电化学方法在丹参天然抗氧化剂研究中的应用

随着自由基医学和自由基生物学的发展,研究表明,当内源性抗氧化体系出现故障或机体处在一些病理或恶劣的生理环境,氧自由基大量产生在错误的时间及部位时,其代谢就会出现失衡,导致细胞损伤,引起心脏疾病、癌症和衰老,所以寻找高效低毒的抗氧化剂尤为重要。文章阐述了电化学方法研究天然抗氧剂的理论基础及研究意义;综述了国内外应用电化学方法研究天然抗氧化剂的现状以及电化学方法在丹参有效成分这类天然抗氧化剂研究中的应用。     

天然抗氧化剂研究进展

综述了天然抗氧化剂的分类、天然抗氧化剂与疾病防治、天然抗氧化剂的作用以及天然产物中的抗氧化剂。     

几种天然抗氧化剂在化妆品中的应用研究

简述了人体皮肤老化的原因和表现形式。从来源上重点介绍了几种常见的天然抗氧化剂茶多酚、迷迭香提取物、竹叶提取物以及番茄红素在各种化妆品中的应用情况。结合天然抗氧化剂的特点,展望了天然抗氧化剂在化妆品中的发展趋势。     

提高菜籽油抗氧化性的研究进展

综述了人工合成抗氧化剂、天然抗氧化剂、复合型抗氧化剂和物理方法在提高菜籽油抗氧化性能中的应用和研究进展。发现人工合成抗氧化剂对人体存在安全性的风险;复合型抗氧化剂操作过程繁琐;物理方法无污染但成本大,在生产销售过程中难以实现严格的条件控制;发现使用天然抗氧化剂效果好,可以减少对人体的毒副作。     

天然抗氧化剂在食品加工中的应用

本文对国内外研究天然植物性抗氧化剂的状况进行了阐述,对植物香辛料、茶叶、果蔬类植物的抗氧化性能进行了具体的研究,介绍了3种新型天然食品抗氧化剂,并指出今后研究植物性天然杭氧化剂的方向,为利用、开发天然食品抗氧化剂提供参考和信息。     

酚酸类化合物的测定方法研究

阐述了酚酸类化合物作为天然抗氧化剂的机理，从光化学方法、色谱法及电化学分析法等方面综述了近年来国内外的多种酚酸类化合物的测定方法，引用文献85篇。     

山茶提取物对润肤油抗氧化效果的研究

研究了天然抗氧化剂"山茶提取物"在化妆品植物润肤油体系中的抗氧化效果。通过在化妆品润肤油中添加不同种类的抗氧化剂,以润肤油体系中油脂氧化诱导时间、DPPH自由基清除率、不同存储条件下的色差作为油脂稳定性评价指标。结果表明:山茶提取物对润肤油的氧化稳定性能较其它抗氧化剂更好。     

天然抗氧化剂及其在食品中的应用

本文综述了天然抗氧化剂的种类、来源及其在食品保存中的应用与进展。     

植物多酚在食用油脂中的应用研究进展

由于天然植物多酚类化合物作为抗氧化剂具有安全性高、无毒、来源广泛、抗氧化性强等特性，其应用于食用油脂抗氧化受到国内外研究者广泛关注。本文综述了近年来在食用油脂中添加天然植物多酚的研究现状，着重介绍了天然植物多酚的来源、提取方法，重点综述了大豆油、葵花籽油、橄榄油等添加天然植物多酚抗氧化剂的主要研究进展，为植物源天然抗氧剂的提取、开发、应用提供科学参考。     

马蹄皮资源化利用研究

综述了马蹄皮资源利用研究现状,结果表明,当前可行的马蹄皮资源化利用技术包括提取棕色素、抗菌物质、抗氧化剂和生产保健饮料等,其中以提取天然抗菌物质和天然抗氧化剂更为引人注目。     

抗氧剂在塑料中的应用

以实例说明了天然抗氧剂、反应型抗氧剂、非酚类抗氧剂等几种抗氧剂在塑料中的应用,并提出应注重抗氧剂的应用研究.     

An approach to assess the synergistic effect of natural antioxidants on the performance of the polypropylene stabilizing systems

A study on the efficiency of natural antioxidants from agri‐food industry wastes as long‐term antioxidants for polypropylene (PP) is reported. Special attention is paid to the usage of vegetal wastes as a source of natural antioxidants such as alternatives to synthetic long‐term antioxidants. The potential of the lignin‐derived fractions generated during autoydrolysis processing of lignocellulosic agricultural, forestal, and food wastes was assessed. The measurements of oxidation induction time were used for obtaining information on long‐term antioxidant effectiveness, showing the protective effect of natural extracts. The protective effect was improved in combinations of natural extracts with 0.1% and 0.2% of Irgafos 168 (short‐term antioxidant) besides a synergistic effect was exhibited when 0.4% of Irgafos 168 is added. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

大麦天然酵素抗氧化性能的初步探究

大麦天然酵素为大麦经过天然发酵过程得到的发酵液,富含抗氧化活性物质。对大麦天然酵素抗氧化性能进行了初步探究。结果表明,天然发酵过程制得的大麦酵素具有较强的抗氧化活性,对羟基自由基、DPPH自由基、超氧自由基和ABTS自由基具有较高的清除能力;大麦天然酵素展现了较高的抗氧化能力,其抗氧化活性的大小与酚类物质含量具有一定相关性。本研究结果可为天然酵素产品的研发和生产工艺的改进提供一定的支持,为大麦的多功能开发利用提供新的思路。     

抗氧剂的抗氧机理及发展方向

总结了抗氧剂的作用机理、发展趋势和结构与抗氧性的关系。抗氧剂作用机理包括链终止剂、过氧化物分解剂和金属离子钝化剂,其中链终止剂包括氢给予体、自由基捕捉剂和电子给予体;抗氧剂的发展趋势包括多功能化、反应型和天然抗氧化。     

Natural antioxidants from herbs and spices

There is a growing interest in natural antioxidants found in plants because of the world‐wide trend toward the use of natural additives in food and cosmetics. Herbs and spices are one of the most important targets to search for natural antioxidants from the point of view of safety. This review presents the results on stabilization of lipids and lipid‐containing foods with different herbs and spices (ground materials or extracts) and reports the structure of the main antioxidatively acting compounds isolated from them. The review presents information about the antioxidative effects of rosemary, sage, oregano, thyme, ginger, summer savory, black pepper, red pepper, clove, marjoram, basil, peppermint, spearmint, common balm, fennel, parsley, cinnamon, cumin, nutmeg, garlic, coriander, etc. Among the herbs of the Labiatae family, rosemary has been more extensively studied and its extracts are the first marketed natural antioxidants. Sage and oregano, which belong to the same family, have gained the interest of many research groups as potential antioxidants.     

油酸抗氧剂的筛选及应用

对市售合成抗氧剂及少量天然抗氧剂进行筛选及机理研究,结果为复合抗氧剂优于单一抗氧剂。     

The effect of antioxidants on butter in relation to storage temperature and duration

The effects of antioxidants on the oxidative stability of butter, under different storage time and temperature conditions, were evaluated. Natural (α‐tocopherol) and synthetic (BHA and BHT) antioxidants were added to the butter samples at two concentrations (50 and 100 ppm) immediately after the butter samples were produced from the pasteurised sweet cream, after which they were kept in the dark at 4 and ?20 °C for 6 months. Peroxide value (PV) and thiobarbituric acid (TBA) number and the residual antioxidants of the samples were examined at 30‐day intervals, starting on the second day until the end of the storage period. The measurements obtained by assaying PV and TBA number in butter samples showed that both the synthetic and natural antioxidants used were capable of protecting the butter samples against oxidation during storage at both temperatures. The butter samples with 50 ppm antioxidant could be stored for more than 180 days at 4 °C without spoilage. At ?20 °C, the addition of BHA, BHT and α‐tocopherol caused a reduction in the TBA number from 0.31 (control) to 0.21, 0.23 and 0.27 mg malonaldehyde/kg butter, respectively, and the PV decreased from 0.75 (control) to 0.46, 0.56 and 0.54 meq O₂/kg butter, respectively, after 6 months of storage. The highest residue values were determined in both the 100 and 50 ppm α‐tocopherol‐containing samples. These results indicate that α‐tocopherol exhibited a very strong antioxidant activity, which was almost equal to that of the synthetic antioxidants. Therefore, the use of α‐tocopherol is recommended as a natural antioxidant to suppress the development of rancidity in butter.     

Dependence of Mooney scorch time of SMR L,ENR 25, and ENR 50 on concentration and types of antioxidants

The effect of concentration of antioxidants on the Mooney scorch time of two grades of epoxidized natural rubbers (ENR 25 and ENR 50) and one grade of natural rubber (SMR L) was studied using a Monsanto automatic Mooney viscometer (MV 2000). Three types of antioxidants, viz., 2,2′‐methylene‐bis(4‐methyl, 6‐tertbutylphenol) (AO 2246), N‐isopropyl‐N′‐phenyl‐p‐phenylenediamine (IPPD) and poly‐2,2,4‐trimethyl‐1,2‐dihydroquinoline (TMQ) were used, and the concentration range was varied from 0 to 5 phr. The conventional vulcanization system with 2‐mercaptobenzothiazole (MBT) as the accelerator was used throughout the study. Results show that increasing the phenol‐based antioxidant (AO 2246) concentration will increase the scorch time of ENR at a lower temperature of vulcanization while its effect on SMR L is not significant. This retardation effect is attributed to the “solvation” of epoxide group by the phenolic group in AO 2246, thus reducing the activation of adjacent double bond in ENR. The scorch time, however, is shortened by the amine‐based antioxidants (IPPD and TMQ) for the three rubbers studied, a phenomenon associated with the ability of the amine group to enhance the formation of more active sulfurating agent and subsequently increases the cure rate as the concentration of the amine‐based antioxidants is increased. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2940–2946, 1999     

Comparative study on natural antioxidant as an aging retardant for natural rubber vulcanizates

The research aim is mainly to investigate the effectiveness of natural antioxidant (NA) obtained from oil palm leaves (Elaeis guineensis) as an aging retardant in natural rubber (NR) vulcanizates. Comparison of NA with other commercial antioxidants, trimethyl quinoline (TMQ) and butylated hydroxy toluene (BHT), is investigated. The effect of natural and commercial antioxidants on NR vulcanizates was explored before and after aging. Aging test was carried out at 70°C for three different periods, 4, 7, and 14 days to determine aging property by performing the tensile and tear tests. NA shows lower tensile properties, crosslink density, tack strength but high tear strength compared to the commercial antioxidants, BHT and TMQ. However, upon aging NR vulcanizates with NA retains its properties equivalent to that of commercial antioxidants, BHT and TMQ. Thus, NA can be used as an aging retardant for short‐term protection in application requiring moderate tensile properties and can be used as alternative source for commercial antioxidant. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012