Combination of nisin, lysozyme, and tea polyphenols altered the bacterial communities and flavor profiles of sturgeon caviar during cold storage

Caviar, known for its high-value and nutrition, is prone to quality deterioration. This study explored the effects of nisin, lysozyme, and tea polyphenols on the flavor profiles and bacterial community in sturgeon caviar during cold storage. Results demonstrated that these natural preservatives significantly (p < 0.05) delayed protein breakdown (TVB-N reduced by 22.2 %) and lipid oxidation (TBARS reduced by 34.4 %) by day 100. GC-IMS analysis identified key spoilage-related aldehydes (e.g., heptanal, hexanal), whose formation was effectively controlled by the natural preservatives. The preservatives also markedly reduced bacterial community diversity and altered the bacterial community composition, delaying spoilage bacteria growth and potential metabolic activity. Notably, Psychrobacter emerged as the potential biomarker, constituting 97.30 % of the bacterial community in treated caviar by the end of storage. These results provided a foundational basis for the potential application of natural antibacterial agents and antioxidants complexes as preservatives in caviar production.