Characterization of soybean protein isolates The effect of calcium presence

Results of a study of the effect of calcium addition on polypeptide composition, hydrophobicity, sulfhydryl content, thermal stability, enthalpy of denaturation, and water solubility of soybean protein isolates suggest that the addition of small amounts of calcium (1.23–5.0 mg/g protein) induced the formation of α, α′ soluble aggregates, whereas large amounts (5.0–9.73 mg/g protein) induced the selective insolubilization of the glycinin fraction. The addition of this ion also produced thermal stabilization of the soybean proteins, mainly the glycinin fraction, and increased the enthalpy of denaturation. A decrease in the surface hydrophobicity of proteins with increasing calcium content was also observed. The results obtained suggested the existence of specific calcium-soy protein interactions, especially with the glycinin fraction.     

Effects of processing on the oxidative stability of soybean oil produced in Mexico

The stability parameters of 22 samples of soybean oil produced in Mexico were determined. Samples were analyzed for moisture, color, free fatty acids, peroxide value, p-anisidine value, fatty acid profile, metals, flavor, and Rancimat test for oxidative stability. Results obtained were compared with the stability parameters of soybean oil sproduced in the United States and Costa Rica. The fatty acid profile in all samples analyzed corresponded to the expected profile for a 100% soybean oil. Sixty-four percent of the oils had oxidative stabilities similar to those reported for soybean oils from the United States and Costa Rica. This suggests that in spite of the good quality, the soybean oil production process in Mexico needs further improvement. Especially important is maintaining appropriate control during the degumming and bleaching steps. Special consideration should be given to preserving the natural antioxidants present in the oil.     

生漆改性研究及漆酚金属高聚物

本文综述了生漆改性研究的概况 ,总结了漆酚金属高聚物的合成方法、结构特征及其主要性能 ,提出了今后生漆改性研究的发展方向和重点内容     

使用在线钙铁仪提高生料均化效果

介绍了生料成分在线控制对提高生料均化效果的作用、各类在线控制系统的特点及国产在线钙铁仪的实际应用效果，尤其是针对无原料预均化和生料均化库能力不足的水泥生产线，给出了提高生料均化效果较为经济有效的解决途径。     

我国橡胶工业原材料进展

概述了我国橡胶工业原材料－天然橡胶,合成橡胶,骨架材料,碳黑和橡胶助剂的现状及发展趋势。     

Effect of triacylglycerol composition and structures on oxidative stability of oils from selected soybean germplasm

The oxidative stability of soybean oil triacylglycerols was studied with respect to composition and structure. Crude soybean oils of various fatty acid and triacylglycerol composition, hexane-extracted from ground beans, were chromatographed to remove non-triacylglycerol components. Purified triacylglycerols were oxidized at 60°C, in air, in the dark. The oxidative stability or resistance of the substrate to reaction with oxygen was measured by determination of peroxide value and headspace analysis of volatiles of the oxidized triacylglycerols (at less than 1% oxidation). The correlation coefficients (r) for rates of peroxide formation (r=0.85) and total headspace volatiles (r=0.87) were related positively to oxidizability. Rate of peroxide formation showed a positive correlation with average number of double bonds (r=0.81), linoleic acid (r=0.63), linolenic acid (r=0.85). Rate of peroxide formation also showed a positive correlation with linoleic acid (r=0.72) at the 2-position of the glycerol moiety. A negative correlation was observed between rate of peroxide formation and oleic acid (r=−0.82). Resistance of soybean triacylglycerols to reaction with oxygen was decreased by linolenic (r=0.87) and increased by oleic acid (r=−0.76)-containing triacylglycerols. Volatile formation was increased by increased concentration of linolenic acid at exterior glycerol carbons 1,3 and by linoleic acid at the interior carbon 2. Headspace analysis of voltiles and high-performance liquid chromatography of hydroperoxides indicated that as oxidation proceeded there was a slight decrease in the linolenic acid-derived hydroperoxides and an increase in the linoleic acid-derived hydroperoxides. The oxidative stability of soybean oil triacylclycerols with respect to composition and structure is of interest to the development of soybean varieties with oils of improved odor and flavor stability. Presented at the 81st Annual American Oil Chemists' Society Meeting, Baltimore, MD, April 18–21, 1990.     

烧结法生料浆流变性的研究

为了降低烧结法氧化铝生产中烧结过程的能耗,从流变学角度测量生料浆在6个不同剪切速率下的剪切应力,通过其流变曲线,研究了生料浆的触变性及水分质量分数、温度、表面活性剂对生料浆流变性的影响。结果表明:含水质量分数为35%的生料浆具有触变性;随着生料浆含水质量分数从34.7%增加到39.7%、温度从40℃升高到80℃,添加适当表面活性剂R—COONa,可降低生料浆的屈服应力和表观粘度,使生料浆的流动性得到一定改善。     

Effect of oxidative damage due to excessive protein ingestion on pancreas function in mice

The present study was undertaken to evaluate the effect of oxidative damage due to excessive protein diet on pancreas function in mice. For this purpose, thirty male (C57BL/6J) mice were randomly divided into three groups and fed on different diets as follows: group 1 was fed on a normal diet, group 2 was fed on an excessive protein diet and group 3 was fed on an excessive protein diet supplemented with 0.06 g/kg cysteamine. Each group was fed for 2 weeks, and then pancreas samples were collected to examine oxidative and antioxidant parameters and pancreas function. The results showed that ingestion of an excessive protein diet markedly increased contents of malondialdehyde (MDA) and decreased T-AOC and activities of antioxidants SOD and GSH-Px, compared with a normal diet (P < 0.05). Pancreas weight and concentration of protein, DNA and RNA were significantly higher (P < 0.05), digestive enzyme activities were significantly lower and levels of somatostatin and insulin were higher in mice fed with an excessive protein diet than those fed with a normal protein diet. In the group fed with excessive protein diet supplemented with cysteamine, oxidative stress was mitigated and pancreas function was improved. These data demonstrate that excessive protein ingestion could increase oxidative damage of free radicals on pancreas function through destroying the balance of oxidants and antioxidants.     

Effect of tea polyphenol on oxidative injury in s180 cells induced hepatocarcinoma mice

The purpose of this study was to evaluate the antioxidant nature of tea polyphenol on S180 cells induced liver cancer in mice. In the present study, hepatocellular carcinoma was induced by tumor transplantation of liver in situ. The antitumor activity of tea polyphenol has been determined in vivo in hepatocellular carcinoma mice after treatment of drug (50, 100, 150 mg/kg body weight) by gavage for 20 days. Results showed that a significant increase in serum aspartate transaminase (AST), alkaline phosphatase (ALP), alanine aminotransfere (ALT), malondialdehyde (MDA) level, decrease in serum white blood cells (WBC), serum total protein (TP), albumin (ALB), A/G, tumor necrosis factor-α (TNF-α) and interferon-gamma (IFN-γ), liver reduced glutathione (GSH) levels were observed. In addition, the levels of enzymic and non-enzymic antioxidants were decreased when subjected to S180 cells induction. These altered enzyme levels were ameliorated significantly by administration of tea polyphenol at the concentration of 50, 100, 150 mg/kg body weight in drug-treated animals. These results indicate that the protective effect of tea polyphenol was associated with inhibition of MDA induced by S180 cells and to maintain the antioxidant enzyme levels.     

玻璃原料水分含量分析误差的实验研究

对玻璃原料的水分含量测定方法进行了试验,用数理统计法对试验误差进行了分析,提出了合理的分析误差标准,对于原料生产、商务贸易以及玻璃配料控制均具有指导意义.     

椰子油和大豆油的乙氧基化物对小鼠肝脏的脂质过氧化效应研究

为探讨椰子油乙氧基化物-36EO(COE-36)和大豆油乙氧基化物-42EO(SOE-42)对小鼠肝脏的脂质过氧化作用,采用腹腔注射技术,测定COE-36处理组、SOE-42处理组、氯化镉阳性对照组(小鼠单位体质量的氯化镉用量为2.5μg.g-1)和生理盐水阴性对照组小鼠肝脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)生成量。结果表明,氯化镉显著抑制了小鼠肝脏SOD和CAT活性,增加了MDA生成量;在所测3个指标中,COE-36和SOE-42的3个用量组(以小鼠单位体质量的用药量计)与生理盐水阴性对照组相比均无显著性差异;与氯化镉阳性对照组相比,不同用量COE-36作用下SOD和CAT活性变化、不同用量SOE-42作用下CAT活性变化以及低用量(3 mg.g-1)COE-36或SOE-42作用下MDA生成量变化均有显著性差异,说明在所试用量(3～5 mg.g-1)下,这2种表面活性剂不会引起小鼠肝细胞的脂质过氧化。     

The effect of the N-linked glycans on structural features and physicochemical functions of soybean β-conglycinin homotrimers

β-Conglycinin is a trimeric protein consisting of three subunits, α,α′,and β, which are N-glycosylated. The α and α′ subunits contain extension regions in addition to core regions common to all subunits. We purified homogeneous trimers consisting of only α, α′, or β from mutant soybean cultivars containing β-conglycinin lacking one or two subunits: α homotrimers from an α′-lacking mutant, α′ homotrimers from an α-lacking mutant, and β homotrimers from an α-and α′-lacking mutant. Structural features and physicochemical functions of the three homotrimers were examined and compared with those of recombinant homotrimers having no N-linked glycans. The native homotrimers have secondary structures very similar to those of the recombinant ones. In analogy with the recombinant homotrimers, the native ones exhibit different thermal stabilities from one another (β>α′>α), and the native α and α′ homotrimers exhibit better solubility, emulsifying ability, and heat-induced association than the native β homotrimer. Further, the N-linked glycans contribute to solubilities of the three subunits at low ionic strength (μ=0.08) and to the emulsifying ability of the native β homotrimer. N-Linked glycans also prevent heat-induced associations of the native α and α′ homotrimers but do not contribute to the secondary structure and the thermal stability of β-conglycinin.     

未来中国聚氯乙烯生产原料来源分析

介绍了用石油生产乙烯、电石生产乙炔、天然气制备乙炔、合成气制备乙烯等方法，列举了由粮食、纤维和半纤维材料、农产品加工排放渣、工业废料等制取乙醇，由乙醇脱水生产乙烯的简要工艺。指出国内聚氯乙烯产能正处在快速增长时期，但用于生产聚氯乙烯原料的天然资源已临近枯竭，应因地制宜，充分发挥区域优势，原料来源多元化是中国未来聚氯乙烯生产原料来源的特点；完全依靠可再生资源将是实现聚氯乙烯可持续发展的根本保证。     

国内原盐生产市场及发展建议

介绍了2009年上半年国内原盐及烧碱工业和纯碱工业的生产情况及市场需求,结合具体数据,对国内原盐未来的需求作出预测,并针对原盐工业的实际情况提出发展建议。     

The effects of bleached and unbleached rosemary oleoresins on light-sensitized oxidation of soybean oil

Bleached and unbleached forms of a rosemary oleoresin (RO) in stripped and nonstripped soybean oil behave both as antioxidant and prooxidant in a light-induced oxidative system. At 0.02 and 0.05% levels, RO had the greatest antioxidant activity, while at 0.01 and 0.5% levels it had the highest prooxidant activity in both stripped and nonstripped soybean oil. Treatment of both soybean oil systems with tertiary butylhydroquinone controlled light-induced oxidation of the oil better than did the oleoresin treatments. The prooxidant activity of the 0.5% RO level was probably due to an excess of prooxidant components being carried into the oil at that level, whereas the reduced antioxidant activity at 0.01% was probably due to the low initial level of active antioxidant components being added to the oil. Published as Journal Series No. 10072, Nebraska Agricultural Research Division, Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583-0919.     

Antihyperglycemic effect of ganoderma lucidum polysaccharides on streptozotocin-induced diabetic mice

The current study evaluated the glucose-lowering effect of ganoderma lucidum polysaccharides (Gl-PS) in streptozotocin (STZ)-induced diabetic mice. The diabetic mice were randomly divided into four groups (8 mice per group): diabetic control group, low-dose Gl-PS treated group (50 mg/kg, Gl-PS), high-dose Gl-PS treated group (150 mg/kg, Gl-PS) and positive drug control treated group (glibenclamide, 4 mg/kg), with normal mice used as the control group. Body weights, fasting blood glucose (FBG), serum insulin and blood lipid levels of mice were measured. After 28 days of treatment with Gl-PS, body weights and serum insulin levels of the Gl-PS treated groups was significantly higher than that of the diabetic control group, whereas FBG levels was significantly lower. Moreover, total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterol (LDL-C) levels of the Gl-PS treated groups had dropped, whereas the high density lipoprotein cholesterol (HDL-C) levels had increased. In addition, according to acute toxicity studies, Gl-PS did not cause behavioral changes and any death of mice. These data suggest that Gl-PS has an antihyperglycemic effect. Furthermore, considering the Gl-PS effects on lipid profile, it may be a potential hypolipidaemic agent, which will be a great advantage in treating diabetic conditions associated with atherosclerosis or hyperlipidemia.     

The effect of multiwalled carbon nanotube agglomeration on their accumulation in and damage to organs in mice

Purified carboxylated multiwalled carbon nanotubes (MWCNTs) with different agglomeration propensities were evaluated in mice following a single dose intravenous injection. Both agglomerated and the well suspended MWCNTs were taken up by mononuclear phagocyte system organs. MWCNTs with higher degree of agglomeration were retained in lungs and later in the liver and were not eliminated completely in 28 days, while the well-dispersed ones remained well dispersed and formed fewer aggregates in the lungs and liver, and seemed to be easily eliminated. Persistent accumulation of agglomerated MWCNTs in the lungs caused inflammatory responses while the well-suspended ones did not. Although the elimination of MWCNTs is still to be evaluated quantitatively, the formation of a stable suspension is one of the key requirements for safe applications in medicine.     

旋流一体式强化混凝设备设计优化及低浊度微污染原水处理研究

根据混凝反应的基本原理,针对低浊度微污染原水的特性,设计了一种新型旋流一体式强化混凝净水器.该净水器在动力学原理上可以大幅提高颗粒的碰撞频率Ng,在水力结构上可以有效地消除无序旋涡以及使G值平滑逐渐减小,在整体结构上通过将絮凝和沉淀区域一体化,充分利用沉淀部分的时间来进行后期强化絮凝,从而达到了强化絮凝效果、缩短流程反应时间、提高出水水质的目的.进一步利用所设计的小试设备处理了微污染珠江原水,取得了砂滤出水的浊度为0.080-0111 NTU的良好结果,验证了旋流一体式强化混凝净水器具有高速、高效的优点.     

柚皮黄酮抑制硝化和氧化作用的研究

以抑制过氧亚硝酸根硝化酪氨酸生成3－硝基酪氨酸评价了柚皮黄酮的抗硝化作用;以Fenton反应产生羟基自由基体系和邻苯三酚自氧化产生超氧阴离子自由基体系,用紫外可见分光光度法测定了柚皮黄酮对羟基自由基和超氧阴离子自由基的清除效果。结果表明．柚皮苷的抗硝化作用较强,而芦丁和橙皮苷没有明显的抗硝化作用;3种柚皮黄酮清除羟基自由基的效果在μg·mL^-1水平就已经比较显著（超过50％）．且显示出浓度依赖性．作用大小依次为;柚皮苷〉橙皮苷〉芦丁13种柚皮黄酮在μg·mL^-1水平清除超氧阴离子自由基的作用大小依次为：芦丁〉柚皮苷〉橙皮苷。     

关于氟化氢生产中原料混合问题的讨论

在无水氟化氢生产原料中，添加了发烟硫酸作为新原料。由于液体原料混合方法的不同，在生产中会产生不同的效果。本文介绍了预混合法和在线混合法的优缺点。