In this study, strains of probiotic bacteria have been selected for tolerance to low pH, bile, sucrose, oxygen in media and low storage temperatures. Lactobacillus acidophilus 2401 and Bifidobacterium infantis 1912 were selected as strains able to survive in these conditions. These two strains were then offered further protection from the adverse conditions of food processing and storage by microencapsulation in a calcium alginate and starch gel matrix. Encapsulation in calcium alginate increases survival in yoghurt. In cheddar cheese the free L. acidophilus 2401 and B. infantis 1912 cells survived better than the encapsulated cells, probably due to the dense nature of the cheddar cheese matrix combined with the encapsulation restricting the flow of the nutrients and metabolites between the outside environment and the cells. In ice cream survival was high, probably due to the high fat and solids nature of the ice cream combined with the low storage temperature. The trial results of the laboratory scale production was consistent with the survival results for yoghurt and cheddar cheese. Incorporation of encapsulated probiotic bacteria into ice cream and cheddar cheese was acceptable by sensory standards and largely unnoticeable in comparison with the same foods without capsules. The capsules were visible and able to be felt on the tongue when eaten in yoghurt causing the product to be disliked by the panellists. / Master of Science (Hons)
| Identifer | oai:union.ndltd.org:ADTP/182028 |
| Date | January 2000 |
| Creators | Yam Godward, Georgia Nga-Mun, University of Western Sydney, Hawkesbury, Faculty of Science and Technology, School of Science, Food and Horticulture |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Source | THESIS_FST_SFH_YamGodward_G.xml |
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