大米陈化过程中表面油脂变化特征初探  

Changing characteristic of surface lipids during rice storage

作　　者：徐欣源[1] 付桂明[1] 刘成梅[1] 罗舜菁[1] 钟业俊[1] 周晓晴[1] 汪志宇[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,江西南昌330047

出　　处：《食品工业科技》2013年第2期327-330,335,共5页Science and Technology of Food Industry

基　　金：国家科技支撑计划(2012BAD37B02-02)

摘　　要：研究了糙米和精米在人工陈化过程中表面油脂的变化情况。结果表明:糙米和精米陈化过程中游离脂肪酸值的含量和增加速率不同,精米游离脂肪酸占总脂肪质量百分比比糙米要高且增幅也比糙米大;丙二醛含量检测后发现,精米的含量达到峰值时,其含量占总脂肪质量百分比比糙米高。在37℃和25℃下储藏后期丙二醛含量出现下降。精米丙二醛含量下降幅度也较糙米大。可见精米陈化过程中油脂过氧化程度比糙米大且对丙二醛的耐受性较差;对游离脂肪酸值变化进行动力学分析后显示,零级动力学模型能够很好地反应这个指标的变化趋势,并且陈化过程中脂肪酸值的增加随绝对温度的倒数的变化符合Arrhenius方程,糙米表面油脂发生水解反应的活化能要高于精米,可见糙米相比精米稳定性高。The surface lipids changes in brown rice and milled rice were studied under thermostatically manual controlled storage condition. The results showed that the content changes and increasing rates of FFA in brown rice and milled rice were different,the FFA of milled rice was higher and increased much more rapidly than that of brown rice. Milled rice had a higher MDA content during storage. The contents of MDA of both kinds of rice declined at the later period of storage under 37℃ and 25℃. The MDA of milled rice（% lipid w/w） decreased much more rapidly than that of brown rice. These showed that milled rice had a large extent of lipids peroxidation than that of brown rice but a bad tolerance of MDA. The Kinetic analysis of FFA changes showed that zero-order kinetics model could likeliest fit the trend of this indicator,and the increase in the value of fatty acids in the aging process with the reciprocal of the absolute temperature change matches the Arrhenius equation. Brown rice is much more stability than milled rice according to its higher Eα of surface lipid hydrolysis reaction.

关 键 词：糙米 精米 游离脂肪酸值 丙二醛 动力学 

分 类 号：TS201.1[轻工技术与工程—食品科学]