Chemical and Microbiological evaluation of Set yoghurt during shelf life

Abstract

A study was performed to determine the effect of shelf life on chemical and microbiological characteristics of set yoghurt manufactured in Khartoum State. Samples were collected and kept in the laboratory at refrigerator temperature. The chemical analysis was carried out to determine the contents protein, fat and total solids contents. The physiochemical analysis included titratable of acidity and wheying-off. Whereas should be analyzed and microbiological examination (coliform, lactobacillus bulgaricus and yeasts and molds counts) were performed at 1, 3, 6 and 9 day intervals. Results revealed that protein, fat, total solids and acidity and whey-off did not show any significant difference (P>0.05) effects throughout the storage period. Results of microbiological examination showed non significant variation (P>0.05) in the count of coliform bacteria, yeasts and molds and Lactobacillus bulgaricus throughout the shelf life of 9 days.