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Revealing the Structure-Property Difference of Natural Rubber Prepared by Different Methods: Protein and Gel Content are Key Factors

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chinese Journal of Polymer Science 2024年第4期42卷 457-467页

作者： Shao-Qi Huang Jun-Qi Zhang Yong Zhu Ling-Min Kong Lu-Sheng Liao Fu-Quan Zhang Zheng-Tian Xie Jin-Rong Wu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China Hainan Provincial Key Laboratory of Natural Rubber processing Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural SciencesZhanjiang524001China

Natural rubber (NR) is widely used in various fields including aerospace, military industry and transportation due to its superior elasticity and comprehensive mechanical properties. Nonetheless, the commercial NR prepared by different methods usually exhibits different mechanical properties, primarily due to variations in processing conditions during the conversion from latex to bulk rubber material. Consequently, this poses challenges in scientific research and industrial production of NR. In order to assess the properties of various commercially available NR and identify key structural and compositional components, this study systematically compares and analyzes four representative NR raw materials: air dried sheet (ADS), ribbed smoked sheets (RSS), constant viscidity NR (CV), and whole field latex rubber (WF). The investigation focuses on evaluating their static mechanical behavior, SIC behavior, wear resistance, and fatigue resistance. The findings indicate that protein and gel content exhibit a crucial influence on the NR properties. These constituents contribute to the formation of a high-crosslinking density region, generating a heterogeneous network structure within the rubber. This structure amplifies strains during deformation, leading to earlier and stronger strain-induced crystallization (SIC). Among the four commercial NR brands, RSS demonstrates superior overall mechanical and dynamic properties owing to its high protein and gel content. This study serves as a valuable reference for comprehending the differences in properties among various commercial NR, thereby offering guidance for the actual processing and selection of NR.

关键词： Natural rubber processingmethod Protein Gel content Property

Effects of Milling Methods on Rice Flour Properties and Rice product Quality:A Review

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Rice science 2024年第1期31卷 33-46页

作者： TIAN Yu SUN Jing LI Jiaxin WANG Aixia NIE Mengzi GONG Xue WANG Lili LIU Liya WANG Fengzhong TONG Litao institute of Food Science and Technology/Western research institute Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products ProcessingMinistry of Agriculture and Rural AffairsBeijing 100193China

High-quality rice flour is the foundation for the production of various rice-based *** is an essential step in obtaining rice flour,during which significant changes occur in the physicochemical and quality characteristics of the *** rice flour obtained through mainstream wet milling methods exhibits superior quality,low production efficiency and wastewater discharge limit the development of the *** milling,on the other hand,conserves water resources,but adversely affects flour performance due to excessive heat *** an emerging powder-making technique,semi-dry milling offers a promising solution by enhancing flour quality and reducing environmental *** is achieved by minimizing soaking time through hot air treatment while reducing mechanical energy consumption to reach saturated water absorption ***,continuous production remains a *** comprehensive review summarizes the effects of various milling technologies on rice flour properties and product *** also discusses key control indicators and technical considerations for rice flour processing equipment and processes.

关键词： flour property milling equipment milling method rice flour rice product quality semi-dry milling

New indole derivatives from endophytic fungus Colletotruchum sp. HK-08 originated from leaves of Nerium indicum

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chinese Herbal Medicines 2024年第2期16卷 235-238页

作者： Huiqin Chen Hao Zheng Caihong Cai Hao Wang Cuijuan Gai Zhiqiong Tan Haofu Dai Wenli Mei Hainan Key Laboratory of research and Development of Natural product from Li Folk Medicine Institute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikou 571101China Hainan institute for tropical agricultural Resources Haikou 571101China School of Life and Pharmaceutical sciences Hainan UniversityHaikou 570228China

Objective: To study secondary metabolites from endophytic fungus Colletotruchum sp. HK-08 originated from the leaves of Nerium ***: The compounds were isolated by various column chromatographic techniques, and their structures were elucidated by spectroscopic techniques [high resolution electrospray ionization mass spectroscopy(HRESIMS), one-dimensional(1D) and two-dimensional(2D) nuclear magnetic resonance spectroscopy(NMR)], as well as comparison with literature data. The Ellman method was used to determine the acetylcholinesterase(ACh E) inhibitory ***: Four indole derivatives were identified from Colletotruchum sp. HK-08, including 6’-hydroxymonaspiloindole(1), 2-(2-oxoindolin-3-yl)ethyl 2-(4-hydroxyphenyl) acetate(2), 2-(2-oxoindolin-3-yl)ethyl 2-(2-hydroxyphenyl)acetate(3), and monaspiloindole(4). Compound 4 presented weak ACh E inhibitory activity with IC50value of(69.30 ± 6.27) μmol/L [tacrine as the positive control, with IC50value of(0.61 ± 0.07) μmol/L].Conclusion: Compounds 1–3 were new compounds, and compound 4 had weak ACh E inhibitory activity.

关键词： Colletotruchum sp. endophytic fungus indole derivatives Nerium indicum Mill. secondary metabolites

Evaluation of in situ spoilage ability of common facultative anaerobic bacteria and confirmation of volatile spoilage markers in vacuum-packaged lamb

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Food Science and Human Wellness 2024年

作者： Xiangyuan Wen Dequan Zhang Su Wang Zhiyuan Xiao Xin Li Debao Wang Wei Yang Chengjun Min Chengli Hou institute of Food Science and Technology chinese academy of agricultural sciences Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process Ministry of Agriculture and Rural Affairs institute of agricultural product processing and Nutritional Health chinese academy of agricultural sciences (Cangzhou) Sunrise Material Co. Ltd Jiangyin Beijing Ershang Meat Food Group Co. Ltd

Microbial growth causes lamb spoilage. This study explored the spoilage ability of Latilactobacillus sakei (L. sakei)， Serratia proteamaculans (S. proteamaculans) and Hafnia proteus (H. proteus) in vacuum-packed raw lamb， including growth ability， degradation of protein and lipid， and change of volatile organic compounds (VOCs) profile， meanwhile screened the key VOCs produced by the targeted strains with meat background excluding， finally confirmed the volatile spoilage marker of vacuum-packaged lamb by comparing with our previous work. The results showed that L. sakei， S. proteamaculans and H. proteus had excellent growth ability. L. sakei inoculated group significantly reduced the pH value， showed higher TCA-soluble peptides content， and excellently degraded sarcoplasmic and myofibrillar proteins. About free amino acids， L. sakei significantly degraded serine， arginine and aspartic acid， while S. proteamaculans and H. proteus significantly degraded serine and lysine. In addition， L. sakei had a strongest effect on promoting free fatty acids production， followed by S. proteamaculans and finally H. proteus. Evaluating from various indicators， the co-culture of the three strains did not have any effect. The key volatiles produced by L. sakei were 1-hexanol， acetic acid and hexanoic aicd， S. proteamaculans were 1-hexanol and acetoin， and H. proteus was 1-hexanol， acetic acid and acetoin. In the end， 1-hexanol， hexanoic acid and acetoin were proven to be spoilage markers for vacuum-packaged and chilled lamb. This study can provide fundamental information for inhibiting and rapid identification of spoilage in vacuum-packaged lamb.

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Residue behaviors and dietary risk assessment of dinotefuran and its metabolites in Lycium barbarum from farm to fork

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Food Science and Human Wellness 2024年

作者： Ouli Xiao Minmin Li Jieyin Chen Ran Wang Xiaofeng Dai Zhiqiang Kong State Key Laboratory for Biology of Plant Diseases and Insect Pests institute of Plant Protection chinese academy of agricultural sciences Western agricultural research Center chinese academy of agricultural sciences Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process Ministry of Agriculture and Rural Affairs/institute of Food Science and Technology chinese academy of agricultural sciences institute of Plant Protection Beijing academy of Agriculture and Forestry sciences

Lycium barbarum， known as wolfberry or goji berry， is consumed by humans as a medicine and a food homology product. Conventionally grown wolfberry is often treated extensively with pesticides， which could pose a hazard to humans. Here， the degradation dynamics of dinotefuran and its two metabolites (UF and DN)， during wolfberry cultivation and processing was investigated. The half-life (T1/2) of dinotefuran was 11.36 d and 9.12 d， respectively， under the recommended dosage and double the recommended dosage. During the oven and sun drying processes， processing factors (PFs) of dinotefuran were 1.07 - 1.34， implying the enrichment of pesticide residues. Decoction process made the removal rate of dinotefuran reach 87.48%， which is higher than that of the brewing process (14.7%)， while dinotefuran remained in the wine with high ethanol content in the alcohol soaking process. The hazard quotient (HQ) of dinotefuran， as determined via dietary risk assessment combined with PFs， was gastric (5.45% - 86.72%) > oral (23.18%) via in vitro simulated digestive system. These findings provide scientific evidence for reasonable application and risk assessment of dinotefuran residues in wolfberry.

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Two types of coumarins-specific enzymes complete the last missing steps in pyran- and furanocoumarins biosynthesis

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Acta Pharmaceutica Sinica B 2024年第2期14卷 869-880页

作者： Yucheng Zhao Yuedong He Liangliang Han Libo Zhang Yuanzheng Xia Fucheng Yin Xiaobing Wang Deqing Zhao Sheng Xu Fei Qiao Yibei Xiao Lingyi Kong Department of Resources Science of Traditional chinese Medicines School of Traditional Chinese Pharmacyand State Key Laboratory of Natural MedicinesChina Pharmaceutical UniversityNanjing 210009China College of Bioscience and Biotechnology Hunan Agricultural UniversityChangsha 410128China Jiangsu Key Laboratory of Bioactive Natural product research and State Key Laboratory of Natural Medicines Department of Natural Medicinal ChemistryChina Pharmaceutical UniversityNanjing 210009China Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China Ministry of AgricultureTropical Crops Genetic Resources InstituteChinese Academy of Tropical Agricultural SciencesHaikou 517317China institute of Botany Jiangsu Province and Chinese Academy of SciencesNanjing 210014China Department of Pharmacology School of Pharmacyand State Key Laboratory of Natural MedicinesChina Pharmaceutical UniversityNanjing 210009China

Pyran-and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans,respectively,exhibiting diverse physiological and medical ***,the biosynthetic mechanisms for their core structures remain poorly *** we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in *** included three distinct *** prenyltransferases(PpPT1e3)responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors,and two novel CYP450 cyclases(PpDC and PpOC)crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran *** analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring *** possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific *** identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic *** study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.

关键词： Tetrahydropyrans Tetrahydrofurans Baldwin rules Coumarins CYP450cyclase

Succession of bacteria communities during production and application of dairy bedding by membrane-covered aerobic fermentation

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International Journal of agricultural and Biological Engineering 2024年第1期17卷 232-240页

作者： Hongjie Yin Jianfei Zeng Chen Fang Xueqin He Ya Su Jinpeng Xiong Lujia Han Guangqun Huang College of Engineering China agricultural University Beijing 100083China institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China College of Agriculture Guizhou UniversityGuiyang 550025China

The cost of dairy manure treatment and bedding material purchase increases the operating cost of the dairy ***-covered aerobic fermentation system has been widely used for dealing with dairy manure and recycling the final product as bedding ***,the microbial safety in each processing step is still *** better understand the bacterial community dynamics during the whole bedding conversion process,a full-chain and large-scale experiment including 16-day membrane-covered aerobic fermentation and 11-day bedding material application was *** results showed that the pile temperatures in the fermentation stage rapidly increased to 80°C and maintained>50°C for more than 11 days and the use of fermentation product as bedding material provided cows with a stable and comfortable bedding *** Chao1 and Shannon index decreased at the end of the fermentation stage and remained stable in the application stage,indicating that membrane-covered aerobic fermentation effectively killed some pathogenic bacteria and guaranteed both the maturity and stability of the final *** dominant bacteria in the fermentation stage were Acinetobacter,Thermus,and Rhodothermus at genus *** common potential pathogens of mastitis(Staphylococcus,Enterococcus,Serratia,Pseudomonas,Corynebacterium,Mycobacterium,and Bacillus)were found at the end of fermentation stage but the relative abundance was low(0.0025%-0.2727%).The dominant bacteria in the application stage mainly included Acinetobacter,Pseudomonas,and Flavobacterium at the genus *** relative abundance of Pseudomonas increased in the application stage,which was a reminder to the dairy farm to pay attention to the disinfection and timely replacement of bedding material to prevent the occurrence of dairy *** results of this study contributed deep understanding of the microorganism-driven bedding conversion process and provide practical guidance and cautions for the bedding

关键词： semi-permeable membrane dairy manure aerobic fermentation bedding material bacterial diversity

Analysis of quality-related proteins in golden pompano(Trachinotus ovatus)fillets with modified atmosphere packaging under superchilling storage

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Food Science and Human Wellness 2024年第4期13卷 2253-2265页

作者： Chuang Pan Xiaofan Zhang Shengjun Chen Yong Xue Yanyan Wu Yueqi Wang Di Wang South China Sea Fisheries research institute Chinese Academy of Fishery SciencesKey Laboratory of Aquatic Product ProcessingMinistry of Agriculture and Rural AffairsNational R&D Centre for Aquatic Product ProcessingGuangzhou 510300China Co-Innovation Center of Jiangsu Marine Bio-industry Technology Jiangsu Ocean UniversityLianyungang 222005China Collaborative Innovation Center of Seafood Deep processing Dalian Polytechnic UniversityDalian 116034China Key Laboratory of Efficient Utilization and processing of Marine Fishery Resources of Hainan Province Sanya Tropical Fisheries Research InstituteSanya 572018China College of Food Science and Engineering Ocean University of ChinaQingdao 266003China

Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem *** mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)*** electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed *** sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and *** Fresh(FS),MAP,and air packaging(AP)groups were *** of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS *** KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein *** analysis found that 52 DAPs were correlated with quality *** them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding *** results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.

关键词： Tandem mass tags(TMT)proteomics Trachinotus ovatus Modified atmosphere packaging Superchilling storage Low-field nuclear magnetic resonance Protein deterioration

Preparation,characterization and antioxidant activity analysis of three Maillard glycosylated bone collagen hydrolysates from chicken,porcine and bovine

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Food Science and Human Wellness 2024年第4期13卷 2002-2013页

作者： Liwei Qi Hongru Zhang Yujie Guo Hong Liu Chunhui Zhang Key Laboratory of Agro-products processing Ministry of Agriculture and Rural AffairsInstitute of Food Science and TechnologyChinese Academy of Agricultural SciencesBeijing 100193China Laboratory of Biomass and Green Technologies University of Liege-Gembloux Agro-Bio TechPassage des déportés 2Gembloux B-5030Belgium

Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant *** glycosylated reaction is considered as a promising method to enhance the antioxidant activity of ***,this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different *** this study,3 glycosylated bone collagen hydrolysates were prepared and characterized,and cytotoxicity and antioxidant activity were analyzed and *** free amino groups loss,browning intensity,and fluorescence intensity of G-Cbcp(glycosylated chicken bone collagen hydrolysates(peptides))were the heaviest,followed by G-Pbcp(glycosylated porcine bone collagen hydrolysates(peptides))and G-Bbcp(glycosylated bovine bone collagen hydrolysates(peptides)).The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction,which may lead to differences in Maillard glycosylated reaction ***,the 3 glycosylated hydrolysates showed no significant *** results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates,and G-Cbcp showed the strongest antioxidant activity,followed by G-Pbcp and ***,compared with the bone collagen hydrolysates,3 glycosylated hydrolysates showed significant characteristic and structural changes,and higher antioxidant activity.

关键词： Bone collagen hydrolysates Glycosylation reaction Antioxidant activity