热碱法脱除游离棉酚的实验研究

介绍了用热碱法对棉籽粕进行脱酚的工艺原理,并对棉籽粕进行了脱酚实验研究。通过正交试验,热碱法脱酚的最适合条件为pH值8～9,温度60℃,时间3h,最终棉籽蛋白液棉酚含量为12×10-6,完全低于联合国咨询委员会规定的食用棉籽蛋白质中游离棉酚含量≤0.06%标准。     

饱和甲醇的己烷溶液浸出棉仁提油脱酚的模拟

为简化双液相溶剂浸出棉仁的流程,探讨了应用饱和甲醇的己烷溶液一步脱除棉仁中棉油和棉酚的可行性,并用串级试验进行了验证。结果表明此设想是可行的。在浸出温度 50℃、4级浸取、溶剂与棉仁比值 8. 7L/kg的条件下,棉粕中残油质量分数低于 1. 3%,游离棉酚和结合棉酚含量可分别低于 450mg/kg和4 000mg/kg,达到了饲料标准。     

甘氨酸在丙酮-水混合溶剂中溶解度的测定与关联

采用平衡法测定了278.15~313.15 K甘氨酸在纯水及丙酮-水混合溶剂中的溶解度;采用Apelbla t经验方程和(CNIBS)/Redlich-Kister方程分别对甘氨酸在纯水和丙酮-水体系中的溶解度数据进行了关联,并对(CNIBS)/Redlich-Kister方程进行了温度影响分析。结果表明,甘氨酸在纯水中的溶解度随着温度的升高而增大;甘氨酸在丙酮-水混合溶剂中的溶解度随着丙酮与水的质量比的增加而变小;当丙酮与水的质量比达到实验中最大值即4时,甘氨酸的溶解度接近于0;在相同丙酮与水的质量比下,甘氨酸的溶解度随着温度升高而有所增大。甘氨酸在纯水及丙酮-水混合溶剂中的溶解度模型关联的标准方差均能达到1×10-4,精度满足工程需要。实验数据及相应模型为甘氨酸结晶过程分析和设计提供了重要依据。     

LiBr在丙酮与水的混合溶剂中溶解度的测定与关联

使用静态法常压下分别测定了LiBr在不同质量百分比的丙酮与水的混合溶剂(水的质量分数为10％ ～40％)中293.15 ～323.15 K范围内的溶解度,并利用LIFAC模型及其参数推算了活度系数及溶解度,计算值与试验值的总平均绝对偏差和总平均相对偏差百分比分别是0.054 0和0.731 3％.结果表明,LIFAC模型可以用来预测LiBr在丙酮与水的混合溶剂中的溶解度.     

六氟丙酮与苯酚和苯胺的反应

介绍了六氟丙酮与苯酚、甲基酚和苯胺的反应机理、过程和结果.     

己烷雌酚纯度标准物质的研究

通过高纯原料制备、定性分析、定值分析、杂质分析、均匀性检验、稳定性考察和不确定度评定,研制了己烷雌酚纯度标准物质。为保证纯度测量的准确性,采用多家联合定值(HPLC法)对己烷雌酚的纯度进行检验。该标准物质定值结果为99.7%,扩展不确定度为0.6%。     

2甲-基吡啶在丙酮-水混合溶剂中的电氧化

在质子交换膜为隔膜的电解槽内,以2甲-基吡啶为原料,在丙酮/水混合溶剂中,以PbO2为阳极,电氧化合成了2-吡啶甲酸。通过循环伏安、线性扫描伏安和恒电位电解实验,考察了丙酮与水体积比、反应温度、硫酸浓度、反应物2-甲基吡啶浓度和阳极电位对选择性和电流效率的影响。结果表明,V(丙酮)∶V(水)=3∶1,硫酸浓度1.0~1.2 mol/L,2甲-基吡啶浓度0.5 mol/L,温度30℃,阳极电位1.75~1.80 V,生成2吡-啶甲酸的选择性可达88.7%,电流效率达到48.3%。而在纯水作溶剂的溶液中,相同条件下生成2-吡啶甲酸的选择性和电流效率仅分别为67.4%和42.2%。     

利用微波提取新型灭鼠剂-棉酚的研究

主要介绍微波辐射技术在提取新型灭鼠剂-非甾体高效抗生育药物棉酚方面的应用。采用正交实验法对影响收率的萃取时间、微波功率及不同萃取液等诸因素进行了讨论,确定了微波萃取的最佳条件。结果显示微波可明显加速萃取的速度,所用时间仅为索氏提取法的4％。     

仰角式游离水脱除器的应力分析及其应用程序

仰角式游离水脱除器作为一种新型高效的油水分离器,是针对高含水采出液而提出的.本研究采用有限元软件ANSYS对仰角式游离水脱除器进行了数值模拟研究.通过改变游离水脱除器的结构参数对游离水脱除器的应力分布及位移变化进行了有限元分析,全面搭配试验及回归分析,确定了挠度、支座反力、当量应力、等效应力和最大轴向拉应力与仰角角度、...     

超急速温升条件下水-丙酮沸腾研究

利用短脉冲激光加热浸没在水 丙酮非共沸工质中的铂薄膜电阻的方法 ,对不同体积配比的工质在超急速温升条件下的沸腾进行研究。研究表明 :往丙酮里加少量水后 ,可以使沸腾汽泡直径变小 ;纯水温度达到42 0K时仍未见到沸腾现象 ,往水里添加少量丙酮液体后混合液体工质里出现细小汽泡 ;往水 (丙酮 )中添加体积配比小于 0 .1的丙酮 (水 )时 ,最高热流密度都增大 ;要使铂薄膜最高温度尽量低 ,混合液体工质体积配比有个最佳值     

Gossypol removal by adsorption from cottonseed miscella

A variety of aluminas (acidic, basic, and neutral), silica, and synthetic magnesium silicates were screened to evaluate their potential use as adsorbents,for reducing the content of gossypol and related compounds from hexane-based cotton-seed miscella. Among the tested adsorbents, one type of silica and two types of magnesium silicate with a relatively high Brunauer-Emmet-Teller (BET) surface area (≥240 m²/g) showed a superior adsorption capacity in reducing gossypol from hexane miscella. As a possible regenerating method for the spent adsorbents, washing with acetone was tested. The effect of pH in the washing solvent was also evaluated. Adsorbents that were regenerated by washing with acetone at pH values between 7 and 7.5 performed better than those at pH values between 6.5 and 7. The pH values of washing solvent were adjusted by using a small amount of caustic and 1 M HCl.     

Effect of Processing Parameters on Gossypol Levels in Protein Isolates from Cottonseed by Alkali Extraction/Ultrafiltration/Diafiltration

Abstract

Three different varieties of cottonseed (S1, S2, and S3) were dehulled, separated, and defatted by hexane extraction under controlled conditions (moisture < 3%, temperature < 50°C). The defatted flours, designated as CS1 and CS2 (glandless) and CS3 (glanded), which had free-gossypol levels of 0.15, 0.28, and 0.68%, respectively, and protein levels of 61.4, 61.7, and 58.5%, respectively, were taken for aqueous extraction using NaOH as the alkali in the presence of Na₂S₂O₄, a reducing agent. The extract, after centrifugation, was immediately taken for ultrafiltration (UF) using polysulfone membranes, followed by diafiltration (DF). Experiments at 40 and 60°C, to examine the UF performance and gossypol binding effect, were carried out with strict control of the feed pH. The intensely yellow-colored permetes, probably due to alkali-soluble sodium gossypolate and gossypol-like pigments, were checked for color intensity as a qualitative measure in ultrafiltration concentrate. The intensity was found to be on the decline, less during UF and more during diafiltration. The final UF/DF dried products were analyzed for free gossypol (FG), bound gossypol (BG), total gossypol (TG), and protein. Protein isolates (PI) from Samples CS1 and CS2 were found to have very low FG, with little effect of the processing conditions on binding of gossypol with the protein. PI from Sample CS3 was found to have slightly high FG with relatively high BG. The effect of temperature was found to result in high permeation rates without much effect on the rejection of the components and the binding of gossypol. The gossypol and protein contents of three UF/DF dried proteins were 0.006, 0.012, and 0.041% FG, and 89.4, 90.1, and 86.4% protein. The colors of PI from Samples CS1 and CS2 were lighter while PI from Sample CS3 was relatively darker.     

Cottonseed extraction with a new solvent system: Isohexane and alcohol mixtures

A solvent system, consisting of isohexane and 5 to 25% alcohol, either ethanol (EtOH) or isopropyl alcohol (IPA), was tested for extracting gossypol and oil from cottonseed. The test results indicate that this new solvent system not only is effective in removing free and total gossypol but also is as efficient as n-hexane when extracting oil. The amino acid analysis of cottonseed meal, produced by the new solvent system, is similar to that produced by commercial n-hexane. Present commercial cottonseed extraction and downstream processing of cottonseed oil refining may need little change to adopt this new solvent system. This new solvent system may lead to a solution to the gossypol problem of cottonseed extraction.     

高效液相色谱法测定食用植物油中的游离棉酚

研究采用高效液相色谱法测定食用植物油中游离棉酚的方法,最佳色谱条件:色谱柱C18柱,流动相为甲醇-磷酸溶液(1%)=84+16,波长240 nm,流速为1.0 mL/min,柱温30℃。曲线方程y=3.1033×10-5x,相关系数r=0.999871,线性关系良好。检出限为2.5 mg/kg,回收率为98.0%～100.2%。该法简便,快速,准确性高,重现性好。     

棉籽油制备生物柴油的研究概况

我国棉籽油原料充足,由棉籽油制备生物柴油具有广阔的发展前景。文章综述了酯交换反应中的酸、碱、酶、超临界法在棉籽油制备生物柴油中的研究概况。     

棉酚开发,应用的若干问题

结合棉酚的物理、化学性质就其提取、应用作一个综合的概括,讨论了作者在提取和精制中所遇到的若干问题。这些问题的解决,定会推进棉酚这一宝贵天然资源的合理开发与充分利用。     

棉籽蛋白的研究进展

我国棉花产量丰富,棉籽仁提油后的棉籽饼粕中,蛋白质含量高达60%。棉籽蛋白是一种营养价值高、品质优良的植物蛋白,在食品行业有着广泛的应用。介绍了棉籽蛋白的提取和水解的方法,阐述了各种方法的优缺点,并综述了其最新研究进展。     

Cottonseed Meal Protein Isolate as a New Source of Alternative Proteins: A Proteomics Perspective

Cottonseed meal (CSM) is a good source of dietary proteins but is unsuitable for human consumption due to its gossypol content. To unlock its potential, we developed a protein extraction process with a gossypol removal treatment to generate CSM protein isolate (CSMPI) with ultra-low gossypol content. This process successfully reduced the free and total gossypol content to 4.8 ppm and 147.2 ppm, respectively, far below the US FDA limit. In addition, the functional characterisation of CSMPI revealed a better oil absorption capacity and water solubility than pea protein isolate. Proteome profiling showed that the treatment improved protein identification, while SDS-PAGE analysis indicated that the treatment did not induce protein degradation. Amino acid analysis revealed that post-treated CSMPI was rich in branched-chain amino acids (BCAAs). Mass spectrometry analysis of various protein fractions obtained from an in vitro digestibility assay helped to establish the digestibility profile of CSM proteins. Several potential allergens in CSMPI were also found using allergenic prediction software, but further evaluation based on their digestibility profiles and literature reviews suggests that the likelihood of CSMPI allergenicity remains low. Overall, our results help to navigate and direct the application of CSMPIs as alternative proteins toward nutritive human food application.     

涤/棉复合裂片型超细纤维针织物碱减量开纤和染色研究

研究了裂片型超细纤维针织物碱减量开纤和染色。实验结果表明,失重率随时间延长而增加,当温度高于90℃、NaOH浓度高于8g/L时,失重率明显增加;在高于140℃对纤维热定型,失重率随温度升高而降低,当热定型温度高于180℃,开纤困难;纤维在染色后发现,K/S随纤维失重率增大而变小:用分散/阳离子染料或分散/酸性染料套染使K/S值有所提高;超细纤维在染色温度超过120℃时K/S值降低,温度越高,比普通涤纶的K/S差值越大