“无添加”防腐剂MIC值的测定结果及应用

本文根据最小抑菌浓度(MIC)测定方法测试了九种"无添加"防腐剂的MIC值,对"无添加"防腐剂在防腐方面最具有说服力的MIC值做出了较为系统和全面的研究。然后又对"无添加"防腐剂进行了挑战性试验,选取了新研制的一个"无添加"防腐体系华科-11K,做了防腐挑战性试验,试验效果良好。     

中药液体制剂中防腐剂的应用

从常用防腐剂的性质,影响防腐剂防腐作用的因素等方面阐述了中药液体制剂中防腐剂的选用原则,并介绍了几类型新防腐剂。     

活性炭对抗毒素中防腐剂含量的影响

为了解使用活性炭去除抗毒素原液的不可溶性杂质试验中对防腐剂含量所产生的影响。方法比较不同用量活性炭吸附抗毒素原液中防腐剂的损失情况;按最低活性炭使用量,观察整个实验过程中防腐剂含量的变化。结果分别以20 g/L、30 g/L、50 g/L活性炭经2 h吸附后,防腐剂量的损失均达到98%;在20 g/L活性炭使用量吸附4 h的试验中,防腐剂量的损失主要发生在最初的1 h。结论使用活性炭去除抗毒素原液中的不可溶性杂质试验中,由于活性炭较强的吸附作用,从而对防腐剂含量产生了很大的影响。     

涂料微生物污染与防腐剂使用情况关系的探讨

为了解涂料的微生物污染与防腐剂使用情况之间的关系,按照ISO 9252-1989(E)检测207件市售涂料微生物指标,利用高效液相色谱检测有微生物检出涂料和40件无微生物检出涂料的防腐剂使用情况。结果发现有12件涂料微生物超标;异噻唑啉酮类防腐剂是本实验检出使用最多的防腐剂;微生物超标涂料防腐剂含量比正常低或者未检测到,种类单一。涂料的防腐剂使用情况与微生物污染程度有着密切的联系,建议建立和完善涂料限用防腐剂标准,指导涂料企业安全生产和质量监督。     

天然食品防腐剂乳链菌肽的性质及其应用

乳链菌肽是一种天然食品防腐剂。本文概述了乳链菌肽的理化性质、抑菌性能、作用机制及在食品防腐中的应用。     

新型防腐剂在淋洗类日化产品中的应用

对三种新型日化防腐剂华科-CAP、华科-11M及华科-11N进行了微生物抑制特性测试,在不同的使用浓度下,对其在淋洗类产品中进行了微生物挑战试验。结果表明,单独使用时浓度为0.6%～0.8%的三种防腐剂均通过了微生物挑战性试验,并优选出了具有良好抑制细菌、真菌生长效果的防腐剂配方。     

体外诊断试剂防腐剂的选择策略

对体外诊断试剂中防腐剂的作用机理及选择原则进行了阐述,并对目前常用的防腐剂如叠氮钠、庆大霉素、硫柳汞、异噻唑啉酮类等的性能进行了比较,为体外诊断试剂的研究开发及生产中防腐剂的使用提供有益指导。     

微生物源天然防腐剂在食品上的应用研究

微生物源天然防腐剂是理想的天然食品防腐剂,具有安全、无毒、高效、无副作用的特点,符合未来食品防腐的发展与使用要求,在食品工业中的应用越来越广泛.该文对天然微生物源防腐剂的来源分类、抑菌特性、抑菌机理及适用范围进行了系统的研究分析与论述.有针对性地对目前两种应用最为广泛的微生物源天然防腐剂乳酸链球菌素和纳他霉素予以介绍,同时对微生物源天然防腐剂使用过程中遇到的问题提出了对策建议.对天然防腐剂的应用与发展具有现实和指导意义.     

抗防腐剂型微生物培养基研究

食品饮料中含有山梨酸、山梨酸钾、苯甲酸及苯甲酸钠等防腐剂会对其中的细菌和真菌的检出造成严重干扰,把测定体系的抗防腐剂指数控制在８１．１～９４．５之间,可较好地消除防腐剂对微生物生长的抑制。防腐剂解抑剂Ⅲ的抗防腐剂指数为９２．３４,对细菌和真菌的生长无抑制作用,加入经改良和优化的普通培养基后,制得５种抗防腐剂型培养基,在灭菌前后和一年保存期内,它们的抗防腐剂指数基本保持不变。与普通培养基比较,当采用大样倾注平板法和液体大样法检测含有防腐剂的样品时,抗防腐剂型培养基可极大地提高样品中的细菌和真菌的检出率。     

抗防腐剂型微生物培养基研究*

食品饮料中含有山梨酸、山梨酸钾、苯甲酸及苯甲酸钠等防腐剂会对其中的细菌和真菌的检出造成严重干扰,把测定体系的抗防腐剂指数控制在８１．１～９４．５之间,可较好地消除防腐剂对微生物生长的抑制。防腐剂解抑剂Ⅲ的抗防腐剂指数为９２．３４,对细菌和真菌的生长无抑制作用,加入经改良和优化的普通培养基后,制得５种抗防腐剂型培养基,在灭菌前后和一年保存期内,它们的抗防腐剂指数基本保持不变。与普通培养基比较,当采用大样倾注平板法和液体大样法检测含有防腐剂的样品时,抗防腐剂型培养基可极大地提高样品中的细菌和真菌的检出率。     

聚赖氨酸的研究进展

聚赖氨酸(ε-PL)是由20～35个赖氨酸残基通过α-羧基和ε-氨基聚合成的具有抑菌功效的多肽。它具有安全性高、对革兰氏阳性菌,革兰氏阴性菌,真菌等都有广泛的抑制繁殖作用等优点且热稳定性,水溶性好。在食品保鲜防腐、医学等方面都有广泛的应用。     

Evaluation of recalcitrance of mascara in a cartridge container system to microbial challenge

Summary A cartridge mascara system designed to minimize the exposure of mascara to the environment during use was evaluated for recalcitrance to bacteria. The design of the system contributed to low numbers of bacteria found in the mascara, but the need for preservatives was not alleviated.     

The antioxidant activities of seasonings used in Asian cooking. Powerful antioxidant activity of dark soy sauce revealed using the ABTS assay

Scavenging of the ABTS (2,2′-azinobis[3-ethylbenzothiazoline-6-sulphonate])-derived nitrogen-centred radical cation (ABTS^?+) was used to compare the total antioxidant activities of several seasonings used in Asian cooking. The results were expressed as Trolox equivalent antioxidant capacity (TEAC). The TEAC activities of dark soy sauces were found to be exceptionally high. In evaluating the TEAC of commercial products, attention must be paid to the addition of preservatives by manufacturers to the seasonings tested. Sodium benzoate (a preservative added to several seasonings) did not react significantly with ABTS^?+, but the sulphite content of certain white wines may have led to an over-estimation of their TEAC.     

Antimicrobial activity of polyphenolic compounds from Spirulina against food-borne bacterial pathogens

Food-borne drug-resistant bacteria have adverse impacts on both food manufacturers and consumers. Disillusionment with the efficacy of current preservatives and antibiotics for controlling food-borne pathogens, especially drug-resistant bacteria, has led to a search for safer alternatives from natural sources. Spirulina have been recognized as a food supplement, natural colorant, and enriched source of bioactive secondary metabolites. The main objectives of this study were to isolate polyphenolic compounds from Spirulina and analyze their antibacterial potential against drug-resistant food-borne bacterial pathogens. We found that fraction B of methanol extract contained a high quantity of polyphenols exhibiting broad spectrum antimicrobial effects against drug-resistant food-borne bacterial pathogens. Potential secondary metabolites, such as benzophenone, dihydro-methyl-phenylacridine, carbanilic acid, dinitrobenzoate, propanediamine, isoquinoline, piperidin, oxazolidin, and pyrrolidine, were identified by gas chromatography and mass spectrophotometry (GCMS). These metabolites are active against both gram-positive and gram-negative pathogens. Our work suggests that phenolic compounds from Spirulina provide a natural and sustainable source of food preservatives for future use.     

Tolerance to wood preservatives by copper-tolerant wood-rot fungi native to south-central Chile

Understanding the effect of heavy metals and wood preservatives on the growth of wood-rot fungi native to a certain region may improve reliability in determining the effectiveness of antifungal products, particularly when dealing with new formulations. In this investigation, strains of copper-tolerant wood-rot fungi native to south-central Chile were evaluated against two preservatives: commercial chromated copper arsenate type C (CCA-C) and a new formulation with boron and silicon (BS). Thirteen native strains, mainly white-rot fungi, were selected for their high growth rates in solid medium containing 3 mM of copper. A short-term test was then carried out, consisting of adding cellulose disks impregnated with different concentrations of preservatives to solid culture media inoculated with selected copper tolerant strains. There was a great variability in interspecific and intraspecific responses to the presence of copper and preservatives in culture media. Among the native and commercial strains evaluated, the white-rot fungi Trametes versicolor 38 and mainly Ganoderma australe 100 were notable for their tolerance to all the CCA-C and BS concentrations. The brown-rot fungus Wolfiporia cocos, used as reference strain, showed a high tolerance to CCA-C, but not to BS preservative. T. versicolor 38 and G. australe 100 were selected for subsequent studies on preserved wood degradation.     

不同保鲜剂对大花飞燕草切花生理特性的影响

以大花飞燕草‘夏季天空’切花为材料,以清水为对照,采用14种不同保鲜剂对其进行保鲜处理。结果表明,SOD活性总体变化先上升再下降;CAT活性变化与SOD类似;POD活性,6-体呈上升趋势;MDA含量呈波动上升趋势;Pro含量呈先减少后又波动增加;可溶性蛋白质含量先增后减。同时发现各保鲜剂均能不同程度延长大花飞燕草切花的瓶插寿命,提升酶促系统的综合作用,降低MDATZPro含量,减缓蛋白质降解,延缓切花衰老,提高观赏品质,其中以保鲜剂1％蔗糖＋200mg·L-1 8-HQS＋50mg·L-1 AgNO3＋50mg·L-1 Al2（SO4）3保鲜效果最佳。     

迷迭香中天然防腐剂的提取方法及其抑菌作用研究

本文研究了迷迭香中天然防腐剂的提取方法和抑菌作用,结果表明,用食用乙醇提取迷迭香中防腐物质的最佳提取工艺参数为:固液比1:15、提取温度80℃、提取时间为15 h。迷迭香醇提取物对实验用常见食品污染菌有较强的抑制作用,对金黄色葡萄球菌和枯草芽孢杆菌的最低抑菌质量浓度(MIC)为6.25 g.L-1,对大肠杆菌和汉逊氏酵母菌为12.5 g.L-1,对青霉和黑曲霉为25 g.L-1,对金黄色葡萄球菌、大肠杆菌和枯草芽孢杆菌的抑菌活性pH范围均为4~7,对汉逊氏酵母菌、青霉和黑曲霉为4~6。     

The Effect of Grain Preservatives on the Growth of the Fungus Fusarium Graminearum and on the Quantity of Zearalenone

In the present study, the effects of preservatives, “Luprosil®” (propionic acid) and “Gasol” (contains organic acids and some additional compounds) on the growth of mycelium and the toxin content of stored grain (oats) infected by Fusarium and containing zearalenone have been examined. The toxin quantity was determined before adding the preservatives quantitatively (by liquid chromatography) from the ether extracts of oats cultures and semiquantitatively (by bioassay) from the solid residues of the extracted grain cultures. The total amount of toxin in the contaminated grain was proved to be 2.5 mg per g of dry matter. Preservatives were added to the grain which contained 37 % of dry matter: “Luprosil®” 0.08 ml and “Gasol” 0.12 ml/g dry matter applying average or slightly high recommended doses. The two preservatives completely prevented the growth of a visible mycelium. Propionic acid (“Luprosil®”) had no influence on the toxin content of oats. “Gasol” decreased the percentage of the total toxin about 60 % in 3 days, 85 % in 14 days and 90 % in 28 days. Further investigations into this subject are now proceeding.     

Yeast superoxide dismutase mutants reveal a pro-oxidant action of weak organic acid food preservatives

Saccharomyces cerevisiae could provide a simple experimental system for testing the antioxidant or pro-oxidant actions of chemicals, because it has the capacity for aerobic and anaerobic growth and can readily lose its mitochondrial electron transport chain (the major endogenous source of reactive oxygen species [ROS]). This study showed that yeast superoxide dismutase mutants, in a simple petri dish test, readily distinguish a compound that enhances the detrimental effects of endogenous ROS production by the mitochondrial respiratory chain from another chemical that generates oxidative stress by redox cycling. Using this system, weak organic acid food preservatives are shown to exert a strong pro-oxidant action on aerobic yeast cells. In addition these acids are mutagenic toward the yeast mitochondrial genome, even at levels that are subinhibitory to growth. This raises the concern that the large-scale consumption of these preservatives in the human diet may generate oxidative stress within the epithelia of the gastrointestinal tract.