Non-enzymatic browning (NEB) reduced the colour quality of hot-air dried peppers, but the specific mechanism remains unclear. This may be related to the degradation of chlorophyll, ascorbic acid, and polyphenols. The findings revealed that the surface of pepper gradually browned during hot-air drying, with the Δ E ⁎ value and browning degree (BD) significantly increasing by 119.4 % and 62.9 %, respectively. However, the total phenol content (TPC) and ascorbic acid content decreased by 74.2 % and 84.3 %, respectively. TPC was negatively correlated with BD ( R = −0.86), and its value (31.7 %) was 300 times higher than that of other colour-related components (ascorbic acid, chlorophyll). UPLC-MS/MS analysis further identified 345 polyphenols, among which 1, 3-dicaffeoylquinic acid and 5,7-dihydroxy-3′, 4′, 5′-trimethoxyflavone were the two key monophenols influencing NEB ( R = −0.87). The results suggested that NEB pathways involve chlorophyll a nd ascorbic acid degradation, the Maillard reaction, and polyphenol degradation, with the latter playing a major role.
Qianqian Jiang,Rongrong Lu,Zhihong Ma,Zhaoying He,Wanfu Hou,Mengtong Han,Pan Wang,Xiaoyan Zhao,Dan Wang
The microbial safety and quality properties of fresh-cut peppers ( Capsicum annuum L.) are influenced by disinfection. In this study, the effects of disinfection on the microbial community composition and quality attributes of green peppers stored at 4 ℃ for 8 days were investigated. The findings revealed that disinfection effectively reduced the total bacterial counts to approximately 6 log CFU/g at the end of storage compared to undisinfection samples (>7 log CFU/g) and altered bacterial community composition. Moreover, disinfection suppressed adverse changes in texture, maintained color by delaying chlorophyll degradation, and inhibited the accumulation of 12 screened key volatile organic compounds (VOCs) that produced mixed undesirable flavors, such as 2-hexenal and (E, E)-2,4-decadienal. Through the correlation analysis of microbiota and quality indicators, Pseudomonas was considered a marker of quality deterioration because of its significant negative correlation with firmness and positive correlations with ΔE and odor-causing VOCs, and disinfection decreased the relative abundance of this bacterium over time. These findings will provide vital guidance for fresh-cut pepper practices.
危险品化学品经营许可证（带存储）