Mi Wei,Huiyin Liu,Zhilin Zhang,Xuemin Chen,Zhenhua Guo,Xiangxia Yang
As a specialty food that is medicinal and edible, Anoectochilus roxburghii contains many active ingredients. Herein, optimal conditions to preserve A. roxburghii samples and obtain high physiological activity have been studied. The contents of polysaccharides , kinsenoside, and flavonoids of A. roxburghii were monitored during post-harvest storage for a period of eight months at 25 °C with different packaging methods such as stacking, multilayer pocket and vacuum. The results indicated that packaging method and storage time have significant influences on the preservation of active compounds. Polysaccharides, kinsenoside and flavonoids exhibited a general descending trend during storage for a period of eight months in all packaging conditions. However, the vacuum method is more effective in preservation of polysaccharides and flavonoids than stacking and multilayer pockets methods due to the lower activity of microbial community under vacuum condition. Interestingly, kinsenoside, a characteristic compound of A. roxburghii , responsive for the hypoglycemic function, was not affected by packaging methods. This is because kinsenoside was mainly affected by plant endogenous enzymes instead of microbial community. Two-factor variance analysis showed that packaging method and storage time have significant interactions in preservation. It was further disclosed that the changes of active components were closely related to the plant endogenous enzymes, microbial community and their functions. The findings in this study will shed some light on the storage of A. roxburghii and other herb products.
Zhouyi Xiong,Mingqian Zhou,Shan Xiao,Zhongli Zhang,Dan Li
Tandem Mass Tag (TMT)-based proteomics was employed to elucidate the pivotal role of endogenous enzymes in the quality deterioration of Mandarin fish ( Siniperca chuatsi ) during refrigerated storage. Proclean 300 was used to inhibit the growth of psychrophilic microorganisms, emphasizing the contribution of endogenous enzymes. Quality characteristics, including pH, water-holding capacity, color, texture, and myofibrillar fragmentation index (MFI), were compared between the Proclean 300-treated group (P-group) and the control group (C-group). Correlation analysis underscored the collaborative role of calpain and cathepsin B in postmortem degradation. Pearson correlation analysis showed that texture characteristics were significantly negatively correlated with MFI and significantly positively correlated with whiteness and L* in the P-group. Differentially expressed proteins (DEPs) analysis identified 66 DEPs, with 40 exhibiting low abundance, including cytoskeleton proteins and hemoglobin subunits, and 26 showing high abundance, primarily metabolic enzymes. Bioinformatics analysis revealed significant enrichment of DEPs within the glycolysis/gluconeogenesis pathway. Furthermore, protein-protein interaction analysis highlighted key proteins linked to the quality deterioration of Mandarin fish, including beta-enolase, phosphoglycerate kinase 1, and triosephosphate isomerase B. These findings offer valuable insights into the mechanisms behind the quality deterioration of refrigerated Mandarin fish and the intricate relationship with endogenous enzymes.