Quality Evaluation of Set Yoghurt Produced by Two Factories in Khartoum State, Sudan

Abstract

This study was carried out to chemically and microbiologically
evaluate set yoghurt produced by two factories (F1 and F2) in Khartoum
State. Ninety samples (45 from each factory) were collected and
chemically and microbiologically analyzed at 1, 5 and 10 day intervals.
The results showed that fat and total solids contents and titratable acidity
were higher in F2 than in F1, while protein and solids-non-fat contents
were higher in F1. Lacobacillus bulgaricus, coliform bacteria and yeasts
and moulds counts were higher in F1. During storage, fat content
increased in F1 and decreased in F2, while protein content increased in F1
and followed an irregular pattern in F2. Total solids and solids-non-fat
contents increased till day 5, and then decreased at the end of the storage
period in the two factories, while titratable acidity steadily increased
towards the end in the two factories. Lactobacillus bulgaricus count
increased till day 5 then decreased towards the end in both factories,
while coliform bacteria and yeasts and moulds counts increased towards
the end.