油茶籽油甾醇存在形态及其在精炼和贮藏过程中动态变化分析

Speciation Analysis of Phytosterols in Camellia Seed Oil and Their Dynamic Changes during Refining and Storage

采用气相色谱-质谱联用技术对我国主要油茶籽油产品甾醇及存在形态进行分析,研究其在精炼和贮藏过程中的动态变化。结果显示:油茶籽油产品中共检测到9种甾醇,均以结合和游离形态存在,总含量为3072.87~5713.48 mg/kg,其中以结合态甾醇为主,占97.4%~99.4%,主要甾醇化合物包括羊毛甾醇、β-香树脂醇、β-谷甾醇等;游离态甾醇受精炼工艺影响较大,精炼后含量降低了94.1%,结合态降低了25.1%,其中脱酸工艺对2种甾醇影响均最大;在贮藏过程中,结合态和游离态甾醇含量分别下降12.0%和40.9%,结合态甾醇表现出更强的氧化稳定性;通过主成分分析及各性状荷载分析发现,结合态羊毛甾醇和游离态β-谷甾醇是油茶籽油的最主要特征成分,在油茶籽油中存在最为稳定。

Gas chromatography-mass spectrometry(GC-MS)was used for the speciation analysis of phytosterols in camellia seed oils from the 11 major producing regions in China,and the dynamic change of phytosterols during the refining and storage of camellia seed oils was investigated.The results showed that a total of nine sterols were detected at concentrations of 3072.87–5713.48 mg/kg in the oil samples,existing in bound and free forms,with the bound ones being dominant,accounting for 97.4%–99.4%of the total amount.The major sterols included lanosterol,β-amirin andβ-sitosterol.After refining,the content of free sterols decreased by 94.1%,and the content of bound sterols decreased by 25.1%;the deacidification process affected both forms of sterols most.After storage,the contents of bound and free sterols decreased by 12.0%and 40.9%,respectively,suggesting that bound sterols showed stronger oxidation stability.Through principal component analysis(PCA),it was found that bound lanosterol and freeβ-sitosterol were the major characteristic components of camellia seed oil and were the most stable.