共查询到20条相似文献,搜索用时 546 毫秒
1.
2.
天然植物单宁是指分子量为500~3000,在制革过程中能与动物生皮胶原结合的多酚化合物。植物单宁分水解和凝缩两大类。桔单宁不仅在制革方面具有商用价值,还可以作为生产没食子酸的原料。化学工业和制药工业以没食子酸作合成中间体。人们最为熟知的桔单宁是土耳其倍子单宁,这是山毛榉科染色栎(Quercus infectoria)上获得的一种病理赘瘤,可作药用单 相似文献
3.
二、五倍子单宁的水解水解是没食子酸生产的主要工序,也是决定产品收率、成本高低的关键。 1.水解的原理及其影响因素五倍子单宁由没食子酰基与β-D-葡萄糖以酯键连接而成。在酸或酶的作用下,酯键很容易断裂分解成没食子酸和葡萄糖。 相似文献
4.
5.
塔拉单宁水解废液回收奎尼酸的工艺试验 总被引:3,自引:0,他引:3
从塔拉单宁水解制备没食子酸的废液着手,用真空蒸发法分离去除盐酸,用不同的溶剂萃取法分离去除没食子酸,用活性炭吸附法和强碱阴离子交换法分离去除色素和糖类物质。从而提出了从塔拉单宁水解废液中回收目标产品奎尼酸的方法,产品得率约为理论值的78%。 相似文献
6.
7.
五倍子制备没食子酸的研究进展 总被引:3,自引:0,他引:3
没食子单宁是没食子酸与多元醇制成的酯,易在酸、碱、酶的催化作用下水解,由此可制备多种与没食子酸相关的衍生物.以五倍子为原料提取没食子酸的方法有化学法和生物法两种,与化学水解法相比,生物法最显著的特点是水解完全,水解副产物葡萄糖可作为能源与碳源被生物催化剂代谢,不仅提高了资源的有效利用率,而且发酵废液易于处理,有利于环境保护. 相似文献
8.
9.
设计了对羟基苯甲醚的合成路线,以对氨基苯甲醚为起始原料,经重氮化、水解两步合成得到了目的物。通过实验优化,得到在n(对氨基苯甲醚):n(硫酸)为1:2.0,重氮化温度为-5℃,水解温度为60℃的最佳工艺条件下,以对氨基苯甲醚计算两步总收率为71.2%,目标化合物结构经IR、MS分析确证。 相似文献
10.
响应面优化马桑皮没食子酸的酶法提取技术 总被引:1,自引:0,他引:1
采用单宁酶法从马桑皮中提取没食子酸,以单因素-响应面实验优化了提取工艺,对得到的没食子酸进行了纯化和结构鉴定,考察了纯化后没食子酸的抗氧化活性,并与传统的酸提取法相对比.结果表明,在马桑皮质量2.00 g、固液比1:40(g:mL)、单宁酶添加量为20 U/g(以马桑皮的质量为基准)、体系pH 5.0、提取温度48℃、提取时间4 h的条件下,没食子酸提取率可达10.79%±0.65%.经NKA-9大孔吸附树脂纯化后,酶法制备的没食子酸的纯度为96.0%,高于酸提取法制备的没食子酸纯度(81.5%).与酸提取法相比,酶法制备的没食子酸具有更强的抗氧化活性,在质量浓度为256 mg/L时,其对1,1-二苯基-2-三硝基苯肼自由基(DPPH?)和羟基自由基(?OH)的清除率分别为78.81%和61.99%,对Fe3+还原能力为0.427. 相似文献
11.
我国脂肪酸的生产和应用 总被引:3,自引:0,他引:3
陆蠡珠 《精细与专用化学品》2007,15(1):24-28
简要介绍脂肪酸的分类、原料来源、生产工艺、品种以及用途。并对我国脂肪酸的生产现状进行了分析。重点介绍了脂肪酸在我国橡胶工业中、塑料助剂等领域的应用,脂肪酸甲酯作为表面活性剂在不同领域的广泛应用,最后还简述了癸二酸和改性醇酸树脂应用。 相似文献
12.
酸液体系的研究现状分析和现场应用 总被引:1,自引:0,他引:1
酸化解堵与压裂改造相比,它具有施工相对简单和成本相对较低等特点,所以酸化解堵是一项各油田广泛使用的油气田增产技术。酸化解堵技术已有将近100历史,现已研制出具有不同特点的酸液体系,如乳化酸、泡沫酸、固体酸、多氢酸等,基本能满足复杂地质条件对酸液的要求。 相似文献
13.
14.
介绍了磷钼杂多酸的合成。通过正交试验探讨了反应物料量比、三氧化钼浓度、反应温度和反应时间对产物产率的影响。结果表明,最适宜的反应条件为:反应物量比n(三氧化钼)∶n(磷酸)=12∶1.0、反应温度t=70℃、反应时间7 h、三氧化钼与水的质量比1∶8。经红外光谱分析及熔点测定确定所得产品为磷钼杂多酸化合物。并以磷钼杂多酸取代硫酸作催化剂制备乙酸乙醋来研究其催化活性,并与硫酸做催化剂进行对比实验收率为70.75%,超过硫酸催化剂水平。 相似文献
15.
Claudio Guilherme Portela de Carvalho Luana Fernanda Mazzola Andressa Caldeira Flávio Carlos Dalchiavon José Marcos Gontijo Mandarino 《Journal of the American Oil Chemists' Society》2019,96(7):789-794
The objective of this work was to evaluate the quality of the oil extracted from sunflower achenes grown in Campo Novo de Parecis, the main producing region of Brazil, to optimize its use by the processing and food industries. In addition, the fatty acid profiles of the oil were checked for their adherence to the CODEX STAN 210–1999. Traditional and high-oleic genotypes were grown between 2014 and 2017 during trials with a randomized complete block experimental design with four replications. The contents of oleic, linoleic, palmitic, and stearic acids were determined using gas chromatography. The fatty acid profiles of traditional genotypes were observed to be outside the ranges established by the CODEX, with an oleic acid content above 39.4% and linoleic, palmitic, and stearic acid values lower than 48.3%, 2.7%, and 5.0%, respectively, as well as high-oleic sunflower oil with a stearic acid content of less than 2.6%. The availability of this information can, on the one hand, positively impact industries and encourage the use of better quality raw materials that are more technologically and nutritionally adequate. On the other hand, the commercialization of sunflower oil with a fatty acid profile outside the ranges established by CODEX can be difficult, because the contents are out of specification due to the climatic conditions in the cropping region. 相似文献
17.
P. Sanjeev D. P. Chaudhary P. Sreevastava S. Saha A. Rajenderan J. C. Sekhar G. K. Chikkappa 《Journal of the American Oil Chemists' Society》2014,91(6):1001-1005
Increasing utilization of specialty maize prompted us to evaluate its fatty acid profile. For this purpose maize germplasm, classified as low oil normal maize (group 1), high oil normal maize (group 2), quality protein maize (QPM) (group 3) and sweet corn (group 4) was evaluated for oil, starch, protein and fatty acid composition mainly palmitic, stearic, oleic and linoleic acid. High oil content was observed in sweet corn samples which might be result of shriveled grain texture because of an increased embryo to kernel ratio. Individual fatty acids showed wide differences among different groups. A slightly higher amount of palmitic acid was reported in specialty maize as compared to normal maize. In contrast, stearic acid content was significantly low in high oil normal maize (56 %), QPM (36.2 %) and sweet corn (28.4 %) in comparison to low oil normal maize. Although no significant differences were observed for oleic acid between low oil normal and high oil normal maize, but sweet corn samples showed significantly reduced oleic acid compared to low oil normal maize. However, the most important observation was the higher content of linoleic acid in specialty maize (groups 2, 3 and 4) as compared to low oil normal maize. Further, the ratio of MUFA/PUFA was also discussed. It was concluded that specialty maize possesses a better oil quality in comparison to low oil normal maize. 相似文献
18.
介绍了邻苯二甲酸酐-一缩二乙二醇-丙烯酸酯(简称PA—DEG—AA)的合成方法,通过正交试验分析了合成过程中反应温度、催化剂用量、原料配比、反应时间等因素的影响,并以之为单体配制了一种新型厌氧胶黏剂,测试了胶黏剂的粘结性能。 相似文献
19.
20.
采用PES纳滤膜对不锈钢酸洗废液进行回收处理,在1.6~3.8 MPa的常温生产工况下进行全样本检测和回归分析,结果表明:废混酸中游离硝酸的浓度变化对金属离子的渗透率无明显影响;废混酸中金属离子含量变化时,渗透液中的金属离子也同步呈现正比例关系。纳滤对于废混酸的金属离子拦截率为20%~30%;游离硝酸的渗透率在80%~95%之间。纳滤膜用于不锈钢酸洗废液回收处理时,由于金属离子高导致酸不平衡而外排,必须采取措施提高金属离子拦截率,否则将制约纳滤膜在不锈钢废混酸回收领域的工业化应用。 相似文献