دور بكتريا Lactobacillus casei في خفض نسبة الكولسترول و تحسين بعض الخصائص الحسية و الميكروبية في المتخمرات اللبنية المصنعة من حليب فول الصويا و حليب الغنم

Abstract EN

Soybean milk and sheep milk were used in different ratio (0:1 ,1:3, 1:1, 3:1 and 1:0) soybean : sheep's milk to prepare probiotic fermented milk after individually inoculation with 5% of Lactobacillus casei and yogurt starter bacteria (Lactobacillus delbrueckii ssp.

bulgaricus and Streptococcus salivarius ssp.

thermophilus) , The fermentation process was carried out at 37 c˚ for 24 hours after inoculation by Lb.casei and 42 c˚ for 2.5-3 hours when inoculated with yogurt starter bacteria, The microbial quality of fermented milk samples (0:1 ,1:3, 1:1, 3:1 and 1:0) soybean: sheep's milk were examined and the total count of Lb.casei 11 ×109, 96 ×109, 24 ×109 , 29 ×109 and 13 ×108 cfu / cm3, respectively, were recorded the total counts of yogurt starter bacteria were 93 ×107, 75 × 108, 61 ×108 , 55 ×108 and 9 ×107 cfu/ cm3, respectively.

Coliform bacteria , yeast and molds and spore forming bacteria did not show up in fermented milk samples.

The pH value of fermented milk samples were (0:1, 1:3, 1:1, 3:1 and 1:0) soybean: sheep's milk were 4.62, 4.42, 4.48, 4.44 and 4.85 respectively, when using Lb.casei, while pH value were 4.83, 4.20, 4.23, 4.21 and 4.71 for fermented milk samples respectively, when yogurt starter bacteria was used Cholesterol was estimated in the fermented milk samples, The products inoculated with Lb.casei were superior in reducing cholesterol compared to other products inoculated with yogurt starter bacteria, The fermented milk products were evaluated sensory by the professionals in dairy industry, and product (1:3) soy: sheep's milk inoculated with Lb.casei was found to be superior in the characteristics of sensory compared to other products.