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Chilling is an essential process in chilled meat production, and various chilling methods are available for actual production. Different chilling methods have different effects on meat quality. Very fast chilling has several advantages like shortening the chilling time of livestock and poultry meat, reducing the chilling loss, delaying the postmortem physiological and biochemical processes, and reducing the proliferation of microorganisms on the surface of meat. However, no consensus has been reached on the effect of very fast chilling on the tenderness of meat, which may be associated with its unclear mechanism. This limits the application of very fast chilling technology. Therefore, this article systematically reviews recent progress in understanding the effect of very fast chilling on postmortem muscle tenderness, with a focus on its potential mechanism from five aspects: physical restraint, physical damage, early postmortem release of calcium, the glycolysis process and the apoptosis process, in order to provide a theoretical basis for the development and application of very fast chilling technology.

In order to identify the major virus species and infection types affecting cigar tobacco (Nicotiana tabacum) in Hainan Province, tobacco leaf samples suspected of being infected with viral diseases were collected from 7 cigar tobacco growing regions in Hainan. Specific primers of 6 viruses and universal primers of geminivirus were used for PCR detection, and the primers were designed according to the amplified sequences of TYLCV, SiLCV and AYVCNV to obtain their complete genome sequence. The results showed that 59 out of 64 samples were detected with 5 viruses (TMV, CMV, TYLCV, SiLCV and AYVCNV), and the detection rate was 92.19%. The detection rate of TMV was the highest (73.45%), followed by CMV (39.07%). The single infection rate was 60.94%, with TMV (45.31%), accounting for the highest proportion. The mixed infection rate was 31.25%, and the proportion of TMV+CMV was the highest (26.57%). Therefore, TMV was the dominant virus affecting cigar tobacco in Hainan, and the main type of mixed infection was TMV+CMV. In addition, the complete DNA-A sequences of TYLCV, SiLCV and AYVCNV were obtained. [ABSTRACT FROM AUTHOR]

Shading or low light conditions are essential cultivation techniques for cigar wrapper tobacco leaves production, yet their impact on protein and metabolic regulatory networks is not well understood. In this study, we integrated proteomic and metabolomic analyses to uncover the potential molecular mechanisms affecting cigar tobacco leaves under shading treatment. Our findings include: (1) Identification of 780 significantly differentially expressed proteins (DEPs) in the cigar wrapper tobacco leaves, comprising 560 up-regulated and 220 down-regulated proteins, predominantly located in the chloroplast, cytoplasm, and nucleus, collectively accounting for 50.01%. (2) Discovery of 254 significantly differentially expressed metabolites (DEMs), including 148 up-regulated and 106 down-regulated metabolites. (3) KEGG pathway enrichment analysis revealed that the mevalonate (MVA) pathway within 'Terpenoid backbone biosynthesis' was inhibited, leading to a down-regulation of 'Sesquiterpenoid and triterpenoid biosynthesis'. Conversely, the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway was enhanced, resulting in an up-regulation of 'Monoterpenoid biosynthesis', 'Diterpenoid biosynthesis', and 'Carotenoid biosynthesis', thereby promoting the synthesis of terpenoids such as carotenoids and chlorophylls. Simultaneously, the Calvin cycle in 'Carbon fixation in photosynthetic organisms' was amplified, increasing photosynthetic efficiency. These results suggest that under low light conditions, cigar tobacco optimizes photosynthetic efficiency by reconfiguring its energy metabolism and terpenoid biosynthesis. This study contributes valuable insights into protein and metabolic analyses, paving the way for future functional studies on plant responses to low light., Competing Interests: All authors were employed by the company Hainan Provincial Branch of China National Tobacco Corporation. The authors declare that this study received funding from Science and Technology Major Project of China National Tobacco Corporation (110202201038(XJ-09), 110202103017, 110202101012(XJ-04)). The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication., (Copyright © 2024 Yan, Cai, Li, Guo, Xia, Lv, Lin, Gao and Geng.)