Microbiological quality and safety of commercial local yogurt products in Giza Governorate- Egypt
Yogurt is the most popular dairy product in Egypt. The popularity of yogurt can be attributed to its sensory characteristics and nutritional value. The microbiological characteristics of yogurt also contribute greatly to in the quality and shelf life of the final product. Thus, the objective of this study was to examine the microbiological quality and safety of yogurt products available in the local market in Giza Governorate, Egypt. One hundred yogurt samples were collected from local stores and stored in refrigerators prior to microbiological examination which was done within 24 h. Samples were stored under chilled conditions for 14 days at 7ºC ±1 and examined for yogurt culture viability, psychrophic bacteria (Pseudomonas), Salmonella, Staphylococcus, E. coli, Aspergillus, and Bacillus. The identification of each isolate was molecularly conformed using 16s rRNA. Our results showed that the yogurt culture maintained 6-7 log CFU/ml during the chilled storage. The psychrophic bacteria ranged from 5-6 log CFU/ml, whereas the other tested groups ranged from 2-4 log CFU/ml. The population of the tested bacteria did not change during chill storage. Our findings demonstrated that pathogenic bacteria could survive in commercial yogurt products. However, the presence of yogurt culture could help prevent foodborne illness in consumers. Our research demonstrates the importance of having standardized hygienic quality control practices in place to ensure the highest yogurt quality. Therefore, the implementation of HACCP or an equivalent safety protocol is paramount in preventing future outbreaks of foodborne illness in such popular dairy products in Egypt.
Keywords: yoghurt, foodborne,quality.