Flavor profiles and microbial communities of Chinese acid-curd cheeses: A review of recent research

Chinese acid-curd cheeses (CACCs) are iconic traditional foods deeply rooted in the cultural heritage of Chinese national minorities. These CACCs, encompassing diverse types such as milk fan, milk cake, qula, kurut, and hurood, are prized for their unique flavors. Microorganisms are of paramount importance in the formation of flavor components in CACCs, and an in-depth knowledge of the interaction between microorganisms and flavor substances within CACCs is thus essential. This review summarizes research advances concerning flavor substances and microorganisms of CACCs in recent years. It focuses on CACCs characteristics and processing, flavor profiles, key flavor substances, microbial species, and interactions between flavor substances and microorganisms. CACCs exhibit milky and milder flavor notes and share some key aroma compounds, such as butanoic acid, octanoic acid, and acetoin. The main microorganisms found in CACCs include Lactobacillus and Lactococcus, and other lactic acid bacteria and yeast strains, such as Streptococcus and Kluyveromyces, also play essential roles in the fermentation process. Microorganisms play a pivotal role in shaping the distinctive flavor profiles of different CACC varieties, either through their individual metabolic activities or through synergistic interactions with other microbial species. This review is expected to summarize the recent advances in CACCs, evoking innovative ideas for improvements in their flavor profiles and thereby promoting their production and consumption in China.