浸出与冷榨山茶油中脂肪酸的测定及品质评价

Quality Evaluation and Content Determination of Fatty Acids in Camellia Oil Extracted by Method of Infusion and Cold Pressing

目的:进行两种不同提取方法的山茶油的含量和脂肪酸组成及其它相关理化指标的比较和分析。方法:运用脂肪酸标准品的气相色谱比对的方法分析浸出的山茶油与冷榨山茶油里面脂肪酸成分的组成及其含量,通过观察此两种不同提取方法山茶油的透明度、其颜色及光泽度,采用国家规定的标准的检测方法,对其皂化值、不皂化物、碘值、折光率、水分、易挥发性物质、不可溶性的杂质、过氧化值、酸值、相对密度等理化指标进行了详细的检测鉴别和分析。结果:浸出山茶油检出了14种脂肪酸,冷榨山茶油检出了12种脂肪酸,其中油酸(79.37%、80.55%)、棕榈酸(8.79%、8.81%)、亚油酸(7.49%、7.16%)为主要脂肪酸,及花生一烯酸等不饱和脂肪酸(0.02%、0.96%)与硬脂酸(2.11%、2.07%)等饱和脂肪酸;两种工艺山茶油理化指标符合质量指标要求,冷榨山茶油与浸出山茶油比较,体外抗氧化效果与体内抗疲劳效果差异没有统计学意义(p> 0.05),浸出山茶油酸值和过氧化值高于冷榨山茶油,且差异有显著差异(p <0.05)。结论:本试验采用的冷榨山茶油与浸出山茶油均符合国家标准,从脂肪酸含量、理化指标、体外抗氧化试验与体内抗疲劳试验结果综合比较,冷榨山茶油品质略优于浸出山茶油。

Objective： To investigate fatty acid composition and contents in camellia oil extracted by method of infusion and cold pressing,physicochemical properties,quality evaluation by their physicochemical properties. Methods： Fatty acid composition and contents in camellia oils were determined by method of gas chromatography.Transparency,colour and luster were observed,physicochemical properties such as relative density,refractive index,iodine value,saponification value,unsaponifiables,moisture and volatile matter content,insoluble impurity,acid value,peroxide value were analyzed in accordance with methods of national standards.Results： Fourteen and twelve fatty acids were detected from camellia oil extracted by method of infusion and cold pressing,respectively. Oleic acid,palmitic acid,linoleic acid were the major fatty acids（ 79.37%,8.79%,7.49% in infusion; 80.55%,8.81%,7.16% in cold pressing,respectively）,other unsaturated fatty acids such as arachidonic acid（ 0.02%,0.96%,respectively） and saturated fatty acids such as stearic acid（ 2.11%,2.07%,respectively） were detected,physicochemical properties of the two kinds of camellia oils met the quality specification requirements,the antioxidant levels in vitro and anti-fatigue effects in vivo were identical basically. There were a significant difference between the acid value（ p 0.05） and peroxide value of camellia oils extracted by method of infusion and cold pressing.Conclusion： Both the cold-pressed camellia oil and the leached camellia oil used in this experiment were in compliance with national standards.Compared with the results of fatty acid content,physicochemical indexes,in vitro antioxidant test and in vivo anti-fatigue test,the quality of coldpressed camellia oil was slightly better than that of leaching camellia oil. By the comprehensive comparison of various parameters,camellia oil extracted by method of cold pressing was superior to method of infusion in term of the physicochemical properties.