Effect of Some Preservatives on the Poultry Lipids

Some treatments were conducted for prolonging the self life of broiler meat such as storage at two different temperatures (3 °C and -18 °C) with and without adding chemical preservatives (NaCl, polyphosphate and a mixture of them). Fatty acid composition of blended skin tissue and subcutaneous carcasses lipids were qualitatively and quantitatively determined by gasliquid chromatography. The fatty acid analysis indicated that 16:0 and 18:1 were the most predominant saturated and unsaturated acids of fresh skin tissue and subcutaneous carcasses lipids. Dipping carcasses in hot water alone and with NaCl, polyphosphate or a mixture of them exhibited very little effect on the fatty acid pattern. Storage at 3 °C led to conversion of some long-chained and unsaturated fatty acids to mediumchained and saturated ones. Dipping carcasses in tap or hot water with or without preservatives caused quantitative changes in 16 :0,18 :0,18 :1 and 18 :2 acids. In general, the most efficient treatment towards keeping carcasses quality is storage at -18 °C without adding any chemical preservatives.     

Investigation of antioxidant activity and lipophilicity parameters of some preservatives

The preservatives have been widely used in food, drugs and cosmetic products to prevent their aging and decay. Antioxidant and antimicrobial activities of some preservatives, such as benzoic acid, sorbic acid and alkyl-parabens, were considered in this work. Study of antioxidant properties of these compounds was carried out by differential pulse voltammetry together with evaluation of their influence on the kinetics of the electrochemical oxygen reduction. Mathematical models of the processes were obtained and their adequacy was estimated using design of experiment methods. As a result, the kinetic parameters of interaction between reactive oxygen species and preservatives were evaluation. Finally, the use of these substances as antimicrobials and antioxidants ensured product stability and safety has been recommended.     

Untersuchungen über die Wirksamkeit von Konservierungsmitteln in anionaktiven Tensiden II

Investigations on the Efficacy of Preserving Agents in Anion Active Surfactants II The authors investigated the preserving action of p-chloro-m-cresol and of pHB-methyl/ethyl ester combination (1 + 1) in solutions of anion active surfactants. The preservatives were employed at two different concentrations. The concentration of the surfactants (lauryl sulfate and protein-fatty acid condensate as sodium, potassium and triethanolamine salts) was varied from 0.1 to 10.0 g/100 g. The pH of the solutions was 7. The deactivation of the preservatives investigated here by the anion active surfactant occurs only after a certain ratio of surfactant to preservative is reached. Under this ratio the preservatives are fully effective; above this, however, are the preservatives deactivated.     

Keimgehalt von Körperpflegemitteln

Germ Content of Cosmetics Different charges of indigenous and foreign products consisting of 26 skin nourishing creams, 11 skin cleansing preparations, 5 skin tonics, 11 vanishing creams and 7 cold creams were investigated bacteriologically in order to find out as to how far these preparations are hygienically unobjectionable. The difficulties in testing due to the consistency and composition of the base as well as due to the addition of mostly bacteriostatic preservatives could be largely overcome. The result, according to which more than one fourth of the cosmetics tested were not hygiene-esthetically unobjectionable, clearly shows that from the prophylactical point much is still to be done in production and filling.     

IBX在有机合成中的研究进展

综述了近年来有关邻碘酰苯甲酸（IBX）的各类反应,优化的反应条件及IBX的类似物.     

中草药凉茶中苯甲酸、山梨酸、对羟基苯甲酸酯类同时测定的方法研究

目的：建立一种应用高效液相色谱法同时测定中草药凉茶中五种防腐剂含量的新监测方法。方法：样品经ODS-C18层析柱固相萃取净化、分离,20 mmoL乙酸铵与乙腈为流动相,进行梯度洗脱。结果：可将五种防腐剂完全分离,在8～200μg/mL线性范围内（r均大于0.9999）,回收率在88.9%～110.8%之间,RSD在1.18%～6.82%之间（n=6）。最低检出限分别为：2.66×10-4、3.36×10-4、7.36×10-4、3.88×10-4、3.12×10-4 mg/kg;最低定量限分别为：1.33×10-3、1.68×10-3、3.68×10-3、1.94×10-3、1.56×10-3 mg/kg。结论：通过对样品前处理条件的选择和优化,能较好地除去大部分杂质的干扰。本方法能满足中草药凉茶中苯甲酸、山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯同时测定的要求,具有较好的推广意义;亦可作为监测儿童中药合剂和凉茶饮料防腐剂含量限制的参考。     

Anodic oxidation of parabens in acetic acid�Cacetonitrile solutions

The electrochemical properties of esters of p-hydroxybenzoic acid, called parabens, were investigated on a carbon fiber microelectrode and on a glassy carbon macroelectrode in glacial acetic acid containing 20?% acetonitrile (v/v) and sodium acetate as a supporting electrolyte. The anodic oxidation of parabens in this medium proceeds in a single stage giving well-shaped peaks or waves in the same potential region of above 1.0?V (vs. Ag/AgCl). The electrode process was characterized as being quasireversible, diffusion-controlled, and proceeds with the exchange of one electron and one proton. Phenoxyl radicals as products of the electrode process are chemically unstable and participate in the successive irreversible homogenous reactions resulting in electroinactive products (E _q C _i mechanism). Smaller oxidation potentials for parabens in comparison to such unsaturated fatty acids as oleic, linoleic, and linolenic ones indicate that these compounds can show antioxidative properties. Since parabens are often used as preservatives in many products, the results presented can be found useful in the determination of their total content in real samples.     

几种复合防腐剂在化妆品中的防腐效果及评价

目的考察不同复配比的防腐剂在化妆品基质中的作用效果,寻求一种新型复合防腐剂。方法采用微生物挑战性实验验证复合防腐剂对微生物的抑菌能力。结果在面膜液基质中,对羟基苯甲酸酯类复配而成的复合防腐剂对抑制细菌效果较好,抑制霉菌效果较弱。对羟基苯甲酸酯类及苯氧乙醇复配而成的复合防腐剂抑菌效果较好。在粉底霜基质中,由含量分别为0.20%、0.10%和0.20%的对羟基苯甲酸甲酯、对羟基苯甲酸丙酯及苯氧乙醇复配而成的复合防腐剂对抑制细菌、霉菌效果达到最好且含量相对较低,为最优复合防腐剂。结论应用于面膜基质液和粉底霜基质液的复合防腐剂:0.12%甲酯、0.02%丙酯、0.3%的苯氧乙醇和0.20%甲酯、0.1%丙酯、0.2%苯氧乙醇通过了挑战性实验。根据化妆品的配方结合实际情况,该两种新型复合防腐剂可行性强。     

Organocatalytic Application of Direct Organo-Functionalized Mesoporous Catalysts Prepared by Microwave

The organic functional groups such as primary and quaternary amine, sulfonic acid, and amino acid, especially l-proline, have been tried to immobilize onto mesoporous materials by the direct synthesis method using microwave. Microwave induced direct functionalization enabled to get well ordered mesoporous structures and stable organic tethered groups with enhanced hydrothermal stability due to more hydrophobic surfaces as well as enhanced activity. The method is also useful for overcoming several shortcomings in the post-synthesis grafting method which suffers from pore blocking at the aperture, and difficulties in controlling the as obtained from the direct co-condensation method had their functional groups spatially loadings, as well as the dispersion of active sites. The organo-functionalized mesoporous silica dispersed on the surface which could play roles as single site catalysts. Direct tethering of organic functional groups was preferably synthesized by microwave, gave morphological control and illustrated superiority in some organocatalytic application such as Knoevenagel and Henry reactions base catalytic reaction, Claisen–Schmidt condensation, and diethyl malonate addition reactions.     

20种食品防腐剂抗氧化剂的分子结构与其急性毒性的相关关系研究

对苯甲酸等14种食品防腐剂及叔丁基对苯二酚等6种食品抗氧化剂的大鼠急性经口毒性[Log(LD50)]与其化学结构的关系进行了探讨,求出了这些防腐剂、抗氧化剂的部分分子连接性指数,并参照图论法对分子中各种基团进行了分类.采用多元线性拟合法, 求出了各防腐剂分子中各种基团的个数及分子连接性指数与其大鼠急性经口毒性关系的回归方程, 能得到方程的计算值与文献值一致的结果.     

化妆品中甲醛含量的测定方法

甲醛由于其亲水性好、杀菌效率高、价格低廉以及不受体系中的酸碱度的影响等优点,而用作化妆品的防腐剂。但甲醛对人体健康的危害很大,因此需要对化妆品中的甲醛含量进行检测。本文详细介绍了测定化妆品中甲醛含量的方法,并对每种方法进行评价和总结。随着化妆品防腐技术的不断发展,未来的化妆品中将会彻底禁用甲醛。     

Physico‐chemical composition,fractionated glycerides and fatty acid profile of chicken skin fat

Skin is one of the several co‐products of chicken meat industries, considered as waste, being rarely utilized or underutilized. Brazil is the world leader in chicken exports (3.6 million tons) and the third largest producer with 10.9 million tons, from which 440 000 ton/year are residues. This work aimes at characterizing chicken skin fat (CSF), comparing it with soybean oil, a well‐known and abundant compound, evaluating the physico‐chemical composition, fractionated glycerides and fatty acid profile, searching for CSF use in interesterification reactions. For that, determination of peroxide and p‐anisidine values, as well as thiobarbituric acid, iodine, saponification, acidity, unsaponified matter and refraction indexes were accomplished, besides the glycerides fractionation, followed by FAME derivatization and identification by GC. The nutritional quality indexes were calculated from the lipid profile. CSF showed satisfactory quality due to low acidity (0.65 g oleic acid/100 g), peroxide (2.14 meq/kg), p‐anisidine (0.70 absorbance units/g) values, besides presenting high proportion of MUFA (40%). However, due to CSF low hypocholesterolemic/hypercholesterolemic value (HH = 2.72), it may be difficult to use it for nutritional purposes the way it is found, once it tends to increase cholesterol. CSF it is a promising residue for different purposes including interesterification reactions and biodiesel production.     

气相色谱-质谱联用法测定烟用香精和料液中的防腐剂

采用乙醇作为溶剂,使用气相色谱/选择离子质谱联用法,同时实现烟用香精和料液中山梨酸、苯甲酸和4种对羟基苯甲酸酯类化合物的分离检测。该方法前处理快速简便,方法稳定性好,结合了保留时间与提取定性离子的分析,使定性准确度提高。而含量检测的相对标准偏差小于5%;加标回收率为88.0%~101.1%;方法检出限为0.003~0.05μg/g。用该方法对10种烟用香精与料液样品中的防腐剂进行定量检测,结果表明4个样品含有山梨酸和苯甲酸,全部样品未检出对羟基苯甲酸酯类物质。     

Formation of By‐products in Pure and Aqueous Acrylic Acid – Kinetic Measurements and Formation Mechanisms

During acrylic acid (AA) storage, a quality loss occurs due to the formation of by‐products such as diacrylic acid (DiAA), triacrylic acid (TriAA), and higher oligomers. This problem intensifies in the presence of water since the formation rate of oligomers increases and further by‐products such as 3‐hydroxypropionic acid (3‐HPA) and 3‐hydroxydiacrylic acid (3‐HDiAA) are formed. However, water is often essential during storage and transport to raise the flash point or reduce the melting point. In this work, the formation kinetics are investigated for all mentioned components in pure and aqueous AA. The formation mechanisms of 3‐HPA and 3‐HDiAA are assumed as acid‐catalyzed ester hydrolyses of DiAA or TriAA. The introduced reactions are modeled with the measured kinetic data in order to confirm the proposed reactions.     

Towards the Enhancement of Essential Oil Components’ Antimicrobial Activity Using New Zein Protein-Gated Mesoporous Silica Microdevices

The development of new food preservatives is essential to prevent foodborne outbreaks or food spoilage due to microbial growth, enzymatic activity or oxidation. Furthermore, new compounds that substitute the commonly used synthetic food preservatives are needed to stifle the rising problem of microbial resistance. In this scenario, we report herein, as far as we know, for the first time the use of the zein protein as a gating moiety and its application for the controlled release of essential oil components (EOCs). The design of microdevices consist of mesoporous silica particles loaded with essential oils components (thymol, carvacrol and cinnamaldehyde) and functionalized with the zein (prolamin) protein found in corn as a molecular gate. The zein protein grafted on the synthesized microdevices is degraded by the proteolytic action of bacterial enzymatic secretions with the consequent release of the loaded essential oil components efficiently inhibiting bacterial growth. The results allow us to conclude that the new microdevice presented here loaded with the essential oil component cinnamaldehyde improved the antimicrobial properties of the free compound by decreasing volatility and increasing local concentration.     

食品防腐防霉剂——富马酸二甲酯的生产与应用

本文综述了ＤＭＦ的性质、特征、合成方法、以及在各领域的应用，尤其是它的防霉性能优于丙酸钙和山梨酸。笔者认为ＤＭＦ作为食品饲料防霉剂应加以重视。     

Rate enhancement in palladium catalyzed Heck reactions by Lewis acid promoters

Significant enhancement in the rate of Heck reactions has been achieved when catalytic amounts of Lewis acid (like FeCl₃) promoters in the presence of trace amounts of water (>2000 ppm) are used along with Pd complex catalysts. Experiments with different aryl halides, bases as well as olefins have been carried out to demonstrate the role of Lewis acid promoters. The increase in the reaction rates is due to the weakening of Ar–X bond by the Lewis acid in the manner similar to Friedel–Crafts reaction.     

防腐剂的功与过

化妆品中防腐剂的安全性和过敏性早已引起消费者的关注。并持续地推动防腐剂品种的变化。为了最大限度地降低化妆品的过敏性，不同的化妆品制造商采用了不同的措施，例如寻找防腐剂的替代品，采用气密性包装等。     

木材防腐剂CCB中有效成分硼的测定方法探讨

采用一种常规化学滴定分析方法对CCB木材防腐剂中的有效成分硼进行分析测定,结果表明:该测定方法的准确度和精密度较高,且操作简便,是一种适合于在工业生产中检测CCB有效成分硼的方法。     

Untersuchungen über die Wirksamkeit von Konservierungsmitteln in anionaktiven Tensiden I

Investigations on the Effectiveness of Preservatives in Anion Active Surfactants The preserving action of five preservatives was tested at pH values of 6, 7 and 8 in 10% solutions of the anion active surfactants sodium lauryl sulfate, protein-fatty acid condensate and sodium laurylether sulfate. It was found that the three difficultly water-soluble compounds p-chloro-m-cresol, pentachlorophenol and the combined methyl and ethyl esters of the p.H.B. esters are ineffective at usual concentrations. Both of the watersoluble preservatives polyoxymethyleneglycol and chloroacetamide were effective. Furthermore, it was observed that the preservative action of chloroacetamide is enhanced by anion active surfactants. The inactivation of the difficulty watersoluble preservatives is traced back to the solubilization of these compounds by the micelle of the anion active surfactants.