南五味子乙醇提取物对食品腐败细菌的抑菌活性研究

目的:研究南五味子乙醇提取物的体外抑菌活性,以期为寻求新的天然食品防腐剂提供实验依据。方法:以抑菌圈直径、最低有效抑菌浓度等为指标,以金黄色葡萄球菌、乙型副伤寒沙门氏菌等7种食品腐败细菌作为供试菌,研究南五味子乙醇提取物的体外抗菌活性。结果:南五味子乙醇提取物对供试菌的抑菌圈直径均>20mm,且对革兰氏阳性细菌的抑制效果强于革兰氏阴性细菌。乙醇提取物对供试菌的MIC值和MBC值分别为金黄色葡萄球菌3.125,6.25mg/mL,蜡样芽孢杆菌1.562,3.125mg/mL,大肠杆菌25,25mg/mL,变形杆菌12.5,25mg/mL,枯草芽孢杆菌、乙型副伤寒沙门氏菌、宋内氏志贺氏菌、铜绿假单胞菌的MIC值和MBC值均为12.5mg/mL。提取物对供试菌的抑菌率随抑菌作用时间的延长,提取物浓度的增加而升高。提取物对蜡样芽孢杆菌抑菌能力大于苯甲酸钠和山梨酸钾;对金黄色葡萄球菌的抑菌能力与苯甲酸钠相同,稍差于山梨酸钾。结论:南五味子乙醇提取物对食品腐败细菌具有显著的抑菌活性,有望开发成天然食品防腐剂。     

OBTAINING SCARLET SAGE (SALVIA COCCINEA) EXTRACT THROUGH HOMOGENIZER- AND ULTRASOUND-ASSISTED EXTRACTION METHODS

Scarlet sage (Salvia coccinea) leaves were extracted with water, ethanol, methanol, and aqueous mixtures of those solvents by homogenizer-assisted extraction (HAE) and ultrasound-assisted extraction (UAE) methods, which are novel technologies used for this purpose. The best results were compared with those obtained by the conventional Soxhlet method (SM). Total phenolic content was expressed in gallic acid equivalent (GAE) per g of dried leaf. Free radical scavenging activity for the antioxidant capacity was tested by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical. The greatest amount of extraction was achieved by pure water with the value of 368.87 mg/g dried matter and the highest total phenolic content was observed by 100% methanol as 43.18 mg-GAE/g dried matter, both obtained by the HAE method. The mint leaves extracted by SM exhibited the highest antioxidant capacity, with a value of 90.55% for inhibition of DPPH radical.     

基于广泛靶向代谢组学分析黑老虎种子中氨基酸和脂质组分

为探究黑老虎种子作为新兴植物油料资源的潜力,利用广泛靶向代谢组学技术检测分析其氨基酸和脂质组分。结果表明：在基于鉴定出的代谢物结构配置分类下,黑老虎种子含脂质类、氨基酸及衍生物类化合物分别为121种和89种,前者数量和相对含量(30.7%)在11类成分中最高,后者数量居其次,相对含量(17.8%)位于第三;鉴定出20种基础氨基酸和8种人体必需氨基酸,其中L-脯氨酸、L-天冬氨酸、L-丝氨酸等7种药效氨基酸和L-亮氨酸、L-苏氨酸、L-异亮氨酸、L-苯丙氨酸和L-赖氨酸5种人体必需氨基酸含量较高;黑老虎种子中富含亚油酸、γ-亚麻酸、α-亚麻酸等脂肪酸和以溶血磷脂酰胆碱18∶2和18∶2(2n异构)为主的磷脂。黑老虎种子氨基酸类和脂质类组分丰富,多种高度富集成分具有突出的营养功能、活性作用和药用功效,在优质植物油脂开发等领域具有较高的价值。     

南五味子提取物对食品常见致病菌抑制作用的研究

探讨南五味子提取物对食品常见致病菌的抑制作用。采用乙醚、70%乙醇和水3种提取剂对南五味子进行提取,以大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)和乙型副伤寒沙门氏菌(Salmonella paratyphi B)为供试菌种,通过琼脂平板扩散法测定抑菌圈;琼脂平板二倍稀释法测定最低抑菌浓度(MIC,g/mL)。3种提取物的抑菌效果大小为:70%乙醇提取物>水提取物>乙醚提取物。70%乙醇提取物抑菌效果最好,对大肠杆菌、金黄色葡萄球菌和沙门氏菌的抑菌圈分别达到26.4,25.2,23.3 mm,MIC分别为0.0125,0.0125,0.025 g/mL。南五味子提取物对食品常见致病菌的抑制作用显著,可开发成安全有效的天然食品防腐剂。     

冷饭团化学成分及其活性研究进展

对国内外冷饭团化学成分及其生物活性研究现状作了综述。冷饭团主要含有木脂素类成分,这类化学成分具有保护肝脏、抗氧化、抗HIV病毒、拮抗血小板活化因子等活性,并对后续的研究方向进行了展望。     

南五味子乙醇提取物对鸡蛋中腐败菌的抑制作用研究

由腐败的鸡蛋中培养,分离,鉴定出金黄色葡萄球菌、大肠杆菌、沙门氏菌和变形杆菌,并用南五味子乙醇提取物对其进行体外抑菌试验。试验结果表明,在pH6条件下,南五味子70%乙醇提取物对鸡蛋中分离出的4种腐败菌的最小抑菌质量浓度(MIC)分别为3.125、25、12.5和12.5mg/mL。该提取物具有良好的抑制作用,为鸡蛋防腐保鲜提供相关研究依据。     

Antioxidant activity of polyphenol and anthocyanin extracts from fruits of Kadsura coccinea (Lem.) A.C. Smith

Polyphenols and anthocyanins were extracted from Kadsura coccinea fruit. The contents of total phenolics and anthocyanins, influences of pH and temperature on anthocyanins, and antioxidant activities of extracts were further analyzed. The results showed that the total phenolic content of peel extracts was superior to that of pulp extracts. The total anthocyanin content of peel extracts was 180 ± 2.91 mg/100 g of fresh peel tissues. K. coccinea anthocyanins were stable below pH 4, whilst high temperature and extended heating time induced their degradation. Metal-chelating capacity (MCC) assay indicated that no ortho-dihydroxy aromatic moiety existed in the B-ring of the anthocyanin molecules, but there might be a catechol group in the B-ring of the polyphenol molecules. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and reducing power of extracts decreased in the following order: peel polyphenol extracts > anthocyanin extracts > pulp polyphenol extracts. It would be worthwhile to introduce this rare fruit into more countries.     

南药五味子提取物清除自由基活性的研究

以南药五味子为原料,应用DPPH法、结晶紫法、邻苯三酚自氧化法,分别测定以蒸馏水和70%乙醇为溶剂的五味子提取物清除1,1-二苯基-2-苦苯肼自由基(DPPH·)、羟自由基(·OH)、超氧阴离子(O2-·)的能力,及其对脂质过氧化反应的抑制能力。结果表明,在试验条件下,五味子乙醇提取物对DPPH·、·OH、O2-·、脂质过氧化体系清除活性分别为93.83%,32.26%,18.22%,66.72%;蒸馏水提取物的清除率分别为86.16%,63.17%,13.37%,54.62%。可知,五味子的70%乙醇和水提取物具有较好的清除自由基能力,两者相比较,70%乙醇提取物清除的自由基的能力强于水提取物。     

不同1-MCP对布福娜保鲜效果的影响

目的通过探究不同的1-甲基环丙烯(1-Methylcyclopropene,1-MCP)处理对布福娜保鲜效果的影响。方法以布福娜为实验材料,分别采用不同含量(0,0.5,1.0,1.5μL/L)的1-MCP处理布福娜,4组果实均置于(4±1)℃低温下贮藏,在贮藏期间每10 d测定1次布福娜果实的生理指标。结果不同的1-MCP处理均能有效抑制布福娜贮藏期的果实呼吸强度,不仅可以延缓质量损失率、腐烂率、相对电导率、pH值和丙二醛的增加速度,还可以抑制含水率,以及还原糖、可溶性固形物、可滴定酸和Vc等含量的降低。其中,1.0μL/L的1-MCP处理效果要优于0.5,1.5μL/L处理。结论 1-MCP处理布福娜果实的保鲜效果良好,有利于延长布福娜果实的贮藏期,保持较好的果实品质,以1.0μL/L的1-MCP处理效果最佳,可用于布福娜采后保鲜。     

Differential metabolome landscape of <i>Kadsura coccinea</i> fruit tissues and potential valorization of the peel and seed tissues

Kadsura coccinea (Lem.) is a woody wine plant with a peculiar fruit enriched in important health-promoting compounds. The non-editable part of the fruit, i.e., the seed and peel, represents more than 60% of the fruit and is considered a biowaste. This significantly restricts the development of the K. coccinea fruit industry. Clarifying the metabolic components of the different fruit parts can help to improve the utilization rate and valorization of K. coccinea. Herein, we evaluated K. coccinea fruit peel, pulp, and seed using widely-targeted metabolomics and quantified a set of 736 bioactive compounds from 11 major metabolite classes. The most prominent metabolite classes included lipids, amino acids, flavonoids, and lignans. Furthermore, our results emphasized a significant accumulation of flavonoids in pulp tissues, while alkaloids and lignans were abundant in peel and seed tissues, respectively. A total of 183 metabolites were differentially accumulated among the three tissues. Procyanidin C2, rutinoside, 2-hydroxyoleanolic acid, 5-hydroxymethyluracil, nootkatol, isoquercitrin, isohyperoside, quercetin-7-O-glucoside, hyperin, and rutin showed elevated accumulation in the peel. In the seed, kadsuralignan G, kadcoccilactone A, kadsuralignan H, lysoPE 20:5, iso-schisandrin ethyl alcohol, and kadangustin were significantly enriched. Our results highlight the diverse metabolome composition of K. coccinea fruit parts, which can be further exploited for its valorization in various industries.