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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 43580 (06)
- University: Sharif University Of Technology
- Department: Chemical and Petroleum Engineering
- Advisor(s): Alemzadeh, Iran
- Abstract:
- Probiotics are defined as essential live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. In order to provide health benefits for probiotic bacteria it has been recommended that they must be present at a minimum level of 106 CFU/g of food product or 107 CFU/g at point of delivery or be eaten in sufficient amounts to yield a daily intake of 108 CFU. Several studies have shown that certain strain of lactic acid bacteria, such as Bifidobacterium bifidum and Lactobacillus acidophilus prevent some diseases linked to the gastro-intestinal tract. however, many reports have demonstrated their poor survival and stability. Their survival in the gastro-intestinal tract is also questionable. Providing probiotic living cells with a physical barrier against adverse environmental conditions is an approach currently receiving considerable interest. Microencapsulation technologies are hypothesized to be a promising prospect for introducing viable probiotic bacteria in foods because the encapsulation matrix can provide a physical barrier against harsh environmental conditions such as freezing and those encountered during gastric juice passage. The microencapsulation of probiotic bacteria was performed usingthe emulsion technique. In this study The emulsion technique of microencapsulation was carried out to encapsulating a certain species of probiotic bacteria named lactobacillus acidophilus(PTCC 1643). aqueous phase prepared by mixing of probiotic bacteria cells and Sodium alginate solutions that was used as encapsulating material in different concentrations (1%, 2.5% and 4%). The emulsion also contained oil phase consisted of corn oil emulsified with Tween 80 was used as an emulsifier in different concentrations (0.1%,0.15% and 0.2%). cell viabilities were also examined under conditions simulating the gastro-intestinal environment. The results showed the size of microcapsules and the survival of encapsulated bacteria increased proportionately with increasing alginate concentrations and decreasing Tween 80 concentrations. Also the survival of encapsulated probiotic bacteria was higher than free cells. This work showed that the microencapsulation of L.acidophilus with sodium alginate offers an effective means of delivery of viable bacterial cells to the colon and maintaining their survival during simulated intestinal juice.
- Keywords:
- Microencapsulation ; Sodium Alginate ; Emulsion ; Probiotic ; Lactobacillus Acidophilus Bacteria
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