| Author | Manjith Silva, Ranbaranage Pramuda |
| Call Number | AIT Caps. Proj. no.BSE-18-12 |
| Note | A capstone project report submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Engineering Biosystems Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Caps. Proj. ; no. BSE-18-12 |
| Abstract | The greatest hindrances that probiotic bacteria must overcome high processing temperatures
during feed processing, gastrointestinal harsh environment such as high acidic and presence of
bile as well as storage stability. The main purpose of this study were to develop a novel
encapsulation technique to enhance the stability of thermal and acidic protection of probiotic
bacteria. The selected probiotic bacteria L. plantarum was encapsulated using different types of
biomaterials used as wall material. The capsules of different concentrations of sodium alginate,
resistant starch and chitosan were analyzed for their stability. Hi-maize starch and Banana starch
used as resistant starches, to figure out which gives the best encapsulation properties. The
different capsules were further tested for their thermal stability to be incorporated into poultry
feed. Alginate-Hi-maize-Chitosan capsules proved better viability at high processing
temperatures up to 90oC for 120s. Hi-maize starch capsules were appeared to be more thermal
stability than banana starch capsules at 90oC for 120s. 3%Alginate-4%Hi-maize-Chitosan
capsules were selected as the best combination of thermotolerant wall materials combination,
and were further subjected for long term thermal stability. Furthermore the competence of acid
tolerance of the encapsulated cells was compared with the free cells in an in-vitro gastric model
which significant (p<0.05) survival was recorded for encapsulated cells. A similar vogue was
observed in the presence of bile salts.
The physical properties of capsules were characterized by, diameter, hardness and morphology.
The mean diameter of wet gelled and oven dried capsules of the combination of 2%-3 %( w/v)
Sodium alginate, 4% (w/v) Himaize-2% (w/v) Banana starch-0.8% (w/v) Chitosan were found
to be in an acceptable range. The average acceptable particle diameters of 1.75±0.02 and
0.81±0.01 mm for wet and dried capsules, respectively. The hardness of capsules was increased
15%-20% after coating from chitosan. Regarding the viability of encapsulated probiotic cultures
during storage periods and temperatures, all treatments were viable, with suitable values to
confer the probiotic effects (<6 log CFU/mL) after 30 to 50 days of storage at 4oC. After series
of evaluations, the capsules were transferred to a poultry feed mixture in order to prepare feed
pellets. Two pelletizing methods had been operated to prepare feed pellets, titled as via feed
pellet extruder and via manual method. The manual method sums-up to be the upper hand
method based on the feed efficacy and probiotic viability. |
| Year | 2018 |
| Corresponding Series Added Entry | Asian Institute of Technology. Caps. Proj. ; no. BSE-18-12 |
| Type | Capstone Project |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Bachelor of Science in Engineering Biosystems Engineering (BSE) |
| Chairperson(s) | Anal, Anil Kumar; |
| Examination Committee(s) | Datta, Avishek;Salin, K. R.; |
| Degree | Capstone Project (B.Sc.)-Asian Institute of Technology, 2018 |