Effect of Refrigeration Processing and Milk Treated on Probiotic Lactic Acid bacteria Used in The Production of Therapeutic Fermented Dairy Low Lactose

Abstract

The study included the use of different kinds of probiotic bacteria as Lactobacillus acidophilus , Lactobacillus casie, Streptococcus thermophilus, and Bifidobacterium animalis to production of dairy containing little lactose sugar is fermented milk from whole milk T1 and from with adding lactase enzyme to the milk T2 and from the milk of a filtrated through the bacterial filtrations T3 and milk from the milk UHF T4 and stored fermented milk produced for four weeks in refrigeration on temperature (4-10 c) .Conducted tests on this dairy in first day and then every week a chemical tests like, estimating acidity, PH, total solids, fat, flavor compounds (Diactyle) and study microflora content included the total number of bacteria and lactic acid bacteria, and sensory evaluation :( flavor 45% , consistency 30% , appearance 15% and acidity taste 10%). The three treatments (T1,T2,T3) were performed in the Department of Food Science-University of Mosul-Iraq, but the treatment (T4) was worked out in the Department of Food Science-University of Nebraska-USA. Outperformed a fermented milk product sample of milk treated with lactase enzyme in recording higher acidity and lower pH 0.83% and 4.73 respectively and continued acidity increase during storage with low pH of up to 1.31% and 3.67 respectively at the fourth week of conservation.We find the proportion of sugar lactose as high as possible in the fermented milk from whole milk 4.22% and began to decline for up to 2.12% in the fourth week as a result of consumption by lactic acid bacteria, while the proportion of total solids and fat increased during storage in all transactions unlike flavor compounds began to decline dissuade storage and was highest in milk from whole milk product. Whereas the numbers of bacteria lactic acid highest number in the fermented milk product of milk add to it lactase enzyme and the fewest in the fermented milk from the milk UHF, during cryopreservation for four weeks began setting to decline but prepared were within acceptable limits universally throughout the storage of than 106 c.f.u. / ml a match by the laws the World Health Organization (WHO) and the Food and Agriculture Organization (FAO). Concerning the sensory evaluation, the treated fermented milk from whole milk surpassed in flavour charactenistic whereas the treated fermented milk with adding lactase enzyme to the milk surpassed in consistency, appearance, and overall sensory charactenistics and the third treatment surpassed in acidity evaluation.