Microbiological evaluation of some dried dairy drinks sold in Assiut City

الملخص EN

This study was aimed to evaluate some dried dairy drinks as salep, hot chocolate and coffee milk powder.

A total of 75 random samples (25 each) were purchased from different dairy shops and supermarkets in Assiut city, Egypt.

Each sample was microbiologically examined in both forms; powdered form (as it was packed) and reconstituted form (as manufacturing instructions) as well as isolation of Bacillus cereus and detection of its toxigenic genes (cytK, and hblC) using PCR technique was performed.

The obtained results showed that the average psychrotrophic counts in the powdered form were 1.2x103, 3.6x102 and 80cfu/g, respectively; and the counts in the reconstituted form were 1.25x104, 1.69x104 and 7.8x103cfu/g, respectively.

Moreover, the average thermophilic counts in the powdered form were 2.68x103, 40 and 40 cfu/g, respectively; and in the reconstituted form were 6.8x102,40 and <10 cfu/g, respectively.

The average counts of total yeasts and molds in the powdered form of the examined samples were 1.72X103, 1.6X102 and 1.01X103 cfu/g, respectively, and the counts in the reconstituted form were 9.6X102, 9.2X102 and 2.6X103 cfu/g, respectively.

Regarding the total Bacillus count, the average counts in the powdered form were 4x102, 3.2x102 and 40cfu/g, respectively; 1.8x103, 1.96x103 and 2x102cfu/g were the counts in the reconstituted form, respectively.

In addition, identification of the isolated Bacillus species was performed and recorded in the previous products.

By using PCR, twenty eight strains of the isolated B.

cereus were enterotoxigenic