Chemical composition and microbial load of camel (Camelus dromedarius) milk in Khartoum State, Sudan

Abstract

The aim of this study was to evaluate some chemical composition and microbiological load during storage period of plain set yoghurt samples present on local market in Khartoum State. Ninety- six commercial yoghurt samples, from different manufacturers produces plain set yoghurt from recombined milk powder (A, B), and fresh milk (C, D), were collected from 4 shops in Khartoum North during the period November 2008 - February 2009. Analysis of yoghurt samples, collected from different manufacturers revealed significant (P<0.01) differences in total solids (TS), solids not fat (SNF), fat, protein and ash contents and titratable acidity due to the variations of manufacturers and type of milk used. The titratable acidity showed no significant effect due to the type of milk used. Yoghurt samples obtained from different manufacturers and type of milk significantly (P<0.01) affected TS, SNF, protein contents, and titratable acidity during storage period, whereas fat and ash contents were not significantly affected by storage period. Microbiological analysis showed that total bacterial count, coliform count and yeast and mould count were significantly (P<0.05) affected by the manufacturers. On the other hand, coliform count and yeast and mould count were not significantly affected by the type of milk used. Total bacterial count, coliform count and yeast and mould count were significantly affected by storage period in all yoghurt samples. The study concluded that the plain set yoghurt made from recombined milk powder and fresh milk agrees with the Sudanese standards for yoghurt chemical composition. Moreover, all plain yoghurt samples revealed high contamination, and the storage period had a significant effect on both chemical and microbiological load. vii Hence, it is recommended that determining the maximum level of all harmful microorganisms associated with a product, provides a good hygienic conditions during processing. Also, more research is needed on the type of milk used, the conditions of processing and storage of yoghurt and its association with the quality of the product.