S289 : Investigation of produce fermentative dairy products using isolated Lactic Acid Bacteria from traditional dairy products
Thesis > Central Library of Shahrood University > Agricultural Engineering > MSc > 2015
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Abstarct: In this study ‚ using the bacteria taken from Amul dairy products‚ including yogurt ‚ cheese‚ drinking yogurt and probiotic bacteria (taken from the local-non-industrial – dairy products) different samples were made and their physical and chemical properties were evaluated. Then‚ the panelists evaluated the samples sensory properties. Samples with the highest acceptance rate were selected for the final sample. These samples included two kinds of bacteria taken from industrial yogurt and one kind if prebiotic bacteria. During 20 days of storage at 4 c ‚ the sample made of prebiotic bacteria was compared with the one made of industrial starter and their physical ‚chemical and microbial properties were evaluated. The results of rheological test clearly showed a thinning behavior upon shear .The viscosity rate of both samples during 20 days was significantly different. After twenty days of storage‚ the yogurt made by prebiotic starter exhibited more solidity of tissue in comparison to the industrial yogurt. During the 20 days of storage‚ pH samples of industrial yogurt decreased and its acidity increased. However‚ in the yogurt made by prebiotic starter‚ on the twentieth day‚ pH decreased slightly and acidity increased. From the first day until the tenth day‚ fat changes was 5% which is a reasonable level and showed a decreasing trend. In the yogurt made by prebiotic starter‚ water-holding capacity was higher thus it oozed lesser water. Likewise‚ no microbial contamination (E.coil‚ coliform‚ mold and yeast) more than standard level of twenty day storage was observed. In comparison to industrial yogurt‚ the yogurt made by prebiotic starter had higher sensory acceptance among panelists.
Keywords:
#Yoghurts، Yogurt with native primers، Chemical properties، Organoleptic properties، Physical properties Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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