高效液相色谱法同时测定棉籽油中游离棉酚及其降解产物四甲氧基棉酚含量

建立高效液相色谱法测定市售棉籽油中游离棉酚及其降解产物四甲氧基棉酚的含量方法,为棉籽油质量控制提供科学依据。采用Inertsil? ODS-3（250 mm×4.6 mm,5 mm）色谱柱,以甲醇-2%磷酸（85∶15,V/V）溶液为流动相,流速1.0 mL/min,柱温32 ℃,检测波长235 nm,进样量10 mL。棉酚在0.245～1.226 mg/mL质量浓度范围内线性关系良好（r=0.999 5）,精密度检测相对标准偏差为0.88%（n=6）,重复性检测相对标准偏差为1.73%（n=6）,平均回收率为101.2%,相对标准偏差为1.75%（n=3）。四甲氧基棉酚在0.211～1.056 mg/mL质量浓度范围内线性关系良好（r=0.999 6）,精密度检测相对标准偏差为1.56%（n=6）,重复性检测相对标准偏差为1.11%（n=6）,平均回收率为100.3%,相对标准偏差为1.12%（n=3）。90 批市售棉籽油中有25 批检测到棉酚,且质量浓度为0.159～1.661 mg/mL,有56 批检测到四甲氧基棉酚,且质量浓度为0.093～1.661 mg/mL。该法有良好的准确度、精密度,操作简便,可较广泛用于监控棉籽油的脱毒情况。     

Safety of Low Gossypol Cottonseed Kernels

The safety of low gossypol raw, cooked, or roasted cottonseed kernels ground into flour was determined. Growing females utilized cooked or roasted cottonseed more efficiently than raw cottonseed or control diet. The percentages of pups alive at birth surviving to 4 days were significantly higher for rats fed raw or cooked cottonseed than roasted cottonseed. There were no significant differences observed in average body weight at parturition, at weaning time of dams or weight of offspring due to diet. No detrimental effects due to feeding cottonsed at 20% of the diet were observed.     

Effects of Ultrafine Grinding and Pulsed Magnetic Field Treatment on Removal of Free Gossypol from Cottonseed Meal

The main objective of this research was to study the effects of ultrafine grinding and pulsed magnetic field (PMF) treatment on free gossypol (FG) content in cottonseed meal (CSM). The results revealed that FG content decreased from 831 to 584 mg kg^?1 after CSM was ultrafine ground with an airflow crusher. A further decrease of FG content was achieved by processing with PMF. Response surface methodology (RSM) was applied to optimize the process of detoxification, and results showed that the influence of PMF intensity and pulse numbers was remarkable. Removal efficiency increased distinctly with increasing of PMF intensity (50–500 mT) and pulse numbers (10–60) but decreased slightly with increasing of sample weight (0.5–10 g). The relationship between the removal ratio of FG and PMF intensity, pulse numbers, and sample weight all can be expressed with quadratic equations, respectively. The total removal ratio of FG even reached 83.39 % after cottonseed coarse powder (CSCP) was processed with ultrafine grinding and PMF under conditions of PMF intensity (500 mT), pulse number (50), and sample weight (3 g). And the Box–Behnken design (BBD) generated satisfactory mathematical models that accurately explained the behavior of the system, allowing one to predict the removal efficiency of FG from CSM.     

小米-豆粕复合挤压中有效赖氨酸损失的动力学

小米一豆粕按不同比例混合后在不同的操作条件下进行挤压,测定了混合物料在挤压机内的停留时间分布,分析了挤压产品中有效赖氨酸的含量.结果表明,小米-豆粕复合挤压后有效赖氨酸的损失率在29.2%～64.3%之间;套筒温度是影响有效赖氨酸含量的主要因素,温度越高,有效赖氨酸的含量越低;有效赖氨酸损失的动力学级数为1.5,反应速率常数在0.000 41～0.001 26 s-1之间.     

Methylene Chloride Extraction of Gossypol from Cottonseed Products

Methylene chloride was used to reduce the amount of free and total (free plus bound) gossypol in hexane-defatted meal and the liquidcyclone-processed (LCP) underflow fraction of glanded cottonseeds from 2.6% and 3.4% to 0.013% and 0.15%, respectively (the accepted level of free gossypol in cottonseed products for food is 0.045%). The cottonseed meals were pretreated one of three ways to rupture the gossypol glands: (a) equilibrated with additional water; (b) suspended in various water-propylene glycol mixtures; or (c) mixed with an acetic acid-water-propylene glycol solution. The gossypol was then readily extracted from the meals with methylene chloride. Low levels of water and acetic acid in propylene glycol aided methylene chloride in the removal of free and total gossypol and did not greatly alter the proximate composition, solubility, and gel electrophoretic properties of proteins; amino acid content; and chemical scores of the treated meals. Success with this process should improve the potential of LCP-cottonseed by-product (underflow) as feed or food.     

棉籽粕中棉酚的超声辅助脱除研究

棉籽蛋白类似大豆蛋白,是一种营养价值高且具保健功能的蛋白质。而棉酚的存在严重影响棉籽蛋白的应用并造成蛋白质资源的浪费。采用超声波辅助盐酸-乙醇溶液脱除法及响应面设计法对棉子饼粕中棉酚的脱除工艺进行研究。在单因素的基础上,选定液料比、超声时间、超声温度及盐酸浓度4个因素,通过响应面分析以及岭嵴分析得到了优化组合条件。最佳工艺条件是:液料比23∶1,超声时间53 min,超声温度77℃,盐酸浓度1.5 mol/L,超声功率50 W,棉酚脱除量为9.5 mg/g。脱酚后的棉籽粕含蛋白质为57.17%,比脱酚前提高7.52%。     

Effect of Gamma-Radiation on Gossypol in Cottonseed Meal

The effect of gamma–radiation, in the range 5–30 KGy on free, total and pure gossypol was investigated in an attempt to reduce or eliminate gossypol from cottonseed meal using different solvent systems. Maximum reduction in gossypol concentration was attained at a dose of 25 KGy of gamma-radiation with chloroform as a solvent, a spectrometric method was used for analysis. The reductions attained for pure, free and total gossypol were found to be 96%, 60% and 80%, respectively.     

超声波强化技术在萃取皂脚棉酚中的应用

棉油皂脚为棉毛油碱炼的下脚料,但其中含有的棉酚却具有抗肿瘤作用。为了高效地从棉油皂脚中分离出醋酸棉酚,联合使用超声波萃取和超声波诱导结晶强化技术,探讨了超声萃取时间、热处理时间、酸度和超声结晶时间对醋酸棉酚粗品质量和含量的影响。结果表明:利用超声波萃取和诱导结晶协同效应可以直接从棉油皂脚中获得醋酸棉酚含量高达96%的粗品,并且经纯化后,具有和标准品相同的熔点范围。超声波强化技术可以将醋酸棉酚的生产周期缩短为传统工艺的25%,提高了产品纯度,减轻了重结晶压力,是未来分离纯化醋酸棉酚的一种先进技术。     

膨润土对氟及游离棉酚的吸附效果试验

利用膨润土的强大的吸附特性，对氟及游离棉酚进行吸附效果实验，并模拟动物肠道碱性环境，即用pH8.0溶液对PH2．0和PH8．0的吸附效果实验，研究结果表明，膨润土对氟和游离棉酚有吸附作用，其吸附量随着氟和游离棉酚含量的增加而升高，另外，PH值的大小对膨润土的吸附性能也有不同程度的影响，氟在PH2．0和PH8．0时均有较好的吸附稳定性，游离棉酚在PH2．0时吸附稳定性好，而在PH8．0时稳定性差。     

Measurement of Available Lysine Using the Guanidination Reaction

Available lysine with its free ε-amino group can be chemically converted to homoarginine by means of a guanidination reaction using methylisourea (MIU). Various factors that can affect this reaction were investigated. For milk protein optimum conditions were found to be pH 10.8 for 96 hr at 20°C with a MIU concentration of 0.5M. Other protein sources had a different optimum pH for the guandination reaction. Addition of various carbohydrate sources and amounts did not interfere with the quantitation of available lysine.     

Available Lysine in Protein, Assay Using o-Phthalaldehyde/ N-Acetyl-L-cysteine Spectrophotometric Method

An assay was based on reaction of free ε-amino groups in proteins with the o-phthalaldehyde/N-acetyl-L-cysteine reagent to form isoindoles, which absorb at 335 nm. The procedure was suitable for proteins or mixtures of proteins with available lysine contents of more than 5 moles lysine/mole protein and required absence of free amino acids and peptides. This method was simpler and more convenient than other methods, since it did not require hydrolysis, amino acid analysis, long heating periods or solvent extraction.     

高纯度大豆染料木苷的制备工艺研究

从低温脱溶豆粕超声提取大豆染料木苷,水洗纯化染料木苷粗提物.通过单因素及正交试验,优化制备高纯度大豆染料木苷的最佳工艺条件为:乙醇浓度为70％、超声时间为40 min、提取温度为40℃、水洗纯化温度为90℃、染料木苷粗提物与水体积比为1∶50(mL/mL)、压滤机的压强为0.25 MPa.此条件下制备的染料木苷纯度高达...     

微生物降解棉酚的响应面分析优化

利用SAS软件的Plackett-Burman设计法对微生物固态发酵脱毒棉酚的发酵参数进行筛选,得出3个影响较大的重要因素,即料水比、发酵时间、装料量,再用SAS软件二次响应面分析法进行回归分析,得到了各因素的优化水平值,经过响应面法的优化,脱毒事提高近20%。     

高效液相色谱法分析大豆和大豆低聚糖浆中糖的组成与含量

采用高效液相色谱法(HPLC)对大豆种子及市售的大豆低聚糖浆中的可溶糖进行了分析,并利用α-半乳糖苷酶酶解大豆低聚糖浆及结合HPLC分析来推测大豆低聚糖浆的糖组成。HPLC分析条件为:Sugar-D色谱柱,75%乙腈为流动相,柱温40℃,流速为1.0ml/min,示差折光检测器。Sugar-D色谱柱的分离效果好,基线稳定,相对标准偏差1.0%～2.0%,标准回收率96.7%～100.7%。分析结果表明大豆种子和市售的大豆低聚糖浆中均含有果糖、蔗糖、蜜二糖、棉子糖、水苏糖以及二种保留时间介于蔗糖与蜜二糖之间的未知成分,而大豆低聚糖浆中还含有葡萄糖(半乳糖)和甘露三糖;大豆种子中主要含有蔗糖和水苏糖,而大豆低聚糖浆中含有较多的蔗糖、果糖、水苏糖和葡萄糖(半乳糖),功能性低聚糖主要为水苏糖和甘露三糖。     

Gossypol Removal and Functional Properties of Protein Produced by Extraction of Glanded Cottonseed with Different Solvents

Cottonseed flakes were extracted with one of the following solvents: (A) hexane; (B) 1:1 mixture of 85% isopropanol and hexane; and (C) acetone followed by 1:1 mixture of isopropanol and hexane. Meal B had the lowest free gossypol content of 0.069%. The functional properties and the protein content of all the meals were similar. Ultracentrifugation did not reveal any change in the proportion of the protein fractions. Gel electrophoresis indicated minor differences.     

食用无腺棉籽蛋白粉的试制

无腺棉籽仁经低温直接溶剂浸出,真空水蒸汽脱溶法制得了食用棉籽蛋白粉。并得到优质棉籽油。对产品进行了成分分析。     

无腺体棉籽蛋白粉的研制

介绍了一次浸出法制备无腺体棉籽蛋白粉的试验结果 ,优化后得到的工艺条件为 :温度 5 0℃ ,料液比 1∶6 ,水分 7% ,时间 12 0min。试验结果为 :残油率 0 93% ,残留溶剂 17 6× 10 -6,粗蛋白含量 6 2 2 5 % (比大豆蛋白粉高 10 % )。产品的氨基酸齐全平衡 ,具有较高的营养价值 ,完全可作为食用蛋白粉     

无腺体棉籽蛋白产品的研制

研究了各种无腺体棉籽蛋白产品的制备，并借助计算机对部分蛋白制备工艺进行了优化；通过成分及氨基酸分析证明，棉籽蛋白同样可以用于食用目的。