Consumers and food safety: Application of metataxonomic analyses and multivariate statistics in order to identify behaviours affecting microbial contaminations in household kitchens

Microbial contamination of the domestic environment can lead to food spoilage, food waste and food-borne illness generating public health concern. The present study was aimed at evaluating: microbiological contamination of domestic refrigerators using both traditional microbiological and metataxonomic methods, linking these results with consumers’ characteristics, observed/stated practices in food handling and storage in households. Data were collected by means of an online survey focused on consumer habits and characteristics, and by direct observation of practices, through consumers’ kitchens inspections where surface samples from refrigerators (n = 64). Microbiological and metataxononimc analyses on those samples allowed the evaluation of microbial contamination and its composition. Multivariate analysis was applied to the core Amplicon Sequence Variants composition in order to highlight relations between contamination agents and consumer practices. Consumer analysis evaluated correlation among stated/observed practices with respondents’ objective knowledge of hygiene practices. Finally, multivariate dimensions derived by genera analysis were used to evaluate the role of consumer characteristics and habits in domestic contamination. The results indicated a low level of contamination. Metataxonomic analysis provided a set of microbial genera, of which, 12 were the main responsible for fridge contaminations. The respondents’ objective knowledge of hygiene practices was found to be significantly related to stated practices, whereas there was no significant result in combination with observed ones. Therefore, with limited sample dimension, theoretical knowledge showed a stronger relation to stated practices, whereas it did not always reflect real-life habits. However, the direction of correlations suggests that improving consumer knowledge of good hygiene practices through more practical awareness-raising actions, could reduce food contamination and the risk of food-borne illnesses. Finally, the application of the multivariate analyses allowed the observation of two clusters with different characteristics in terms of genera composition and consumers habits (such as refrigerator’s temperature checking and food arrangement in it). Thus, such an innovative approach led to identifying the putative factors which are the most in relation with microbial contamination/general composition of fridges. Nonetheless, the combination of microbiological methods with the social evaluation of consumers could provide useful insights to tackle the causes of food contamination.