共查询到17条相似文献,搜索用时 196 毫秒
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单宁酶全称是单宁酯酰水解酶(Tannase,EC3.1.1.20),它可以水解没食子酸单宁中的酯键和缩酚羧键,生成没食子酸和葡萄糖.主要来源于微生物,存在于细胞内和细胞外,目前研究得较多较为深入的是青霉和黑曲霉.本实验对五倍子生料固体发酵产单宁酶进行了研究,发酵条件的单因素优化后得到:初始水分含量80%,接种量1%,20%五倍子,温度30℃为最佳产酶条件.在此基础上,利用正交实验对显著影响产单宁酶的培养基及培养条件因素进行优化,得到固体发酵黑曲霉诱变菌株最佳产单宁酶条件为:湿度80%、接种量1%、发酵温度33℃、五倍子含量15%.其中温度对黑曲霉产单宁酶酶活性的影响是显著的,并测得在此最佳发酵条件下产单宁酶活性达57.32U/gds. 相似文献
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没食子酸及其衍生物是一种重要的抗氧化剂,可以用作食品添加剂,也可作为化工原料,用于医药工业、饲料工业、化妆品等工业.没食子酸的传统生产方法是酸水解法和碱水解法,而近年来,微生物发酵法和酶转化法研究正在兴起.黑曲霉B0201直接生料固体发酵五倍子原料,未能检测到没食子酸产物.如果先采用生料固体发酵生产单宁酶,然后再用酶法制备没食子酸却是可行的.研究结果表明,分步制备没食子酸反应4h,0.5L反应液中积累了3.83g的没食子酸.没食子酸的制备过程为:生料发酵生产单宁酶--单宁酶的提取--酶法制备没食子酸,初步构建了一种微生物酶分步制备没食子酸的工艺. 相似文献
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单宁酶全称单宁酯酰水解酶(Tannase,EC 3.11.20),能水解水解性单宁酸和没食子酸酯类中的酯键和缩酚羧键,生成没食子酸和葡萄糖。本实验从青柿、未完全成熟的香蕉、茶叶、茶园土壤等富含单宁酸的环境中取样,采用富集培养技术分离筛选出69株产单宁酶的菌株,并对其菌株的外在特性和产酶活力进行了研究和测定,最终获得一株产单宁酶活力较高的酵母菌株FC6-1。在未进行发酵条件优化前,该菌株所产单宁酶酶活达到2.86U/mL。采用薄层色谱法和SBA-40D生物传感分析仪等方法对该酶酶解产物分析,结果表明该菌株产生的单宁酶能够有效的水解单宁酸生成没食子酸和葡萄糖。 相似文献
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响应面法优化黑曲霉产单宁酶的固体发酵条件 总被引:1,自引:1,他引:0
通过固体发酵培养基单因素研究,确定了三个影响单宁酶产率的关键因素,对氮源用量、五倍子用量、培养温度采用响应面法的中心旋转实验设计原理,进行三因素三水平的响应面分析,以获得最佳产单宁酶的培养基及培养条件组成。结果表明,固体发酵黑曲霉最佳产酶条件为:五倍子含量为9%;氮源添加量为2.3%;温度为32℃。在此条件下进行发酵产酶重复实验,酶活力为219.4U/mL。 相似文献
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《食品科技》2020,(7)
单宁酸是一种较强的蛋白质沉淀剂。在酶法制备没食子酸的过程中,高浓度单宁酸会严重抑制单宁酶活性,因此很难直接利用单宁酸进行没食子酸的工业生产。为了解除单宁酸对单宁酶的抑制作用,研究建立了五倍子单宁酸同步提取-酶解工艺,反应90 min,同步提取-酶解工艺没食子酸浓度达到13.9 g/L,没食子酸生产效率明显高于同步提取-酸解工艺和五倍子单宁酸先提取后酶解工艺。对五倍子单宁酸同步提取-酶解工艺进行优化,结果表明在料液比1:50、加酶量32 U/mL、pH6~7、温度50 ℃和提取时间75 min时,没食子酸产量和得率最大,分别达到15.4 g/L和76.8%。在最优条件下进行多次投料试验,没食子酸最终产量可提高至34.0 g/L。 相似文献
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Gloria Fernandez-Lorente Juan Manuel Bolivar Javier Rocha-Martin Jose A. Curiel Rosario Muñoz Blanca de las Rivas Alfonso V. Carrascosa Jose M. Guisan 《Food chemistry》2011
Immobilised derivatives of tannase from Lactobacillus plantarum were able to catalyse the transesterification of tannic acid by using moderate concentrations of 1-propanol in aqueous media. Transesterification of tannic acid was very similar to transesterification of methyl gallate. The synthetic yield depended on the pH and concentration of 1-propanol, although it did not vary much when using 30% or 50% 1-propanol. Synthetic yields of 45% were obtained with 30% of 1-propanol at pH 5.0. The product was chromatographically pure, and the reaction by-product was 55% pure gallic acid. On the other hand, immobilised tannase was fairly stable under optimal reaction conditions. 相似文献
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研究酸解法制备五倍子抗腐败希瓦氏菌活性物质的工艺。采用单因素试验、Box-Behnken试验设计和响应面法对酸解法制备五倍子抗腐败希瓦氏菌活性物质的工艺进行优化,优化的酸解工艺为:盐酸浓度4 mol/L、液料比45 mL/g、温度100℃时提取5 h。在最佳酸解工艺下进行验证试验,五倍子提取液的实际抗菌活性为(23.68±0.68)mm,与预测值(22.63 mm)没有显著差异。研究结果表明响应面法应用于优化酸解法制备五倍子抗腐败希瓦氏菌活性物质的工艺是可行的,为进一步鉴定和开发五倍子抗菌活性物质提供了依据。 相似文献
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Changes in polyphenol and polysaccharide content of grape seed extract and grape pomace after enzymatic treatment 总被引:1,自引:0,他引:1
Grape seed extract and grape pomace are rich sources of polyphenols. The aim of this study was to evaluate the release of polyphenols, the solubilisation of carbohydrate, and the antioxidant capacity of these grape by-products after enzymatic reaction with carbohydrases (cellulolytic and pectinolytic activities) and tannase for 24 h. The use of tannase in these by-products, and pectinase in grape pomace changed the galloylated form of catechin to its free form, releasing gallic acid and increasing the antioxidant activity. In grape pomace, cellulase treatment was not efficient for phenolic release and antioxidant activity improvement. The addition of carbohydrases to grape pomace, either alone or in combination, degraded the cell wall polysaccharides, increasing the content of monosaccharides. These results provide relevant data about the potential of pectinase, tannase and combinations of enzymes on the release of polyphenols and monosaccharides from grape by-products, improving the antioxidant capacity and the nutritional value. 相似文献
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The study of the effect of the enzymes tannase, α-galactosidase, phytase and viscozyme on the phenolic composition of lentil flours, in a semi pilot scale stirred fermentor, shows that important modifications occur. Among them, hydroxycinnamic compounds and proanthocyanidins are significantly decreased after the enzymatic treatments. However, quercetin 3-O rutinoside and luteolin increase and reach the highest concentration with tannase. The formation of trans-resveratrol was observed by the action of tannase and phytase, and gallic acid by the action of phytase, α-galactosidase and tannase. The antioxidant capacity of the methanolic extracts was determined by their free radical scavenging activity, using the DPPH test, to study the differences in the behaviour of polyphenolics compounds as antioxidants after the different enzymatic treatments. The treatments with viscozyme, α-galactosidase or tannase produce an increase in the antioxidant activity when compared to raw lentils. The results of the analysis of principal components to examine the relationship among antioxidant activity (EC50) (DPPH test) and the concentrations of polyphenolics in all lentils samples, show that the quercetin 3-O rutinoside appears to be the compound with the greatest influence on the EC50 values. 相似文献
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Epigallocatechin (EGC) and gallic acid (GA) were prepared by the degalloylation of an epigallocatechin gallate (EGCG) extract from green tea. EGCG was entirely hydrolyzed using a tannase (from Paecilomyces variotii) at pH 6.0, incubating at 40 °C for 30 min. The antiradical properties and the reducing power of these samples were assessed using the DPPH and FRAP assays, respectively. This work established a relationship between the antioxidant effects of epigallocatechin gallate and the enzymatic reaction products (epigalocatechin and gallic acid). The enzymatic reaction products showed higher scavenging activity and antioxidant capacity when compared to epigallocatechin gallate. 相似文献