Development of robust static in vitro gut model to evaluate the behavior of probiotics with dietary fiber | |
| Author | Gurung, Anurag |
| Call Number | AIT Thesis no.FB-21-07 |
| Subject(s) | Functional foods--Development Probiotics--Health aspects |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no.FB-21-07 |
| Abstract | The main aim of this research was to design and fabricate an in vitro gastrointestinal model to study the effects of dietary fiber on the behavior of probiotics in simulated gastrointestinal conditions. In this research, the effect of inulin on the viability and the ability of probiotics to produce short chain fatty acids (SCFAs) during simulated gastrointestinal digestion was studied. Simulated digestion in the in vitro gut model was separated into two batch-type processes which were the gastric digestion and colon fermentation phases. The probiotic bacteria strains, Streptococcus thermophilus and Lactobacillus bulgaricus, were digested in the in vitro gut model in the presence of inulin. For this purpose, yoghurts with inulin at 0.5 %, 1 % and 2 % (w/v) concentrations were prepared using the two specified probiotics. Physiochemical analyses of yoghurt samples found that the addition of inulin had positive effects on its viscosity and probiotic cell count. However, the effects were not found to differ significantly from that of control yoghurt. During in vitro gastric digestion, all types of yoghurts experienced reduction in their total cell log CFU. Yoghurt with 2 % (w/v) inulin had the highest number of viable bacterial cells (3.72 log CFU ± 0.2) at the end of gastric digestion and control yoghurt had the lowest total cell log CFU (2.89 log CFU ± 0.05). Simulated in vitro colonic fermentation of yoghurt samples also resulted in gradual reduction of viable bacterial numbers but not to the same extent as observed during the gastric digestion. Yoghurt with 0.2 % (w/v) inulin had the highest viable bacterial cell numbers (6.63 log CFU ± 0.15) whilst control yoghurt had the lowest (4.6 log CFU ± 0.17). The highest value of SCFA released during in vitro colonic fermentation was recorded for yoghurt with 0.2 % (w/v) inulin (122.5 µmol ± 1.4). The value of SCFA released during simulated colonic fermentation increased with increasing incubation time (h) and was higher for yoghurts with higher concentration of inulin. Therefore, the viability and metabolic activity of bacteria was observed to have been affected positively by the presence of inulin. The static in vitro gut model was also able to successfully simulate the gastrointestinal conditions. |
| Year | 2021 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no.FB-21-07 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Anal, Anil Kumar; |
| Examination Committee(s) | Loc Thai Nguyen;Bhujel, Ram C.; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2021 |