Study on the total bacteria count of market Cheeses in Khartoum State

Abstract

This research was conducted to study the total count of bacteria in selected different types of cheeses offered in the markets of Khartoum State and ready for sale and consumption . Sixty (60) samples of cheese are collected randomly from different sales points ; 15 samples from white soft cheese , 15 from Muddafra , 15 from Lavachequirit and 15 from cheddar cheese . The different samples are then subjected to laboratory test to determine the total bacterial colonies and hence the total count of bacteria in each type of cheese . The average bacterial colonies for all types of cheeses showed significant differences at the different dilutions of the agar medium used . For example at dilution 10-5 the average number of the bacterial colonies was 17.60 ± 15.61 , 47.27 ± 40.58 , 24.00 ± 18.88 and 19.93 ± 16.87 for white soft , Mudafara , Lavachequirit and cheddar cheese respectively . The average number of bacterial colonies in the different types of cheeses per 5 gram ( all dilutions ) was found to be 40.32 , 80.44 , 61.42 , 44.34 for white soft , Mudaffara , cheddar and Lavachequirit cheese . VIII By counting the total number of bacteria / per gram in all types of cheese , it was estimated to be 806.400 , 1.608.800 , 1.228.400 and 886.600 bacteria per gram for white soft , Mudaffara , Cheddar and Lavachequirit cheese respectively . The lower bacteria count is detected in both lavachequirit and white soft cheese , while a higher bacteria count was found in Mudaffara and cheddar cheese . The variation in the total number of bacteria in cheeses is associated with so many factors , such as moisture , added salt , fat content of the milk , pH , organic acids and nitrates and ripening temperature . By comparing the results obtained for the total bacteria count in all studied types of cheese with some standards given for the number of bacteria in cheeses , they are considered as safe for consumption and harmless to consumers . At last certain recommendation are given .