Research Progress of Functional Enzymes inTraditional Fermented Food

Traditional fermented foods could produce a variety of functional enzymes and plenty of flavor compounds through microbial fermentation. The production process of fermented foods would be constantly enriched with abundant enzymes, and it is the current hotspot to study these functional enzymes systematically and scientifically. In this study, the traditional isolation and culture of functional enzymes from fermented food are analyzed, and it can identify the enzyme activity of key functional enzymes. Furthermore, this work summarizes the recent research on functional enzymes in fermented foods by high-throughput technologies, such as PICRUSt analysis based on 16S rRNA and ITS sequencing, metagenome, metatranscriptome and metaproteome. It is found that, compared to analysis by traditional isolation and culture, single high-throughput technology can obtain more functional enzymes information, analyze complex metabolic pathways and identify active functional enzymes. The research on functional enzymes by combinations of high-throughput technologies is also reviewed, and it is found that combination of different methods can obtain more information to analyze the fermentation process of traditional food comprehensively and deeply. It is also found that, based on analysis of high-throughput technology, some researchers have analyzed the specific functional enzymes in traditional foods by heterologous expression. This study comprehensively summarizes results and methods of functional enzymes in various traditional fermented foods, aiming to provide technical foundation for the research and application of functional enzymes in traditional fermented foods.