enfront de la deshidratació osmòtica convencional per via humida, de no requerir l'ús d'una dissolució osmòtica externa evitant, per tant, la gestió de la mateixa com a residu del procés. En canvi, sí es genera una dissolució rica en compostos bioactius per sortida de la fase líquida de l'aliment durant el procés, la qual s'incorpora al producte final amb l'increment del valor funcional del mateix. En el present treball s'ha estudiat la influència del mètode de deshidratació osmòtica (via humida o seca), de la formulació (% de substitució de sacarosa per isomaltulosa i/o fructosa, % de pectina, % d'àcid cítric, sorbat potàssic (ppm ), i del temps de tractament tèrmic sobre les propietats fisicoquímiques (reològiques, mecàniques i òptiques, entre d'altres) i antioxidants de diferents productes untables de tomaca de 20 i 50 ºBrix. Finalment i en base als resultats obtinguts, s'ha optimitzat la formulació d'un producte untable de tomaca de 50 ºBrix. Els resultats obtinguts permeten afirmar que es possible l'elaboració de un producte untable de tomaca de baix índex glicèmic amb un alt valor nutricional, mitjançant el mètode de deshidratació osmòtica per via seca. L'optimització de les variables de procés, bassant-se en maximitzar el seu contingut en antioxidants, aconseguir un color el més paregut possible a la tomaca fresca i una textura adequada, indica que les condicions de procés més adequades per obtenir un producte untable de tomaca de 50 ºBrix per deshidratació osmòtica per via seca són: 50 % de isomaltulosa, 2,5 % de pectina, 0,5 % de àcid cítric, 253,4 ppm de sorbat potàssic i 7,6 minuts a 90 ºC.
Rosa Barbosa, EM. (2016). ESTUDIO DE LA UTILIZACIÓN DE ISOMALTULOSA EN EL DESARROLLO DE PRODUCTOS UNTABLES DE TOMATE DE BAJO ÍNDICE GLICÉMICO [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62580
TESIS

Pese a que las golosinas no son un producto imprescindible en la dieta, no hay que duda de que su consumo está muy generalizado tanto en la población infantil como en la adulta. Sin embargo, su ingesta elevada está relacionada con problemas de sobrepeso, caries y elevado índice glicémico. Para contrarrestar estos problemas se ha invertido mucho esfuerzo en el desarrollo de productos dietéticos. Para ello, se sustituyen los azúcares convencionales por edulcorantes artificiales que dan lugar a productos hipocalóricos, pero que presentan otros problemas relacionados con su efecto laxante y con una posible mayor incidencia de determinados cánceres. Actualmente existen en el mercado azúcares y edulcorantes naturales alternativos a la sacarosa con propiedades funcionales muy interesantes, como es el caso de la Isomaltulosa y la estevia. En el primer caso se trata de un azúcar no cariogénico, que aporta energía de forma gradual (bajo índice glicémico) y en el caso de la estevia se trata de un intenso edulcorante natural acalórico. Estudiar la sustitución total o parcial de los azúcares convencionales de las golosinas por este tipo de azúcares y edulcorantes más saludables y su influencia sobre la calidad de los productos es el objetivo general de este proyecto. Cabe resaltar que no se pretende formular un producto dietético sino un producto energéticamente similar a las golosinas tradicionales pero que aporten energía saludable. La sustitución de ingredientes implica cambios en las características de los productos que deben ser evaluados para optimizar el nivel de sustitución, por lo que es necesario abordar estudios sobre la influencia de estos ingredientes en las propiedades ópticas, mecánicas, sensoriales así como sobre la aceptación del producto y su estabilidad a lo largo del almacenamiento.
Periche Santamaría, A. (2014). STEVIA Y OTROS EDULCORANTES SALUDABLES EN LA FORMULACION DE GOLOSINAS FUNCIONALES: IMPLICACIONES TECNOLÓGICAS Y DE CALIDAD [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/45995
Alfresco

Die vorliegende Arbeit behandelt die heterogen katalysierte reduktive Aminierung von Isomaltulose mit n-Dodecylamin. Ziel der Arbeit ist die Entwicklung eines technischen Verfahrens zur Herstellung bioabbaubarer Tenside aus Nachwachsenden Rohstoffen. Die früheren Untersuchungen haben gezeigt, dass diese Reaktion unter Verwendung eines Palladium-Aktivkohle-Suspensionkatalysators viel versprechende Umsätze und Selektivitäten aufwies. Das Haupthindernis einer technischen Realisierung des Verfahrens war jedoch die zu schnelle Desaktivierung des Katalysators durch Belegung der Katalysatoroberfläche durch, in Parallelreaktionen entstehenden, Maillard-Produkte. Eine mögliche Lösung dieses Problems könnte durch Verwendung eines aktiveren und selektiveren Hydrierkatalysators erreicht werden. Auf Basis dieser Erkenntnisse wurde in einem systematischen Screening-Verfahren eine Reihe von Palladium-Festbettkatalysatoren hinsichtlich deren Performance bei dieser Reaktion untersucht. Bei den Reihenuntersuchungen zum schnellen Informationsgewinn kam ein Batch-Autoklav (1 l) zum Einsatz. Die Hauptkriterien des Screening-Verfahrens bei Pd-Systemen waren: Trägervariation (Aktivkohle, Al2O3, SiO2, TiO2, NbO2 und ZrO2), Variation der Präparationsmethode sowie Dotierung des Katalysators durch ein zweites Metall (Ag, Mg, In und Sn). Im allgemeinen zeigten die 1%-igen Pd/ZrO2 Festbettkatalysatoren hohe Aktivitäten und Langzeitstabilitäten, insbesondere die Schalenkatalysatoren waren bezüglich der aminierten Produkte selektiver gegenüber den Imprägnierkatalysatoren. Eine auf Basis von Gaschromatographie entwickelte Analysenmethode ermöglichte die Identifizierung zahlreicher Komponenten und vertiefte somit das Verständnis des komplexen Reaktionsnetzwerks. Mit Hilfe eines 8 l Autoklaven wurden im Rahmen dieser Arbeit die Hauptproduktisomere 1-N-n-Dodecylamino-1-desoxy-6-O-(α-D-Glucopyranosyl)-D-sorbit/ mannit sowie 2-N-n-Dodecylamino-2-desoxy-6-O-(α-D-Glucopyranosyl)-D-sorbit/ mannit für analytische und anwendungstechnische Untersuchungen in hoher Reinheit synthetisiert. Anhand dieser Ergebnisse wurde ein Verfahrenskonzept für eine technische Umsetzung ausgearbeitet.

Orientador : Helia Harumi Sato
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A isomaltulose é um dissacarídeo redutor, isômero da sacarose, que possui um sabor adocicado suave e propriedades físicas e sensoriais muito similares, que tem sido considerado um substituto promissor da sacarose na indústria de alimentos, devido a algumas características como baixo potencial cariogênico e baixo índice glicêmico, promoção do crescimento de bifidobactérias benéficas da microbiota intestinal, e por apresentar maior estabilidade em relação à sacarose em alimentos e bebidas acidificados, além de poder ser convertido para isomalte, um açúcar álcool dietético e não cariogênico aplicado na indústria de alimentos e farmacêutica. Os objetivos deste trabalho foram otimizar um meio de cultivo, de menor custo, para a produção da enzima glicosiltransferase pela linhagem Erwinia sp. D12 e estudar a produção de isomaltulose a partir de sacarose utilizando-se células livres e células imobilizadas em alginato de cálcio. Na otimização do meio de cultivo, em frascos sob agitação, a máxima atividade obtida foi de 12,4 UA de glicosiltransferase/mL de meio de cultivo após 8 horas de fermentação a 30ºC, em meio composto de 150 g/L de melaço de cana-de-açúcar, 20 g/L de água de maceração de milho- Milhocina®, 15 g/L de extrato de levedura Prodex Lac SDÒ, e pH ajustado a 7,5. No estudo da produção de glicosiltransferase, em fermentador de 6,6 litros, utilizando-se o meio de cultivo otimizado foi obtida máxima atividade de 22,5 UA de glicosiltransferase/mL de meio de cultivo, após 8 horas de fermentação a 27oC. No estudo da produção de isomaltulose por células íntegras imobilizadas de Erwinia sp. D12 em alginato de cálcio foi verificado que o tratamento dos grânulos de células imobilizadas com 0,06% de glutaraldeído, promoveu uma maior taxa de conversão, sendo obtido cerca de 72,3% de isomaltulose, após 12 horas de incubação em frascos sob agitação a 30ºC. As células íntegras imobilizadas e tratadas com 0,06% de glutaraldeído, em colunas de leito empacotado, apresentaram maior estabilidade do que àquelas imobilizadas sem tratamento com o aditivo, e mantiveram a conversão de sacarose em isomaltulose entre 50-60% por 10 dias, a partir de solução de sacarose 35% e fluxo de 0,56 mL/min a 30ºC. Foram estudados diferentes tratamentos para a preparação de células íntegras, células lisadas e extrato enzimático bruto imobilizados em alginato de cálcio. Os métodos que mostraram melhores resultados, em processo em batelada, foi o extrato enzimático bruto imobilizado em alginato de cálcio (EEI), em que foram obtidas taxas de conversão entre 59,7% e 63,3%; e células lisadas por sonicação e imobilizadas (CSI), com taxas de conversão entre 47,6% e 62,3%. A coluna de leito empacotado contendo grânulos de células lisadas imobilizadas (CSI) apresentou maior estabilidade do que a coluna contendo os grânulos de extrato enzimático bruto imobilizado (EEI). A coluna de leito empacotado de CSI converteu 53-59% de sacarose em isomaltulose durante sete dias, posteriormente houve queda lenta e gradual da conversão não havendo mais transformação em isomaltulose após 21 dias. No estudo da produção de isomaltulose utilizando-se células livres de Erwinia sp. D12, em processo em batelada, foi verificado o efeito do pH, da temperatura, da concentração do substrato sacarose e da concentração de massa celular em frascos agitados a 150 rpm e 30ºC. A conversão de sacarose em isomaltulose foi favorecida utilizando-se temperaturas superiores a 30ºC, pH entre 6,0-6,5, massa celular entre 7,5- 12,5% e solução de sacarose de 20-35%, obtendo-se rendimentos de isomaltulose acima de 50%. No estudo da vida útil das células livres em escala de bancada, utilizando-se frascos Erlenmeyers sob agitação, foi verificado que os parâmetros de conversão fixados a: temperatura de 35ºC, pH 6,5, concentração de substrato sacarose 35% e concentração de massa celular 10% foram os mais favoráveis, promovendo um alto rendimento em isomaltulose entre 70-75%, por 16 bateladas. Os ensaios realizados em escala piloto demonstraram a viabilidade da conversão de sacarose em isomaltulose por células livres, em que foram obtidos cerca de 114 litros de xarope com alto teor de isomaltulose (63,40%). Os cristais de isomaltulose, após clarificação e purificação do xarope convertido, apresentaram pureza de 96,5%
Abstract: Isomaltulose is a reducing disaccharide and a structural isomer of sucrose. It has a mild sweet flavour and very similar physical and sensorial properties and has been considered as a promising substitute for sucrose in the food industry, due to some of its characteristics such as a low cariogenic potential and low glycemic index and the promotion of beneficial bifid bacteria in the intestinal microbial flora. It also shows greater stability than sucrose in acidified foods and drinks, and can be converted into isomalt, a dietetic sugar alcohol with no cariogenic potential for use in the food and pharmaceutical industries. The objectives of this research were the optimisation of a culture medium with reduced costs for the production of the enzyme glucosyltransferase by the strain Erwinia sp. D12, and the study of isomaltulose production from sucrose by free and immobilized cells. In the optimisation of the culture medium in shaken flasks, the highest glucosyltransferase activity achieved was 12.4 UA/mL of culture medium after 8 hours of fermentation at 30ºC, in a medium composed of 150 g/L of sugar cane molasses, 20 g/L of corn steep liquor- Milhocina® and 15 g/L of yeast extract Prodex Lac SD®, with the pH adjusted to 7.5. In the study for glucosyltransferase production in a 6.6-liter reactor using the optimised culture medium, the highest glucosyltransferase production achieved was 22.5 UA/mL of culture medium, after 8 hours of fermentation at 27ºC. In the study for isomaltulose production using Erwinia sp. D12 cells immobilized in calcium alginate, it was shown that the addition of 0.06% glutaraldehyde during the immobilization process, promoted a higher conversion rate, reaching about 72.3% isomaltulose after 12 hours of incubation at 30°C in shaken flasks. The immobilized whole cells treated with 0.06% glutaraldehyde, used in packed-bed reactors, presented greater stability than those immobilized without the addition of the additive, and maintained the conversion of sucrose into isomaltulose between 50-60% for 10 days, using a 35% sucrose solution with a flow rate of 0.56 mL/min at 30ºC. Different treatments were studied for the preparation of whole cells, lysed cells and a crude enzyme extract immobilized in calcium alginate. The methods that showed the best results in batch processes were the crude enzyme extract immobilized in calcium alginate (EEI), where conversion rates between 59.7% and 63.3% were achieved; and immobilized lysed cells (CSI), with conversion rates between 47.6% and 62.3%. The packed bed column containing granules of immobilized lysed cells (CSI) presented greater stability than that containing granules of immobilized crude enzymatic extract (EEI). The packed bed column with CSI converted 53-59% of sucrose into isomaltulose during seven days, and then showed a gradual decline in conversion, ceasing completely after 21 days. In the study of isomaltulose production using free Erwinia sp. D12 cells in a batch process, the effects of pH, temperature, sucrose substrate concentration and cell mass concentration were determined in shaken flasks at 150 rpm and 30ºC. The following conditions favoured the conversion of sucrose into isomaltulose: temperatures above 30ºC, pH between 6.0-6.5, cell mass between 7.5-12.5% and a sucrose concentration between 20-35%; when isomaltulose yields above 50% were obtained. The half-life of the free cells was studied on a bench scale in shaken Erlenmeyers flasks and it was shown that the following fixed conversion parameters were the most favourable: temperature of 35ºC, pH 6.5, 35% sucrose substrate concentration and 10% cell mass concentration; promoting high isomaltulose yields between 70-75%, for 16 batches. The pilot scale assays demonstrated the viability of the conversion of sucrose into isomaltulose by free cells, obtaining about 114 liters of high isomaltulose syrup (63.40%). The isomaltulose crystals, after clarification and purification of the converted syrup, showed a purity of 96.5%
Doutorado
Mestre em Ciência de Alimentos

Orientador: Helia Harumi Sato
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A isomaltulose é um dissacarídeo redutor, isômero da sacarose, com propriedades interessantes para a indústria de alimentos. Este açúcar apresenta propriedades similares às da sacarose, entretanto, apresenta baixo potencial cariogênico e baixo índice glicêmico. A isomaltulose é produzida industrialmente através da conversão enzimática da sacarose pela enzima glicosiltransferase produzida por certas linhagens de bactérias, como Protoaminobacter rubrum e Erwinia rhapontici. Este trabalho teve por objetivo purificar e caracterizar a glicosiltransferase produzida pela Erwinia sp. D12 e imobilizar a glicosiltransferase bruta em Celite e pectina de baixo teor de metoxilas (BTM). A glicosiltransferase foi purificada por cromatografia em coluna de troca catiônica SP-Sepharose Fast Flow, obtendo-se duas frações com atividade de glicosiltransferase. A enzima da fração n° 17 foi purificada cerca de 17,9 vezes, e a massa molecular foi estimada em 65 kDa, por SDS-PAGE. A glicosiltransferase bruta e as frações purificadas apresentaram atividade ótima em pH de 6,0 a 6,5 e em temperatura de 30 a 35°C e estabilidade na faixa de pH de 5,0 a 7,0 e em temperaturas inferiores a 30°C, sendo que as frações purificadas apresentaram menor estabilidade. As condições ótimas de imobilização da glicosiltransferase bruta em Celite foram pH 4,0 para adsorção da enzima no suporte, e quantidade de enzima de 1700 U. A glicosiltransferase bruta imobilizada em Celite, em processo de batelada e em coluna de leito empacotado, converteu cerca de 50% de sacarose em isomaltulose, porém a conversão diminuiu com o tempo. O tratamento da glicosiltransferase imobilizada em Celite com 0,1% de glutaraldeído não resultou em aumento da retenção e estabilidade da enzima. A glicosiltransferase imobilizada em gel de pectina BTM com adição de gordura manteve maior atividade de glicosiltransferase que as preparações de enzima imobilizada sem gordura e liofilizadas. Quando essa preparação foi aplicada em processo de batelada foi observada conversão inicial em torno de 30% com queda gradativa nas posteriores bateladas. Em colunas de leito empacotado foi observada conversão de sacarose em isomaltulose máxima de 10,5% em 2 horas, sendo que após 60 horas foi igual a 3%
Abstract: Isomaltulose is a reducing disaccharide and an isomer of sucrose. Because of its properties it is interesting for application in the food industry. This sugar shows similar properties to sucrose, but it has low cariogenic potential and low glycemic index. Industrially, isomaltulose is produced by conversion of sucrose using glucosyltransferase. This enzyme is produced by few bacterial strains such as Protoaminobacter rubrum and Erwinia rhapontici. The aims of this research were the purification and characterization of glucosyltransferase produced by Erwinia sp. D12 and the immobilization of the crude enzyme in Celite and low-metoxyl pectin. The glucosyltransferase was purified using cationic exchange column of SPSepharose Fast Flow and it was obtained two fractions with glucosyltransferase activity. The enzyme found in 17th fraction was purified 17.9-fold, and showed a molecular mass of 65 kDa, by SDS-PAGE. The crude glucosyltransferase and the purified fractions showed optimum activity in pH of 6.0 ¿ 6.5 and 30 ¿ 35°C and stability in pH 5.0 to 7.0 and under 30°C, and the purified preparation was less stable than the crude enzyme. The optimum condition of the immobilization of crude glucosyltransferase was using pH 4.0 for the adsorption of the enzyme into the support, and amount of enzyme of 1700 U. The glucosyltransferase immobilized on Celite was applied to the conversion of sucrose into isomaltulose in a batch system and packed-bed reactor. A conversion rate of 50% was observed, but this decreased over a period of hours. The treatment of the immobilized glucosyltransferase on Celite, with 0.1% glutharaldehyde did not increase the stability of the enzyme. The immobilization of crude glucosyltransferase in lowmetoxyl pectin with a fat addition, presented a higher activity when compared to microcapsules without fat or freeze dried. When this preparation was applied to the conversion of sucrose into isomaltulose, in a batch system, it was observed an initial conversion rate of 30%. However this value decreased in further batches. In the packed-bed reactors, the highest conversion value of sucrose to isomaltulose was 10.5% in 2 hours, but after 60 hours the conversion was 3%
Mestrado
Bioquimica de Alimentos
Mestre em Engenharia de Alimentos

Orientador: Hélia Harumi Sato
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A isomaltulose e a trealulose são dissacarídeos isômeros estruturais, que podem ser obtidos a partir da sacarose utilizando-se glicosiltransferase bacteriana. Esses dissacarídeos são considerados açúcares alternativos de grande potencial para uso nas indústrias de alimentos e farmacêutica porque são hidrolisados e absorvidos mais lentamente e apresentam baixo potencial cariogênico comparado com a sacarose. Foi estudada a imobilização de células de Serratia plymuthica ATCC 15928, produtora de glicosiltransferase por gelificação iônica em gel alginato contendo transglutaminase (TG) e também a utilização de células livres para a conversão de sacarose em isomaltulose e trealulose. Utilizando-se células livres de Serratia plymuthica ATCC 15928 foi obtido 70% de conversão em isomaltulose e 8% de trealulose a 25°C por 10 bateladas de 15 minutos, a partir de solução de sacarose 30%. Entre as cinco amostras de alginato de sódio testadas, para a imobilização das células de S. plymuthica ATCC 15928 com e sem adição de TG, foram obtidos melhores resultados (médio de três bateladas) de conversão de sacarose (37,4% de isomaltulose) utilizando o alginato de sódio B, de alta viscosidade (14.000cP Sigma ¿ A 7128) em presença de TG. Nas condições estudadas (1,7% de alginato de sódio, 30% de massa celular úmida, solução de cloreto de sódio 0,2Mol/L, 2% de TG e 35% de sacarose) também houve maior facilidade de formação de grânulos uniformes. A presença de TG como agente de reticulação na matriz de imobilização melhorou a estabilidade de conversão por três bateladas onde observou-se resultado médio 27% maior com relação a matriz com o mesmo tipo de alginato (B) em ausência de TG. A composição da matriz de imobilização com adição de TG foi otimizada por metodologia de planejamento experimental, assim como a adição de gelatina como fonte de proteína adicional para promoção de ligações cruzadas catalisadas pela TG. Os melhores resultados de conversão de sacarose (solução 35%) em isomaltulose (72,66% de isomaltulose e 8% de trealulose em 4 bateladas de 24horas) foram obtidos utilizando-se matriz de polissacarídeo-proteína composto de 1,7% de alginato de sódio 14.000cP (Sigma®-A7128), 0,25mol/L de CaCl2, 0,5% de gelatina, 3,5% de TG e concentração de massa celular úmida superior a 35% (m:v). Verificou-se que a adição de ALMP na matriz de alginato de cálcio-gelatina-TG para imobilização de S. plymuthica, testada por planejamentos experimentais seqüenciais, não aumentou a estabilidade da taxa de conversão de sacarose em isomaltulose quando comparada com as células imobilizadas em matriz de alginato de cálcio-gelatina-TG. Em processo contínuo utilizando-se coluna empacotada com células de S. plymuthica imobilizadas em matriz otimizada e descrita acima, foi obtida taxa de conversão média de 64% de sacarose em isomaltulose durante 200 horas de processo, equivalente a 0,27g de isomaltulose/g de células imobilizadas/hora em coluna a 25°C e fluxo de substrato (35% de sacarose) 0,2mL/min
Abstract: The isomaltulose and trehalulose are disaccharides and structural isomers, which can be obtained from sucrose using bacterial glycosyltransferase. These disaccharide are considered alternative sugars with great potential for use in the food and pharmaceutical industries because they are hydrolyzed and absorbed more slowly and have a low cariogenic potential compared with sucrose. The conversion of sucrose to isomaltulose and trehalulose was estudied using immobilized and free cells of Serratia plymuthica ATCC 15928. The cells were immobilized by ionic gelation in alginate gel containing transglutaminase. Using free cells of Serratia plymuthica ATCC 15928 was obtained 70% isomaltulose conversion and 8% trehalulose conversion at 25° C in 10 batches of 15 minutes from a 30% sucrose solution. Among the five samples of sodium alginate tested for S. plymuthica ATCC 15928 cells immobilization, with or without the addition of TG, the best results (average of three batches) were obtained using sodium alginate B, high viscosity (14.000cP Sigma - A 7128) in the presence of TG, leading to 37.4% isomaltulose conversion from sucrose. In the studied conditions (1.7% sodium alginate, 30% wet cell mass solution of sodium chloride 0.2 Mol/L, 2% TG, 35% sucrose) was also easier to form uniform granules. The presence of TG as a crosslinking agent in the immobilization matrix improved the stability during three batches, resulting in an 27% higher average conversion with respect to a same type of alginate (B) matrix in absence of TG. Immobilization matrix compositions with addition of TG was optimized by experimental design methodology, as well as the addition of gelatin as a protein source for promoting additional crosslinking catalyzed by TG. The best results conversion of sucrose (35% solution) into isomaltulose (72.66% of isomaltulose and 8% of trehalulose in 4 batches of 24 hours) were obtained using proteinpolysaccharide matrix composed of 1.7% alginate 14.000cP sodium (Sigma® A7128), 0.25 Mol/L CaCl2, 0.5% gelatin, 3.5% TG, and wet cell mass concentration of 35% (w:v). It has been found that the addition of ALMP (amidated low methoxyl pectin) into the calcium alginate-gelatin-TG matrix for immobilization of S. plymuthica, tested by sequential experimental design, do not increase the stability of sucrose to isomaltulose conversions rate when compared with cells immobilized in calcium alginate -gelatin-TG matrix. In continuous process using a packed column with S. plymuthica cell's immobilized in the optimized matrix described above, it was obtained an average conversion rate of 64% sucrose to isomaltulose during a 200 hours process, equivalent to 0.27g isomaltulose per gram of immobilized cell per hour, in a column at 25° C and using flow substrate (35% sucrose) of 0.2 mL / min
Doutorado
Ciência de Alimentos
Doutora em Ciência de Alimentos

Orientador: Helia Harumi Sato
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A sacarose é o principal açúcar utilizado no processamento de alimentos, contudo, o consumo excessivo e não balanceado de alimentos com alto teor de sacarose contribui para a prevalência de doenças como obesidade e cáries dentárias. Nas últimas décadas, tem ocorrido um aumento do interesse pela produção de novos açúcares como alternativa para substituir a sacarose. A isomaltulose (O-a-D-glicopiranosil-1,6-frutofuranosídeo) é um açúcar pouco cariogênico e isômero estrutural da sacarose, encontrada naturalmente no mel em pequenas quantidades. A bactéria Serratia plymuthica ATCC 15928 produz a enzima glicosiltransferase e catalisa a conversão da sacarose em isomaltulose. Neste trabalho, utilizou-se a metodologia de superfície de resposta para estudar o efeito dos componentes do meio de cultivo na produção de glicosiltransferase pela bactéria Serratia plymuthica em frascos sob agitação a 200 rpm e 30ºC. Foi obtida alta produção de glicosiltransferase (14,26 UA/mL, média dos pontos centrais) utilizando-se o meio de cultivo 1, composto de 40 g/L de melaço de cana de açúcar, 15 g/L de peptona bacteriológica da BiobrásÒ e 20 g/L de extrato de levedura Prodex Lac SDÒ. O meio de cultivo 2 (40 g/L de melaço de cana de açúcar e 20 g/L de extrato de levedura Prodex Lac SDÒ), além de render ótima produção de glicosiltransferase (13,54 UA/mL, média dos pontos centrais), teve seu custo reduzido por ser formulado sem a adição do componente peptona bacteriológica da BiobrásÒ. Foi estudado o efeito da temperatura (26ºC, 28ºC e 30ºC) na fermentação da bactéria Serratia plymuthica para produção de massa celular e de glicosiltransferase em fermentador de 6,6 L. A maior produção de glicosiltransferase ocorreu após 6 horas de fermentação na temperatura de 26ºC, sendo obtida atividade enzimática de 25,97 UA/mL. As células livres da bactéria Serratia plymuthica foram utilizadas para a conversão de sacarose em isomaltulose. Utilizando-se concentração de massa celular úmida de 20% (p/v) e concentração de solução de sacarose de 25% (p/v) obteve-se alta porcentagem de isomaltulose (84,33%, valor médio dos meios de cultivo 1 e 2) após 2 horas de reação a 27ºC, em frascos sob agitação a 180 rpm. As células livres cultivadas em meio de cultivo 2 (sem adição de peptona bacteriológica da BiobrásÒ) foram reutilizadas por nove bateladas sucessivas e obteve-se eficiente conversão de sacarose em isomaltulose (75,20%, média das bateladas). Foi estudada a produção de isomaltulose a partir de sacarose por células da bactéria Serratia plymuthica imobilizadas em alginato de cálcio. A conversão de sacarose em isomaltulose pelas células imobilizadas foi feita em bioreatores de leito empacotado mantidos a temperatura de 25°C. O tratamento das células imobilizadas em alginatoSynthÒ 2% com glutaraldeído aumentou a atividade enzimática, sendo obtida conversão de sacarose em isomaltulose acima de 64% por 15 dias. A goma gelana KELCOGELÒ F foi utilizada como suporte para imobilização das células de Serratia plymuthica. As células imobilizadas em goma gelana tratadas com glutaraldeído foram secas por 36 horas, sob refrigeração a 10°C. As células imobilizadas foram transferidas para bioreatores mantidos a 25ºC e usadas na conversão contínua de sacarose em isomaltulose. Quando as células imobilizadas secas foram utilizadas no processo contínuo, a conversão de sacarose em isomaltulose manteve-se acima de 69% por 15 dias. Esse estudo demonstrou a possibilidade do uso da goma gelana KELCOGELÒ F como suporte para imobilização das células de Serratia plymuthica. O suporte utilizado combina a simplicidade na técnica de imobilização celular, boa estabilidade operacional e altas taxas de bioconversão
Abstract: Sucrose is the main sweetener used in food processing, but, the excessive and imbalanced consumption of high-sucrose foods is a contributory factor in obesity and dental caries. In the last few decades, the production of new sweeteners as alternatives to sucrose has aroused great interest. Isomaltulose (O-a-D-glucopyranosyl-1,6- fructofuranose) is a low cariogenic sweetener and a structural isomer of sucrose, naturally present in honey in small quantities. The bacteria Serratia plymuthica ATCC 15928 produces the enzyme glucosyltransferase and catalyses the conversion of sucrose into isomaltulose. In this work, response surface methodology was applied to study the effect of culture medium components in the production of glucosyltransferase by Serratia plymuthica in shaken flasks at 200 rpm and 30ºC. Higher glucosyltransferase production (14.26 UA/mL, average of the central points) was obtained in culture medium 1, composed of 40 g/L of sugar cane molasses, 15 g/L of BiobrásÒ bacteriological peptone and 20 g/L of Prodex Lac SDÒ yeast extract. Culture medium 2 (40 g/L of sugar cane molasses and 20 g/L of Prodex Lac SDÒ yeast extract, formulated without the component BiobrásÒ bacteriological peptone, resulted in a low cost medium and optimized glucosyltransferase production (13.54 UA/mL, average of the central points). The influence of temperature (26ºC, 28ºC and 30ºC) on the growth of the bacterium Serratia plymuthica for cell mass and glucosyltransferase production in a 6.6 L bioreactor, was also studied. The highest production of glucosyltransferase (25.97 UA/mL) was obtained in culture medium 1 after 6 hours at 26ºC. Free Serratia plymuthica cells were used for the conversion of sucrose into isomaltulose. A higher isomaltulose production (84.33%, mean value for culture media 1 and 2) was obtained at a temperature of 27ºC, 20% (w/v) wet cell mass and 25% (w/v) sucrose solution after 2 hours of reaction in shaken flasks at 180 rpm. The free cells cultivated in the culture medium 2 (without BiobrásÒ bacteriological peptone) were reused for nine successive batches, with efficient conversion of sucrose into isomaltulose (75.20%, average of the batches). Furthermore, the conversion of sucrose into isomaltulose using Serratia plymuthica cells immobilized in calcium alginate was also studied. The continuous production of isomaltulose by immobilized cells was accomplished in packed bed bioreactors maintained at 25°C. The treatment of cells immobilized in 2% SynthÒ alginate with glutaraldeyde increased enzyme activity obtaining an isomaltulose production of over 64% for 15 days. The gellan gum KELCOGELÒ F was also used as a support in the immobilization of Serratia plymuthica cells. The cells immobilized in gellan gum and treated with glutaraldeyde, were dried for approximately 36 hours at 10°C and used for the continuous production of isomaltulose. The immobilized cells were packed into bioreactors maintained at 25°C. When dry immobilized cells were used in the continuous process, the conversion of sucrose into isomaltulose was over 69% for about 15 days. This study demonstrated the feasibility of using KELCOGELÒ F gellan gum as a support in the immobilization of Serratia plymuthica cells. This support used combines the simplicity of the immobilization technique with good operational stability and high levels of bioconversion
Doutorado
Doutor em Ciência de Alimentos

Dans un contexte de raréfaction des ressources pétrolières, il est essentiel d'établir de nouvelles voies d'accès aux produits d'usage courant ainsi qu'à des produits de spécialités à partir de matières premières renouvelables issues de la biomasse. Des possibilités de valorisation chimique du saccharose et d'autres disaccharides largement disponibles comme l'isomaltulose ont été étudiées. Des monohydroxyalhyléthers de saccharose tensioactifs ont été préparés par ouverture nucléophile d'un époxyde gras et leurs propriétés physico-chimiques ont été évaluées. Une étude mécanistique approfondie a permis de mieux comprendre le rôle joué par les amines tertiaires utilisées comme catalyseurs. La préparation de la 3,4,6-tri-O-acytul-[alpha]-D-glucopyranoside-2-O-lactone à partir d'isomaltulose et d'isomalt a aussi été étudiée. Ce synthon a ensuite été exploité pour la synthèse de pseudo disaccharides à lien amide, de pseudo glycoaminoacides et d'un système trivalent glycosylé