Color is one of the important indicators affecting the quality of fermented pepper sauces, and it is closely related to carotenoid composition. This study systematically analyzed the changes in carotenoids and related physiochemical indices during the fermentation of yellow lantern pepper sauce. The CIELab color values indicated that L* and C* displayed a significant decreasing trend during fermentation. After 35 days of fermentation, the total carotenoid content significantly reduced from 3446.36 to 1556.50 μg/g DW (p < 0.05), and the degradation rate was 54.84%. Among them, the total content of carotene decreased by 56.03% during fermentation, whereas the degradation rate of xanthophylls and their esters was 44.47%. According to correlation analysis, violaxanthin myristate and lutein played a pivotal role in L*, a *, b *, chroma (C*), and yellowness index (YI). Moreover, PCA analysis indicated that lactic acid and acetic acid were the important qualities affecting the stability of pigment in fermented yellow lantern pepper sauce, which might also be the inducement of the color change. This work gives additional information concerning the discoloration of yellow lantern pepper sauce during fermentation and provides theory evidence regulating and improving the sensory qualities of yellow lantern pepper sauce.

To elucidate the mechanisms underlying the formation of the bacterial community predominantly composed of lactic acid bacteria (LAB) in sour bamboo shoots, the dynamics of the bacterial community structure and the influence of organic acids on the growth of dominant species were investigated. The results showed that the dominant bacteria in sour bamboo shoots changed from Enterobacteriaceae at first to LAB after fermentation. Correlation analysis revealed that organic acids, especially lactic acid and acetic acid, had great effects on bacteria. Even low concentrations of organic acids had negative effects on the growth of Enterobacter asburiae, while LAB exhibited remarkable tolerance to 8 g/L of organic acids. Notably, Levilactobacillus spicheri displayed a normal growth rate during incubation in medium containing 4 g/L of malic acid for 48 h. This study clarified the regulation of organic acids on bacterial community formation and provided a new understanding for bacterial control in traditional fermented foods.

Elucidating biogenic amine (BA) enrichment mechanisms in Liuyang Douchi pile-fermentation is crucial for enhancing product safety. This study analyzed spatial-temporal BA profiles and microbial succession. The central zone (M4) exhibited peak temperature (57.44 °C) and BA concentrations (total BAs: 47.70 mg/kg). Dominant genus Bacillus (mean abundance 9.95 %) correlated strongly with tyramine and histamine (r > 0.92, p < 0.01). Additionally, 22 non-dominant genera exclusive to M4 (e.g., Stenotrophomonas) correlated significantly with tyramine, β-phenylethylamine, and cadaverine (r > 0.89, p < 0.02). Five BA-producing strains were isolated, including M. sciuri B2-3 (759.8 mg/L), B. velezensis B2-5 (115.24 mg/L), B. sonorensis M4-2 (26.90 mg/L), and S. maltophilia M4-1 (260.21 mg/L) and M4-3 (40.00 mg/L). BA production by B. velezensis B2-5 and B. sonorensis M4-2 was first reported within their species. High temperature (55 °C) further stimulated BA synthesis in S. maltophilia M4-1 (443.77 mg/L), revealing a key thermal-driven mechanism for core-zone BA enrichment.