A comparison of silver ion HPLC plus GC with Fourier-transform IR spectroscopy for the determination of trans double bonds in unsaturated fatty acids

A rapid procedure has been developed for the isolation of methyl esters of trans-monoenoic fatty acids by silver ion high-performance liquid chromatography. The combined saturated plus trans-monoene fraction was collected for analysis by gas chromatography and comparison with the composition of the unfractionated sample. The trans-monoene contents of partially hydrogenated vegetable oils, determined in this way, are compared with data obtained by Fourier-transform infrared spectroscopy. Alternative methods of base-line correction are discussed. The infrared technique gave values that were a little higher than the chromatographic ones, presumably because the former also detected trans unsaturation in di- and polyunsaturated fatty acids.     

植物蛋白与乳蛋白在肉制品加工中的应用

植物蛋白和乳蛋白由于具有较高的营养价值和优良的功能特性,作为食品配料被广泛应用于肉类工业。本文简要介绍了肉制品加工中使用的植物蛋白与乳蛋白、植物蛋白与乳蛋白在肉制品加工中应用的主要功能特性及植物蛋白与乳蛋白在肉制品加工中的作用。     

带肉梨汁护色及加工工艺的研究(Ⅱ)——SO_2及其它抑制剂对加工梨汁色泽的影响

本研究用热烫、SO_2、抗坏血酸、蔗糖等抑制方法控制带肉梨汁加工过程中的褐变。颜色指标用罗维朋比色计评价。发现在一小时的加工时间内能完全控制梨汁褐变的最佳条件是:100℃热烫3分钟、抑制剂偏重亚硫酸钠的最小用量为20ppm;或抗坏血酸为250ppm;或糖浆浓度为40%。还对糖浆与SO_2的协同作用及不同pH下SO_2对酶的抑制效果作了研究。     

变压器用植物绝缘油的低温特性试验研究

为研究凝点低的植物绝缘油对变压器绝缘强度的影响,用绝缘油耐压测试仪对凝固状态下的植物油、油纸绝缘结构进行耐压试验,并在高低温交变试验室对-30℃下的10 k V/315 k VA冷冻变压器实物进行耐压及局部放电试验。通过对比试验结果表明,对于大豆绝缘油,凝固后的绝缘油耐压下降了3.2 k V;油纸混合结构的耐压水平基本没变,凝固状态下的耐压值提高了1 k V;完全冷冻后的植物油变压器顺利通过耐压试验,且在最低气温为-27℃的内蒙古赤峰挂网运行23个月,运行情况良好。     

Singlet Oxygen Quenching Activities of Various Fruit and Vegetable Juices and Protective Effects of Apple and Pear Juices against Hematolysis and Protein Oxidation Induced by Methylene Blue Photosensitization

ABSTRACT:  Effects of various fruit and vegetable juices on rubrene oxidation induced by a chemical source of singlet oxygen in a microemulsion system have been studied. The singlet oxygen quenching activities of fruit and vegetable juices were greatly different with different juices. The apple and pear juices exhibited the highest antioxidative activity among the tested juices in singlet oxygen–induced rubrene oxidation, showing 56.69% and 59.34% inhibition, respectively. The grape, kumquat, red cabbage, and spinach juices also showed relatively strong antioxidative activity against singlet oxygen–induced rubrene oxidation. Lemon juice showed the least activity, resulting in 0.63% inhibition of rubrene oxidation. The singlet oxygen quenching activities of 1 mL of apple and pear juices were equivalent to 33.97 and 34.64 mg ascorbate, respectively. Singlet oxygen quenching activities of juices had very low correlation with both ABTS radical scavenging activity ( R ²= 0.11) and total phenolic contents ( R ² < 0.1). However, a high correlation ( R ²= 0.66) was found between the ABTS radical scavenging activities and total phenolic contents of juices. The apple and pear juices also significantly inhibited both erythrocyte lysis and protein oxidation induced by fluorescence light illumination in the presence of methylene blue. Electron spin resonance (ESR) spectroscopy data showed that the protective activities of these juices against biological damages induced by photodynamic ways were, to at least some extent, due to their singlet oxygen quenching abilities. This represents first report on the singlet oxygen quenching activities of the apple and pear juices, and their protective activities against photodynamically induced biological damages.     

三种果蔬发酵液抗氧化和免疫调节功能研究

对比研究A、B、C三种果蔬发酵液产品的抗氧化能力和免疫调节能力。采用偶氮二异丁脒盐酸盐(AAPH)诱导的HepG2细胞氧化应激模型评价三种发酵液产品对细胞内活性氧簇(ROS)的影响,应用刀豆蛋白A(ConA)和脂多糖(LPS)诱导小鼠T/B淋巴细胞,检测其增殖能力,应用LPS诱导小鼠腹腔巨噬细胞,检测其吞噬能力和NO释放量。结果表明:三种果蔬发酵液具有较强的降低细胞内ROS含量的能力,果蔬发酵液A可使胞内ROS含量降低至55%;三种果蔬发酵液可提高淋巴细胞的增殖能力和腹腔巨噬细胞的吞噬能力,促进NO释放,在稀释倍数为104时果蔬发酵液A处理组NO释放量最高(4.06μmol/L)。三种果蔬发酵液具有较好的抗氧化活性和增强免疫的功能。     

纤维素纤维改性剂AM的合成及天然植物染料染色性的研究

以环氧氯丙烷、三甲胺、硫酸为原料合成纤维素纤维改性剂AM,研究了反应物量比,反应溶液的pH值及反应温度对产物合成转化率的影响,并得出了合成产物的优化工艺;采用改性剂AM对纤维素纤维织物进行改性,探讨了改性织物对天然植物染料的染色性能.结果表明,纤维素纤维改性织物的植物染料染色性能有明显提高.     

国际标准化组织动植物油脂国际标准制定（网络首发、推荐阅读）

Increasing volumes of oils and fats are produced annually with a large section that are traded internationally. The International Organization for Standardization(ISO) body develops international standards covering almost all aspects of technology and manufacturing with 23,882 standards currently published. Standards in the animal and vegetable fats and oils sector is developed by Technical Committee ISO/TC 34, Food products, Subcommittee SC 11, Animal and vegetable fats and oils. Standards are developed through consensus by national members that represent ISO in their country. Each Standard is developed within a determined timeframe and goes through various pre-determined stages such as project proposal, development, national voting and commenting on the draft Standard to final publication. ISO TC34/SC11 Standards range from sampling of oils and fats, sample preparation to analysis of its composition, the minor components, and quality and identity parameters as well as contaminants. The analysis results are used by industry for product development, labelling, research and to provide peace of mind for consumers on its safety. An important future trend is the focus on the safety concerns from either environmental contamination(e.g. mineral oils) or processing contaminants such as esters of 3-MCPDs(3-monochloropropane-1,2-diol or 3-chloropropane-1,2-diol).     

蔬菜纸形食品滚筒成形的参数优化

本文以青菜为典型物料，以滚筒成形试验台为主要试验设备，对青菜纸形食品加工工艺参数和设备的结构参数及运动参数进行了研究，确定出参数的最优值。