茶皂素提取工艺的优化

茶皂素是从山茶科植物种子或叶中提取出来的纯天然非离子表面活性荆。茶籽饼中含有10%~15%的茶皂素,从茶籽饼中提出茶皂素,对综合利用油茶资源,提高油茶果的经济价值,开发新产品,具有十分重要的社会效益和经济价值。本文以广东产的茶籽榨油后茶粕废料为原料提取茶皂素,工艺条件为:浸提温度75℃,pH=10.0,无水乙醇,料液比1︰12,在此条件下浸提3 h,纯化后茶皂素收率为9.3%。     

油茶副产物在绿色表面活性剂中的 利用与研究进展

用天然的可再生资源生产可降解的绿色表面活性剂是环境和社会发展的需要。而在我国,生产茶油后的副产物油茶籽粕的产量非常大,且其中含量较多的茶皂素和残留的油酸,均可开发成表面活性剂。本文简介了油茶副产物中茶皂素和油酸的利用与研究及其在表面活性剂领域的利用和研究情况,以期促进油茶副产物的加工利用,并对绿色表面活性剂的发展作了展望。     

茶粕(茶麸或茶籽)资源化现状及发展

我国是油茶品种最丰富、生产量最多的国家。油茶是我国一种重要的油料作物,茶粕是油茶籽提油后的副产品,是一种使用价值、营养价值和经济价值比较高的工业副产品。文章提出了茶粕可生产茶皂素、茶籽多糖,茶蛋白等高附加值产品,具有广阔的综合开发前景,概述了其产品的特性、加工工艺及主要应用途径,并结合市场现状对茶粕的开发应用提出期望。     

从油茶果渣、籽仁和脚料中提取茶皂素及回收脂肪酸的研究

对油茶果的深度开发作了较为详尽的研究：在尽可能提高茶油产率的同时，对榨取茶油以后的粕饼或渣，籽仁以及精制茶油后的脚料等物进行再提取或回收，从中又可得到能增值的精细化学的绿色产品——茶皂素和脂肪酸。     

一种天然非离子表面活性剂茶皂素的制备与应用

茶皂素是一种从山茶科植物中发现的天然非离子性表面活性剂,大部分茶皂素是从油茶饼中提取的,采用水提或者超声辅助乙醇结合丙酮沉淀法来进行茶皂素的工业化的提取和纯化。茶皂素不仅能解吸污染土壤中的重金属,还能在彩妆方面、医药行业有很大的应用     

茶皂素提取和纯化工艺研究

以贵州省优势资源油茶利用后产生的油茶籽和废弃茶籽饼为主要原料,从中提取表面活性剂茶皂素,介绍了目前茶皂素的提取和纯化工艺,并进行了一定对比,以对生产实践进行指导。     

超声波—乙醇法提取油茶饼粕中茶皂素的工艺研究

以油茶饼粕为材料,通过单因素实验寻找提取茶皂素的最优工艺条件,研究浸提温度,浸提时间,料液比,乙醇浓度,超声波功率,超声时间,pH等因素对油茶饼粕中茶皂素提取的影响,再利用正交试验法进行工艺的优化,通过正交实验表明:以85%的乙醇为溶剂,浸提取温度80℃,料液比1:20(g:mL),浸提取时间为60 min,超声波功率100 W,超声时间25 min,pH 7.2的工艺条件下,油茶饼粕中茶皂素的提取率可达到7.92%。     

油茶果壳中茶皂素提取工艺研究

本论文研究了水酶法提取油茶壳中茶皂素的工艺参数,通过单因素试验考察酶添加量、料液比、提取时间、温度等因素对水酶法提取茶皂素的影响规律;然后,筛选三个显著性影响因素酶添加量、温度、浸提时间,根据中心组合试验(Box-Behnken)设计原理,以茶皂素提取率为响应值,优化茶皂素最佳提取工艺参数料液比1︰20,酶添加量2mg,温度60℃,浸提时间90min,在此条件下得到茶皂素的提取率为1.40%。     

超声波辅助乙醇法提取茶皂素工艺优化

以脱脂后的茶籽饼粕为原料,采用超声波辅助乙醇法提取茶皂素,并用香草醛-浓硫酸显色法测定茶皂素提取率。以茶皂素提取率为考核指标,通过单因素实验和正交实验确定最佳的提取工艺条件为:乙醇体积分数80%、超声波功率400 W、超声波作用时间40min、温度50℃、液料比8∶1(mL∶g),在此条件下,茶皂素提取率达到13.27%。     

乙醇-氨水浸提法提取油茶饼粕中茶皂素的工艺研究

研究乙醇-氨水浸提法从油茶饼粕中提取茶皂素的提取工艺。以乙醇为提取剂,分别考察提取次数、氨水量、乙醇浓度、料液比、提取温度、提取时间对茶皂素得率的影响,再经正交试验L16(45)得到茶皂素最佳提取工艺为:提取温度78℃,脱脂茶枯质量与溶剂体积的比值(料液比)为1∶10(g/mL),提取时间55 m in,乙醇水溶液的体积分数为70%,氨水的体积分数为0.1%,其茶皂素得率达到22.41%。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.