食品科学 ›› 2020, Vol. 41 ›› Issue (17): 60-67.doi: 10.7506/spkx1002-6630-20190726-351

• 基础研究 • 上一篇    下一篇

对羟基苯甲酸及其烷基酯在水包油乳液中抗氧化效率的假相模型解释

黄师荣,万慧,颜思念,陈东方   

  1. (1.湘潭大学化工学院,湖南 湘潭 411105;2.湘潭大学“环境友好与资源高效利用化工新技术”湖南省高校2011协同创新中心,湖南 湘潭 411105)
  • 出版日期:2020-09-15 发布日期:2020-09-16
  • 基金资助:
    湖南省自然科学基金项目(2016JJ2120)

Pseudophase Model Interpretation of the Antioxidant Efficiency of p-Hydroxybenzoic Acid and Its Alkyl Esters in Oil-in-Water Emulsion

HUANG Shirong, WAN Hui, YAN Sinian, CHEN Dongfang   

  1. (1. College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China; 2. Collaborative Innovation Center of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization, Xiangtan University, Xiangtan 411105, China)
  • Online:2020-09-15 Published:2020-09-16

摘要: 以对羟基苯甲酸(p-hydroxybenzoic acid,HA)和系列正烷基醇为原料,采用直接酯化法合成4 种HA烷基酯。通过1,1-二苯基-2-苦肼基(1,1-diphenyl-2-picrylhydrazyl,DPPH)法研究了HA及其烷基酯在均相甲醇溶液中的抗氧化效率,采用Schaal烘箱实验法研究了HA及其烷基酯在油-水体积比为2∶8的水包菜籽油乳液中的抗氧化效率。结果发现:HA辛酯在甲醇溶液中的抗氧化效率最高,其DPPH自由基清除能力为339.40 mmol Trolox/mol;而HA丁酯在乳液中的抗氧化效率最高,在乳化剂体积分数为1%时,添加HA丁酯乳液的共轭二烯值达到1所用的时间和p-茴香胺值达到6所用的时间分别为27.1 d和19.8 d;用假相动力学模型得到了HA及其烷基酯在乳液界面区域的分布,以解释其在乳液中的抗氧化行为。结果表明,HA及其烷基酯在乳液中的抗氧化效率与其在界面区域的质量分数基本对应。

关键词: 对羟基苯甲酸;酯化;乳液;抗氧化效率;假相动力学模型

Abstract: Four p-hydroxybenzoic alkyl esters were synthesized by direct esterification reaction from p-hydroxybenzoic acid (HA) and a series of alkyl alcohols. The antioxidant efficiency of p-hydroxybenzoic acid and its alkyl esters in aqueous methanol solution were determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The Schaal oven test was used to determine their antioxidant efficiency in rapeseed oil-in-water emulsions with an oil/water volume ratio of 2:8. Results showed that p-hydroxybenzoic octyl esters had the highest antioxidant efficiency in aqueous methanol solution, and its DPPH radical scavenging capacity was 339.40 mmol Trolox/mol. In contrast, p-hydroxybenzoic butyl esters had the maximum antioxidant efficiency in rapeseed oil emulsions. In the case of the addition of p-hydroxybenzoic butyl esters to emulsions with an emulsifier concentration of 1%, the time needed to reach a conjugated diene value (CDV) of 1 and a p-anisidine value (p-AV) of 6 was 27.1 and 19.8 days, respectively. The distribution profiles of p-hydroxybenzoic acid and its alkyl esters were obtained in the interfacial region of the emulsions by using the pseudophase kinetic model to interpret their antioxidant behaviors in the emulsions. Results showed that the antioxidant efficiency of p-hydroxybenzoic acid and its alkyl esters in the emulsions roughly correlated with their concentrations in the interfacial region.

Key words: p-hydroxybenzoic acid; esterification; emulsion; antioxidant efficiency; pseudophase kinetic model

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