Studying the effect of probiotic strain Enterococcus faecium on chemical, microbial and sensory characteristics of low-fat stirred yogurt containing beta-glucan
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Simindokht Pourkalantar , Alireza Shahab Lavasani * , Salman Taheri , Nazanin Zand  |
Department of Food Science and Technology, VaP.C., Islamic Azad University, Tehran, Iran |
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Abstract: |
In this study, the probiotic strain Enterococcus faecium with a concentration of 108 CFU/mL and the prebiotic beta-glucan at concentrations of 0.2%, 0.4% and 0.6% were added to ewe's milk used to prepare stirred yogurt. The experimental design of the present study was completely randomized and three replications were considered for each treatment. At four specific times, 1, 7, 14 and 21 days, tests including (pH, acidity (Dornic), fat percentage, syneresis percentage, search and counting of Lactobacillus bulgaricus, Streptococcus thermophilus and Enterococcus faecium Log CFU/mL, and evaluation of sensory characteristics of aroma, smell, overall acceptance and texture) were performed on each sample. During the storage period, the pH of all treatments decreased, while the acidity expressed as Dornic increased All treatments had the same fat percentage. The population of Lactobacillus bulgaricus decreased during the storage period, while Streptococcus thermophilus increased until the seventh day of storage and then decreased until the end of the storage period. Probiotic treatments had a standard concentration of probiotic bacteria greater than 6 Log CFU/mL at the end of the storage period. The addition of beta-glucan significantly reduced the sensory properties of yogurt (p<0.05). Treatment T2, a probiotic stirred yogurt from ewe's milk containing 108 CFU/mL of Enterococcus faecium and 0.2% beta-glucan, was more similar to the control treatment in most of the characteristics studied and was recognized as the superior treatment.
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Keywords: Stirred yogurt, Enterococcus faecium strain, beta-glucan, ewe's milk, probiotic |
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Type of Study: Research |
Subject:
General
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