Characterization of the Food Microbiota in Ready-to-Eat Mexican Foods

Abstract

Ready-to-eat food microbiota are the microorganisms present in the dishes that are currently consumed during meals. These microorganisms include those that may have a health benefit, are potentially pathogenic or have not yet been given a function. Foods suitable for consumption are not free of microorganisms; however, within the food industry only yeasts have been given a beneficial function, while other microorganisms such as filamentous fungi and bacteria have been studied for their negative effects on food. We determined the bacterial diversity in samples of highly demanded, freshly prepared, unspoiled ready-to-eat dishes by high-throughput DNA sequencing of 16S rDNA libraries. We found a great bacterial diversity, whereby the most abundant bacterial phyla were Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, TM7 and Thermi, among others. These phyla included bacteria with remarkable abundances in some dishes. The alfa diversity analyses showed that the main dishes had the largest diversity. The beta-diversity analyses clustered the bacterial communities of soups, side plates, desserts, and beverages, and some main dishes. Based on our results we conclude that unspoiled ready-to-eat Mexican dishes contain a rich bacterial diversity, which may contribute to the organoleptic properties of the dishes without representing a sanitary risk for the consumers.

Keywords

• food
• food microbiota
• ready-to-eat food
• high-throughput DNA sequencing