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微波辅助索氏提取法提取欧李仁油的工艺参数优化 总被引:1,自引:0,他引:1
为探讨欧李仁油提取的最佳工艺参数,以欧李种仁为材料,粗脂肪提取率为评价指标,采用随机试验设计和L9(3^4)正交试验设计,测定了不同提取剂、浸提时间、浸提温度、料液比、辐射功率、辐射时间对欧李仁油提取率的影响。结果表明:以三氯甲烷为提取剂,微波辅助索氏提取法提取欧李仁油的最佳工艺参数为:辐射功率462 W,辐射时间3 min,提取时间7 h,提取温度80℃,料液比1∶35,欧李仁油提取率为47.37%,比常规索氏提取法提高了18.63%。 相似文献
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红花黄色素提取工艺研究 总被引:12,自引:0,他引:12
本文对红花黄色素提取条件进行了系统研究.结果表明,红花黄色素在pH值为2.0的95%乙醇溶液,以红花和提取剂为1g:10mL的比例加料,在提取温度为60℃时,浸提2h为最佳提取条件. 相似文献
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恩施碎米荠硒多糖提取条件的研究 总被引:1,自引:0,他引:1
为了探索恩施碎米荠多糖的最佳提取条件,以干制碎米荠粉末为试验材料,以双蒸水为浸提剂,在浸提温度、时间、浸取剂的用量、提取次数和pH等单因素试验的基础上,进行了四元二次通用旋转组合试验.试验结果表明,1g碎米荠干粉,浸提温度90℃、浸提时间3 h-3.5 h、浸取剂的用量30mL、提取次数4~5次和浸提液的pH值为9是多糖适宜的提取条件. 相似文献
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成熟欧李果肉中单宁提取条件的优化 总被引:3,自引:0,他引:3
以成熟欧李为试验材料,乙醇、丙酮、二甲基甲酰胺为提取剂,采用L25(5^6)正交试验设计,从溶剂浓度、固液比、浸提时间、浸提温度等因素的不同水平对欧李果肉中单宁的提取条件进行了研究,结果表明:从欧李果肉中提取单宁的最佳条件为:以丙酮作提取剂,浓度60%,浸提时间4h,浸提温度30℃,固液比1:20;以乙醇作提取剂,浓度30%,浸提时间4h,浸提温度60℃,固液比1:30。 相似文献
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银杏叶黄酮甙浸提工艺的研究 总被引:19,自引:2,他引:17
对黄酮含量偏低的银杏叶子进行浸提研究,确定浸提剂为50%~60%乙醇水溶液,液固比为8:1~6:1,浸提温度为60~70℃,浸提时间3~1h,两次。黄酮的浸提率在85%以上;选用A-1和A-2型树脂混合吸附,得到银杏叶提取物产品,黄酮含量26%~31%,得率为1.6%~1.9%。该工艺已用于中试生产,成本较低。 相似文献
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本文对怀地黄多糖(polysaccharide of Rehmannia glutinosa f.hueichingensis(Chan et Schih)Hsiao,简称为RGP)双酶法提取工艺(Extracting technology by dienzyme,简称DEET)的条件进行了研究和探讨。双酶提取法即在第一次浸提时分别加入纤维素酶和中性蛋白酶两种生物酶进行多糖的辅助提取。本实验选取提取温度、纤维素酶加量、提取液pH、固液比四个因素,以多糖含量作为指标,通过L9(3^4)正交实验确定此工艺的最佳工艺参数。结果表明:RGP双酶法提取的最佳工艺参数为:浸提温度65℃、浸提液pH5.5、纤维素酶加量7.5%、固液比为1:30;浸提液浓缩比为4:1、沉降剂乙醇添加量5倍于浸提液体积;脱蛋白采用浸提过程中中性蛋白酶脱蛋白法与浸提后Sevag脱蛋白法联合应用方法(简称“S+N”法),提取得到的RGP含量及得率可分别为60.26%和8.97%。较传统的水浸醇沉提取工艺RGP含量及得率分别提高了1.5倍和1.4倍。 相似文献
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Peter D. Hedges 《The Annals of applied biology》2019,175(3):254-258
This article outlines the life and career of H.A. (Bert) Hawkes, who has been referred to as one of the founders of field ecology, due to the work he conducted in the late 1940s and 1950s, investigating the fly nuisance emanating from biological filters. Following an overview of his life, there is a focus on his core research, carried out over a period of some 50 years, on two aspects of river pollution control—the prevention of pollution by sewage biological filtration and the monitoring of river pollution by biological surveillance. 相似文献
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离子注入加速棉花陆海杂种农艺性状遗传稳定性的研究 总被引:3,自引:0,他引:3
利用30KeV的N^+离子束注入陆地棉和海岛棉的花粉及杂交F1种子,分析了杂种后代农艺性状遗传稳定性的变化。结果表明:N^+离子辐照能显著地加速杂种后代的遗传稳定性,F4M4代性状稳定度可达90%左右。F1种子辐照后代农艺性状多偏向陆地棉,而且花粉辐照杂交后代农艺性状表现出偏母遗传。同时以^60Coγ射线效应为对照,初步探讨了N^+离主入加速遗传稳定的机制。 相似文献
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三七植物各部位的研究和开发利用 总被引:1,自引:0,他引:1
本文报道了对三七根、绒根、根茎、茎叶、花蕾,果实,果梗等的化学成分研究;皂甙提取分离方法;皂甙及黄酮类成分的生理活性及新药开发利用等的研究概况。 相似文献
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Manuela Stolte Klaus Ooening Sybille Quandt Roy G. Bengis Ingrid Bockhardt 《The Journal of eukaryotic microbiology》1998,45(1):101-104
ABSTRACT Sarcocystis dubeyella n. sp. and S. phacochoeri n. sp. from muscle fibers of the skeletal musculature of two warthogs in South Africa are described by light and and electron microscopy. Sarcocystis dubeyella sarcocysts are macroscopic (up to 12 mm long and 1 mm wide), with a parasite-induced encapsulation of the host muscle fiber in which the plasma membrane of the latter remained unaltered. The sarcocyst wall is characterized by evenly arranged, irregularly semicircular or rectangular villar protrusions (5.0 T. 2.8-11.0 μm) with indented margins and no specific content. Sarcocystis phacochoeri formed filiform microcysts (up to 4 mm long and 0.13 mm wide). Its cyst wall is provided with tightly packed, molarlike villar protrusions (1.6-3.3 T. 1.7-3.3 μm), with smooth margins, hollow on one side, and with longitudinal condensations of the fine granular matrix at various locations in the interior. 相似文献
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Mt. St. Helens is an active volcano on the western flank of the Cascade: range in the southwestern Washington State, USA. It is located at lat. 46˚00′—46˚30′N, long 121˚52′—122˚40′W.We had investigated the alpine vegetation at Pine Creek, Butte Camp on Mt. St. Helens for three times, totaling ten days during August and eptember of 1983.The volcano had erupted sending out much pyroclastic, pumice and lava, which devdstated the vegetation around the crater. They not only mechanically destroyed plants tissue, but also buried entirely or partly of the plants.The radiant heat from the volcanic eruption caused the melting of ice and snow, creating huge mudflows, which estroyed and buried vegetation. The high temperture from direct radiant heat incinerated and scorched all the plants. On the other hand, the higher the elevation is, the stronger the wind and the lower the temperture; also snow was present on the alpine range, and this provided a lee for plants, and consequently some plants survived, and new ones row out of the ground. The alpine vegetation on Mt. St. Helens bears both the characteristic of alpine plants and the brand of volcanic activities: vegetation is sparse, species composition of plants limited, structure of community simple, production low and vegetation propagation being the main type of vegetative reproduction.The different types of lpine vegetation grow in different habitats: The community of Luekea pectinata grow in places covered by ice and snow; the community of Polygonum newberryi, Eriogonum pyroleafolium in localities covered by mudflow; the community of Phyllodace empetriformis on slopes of steep rocks and the community of grasses and sedges on low hills and plains. Hese are the four main communities on Mt. St. Helens. The recovery and succession of the alpine vegetation has been discussed. There are two types of succession, the primary and the secodary, with the secondary being the main one.Finally, the paper has analysed the reason why no forest occurs, on Mt. St. Helens. We think that it is a result of the ctive period of the volcano and that the climate conditions are favouable for forest. Also, we have suggested that some herbaceous plants be sown as soon as possible for they can accelerate the recovery of vegetation, and prevent the runoff of soil and water. 相似文献
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黄土丘陵区柠条林地养分状况及其循环规律 总被引:16,自引:1,他引:15
黄土丘陵区柠条林地养分状况及其循环规律刘增文李雅素(西北林学院,陕西省杨陵712100)FertilityandElementsBio-CyclingsoftheCaraganaMicrophylaL.ForestlandintheRolingLoe... 相似文献
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We have previously characterized the activities, in vitro, of two different helper T-cell subpopulations, primed with human γ-globulin (HGG). One T-cell subpopulation helps the response of B cells to determinants (e.g., haptens) bound to the same antigen to which the T cells are primed (specific help); the other helper T-cell subpopulation responds to the same priming antigen by secreting a nonspecific molecule which helps B-cell responses to erythrocyte antigens co-cultured with the priming antigen (nonspecific help). These subpopulations also differ in their frequency and dose response to antigen, both in vivo and in vitro. They are similarly susceptible to the induction of unresponsiveness to HGG. In order to determine whether these T-cell subpopulations share or differ in their ranges of antigen recognition, we have compared the reaction of these two HGG-primed helper T-cell subpopulations to a number of γ-globulins (γG's) from other species. Plaque-forming cells generated in response to HGG shared little or no cross-reactivity with any of the heterologous (γG's) tested. In contrast, HGG-primed nonspecific helper T cells responded with significant cross-reactivity when challenged in vitro with dog γG, but HGG-primed specific helper T cells did not respond with any such cross-reactivity. No other heterologous γG tested stimulated any significant cross-reactivity from either HGG-primed T-cell subpopulation. Thus, these two T-cell subpopulations differ in their antigenic recognition. Possible explanations of these data include: (i) a difference in receptor specificity; (ii) a difference in the receptor affinity; (iii) a difference in Ia determinants of the two subpopulations. 相似文献
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Deoxyribokinase, which catalyzes the ATP-dependent phosphorylation of 2-deoxy-d-ribose to 2-deoxy-d-ribose-5-P as the first step in the inducible fermentation pathway for this sugar in Salmonella typhimurium, was purified approximately 600-fold from deoxyribose-grown cells. Apparent Km′s for 2-deoxy-d-ribose and ATP were 0.1 and 0.5 mm, respectively. The enzyme had an absolute requirement for divalent cations which was best satisfied by Mg2+. Optimal activity was obtained in the presence of 0.5 m NH4+ or Cs+. Rb+ and K+ also stimulated enzyme activity whereas Na+ and Li+ inhibited. d-Ribose and 2-deoxy-d-ribitol could replace 2-deoxy-d-ribose as phosphoryl acceptor, and several ribo- and deoxyribonucleotides could replace ATP as phosphoryl donor. Molecular weight determinations gave values of 67,800 for the native enzyme and 33,500 for the dissociated enzyme, suggesting the probable existence of two subunits of similar size. 相似文献
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Association rates are calculated for cases where one reaction partner belongs to a chain that has an unspecific affinity to the other. Provided that the unspecific attachment does not completely suppress diffusion along the chain, this channeling may considerably speed up the association. Explicit formulae are derived to show how this effect depends on the chain length and other parameters. The influence of electrostatic forces and reaction barriers is discussed. Time dependent solutions of the diffusion equations are analyzed in order to test the usual steady state assumptions. Experiments on the repressor-operator system seem to be in good agreement with our theory. 相似文献
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目的:对人参(Panax ginseng C.A.Mey.)花蕾的化学成分进行研究。方法:采用多种柱色谱技术进行分离纯化,并通过波谱分析方法鉴定化合物的结构。结果:分离鉴定了9个化合物,分别鉴定为咖啡碱(1)、胡萝卜苷(2)、豆甾醇3-O-葡萄糖苷(3)、α-菠甾醇(4)、7-豆甾烯-3β-醇(5)、人参皂苷Rk3(6)、人参皂苷Re(7)、人参皂苷Rg2(8)、谷甾醇(9)结论:其中化合物1为五加科植物中首次分离得到,化合物3、4、5为人参花中首次分离得到。 相似文献