Dynamic Microbial Succession and Flavor Characteristics During Longyou Rice Cake Fermentation

Abstract

Background and Objective

Longyou fermented rice cake is a traditional Chinese delicacy with a unique flavor. Nevertheless, the pathways involved in the microbiota-driven aroma formation during fermentation remain unclear. This study revealed the dynamic changes in rice slurry during the fermentation of Longyou rice cakes, and the microorganisms therein were analyzed at the genus level. By combining the volatile metabolite results, microbial functional enzymes from high-throughput sequencing, results from the Kyoto Encyclopedia of Genes and Genomes database, and literature data, the metabolic network associated with rice slurry was predicted.

Findings

A total of 33 volatile compounds and 11 key aromatic compounds were identified during the fermentation. Due to the interaction of physicochemical factors and microorganisms, Saccharomyces and Lactobacillus gradually became the dominant microorganisms in rice slurry. Functional predictions showed that the main metabolic pathways of the microorganisms were carbohydrate, energy, and amino acid metabolism, which were significantly correlated with the production of unique flavor compounds in Longyou rice slurry.

Conclusion

A variety of microorganisms are positively associated with key flavor substances.

Significance and Novelty

This study provides insights into the modulation of flavor by microbial genera during fermentation.