Evaluation of encapsulated Lactobacillus bulgaricus for their viability in feed pellets and simulated gastrointestinal conditions of poultry | |
| Author | Azad, Mirza Rajiv |
| Call Number | AIT Thesis no.FB-16-07 |
| Subject(s) | Lactobacillus casei Gastrointestinal system |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Ma ster of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-16-07 |
| Abstract | The greatest hurdles that probiotic bacteria must overcome during feed processing, storage and in the upper gastrointestinal tract are acid and th e presence of bile. T he main purpose of this study was to develop a novel encapsulation techn i que to enhance the stability of thermal and acidic protection of probiotic bacteria. T hree encapsulating bio materials were considered as good potential carrier material s for encapsulating the L actobacillus strain namely Lactobacillus bulgaricus to protect from adverse environmental conditions. Capsules of alginate - whey protein isolate and alginate - resistant starch w ere produced at various concentrations and analyzed for thermal stress to be incorporated in poultry feed . A lginate - resistant starch capsules pr oved better viability at high processing temperature up to 90°C for 90 seconds . In this study , a disaccharide trehalose was also used to incorporate with alginate - resistant starch to increase the resistance to high temperature . Moreover, t he acid tolerance of the encapsulated cells was compared with the free cells in an in vitro gastric model and a significantly higher survival was recorded for encapsulated cells. A similar trend was observed in the presence of bile salts. Physical p roperties of alginate - re sistant starch capsules were also observed. The mean diameter of wet and freeze dried capsules of the combination of 2% (w/v) sodium alginate, 4% (w/v) resistant starch and 1% (w/v) trehalose were found to be in an acceptable range. The particles size had diameters of 1.71 ± 0.15 and 1.41 ± 0.12 mm for wet and freeze dried capsules , respectively. L. bulgaricus encapsulated with alginate - resistant starch - trehalose had higher ability of thermal protection at 90°C; viability was 2.84 Log CFU/g up to 90s for w et capsules than non - encapsulated bacteria l cell. A fter incubation in poultry simulated gastric fluid the viable count reduced from 8.51 to 5.20 log CFU/g for wet capsules whereas free cells were not detectable after 30 min of exposure. There was almost no detrimental effect of bile on encapsulated cells, 1.06 and 1.37 log CFU/g reductions in case of wet capsules for 1% a nd 2% (w/v) bile, respectively. The encapsulated L. bulgaricus released 7.99 log CFU/g viable cells in intestinal c olonic pH 6.8 within 2 h . Storage of encapsulated wet capsules at 37°C proved to be more detrimental to the entrapped cells than at 4°C. |
| Year | 2016 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-16-07 |
| 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) | Nguyen, Loc Thai;Athapol Noomhorm; |
| Scholarship Donor(s) | C.P. Bangladesh Co., Ltd.; |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2016 |