EFFECT OF EDTA ON THE GERMINATION OF AND OUTGROWTH FROM SPORES OF Clostridium botulinum 62-A

SUMMARY –EDTA, in concentrations above 2.5 mM, was found inhibitory to germination of and outgrowth from spores of C. botulinum Type A and to toxin production in a fish homogenate. Inhibitory action was influenced by pH of the medium in the range pH 6.5–8.1, the action increasing with pH. It was influenced by Mg and Ca concentrations in the medium, equimolar concentrations of added CaCl₂ or MgCl₂, completely erasing the growth inhibitory action. Initial spore concentration also influenced inhibitory efficacy–the higher the spore concentration, the higher the EDTA concentration required for inhibition. There was no evidence that EDTA, in any concentration used, promoted spore germination. Release of Ca, Mg and DPA from incubating spores was suppressed to varying extents by 5.0 and 10 mM EDTA.     

EFFECT OF HYDROGEN PEROXIDE ON SOUR CHERRY ANTHOCYANINS

Degradation of sour cherry anthocyanins was studied at different H₂O₂ concentrations (0.233‐11.63 mmol.L^?1) over the temperature range of 20‐55C. Degradation reaction fitted to a first order kinetic model progressed very rapidly even at low H₂O₂ concentrations. Thus, the t_1/2 values at 20C varied between 111‐20 h in the concentration range of 0.233‐2.327 mmol.L^?1 H₂O₂. The degradation of anthocyanins occurred at a faster rate with increasing temperature at 5.82 and 11.63 mmol.L^?1 H₂O₂ concentrations. Between 25‐55C, activation energies (E_a) were 9.53 and 10.60 kcal.mol^?1 for 5.82 and 11.63 mmol.L^?1 H₂O₂ concentrations, respectively. Higher E_a value at 11.63 mmol.L^?1 H₂O₂ concentration indicated that the effect of temperature increased at higher H₂O₂ concentrations. A quadratic relationship (y = ‐0.0031x²+ 0.0218x + 0.0008, R²= 0.996) was found between the degradation rates at 20C and H₂O₂ concentrations of 0.233‐2.327 mmol.L^?1. According to this equation, k of 1.12 × 10^?3 h^?1 and t_1/2 of 26 days at 20C may be expected at 0.5 ppm (0.0147 mmol.L^?1) H₂O₂ concentration, i.e., the max. allowable H₂O₂ level by FDA in the finished food packages.     

TAED及其对H2O2漂白的活化作用

介绍了四乙酰乙二胺(TAED)的合成及其对H202漂白的活化机理，采用TAED作为棉纤维H2O2漂白的活化剂，探讨了碱浓度、TAED浓度及漂白时间对漂白效果的影响．实验表明，在一定的工艺条件下，TAED可以大大提高H202在较低温度和PH值条件下漂白的效果，为TAED作为漂白促进剂的工业化应用提供了理论依据．     

THE FORMATION OF HYDROGEN PEROXIDE DURING OXIDATION OF THIOL-CONTAINING PROTEINS

A brief treatment off malt slurry with acid inactivates many of the enzymes that degrade hydrogen peroxide. It is then possible to show that hydrogen peroxide can be formed by some malt protein fractions (especially those rich in free thiols), when heated or when subjected to intense illumination by visible light. This reaction also occurs with other thiol-rich proteins. Blue light is most effective whilst catalase but not superoxide dismutase, is able to inhibit the reaction .     

蜂胶中有效成分的提取及其抗氧化性能的研究

研究了用乙醇提取蜂胶中有效成分的工艺条件，并对其进行了抗氧化性能的研究。经响应面优化的试验结果表明最佳提取条件为：乙醇浓度为94．51％，提取温度为34．44℃，提取时间为33．86h，料液比为1：15．91。抗氧化试验表明蜂胶的乙醇提取物(EEP)可有效地延缓油脂脂质过氧化反应，通过与维生素E和茶多酚进行比较，其抗氧化性能明显优于二者，表明蜂胶的乙醇提取物是一种很有潜力的天然、安全、高效的油脂抗氧化剂。     

水玻璃稳定双氧水的探讨

通过实验证明使用水玻璃作练漂液中双氧水的稳定时，添加MgSO4或SnCl4均可增加稳定性，提高毛效，降低织物损伤，其中，添加的效果MgSO4好于SnCl4.     

GPL氧漂稳定剂在抽纱钩花制品的应用

探讨了ＧＰＬ氧漂稳定剂的结构,性能及在抽纱钩花制品的应用。     

MODE OF ACTION OF ETHYLENE OXIDE ON SPORES OF Clostridium botulinum 62A

SUMMARY— Death of spores of Clostridium botulinum when exposed to gaseous ethylene oxide followed first order kinetics. Supplementation of a synthetic medium with the purine and pyrimidine bases of DNA and RNA indicated, as judged by outgrowth from spores which had received sublethal ETO treatments, that the lethal action of ETO on the spores was through alkylation of the guanine and adenine components of DNA. Observed impairment of RNA and protein synthesis was considered an indirect effect resulting from alkylation of DNA components; however, additional evidence bearing on this point is needed to support a more definite conclusion.     

非硅酸盐系双氧水漂白稳定剂PST的研制及应用性能

采用多种有机螯合剂与无机盐等复配成双氧水稳定剂PST，测试了其分解率，白度，毛效和手感，并与水玻璃作了比较，试验结果表明：稳定剂PST性能优良，对双氧水稳定效果好，能使织物获得较好的白度，毛效和手段，且成本不高，操作简便，是理想的双氧水漂白稳定剂。