关键词:
Fresh-cut Chinese water chestnut;Ethylene;Browning;Reactive oxygen species (ROS)
摘要:
The phytohormone ethylene responds positively to abiotic stress, but its effect on quality deterioration of freshcut Chinese water chestnuts (CWCs) caused by mechanical damage remains unclear. Here, the effects of single or combination treatments of ethephon (ET) and 1-methylcyclopropene (1-MCP) on fresh-cut CWCs during storage at 10 degrees C for 5 d were investigated. The results indicated that ET treatment was most effective in maintaining CWCs' visual quality, followed by 1-MCP preceding ET treatment, 1-MCP treatment, and 1-MCP following ET treatment. Compared with 1-MCP treatment group, ET-treated fruit exhibited lower expressions of CwPAL, CwCHS1 and CwCHI1 and decreased activity of phenylalanine ammonia-lyase activity to inhibit flavonoid accumulation but higher catalase and superoxide dismutase and peroxidase (POD) activities and lower malonaldehyde content to maintain reactive oxygen species balance and suppress microbial growth. Nevertheless, ET treatment promoted fruit weight loss and CO2 concentration in the package, which was reversed by the preceding 1-MCP application rather than the subsequent 1-MCP treatment. 1-MCP followed by ET treatment not only inhibited the levels of flavonoid compounds and oxidation catalyzed by POD compared with the post-1-MCP treatment, but also reduced H2O2 production and microbial spoilage with a higher catalase activity. These results show that ET could maintain the quality of fresh-cut CWC by boosting antioxidant capacity, inhibiting microbial growth and suppressing enzymatic generation of browning substrates. In addition, compared with ET treatment, 1-MCP followed by ET treatment, despite showing weaker antioxidant enhancement, could inhibit the senescence of fresh-cut CWCs, suggesting its suitability for quality control of fresh-cut CWCs.
作者机构:
[舒少华; 刘和平; 刘金鑫; 唐静; 苏振佳] College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China;[朱闻君] School of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, 430023, China
通讯机构:
[Shu, S.-H.] C;College of Plant Science and Technology, China
摘要:
This study evaluated the changes in phenolic and reactive oxygen species metabolism, and microbial diversity in fresh-cut lotus roots following ethanol treatment to elucidate the potential mechanisms of ethanol in controlling microbial growth and browning. Activity suppression and gene expression downregulation of phenylalanine ammonia-lyase, polyphenol oxidase, and peroxidase took place with ethanol treatment, resulting in the decreased accumulation of total phenols and soluble quinones. The total phenol and soluble quinone contents of ethanol-treated slices were 12.63% and 30.22% lower than those in the control group, respectively, after 12 d of storage. Ethanol treatment changed the level of eleven individual phenols, two of which were associated with antioxidant ability. Besides, the ethanol-treated slices exhibited the reduced production of reactive oxygen species, increased activities of superoxide dismutase and catalase, improved ascorbic acid contents and 1,1-Diphenyl-2-picrylhydrazyl scavenging rate, and the upregulated transcriptional levels of NnGR and NnGST. Moreover, the integrated transcriptomic and metabolomic analyses show the biosynthesis of syringin (an anti-oxidant in various medicinal plants) might be stimulated by ethanol treatment. Ethanol treatment inhibited the abundance of Pantoea, Pseudomonas, Tolumonas and Stenotrophomonas. These findings suggested ethanol treat-ment is a simple and potential technology for preserving the quality and antioxidant ability of fresh-cut products.
作者机构:
[Hu, Xuebo; Zhou, Xinxin; Zou, Dian; Luo, Biaobiao] Huazhong Agr Univ, Coll Plant Sci & Technol, Intitute Med Plants, Wuhan, Peoples R China.;[Hu, Xuebo; Zhou, Xinxin; Zou, Dian; Luo, Biaobiao] Natl & Local Joint Engn Res Ctr Med Plant Breeding, Wuhan, Peoples R China.;[Hu, Xuebo; Zhou, Xinxin; Zou, Dian; Luo, Biaobiao] Hubei Prov Engn Res Ctr Med Plants, Wuhan, Peoples R China.;[Li, Xiaohua] Wuhan Polytech Univ, Coll Life Sci & technol, Wuhan, Peoples R China.;[Faruque, Mohammad Omar] Univ Chittagong, Dept Bot, Ethnobot & Pharmacognosy Lab, Chattogram, Bangladesh.
通讯机构:
[Jian Chen] D;[Xuebo Hu] I;Department of Head and Neck Surgery, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China<&wdkj&>Intitute of Medicinal Plants, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China<&wdkj&>National & Local Joint Engineering Research Center for Medicinal Plant Breeding and Cultivation, Wuhan, China<&wdkj&>Hubei Provincial Engineering Research Center for Medicinal Plants, Wuhan, China
摘要:
Solanum lyratum Thunb is a traditional Chinese medicinal with a significant clinical outcome for tumor treatment; however, chemicals or fractions separated from the herb did not exhibit strong and comparable efficacy. To investigate the potential synergy or antagonism among chemicals in the extract, we obtained the compounds solavetivone (SO), tigogenin (TI) and friedelin (FR) from the herb. The anti-tumor effects of these three monomer compounds alone or in combination with the anti-inflammatory compound DRG were also tested in this study. SO, FR and TI used alone did not inhibit the proliferation of A549 and HepG2 cells, but the combination of the three achieved 40% inhibition. In vitro anti-inflammatory analysis showed that DRG had a stronger anti-inflammatory effect than TS at the same concentration, and the combination of DRG with SO, FR or TI inhibited the anti-tumor effect of DRG. This is the first study that documented the synergistic and antagonistic interactions between different compounds in a single herb.
作者机构:
[Zhan, Shengpeng; Duan, Linlin; Tu, Jiesong; Duan, Haitao; Zhang, Wulin; Jia, Dan; Yang, Tian; Li, Jian] Wuhan Res Inst Mat Protect, State Key Lab Special Surface Protect Mat & Appli, Wuhan 430030, Peoples R China.;[Zhan, Shengpeng; Duan, Linlin; Tu, Jiesong; Duan, Haitao; Zhang, Wulin; Jia, Dan; Yang, Tian; Li, Jian] Hubei Longzhong Lab, Xiangyang 441000, Hubei, Peoples R China.;[Liu, Jianfang] Wuhan Polytech Univ, Coll Life Sci & Technol, Wuhan 430030, Peoples R China.
通讯机构:
[Haitao Duan] S;State Key Laboratory of Special Surface Protection Materials and Application Technology, Wuhan Research Institute of Materials Protection, Wuhan 430030, China<&wdkj&>Hubei Longzhong Laboratory, Xiangyang, Hubei 441000, China
摘要:
Geometric variables and surface chemistry of nanomaterials as lubricant additives both affect the details on the interacting frictional surface. Herein, copper phosphate nanosheets (CPNs) were synthesized by a simple and facile method, which exhibited extraordinary tribological properties as the novel lubricating oil nanoadditives. Compared with the base oil, the friction coefficient (COF) has been reduced by 77% by CPNs at a concentration of 20 wt%, which could also protect the titanium alloy surface from any measurable wear. But as the CPNs content increased to 25 wt%, the shear jamming caused by hydrogen bonding between crystal water in CPNs may interfere with lubrication. Besides, it is significantly effective in preventing the adhesions of titanium alloy on the surface of counterface at a suitable concentration. The extraordinary tribological performance is contributed to the nanosheets of copper phosphate but not the nanoparticles. Moreover, in the presence of CPNs, the tribo-film containing CPNs is formed during sliding contact, but this tribo-film can't hold for a long time without CPNs, indicating that CPNs can well retain the tribo-film. However, the dominant factor for friction reduction and antiwear is not this tribo-film but the solid-liquid interface lubrication between nanosheets and lubricating oil. The Stribeck curves were used to explain how CPNs play a role in boundary lubrication and mixed lubrication.
摘要:
This study investigated the effects of 1 g L-1 ethylene immersion treatment for 1 min on the storage quality, antioxidant capacity and ethylene signal transduction pathway of fresh-cut lotus roots. Phenylalanine ammonia-lyase and polyphenol oxidase activities were increased in ethylene treatment slices, and total phenolic content was increased. The activities of peroxidase, catalase and superoxide dismutase were increased after ethylene treatment, as well as the expression of related genes (NnPOD, NnSOD, NnCAT) was upregulated. The rate of superoxide anion radical and hydroxyl radical production in ethylene treatment fresh-cut lotus roots was inhibited, the hydrogen peroxide content was reduced, and the degree of membrane lipid peroxidation was decreased, which delayed browning during the early storage. However, ethylene treatment inhibited microbial growth and improved 1,1-Diphenyl-2-picrylhydrazyl scavenging capacity only during the early storage, pro-moted respiration and accelerated the decline of hardness and soluble solids content throughout the storage period. At the molecular level, ethylene treatment overall upregulated the transcription of NnmetK, NnACO, NnETR, NnEIN3, and NnERF genes and promoted ethylene biosynthesis and signal transduction. This finding may be related to the senescence of fresh-cut lotus roots during late storage. These results suggest that ethylene treatment improved the antioxidant system, reduced the accumulation of reactive oxygen species, and effectively delayed the early browning of fresh-cut lotus roots, while promoting late senescence.
摘要:
Abstract: To promote the functional applications of lotus root polysaccharides (LRPs), the effects of noncovalent polyphenol binding on their physicochemical properties, as well as antioxidant and immunomodulatory activities, were investigated. Ferulic acid (FA) and chlorogenic acid (CHA) were spontaneously bound to the LRP to prepare the complexes LRP-FA1, LRP-FA2, LRP-FA3, LRP-CHA1, LRP-CHA2 and LRP-CHA3, and their mass ratios of polyphenol to LRP were, respectively, 121.57, 61.18, 34.79, 2359.58, 1276.71 and 545.08 mg/g. Using the physical mixture of the LRP and polyphenols as a control, the noncovalent interaction between them in the complexes was confirmed by ultraviolet and Fourier-transform infrared spectroscopy. The interaction increased their average molecular weights by 1.11~2.27 times compared to the LRP. The polyphenols enhanced the antioxidant capacity and macrophage-stimulating activity of the LRP depending on their binding amount. Particularly, the DPPH radical scavenging activity and FRAP antioxidant ability were positively related to the FA binding amount but negatively related to the CHA binding amount. The NO production of the macrophages stimulated by the LRP was inhibited by the co-incubation with free polyphenols; however, the inhibition was eliminated by the noncovalent binding. The complexes could stimulate the NO production and tumor necrosis factor-α secretion more effectively than the LRP. The noncovalent binding of polyphenols may be an innovative strategy for the structural and functional modification of natural polysaccharides. Keywords: lotus root; polysaccharide; polyphenol; noncovalent interaction; bioactivity