共查询到18条相似文献,搜索用时 109 毫秒
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本文采用丙酮法提取了海南黄帝椒中的多酚氧化酶(PPO),并对其酶学特性进行了研究。海南黄帝椒PPO的米氏常数K m为117.38mmol/L,最大反应速率V max为416.67U/min,最适温度为40℃,最适pH为6.0。不同抑制剂对PPO活力的影响表明,较低浓度的柠檬酸、L-抗坏血酸、半胱氨酸盐酸盐对黄帝椒PPO活力具有一定的的抑制作用,而EDTA抑制效果较差;在单因素实验的基础上,通过正交实验设计对黄帝椒酶促褐变的抑制剂配方进行了优化,结果表明当添加L-抗坏血酸0.35%、半胱氨酸盐酸盐0.02%和柠檬酸0.2%时,黄帝椒的褐变度最小。此研究结果为海南黄帝椒产品的深度开发提供了基础。 相似文献
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从造纸厂采集的土样中,经过富集、初筛和多轮复筛实验,分离得到了5株降解天然树脂能力较强的微生物.采用液体发酵以及稳定性复筛的方法,从这5株微生物中筛选得到了降解天然树脂能力稳定并且降解率较高的菌株Z75、Z37.分别对这2株菌株进行形态学观察,培养24 h后的菌落直径均大于1 mm,菌株Z75菌体长度小于5 μm,初步判断Z75菌株为短杆菌;菌株Z37菌体长度小于0.1μm,初步判断Z37为细球菌.对Z75菌株的降解条件进行研究,结果显示,在35 mL的Z75菌株发酵液中,最适降解反应的树脂底物颗粒(球形)质量为0.2 g,最适降解反应时间≥20 h;发酵条件和培养基初步优化的结果显示,Z75菌株发醉液降解天然树脂的降解率由优化前的6.5%左右提高到43.3%. 相似文献
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传统发酵食品-浆水中微生物的分离与初步鉴定 总被引:4,自引:0,他引:4
通过对浆水中的微生物进行分离培养及数量测定,查明了浆水中的优势菌为乳酸菌及酵母菌,其次尚有少量放线菌,霉菌为污染菌。从不同样品中分离得到了2株乳酸菌、3株酵母菌,1株放线菌及2株霉菌,通过对其形态、培养特征及生物学特性的研究,初步鉴定2株乳酸菌分属于乳杆菌属(Lactobacillus)和明串珠菌属(Leaconostoc);3株酵母菌分属于酒香酵母属(Brettanomyces)、隐球酵母属(Cryptococcus)及裂殖酵母属(Schizosaccharomyces);放线菌属于诺卡氏菌属(Nocardia);2株霉菌分属于青霉属(Penicillium)和曲霉属(Aspergillus)。 相似文献
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Ausaid Garra Sharon Alkalai-Tuvia Alona Telerman Ilan Paran Elazar Fallik Anat Elmann 《International Journal of Food Science & Technology》2020,55(12):3574-3584
Peppers are rich in health-promoting phytochemicals, which are involved in the defence mechanisms against cancer. To select a lead variety of pepper with anti-proliferative activity against colon cancer cells and liver cancer cells, high antioxidant activity, and high concentrations of capsaicin, flavonoids and phenolics, we compared these attributes in nine different pepper accessions belonging to Capsicum annuum and C. chinense. Quality parameters such as weight loss and total soluble solids content were tested as well. The different parameters were determined immediately after harvest and after prolonged storage and marketing simulation. A significant variation of these traits was detected among the accessions. C. chinense line 1745 had the highest antioxidant activity, the highest levels of capsaicin and flavonoids, a high and specific anti-cancer activity, and the lowest weight loss level during postharvest storage. It is proposed that line 1745 has potential for use as a source for health-promoting traits and should be further evaluated for use as a nutraceutical for the prevention and treatment of colon and liver cancers. 相似文献
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啤酒生产中腐败微生物鉴定新技术 总被引:1,自引:3,他引:1
啤酒生产过程中的污染微生物主要有野生酵母,细菌,放线菌和霉菌四大类。新的快速检测技术有聚合酶链式反应(PCR)技术,伏安型生物传感器,自动微生物检测系统(AMS),改良MRS培养基和三磷酸腺苷(ATP)法等,较传统方法迅速,准确。 相似文献
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L. Asnin 《Critical reviews in food science and nutrition》2015,55(2):254-289
An overview of the state of the art in the extraction, isolation, and analytical determination of bioactive compounds in peppers of the genus Capsicum is presented. The review is structured by classes of phytochemicals. Both major and minor constituents of peppers are considered. Modern trends in analytical chemistry of nutrients in regard to pepper analysis with particular focus on chromatographic and related methods are discussed. Attention was paid to controversial questions of pepper analysis, including but not limited to problems of sample degradation and the completeness of extraction of target analytes. The rationale for choosing an optimal strategy of analysis is given. 相似文献
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对一株能粗降解铬革屑菌株的发酵条件进行优化,通过Folin试剂法测定了不同发酵条件下发酵液的蛋白酶活性,确定了菌株W_(1-1)的最适产酶条件。研究表明:菌株的最适产酶条件为葡萄糖9.0%,酵母膏0.5%,CaCl_20.3%,K_2HPO_40.3%,MgSO_4 0.2%,初始pH 8.5,装液量90mL(90/250mL三角瓶),接种量4.0%,种龄14h,发酵温度37℃,发酵时间36h。在此条件下,测得发酵液的蛋白酶活力为37.36u/mL,比优化前的产酶量提高了35.4%;最后,采用该菌株在最适产酶条件下对铬革屑进行降解,降解率达到71.38%。 相似文献