Letteratura scientifica selezionata sul tema "Lactis bb 12 powder"

The market for new functional foods and food supplements is rapidly evolving, with a current emphasis on using natural sources. Algae, probiotics, and colostrum are rich sources of nutrients and bioactive compounds with positive effects on human and animal health. To determine the potential for developing new functional foods combining these components, we evaluated their synergistic effects. We assessed the growth of selected bifidobacteria in a medium supplemented with Chlorella vulgaris and its immunomodulatory and cytotoxic effects on the human peripheral mononuclear cells and colon cancer cell lines Caco-2 and HT29. The hypocholesterolemic effects of Chlorella powder and bovine colostrum fermented by Bifidobacterium animalis subsp. lactis BB12® on lipid metabolism in rats fed a high-fat diet were also determined. Chlorella addition promoted Bifidobacteria growth, with significantly increased inflammatory cytokine (TNF-α and IL-6) levels following 1.0% (w/v) Chlorella stimulation. Rats fed diets containing fermented colostrum with 0.5% (w/v) added Chlorella powder exhibited significantly decreased triglyceride, very low-density lipoprotein, and alanine and aspartate aminotransferase levels, compared to those of the control group. These results support that C. vulgaris is not cytotoxic in intestinal cell models and affords prebiotic and immunomodulatory effects, as well as synergistic triglyceride-lowering effects with bovine colostrum and B. animalis subsp. lactis BB-12.

College students are susceptible to upper respiratory infections (URI) due to inadequate sleep, stress and close living quarters. Certain probiotic strains modulate immune function and may improve health-related quality of life (HRQL) during URI. The present study recruited apparently healthy college students and assessed the effect of probiotics on HRQL outcomes (i.e. self-reported duration, symptom severity and functional impairment of URI) in those who developed URI. Missed school and work days due to URI were also considered. Subjects (n 231) were apparently healthy college students living on campus in residence halls at the Framingham State University (Framingham, MA, USA), and were randomised to receive placebo (n 117) or probiotic-containing powder (daily dose of minimum 1 billion colony-forming units of each Lactobacillus rhamnosus LGG® (LGG®) and Bifidobacterium animalis ssp. lactis BB-12® (BB-12®); n 114) for 12 weeks. Subjects completed The Wisconsin Upper Respiratory Symptom Survey-21 to assess HRQL during URI. The final analyses included 198 subjects (placebo, n 97 and probiotics, n 101). The median duration of URI was significantly shorter by 2 d and median severity score was significantly lower by 34 % with probiotics v. placebo (P< 0·001), indicating a higher HRQL during URI. Number of missed work days was not different between groups (P= 0·429); however, the probiotics group missed significantly fewer school days (mean difference = 0·2 d) compared to the placebo group (P= 0·002). LGG® and BB-12® may be beneficial among college students with URI for mitigating decrements in HRQL. More research is warranted regarding mechanisms of action associated with these findings and the cost–benefit of prophylactic supplementation.

This research involves the comparison of bioactive compounds, volatile compounds and prebiotic activity of white guava (Psidium guajava L.) cv. Pansithong and red guava cv. Samsi. The antioxidant activity values determined by 2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assays were 10.28 µg fresh weight (fw)/µg DPPH and 78.56 µg Trolox equivalent (TE)/g fw for white guava and 7.82 µg/µg DPPH, fw and 111.06 µg TE/g fw for red guava. Ascorbic acid contents were 130 and 112mg/100g fw total phenolics contents 145.52 and 163.36 mg gallic acid equivalents (GAE)/100 g fw and total flavonoids contents 19.06 and 35.85 mg catechin equivalents (CE)/100 g fw, in white and red guava, respectively. Volatile compounds in guava were analyzed by the solid-phase microextraction (SPME)/gas chromatography (GC)/mass spectrometry (MS) method. The major constituents identified in white and red guavas were cinnamyl alcohol, ethyl benzoate, ß-caryophyllene, (E)-3-hexenyl acetate and α-bisabolene. Prebiotic activity scores for Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12 were 0.12 and 0.28 in white guava, respectively, and 0.13 and 0.29 in red guava, respectively.

Background Care homes are an increasingly important sector of care. Care home residents are particularly vulnerable to infections and are often prescribed antibiotics, driving antibiotic resistance. Probiotics may be a cheap and safe way to reduce antibiotic use. Efficacy and possible mechanisms of action are yet to be rigorously evaluated in this group. Objective The objective was to evaluate efficacy and explore mechanisms of action of a daily oral probiotic combination in reducing antibiotic use and infections in care home residents. Design This was a multicentre, parallel, individually randomised, placebo-controlled, double-blind trial, with qualitative evaluation and mechanistic studies. Setting A total of 310 care home residents were randomised from 23 UK care homes (from December 2016 to May 2018). Participants The participants were care home residents aged ≥ 65 years who were willing and able to give informed consent or, if they lacked capacity to consent, had a consultee to advise about participation on their behalf. Intervention A daily capsule containing an oral probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 (n = 155) or matched placebo (n = 155) for up to 1 year. Main outcome measures The primary outcome was cumulative systemic antibiotic administration days for all-cause infections. Secondary outcomes included incidence and duration of infections, antibiotic-associated diarrhoea, quality of life, hospitalisations and the detection of resistant Enterobacterales cultured from stool samples (not exclusively). Methods Participants were randomised (1 : 1) to receive capsules containing probiotic or matched placebo. Minimisation was implemented for recruiting care home and care home resident sex. Care home residents were followed up for 12 months with a review by a research nurse at 3 months and at 6–12 months post randomisation. Care home residents, consultees, care home staff and all members of the trial team, including assessors and statisticians, were blinded to group allocation. Results Care home residents who were randomised to probiotic had a mean 12.9 cumulative systemic antibiotic administration days (standard error 1.49 days) (n = 152) and care home residents randomised to placebo had a mean 12.0 cumulative systemic antibiotic administration days (standard error 1.50 days) (n = 153) (adjusted incidence rate ratio = 1.13, 95% confidence interval 0.79 to 1.63; p = 0.495). There was no evidence of any beneficial effects on incidence and duration of infections, antibiotic-associated diarrhoea, quality of life, hospitalisations, the detection of resistant Enterobacterales cultured from stool samples or other secondary outcomes. There was no evidence that this probiotic combination improved blood immune cell numbers, subtypes or responses to seasonal influenza vaccination. Conclusions Care home residents did not benefit from daily consumption of a combination of the probiotics Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 to reduce antibiotic consumption. Limitations Limitations included the following: truncated follow-up of some participants; higher than expected probiotics in stool samples at baseline; fewer events than expected meant that study power may have been lower than anticipated; standard infection-related definitions were not used; and findings are not necessarily generalisable because effects may be strain specific and could vary according to patient population. Future work Future work could involve further rigorous efficacy, mechanisms and effectiveness trials of other probiotics in other population groups and settings regarding antibiotic use and susceptibility to and recovery from infections, in which potential harms should be carefully studied. Trial registration Current Controlled Trials ISRCTN16392920. Funding This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a MRC and NIHR partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 8, No. 7. See the NIHR Journals Library website for further project information.

The impact of controlled administration of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on the risk of acute infectious diseases was studied in healthy newborn infants. In this double-blind, placebo-controlled study, 109 newborn 1-month-old infants were assigned randomly to a probiotic group receiving a BB-12-containing tablet (n 55) or to a control group receiving a control tablet (n 54). Test tablets were administered to the infants twice a day (daily dose of BB-12 10 billion colony-forming units) from the age of 1–2 months to 8 months with a novel slow-release pacifier or a spoon. Breastfeeding habits, pacifier use, dietary habits, medications and all signs and symptoms of acute infections were registered. At the age of 8 months, faecal samples were collected for BB-12 determination (quantitative PCR method). The baseline characteristics of the two groups were similar, as was the duration of exclusive breastfeeding. BB-12 was recovered (detection limit log 5) in the faeces of 62 % of the infants receiving the BB-12 tablet. The daily duration of pacifier sucking was not associated with the occurrence of acute otitis media. No significant differences between the groups were observed in reported gastrointestinal symptoms, otitis media or use of antibiotics. However, the infants receiving BB-12 were reported to have experienced fewer respiratory infections (65 v. 94 %; risk ratio 0·69; 95 % CI 0·53, 0·89; P = 0·014) than the control infants. Controlled administration of BB-12 in early childhood may reduce respiratory infections.

This study was conducted to investigate the suitability of fresh-cut apple slices as carriers of the probiotic strain Bifidobacterium animalis subsp. lactis BB-12 (B. lactis BB-12). Furthermore, the effect of this strain against the colonization of apple by Escherichia coli O157:H7 was also evaluated. Apple wedges were suspended in an edible solution containing B. lactis BB-12 (greater than 8 log10 cfu mL–1) and/or E. coli O157:H7. Microbiological quality and physicochemical properties (pH, moisture content, soluble solids, titratable acidity, color, and texture) of probiotic samples were evaluated on days 1, 5, 9, and 14 of refrigerated storage. Sensory evaluation was performed on days 1 and 7. The probiotic concentration was above the recommended level of 10⁶ cfu/g during the test period. Co-inoculation with probiotic bacteria neither affected E. coli O157:H7 population dynamics, nor influenced the physicochemical and organoleptic properties of fresh-cut apple wedges. Minimally processed apples seem to be suitable vehicles for probiotic bacteria including B. lactis BB-12. Such probiotic products can be a desirable probiotic food choice for consumers, particularly those who are allergic or intolerant to dairy products. However, further studies are required to address the antagonistic effects of probiotic species on food-borne pathogens.

Three novel dehydrated wheat/rice cereal functional products with an addition of well documented probiotic Bifidobacterium animalis ssp. lactis BB-12® (BB-12®) were developed in Podravka factory for the infants older than 4 months: instant rice cereal, instant rice cereal with fruits and instant wheat cereal with vanilla. Notably, the number of viable BB-12® cells in each of the novel products was higher than the required minimal number of probiotic cells per gram of product (106 CFU/g) during the storage period of 106 weeks. Therefore, BB-12® strain recovery and genome stability were evaluated by strain-specific polimerase chain reaction and amplified fragment length polymorphism fingerprinting analysis. Further aim was to evaluate the influence of these three different cereal food matrices on specific probiotic properties of BB-12® strain in vitro. Applied food matrices positively influenced the survival in the simulated conditions of the gastrointestinal tract and antagonistic activity against undesirable microorganisms, while no influence on auto- and coaggregation ability of B. animalis ssp. lactis BB-12® was observed. Adhesion to extracellular matrix proteins and intestinal epithelial Caco-2 cells together with antibacterial activity emphasized competitive pathogen exclusion from Caco-2 cells by probiotic strain BB-12®.

In order to clarify the effects of the Lactococcus lactis (L. lactis) 11/19-B1 strain, a double-blind controlled study of yogurt fermented with the strain was carried out. For the study, two kinds of yogurt, the control and test yogurt, were prepared; the control yogurt was fermented with Streptococcus thermophiles, Lactobacillus delbrueckii subspecies bulgaricus, and Lactobacillus acidophilus, and the test yogurt was enriched with L. lactis 11/19-B1 and Bifidobacterium lactis (B. lactis) BB-12 strains. Seventy-six volunteers who had not received treatment with pharmaceuticals were randomly divided into two groups with each group ingesting 80 g of either the test or control yogurt every day for 8 weeks. Before and after yogurt intake, fasting blood was taken and blood sugar, blood lipids, and anti-cytomegalovirus cellular immunity were estimated. In the test yogurt group, low-density lipoprotein (LDL) was significantly decreased (159.1 ± 25.7 to 149.3 ± 24.4; p = 0.02), but this effect was not observed in the control yogurt group. When the test yogurt group was divided into two groups based on LDL levels of over or under 120 mg/dL, this effect was only observed in the high LDL group. No LDL-lowering effect of B. lactis BB-12 strain was previously reported; therefore, the hypocholesterolemic effects observed in this study are thought to be caused by the L. lactis 11/19-B1 strain alone or its combination with the B. lactis BB-12 strain.

The raffinose family of oligosaccharides (RFOs) isolated from lupin seeds (Lupinus albus var. Multolupa) was evaluated for bifidogenic effects during the manufacture of probiotic fermented milk. A mixed starter inoculum was composed of Bifidobacterium lactis Bb-12 and Lactobacillus acidophilus (1:1). Lupins are a rich source of RFOs that can be used as functional food ingredients. The addition of RFOs to milk increased B. lactis Bb-12 and L. acidophilus populations at the final fermentation time compared with controls. Final fermentation products are positively affected by addition of RFOs, and time of fermentation was reduced from 12 to 10 h. When RFOs were added to milk, they were preferentially used as a carbon source (57.7%) compared with lactose (23.7%) at the end of fermentation. These results suggest that the eventual choice of B. lactis Bb-12 and L. acidophilus in a mixed culture at a 1:1 ratio and addition of RFOs to produce a fermented milk product would have the advantages of rapid growth and acidification rate and would likely increase the probiotic effect of the final functional product.

Este trabalho teve como objetivo o desenvolvimento e a avaliação das propriedades funcionais, físico-químicas, reológicas, sensoriais de preferência pareada (do cheesecake e de sua cor) e microbiológica (contagens de coliformes fecais/totais e da bifidobactéria) do cheesecake manufaturado com farinha de trigo (ou amido de milho ceroso modificado), queijo fresco, sacarose, eritritol (como substituinte parcial de sacarose), ovos in natura, manteiga [ou frutoligossacarídeos (FOS) - prebiótico - como substituinte da manteiga], curcumina e Bifidobacterium animalis subespécie lactis BB-12 (probiótico). A análise estatística dos dados considerou a existência quatro grupos experimentais, sendo: [2 cheesecakes lights (em açúcar e gordura) potencialmente funcional e simbiótico: T1= farinha de trigo e FOS; T2 = AMCM e FOS] e [2 cheesecake light (em açúcar) potencialmente funcional e probiótico: T3 = farinha de trigo e manteiga; T4 = AMCM e manteiga]. Foi estabelecido um tratamento T0 como padrão da Tese, adaptado da formulação da QuarkTorte por Henning Fleissig (Alemanha). As variáveis de resposta foram do tipo quantitativa, considerando unidades formadoras de colônias (UFC) de bactérias láteas, unidade formadora de colônias (UFC) de coliformes totais e fecais, pH, atividade da água, dureza, adesividade, elasticidade, coesividade, gomosidade e mastigabilidade. Estas variáveis de respostas compuseram um modelo de Análise de Variância com medidas repetidas, pois as unidades experimentais foram observadas após 1, 8, 15, 22 e 28 dias. Medidas (como médias, medianas e desvio padrão), gráficos e ANOVA, foram geradas pelo pacote estatístico STATA® - versão 9.0. Os resultados da ANOVA não mostraram resultados estatisticamente significativos que indicassem existir diferenças entre os grupos experimentais [p-value: 0,7981; 0,4204; 0,9974; 0,6825; 0,6401; 0,4800; 0,6469; 0,4258; 0,4615] e nem entre os valores ao longo do tempo, dentro de cada grupo experimental [p-value: 0,1725; 0,0000; 0,4076; 0,8957; 0,8787; 0,0001; 0,6214; 0,8845; 0,6820] [p-value correspondentes respectivamente a: log de UFC de bactérias láteas; pH; atividade de água (aw); mastigabilidade; gomosidade; coesividade; elasticidade; adesividade; dureza]. Não houve proteção do probiótico pelo prebiótico, ao nível de FOS utilizado neste estudo. Foram efetuadas análises sensoriais de preferência pareada para o cheesecake (em três tratamentos: T0, T1 e T2) e para sua cor (em três amostras com curcumina a: 0%, 0,0076% e 0,0152%). O resultado para o cheesecake revelou que: a amostra mais preferida foi a T0; os tratamentos T1 e T2 não diferem entre si quanto à preferência; T0 não difere da T2; T0 difere da T1. O resultado para a cor do cheesecake revelou que: a amostra mais preferida foi a com curcumina a 0,0076%; e que as três amostras são iguais quanto à preferência da cor. O presente estudo dá sua contribuição para ampliar a oferta de alimentos láteos promotores da saúde humana com características: light, potencialmente funcional e simbiótico.
The aim of this work was the development and the evaluation of the functionals, physical-chemistry, rheological and sensorial analysis for the pairwise ranking test (cheesecake and its color), and microbiological properties of the cheesecake manufactured with wheat flour (or modified waxy corn starch - AMCM), fresh cheese, sucrose, erythritol (as sucrose partial substitute), eggs in nature, butter [or frutooligosaccharide (FOS) - prebiotic - as butter fat replacer], curcumin and Bifidobacterium animalis subspecies lactis Bb-12 (probiotic). The statistical analysis of the data was considered the existence four experimental groups: [2 cheesecakes lights (in sucrose and fat) potentially functional and symbiote: T1= wheat flour and FOS; T2 = AMCM and FOS] and [2 cheesecake light (in sucrose) potentially functional and probiotic: T3 = wheat flour and butter; T4 = AMCM and butter]. It was established a treatment T0 as the standard Thesis, adapted the wording of QuarkTorte by Henning Fleissig (Germany). The response variables were type of quantitative, whereas colony forming units (CFU) of lactic bacteria, forming unit colonies (CFU) of total and faecal coliforms, pH, water activity, hardness, adhesiveness, elasticity, cohesiveness, gumminess, chewiness. These variables of responses comprised a model of Analysis of Variance with repeated measures, because the experimental units were observed after 1, 8, 15, 22 and 28 days. Measures (such as average, median and standard deviation), graphics and ANOVA, were generated by statistical package STATA® - version 9.0. The results of the ANOVA showed no statistically significant results that indicate differences between the experimental groups [p-value: 0,7981; 0,4204; 0,9974; 0,6825; 0,6401; 0,4800; 0,6469; 0,4258; 0,4615] and not between the values over time, within each experimental group [p-value: 0,1725; 0,0000; 0,4076; 0,8957; 0,8787; 0,0001; 0,6214; 0,8845; 0,6820] [p-value corresponding respectively to: log of UFC of lactic bacteria; pH; water activity (aw); chewiness, gumminess, cohesiveness, elasticity, adhesiveness and hardness]. There was no protection of probiotic by prebiotic, at the level of FOS used in this study. Were made sensorial analysis of paired preference for the cheesecake (In three treatments: T0, T1 and T2) and to its color (in three samples with curcumin: 0%, 0.0076% and 0.0152%). The result for the color of the cheesecake revealed that: the sample most preferred was with curcumin to 0.0076%; and that the three samples are equal as the color preference. The present study gives its contribution to extend the offer of lactic food human health promoters with characteristics: light, potentially functional and symbiote.

Orientador: Carlos Raimundo Ferreira Grosso
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Esse trabalho visou a encapsulação de Lactobacillus acidophilus e Bifidobacterium lactis e a avaliação "in vitro" da tolerância desses microrganismos livres e encapsulados quando inoculados em soluções biliares e de pHs ácidos, ou seja, em condições semelhantes às encontradas no intestino e no estômago humano, respectivamente. Além disso, foi determinada a estabilidade de B. lactis livres e encapsulados, incorporados em iogurte que foi mantido sob refrigeração, durante 28 dias. Para tanto, foram utilizados como agentes encapsulantes os polímeros entéricos aceto fitalato de celulose e alginato e os métodos de microencapsulação por spray drying e de imobilização por extrusão, respectivamente. Lactobacillus acidophilus e Bifidobacterium lactis foram extremamente resistentes às soluções biliares, tanto livres, quanto encapsulados. Apresentaram boa resistência quando inoculados em soluções de pH 2. Entretanto, nas soluções de pH 1, as populações das células livres e imobilizadas em alginato foram dizimadas, enquanto as células microencapsuladas em aceto fitalato de celulose apresentaram uma maior resistência. B. lactis não apresentaram uma boa viabilidade em iogurte, em nenhuma das condições testadas. Foi possível encapsular Lactobacillus acidophilus e Bifidobacterium lactis pelos métodos de extrusão e por spray drying mantendo um número elevado de células viáveis. A imobilização em alginato de sódio não foi eficaz na proteção às células de Lactobacillus acidophilus e Bifidobacterium lactis e a microencapsulação em aceto fitalato de celulose foi efetiva na proteção dos mesmos inoculados em soluções ácidas, embora não tenha sido eficiente quando B. lactis microencapsulado foi inoculado em iogurte.
Abstract: This study aimed at encapsulating Lactobacillus acidophilus and Bifidobacterium lactis and at carrying out an "in vitro" studyof the tolerance of these microorganisms, both free and encapsulated, when inoculated into bile solutions and acid pH solutions, that is, into conditions similar to those encountered in the human intestine and stomach respectively. In addition, the stability of free and encapsulated B. lactis was determined, when inoculated into yoghurt and stored under refrigeration for 28 days. The encapsulating agents used for this purpose were the enteric polymers cellulose acetate phthalate and alginate, and the methods of microencapsulation were spray drying and immobilisation by extrusion, respectively. Lactobacillus acidophilus and Bifidobacterium lactis were extremely resistant to bile solutions, both in the free forms and encapsulated. They also presented good resistance when inoculated into solutions at pH 2.0. However at pH 1.0, both the free cells and those encapsulated in alginate were destroyed, whilst those encapsulated in cellulose acetate phthalate showed greater resistance. B. lactis showed poor viability in yoghurt, under ali conditions tested. It was possible to encapsulate Lactobacillus acidophilus and Bifidobacterium lactis by both the methods of extrusion and by spray drying, retaining an elevated number of viable cells. Immobilisation in sodium alginate was not efficient in protecting cells of Lactobacillus acidophilus and Bifidobacterium lactis, and microencapsulation was efficient in protecting these same organisms when inoculated into acid solutions, although it was not efficient when microencapsulated B. lactis was incorporated into yoghurt.
Doutorado
Doutor em Tecnologia de Alimentos

The hypocholesterolemic effect of peptides present in crude casein hydrolysate using trypsin from Bifidobacterium animalis subsp. lactis (Bb-12) culture grown in casein solution or in MRS broth were compared with the control (unhydrolysed crude casein). These samples have shown to reduce cholesterol level in vitro to varying degree between 24-87%. The unhydrolysed crude casein (control) has shown not to have a reducing effect on cholesterol level. The reduction level of cholesterol was found to be dependant on the degree of hydrolysis. Fractions obtained after size exclusion from crude casein hydrolysate formed by trypsin after 48h hydrolysis have shown to reduce cholesterol level to degree vary between 2.7% to 50%. Bb-12 or trypsin crude casein hydrolysates were also found to possess angiotensin-converting enzyme (ACE) inhibitory activity in vitro to a varying degree between 29% and 38%, respectively. Unhydrolysed crude casein showed no real effect on ACE inhibitory activity. Trypsin hydrolysate has slightly more effect on ACE activity than Bb-l2. A relationship was also found between ACE-inhibitory activity and degree of hydrolysis. Fractions of crude casein hydrolysate after 48h hydrolysis with trypsin by size exclusion have shown to have ACE-inhibitory activity varying between 37% and 50%. Several identified ACE-inhibitory peptides from active fractions were found to have Phe, Trp, Tyr, Arg, Lys or Pro at their ultimate C-terminal position, making them a possible candidate for ACE-inhibitory activity. Further analysis on the profiles of casein and whey protein fractions, obtained by fast protein liquid chromatography (FPLC), of skimmed milk and four different commercial types of probiotic health drinks, and casein profile of added Bb-12 culture were investigated to study the possible effect of probiotics on milk proteins. Differences in protein-profile were found between the control and the four commercial probiotic health drinks as well as with added Bb-12 culture. Whey proteins were more resistance to hydrolysis than caseins.

Microorganisms have been known to play a major role in human health since early times. The ingestion of microorganisms as probiotics to restore and/or maintain health is a widely accepted and common practice. The challenge in industry is to ensure viability of probiotics until their ingestion to their site of action, the colon, for health benefits to be realised. Microencapsulation is one of the techniques used to protect probiotic bacteria and ensure viability. A method that does not involve the use of extreme temperatures and/or solvents which would otherwise adversely affect viable cells was developed and patented. The method is solventless and is based on complexation of Food and Drug Administration-approved polymers, poly (vinylpyrrolidone) and poly (vinylacetate-co-crotonic acid) in supercritical carbon dioxide. The use of this method of encapsulation was found to be suitable in target release in earlier studies. Microparticles produced were found to have pH-dependent swellability, protecting bioactives, in this case probiotic bifidobacteria, in acid (simulated gastric acid) and only releasing them in an alkaline environment (simulated intestinal fluid). Further studies were, however, needed to investigate the suitability of the microparticles for food and pharmaceutical applications. The current study therefore aimed to characterize these microparticles in terms of size range, distribution of bacteria within the microparticles, and particle size distribution. The average size of the Bifidobacterium lactis Bb12-encapsulating microparticles was found to be within the acceptable size in food applications. High encapsulation efficiency was obtained, with live bacteria distributed evenly within the microparticles, demonstrating the potential of the microparticles to deliver high numbers of probiotic cultures as required for this type of microorganisms to deliver purpoted benefits to the consumer. Probiotic products are normally kept under refrigerated storage, yet the viability of bacterial cells still decreases. An additional benefit of encapsulation within microparticles would be protection of the encapsulated probiotics from the detrimental factors to which the probiotic products are exposed during storage. In order to investigate this for the microparticles in this study, the shelf life of encapsulated B. lactis Bb 12 powder stored in glass vials was investigated. High temperatures were used for accelerated shelf life studies. Encapsulated B. lactis Bb 12 maintained the viable levels above the therapeutic minimum for the duration of the study (12 weeks), which was 7 weeks more than was the case with unencapsulated probiotic. Thus the microparticles provided protection to the probiotic cultures at temperatures much higher than those normally used for storage of probiotic products. These results further indicate the possibility for storage of the B. lactis Bb12 encapsulated in the tested microparticles, at ambient temperatures for at least two months, without drastic loss of culture viability. Research has recently focused on the development of probiotic foods other than dairy and dairy-based foods. This has been necessitated by increasing vegetarian lifestyle and concerns of allergenicity. A maize-based traditional fermented beverage, mageu, was investigated for use as a vehicle for probiotic delivery. Although no significant difference was noted between survival of encapsulated and unencapsulated probiotic was noted, pH decrease in mageu with encapsulated B. lactis Bb 12 was less than with unencapsulated cells. This suggested that encapsulation would ensure that metabolites produced by encapsulated probiotics, if any, would not negatively affect a product in which they are incorporated. Further studies may be needed for investigation of the effect of the encapsulating microparticles in traditional fermented non-dairy products, using more acid-sensitive probiotic strains as the test strain used in the current study is well-known for its inherent resistance to acidity. This study filled gaps in knowledge in terms of the characteristics of microparticles produced using supercritical technology. The main highlights of the research findings were that the microparticles were suitable for food applications, improved probiotic viability under nonrefrigerated temperatures, and delayed browning of the probiotic powder and minimized drop in pH of the fermented product containing the probiotic encapsulated within. The results showed that microparticles encapsulating B. lactis Bb 12 are appropriate to consumers in areas where refrigeration is absent. Furthermore, the study showed that mageu is a suitable alternative vehicle to dairy-based products, for delivery of probiotic B. lactis Bb 12. This possibility extends accessibility of probiotic products to consumers who do not take dairy products for various reasons. There is also a potential increase of probiotic products on the market. Copyright
Dissertation (MSc)--University of Pretoria, 2012.
Microbiology and Plant Pathology
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