GC-MS分析不同品种油棕果肉中的脂肪酸组分

Analysis of fatty acid components in different species of oil palm fruit by GC-MS

[目的]分析4个品种油棕果肉中的脂肪酸组分,为棕榈油品质改良提供参考依据。[方法]以4个品种的新鲜油棕果为试验材料,参考国家标准GB/T 14772 2008提取果肉脂肪酸,利用氢氧化钾的甲醇溶液对脂肪酸进行甲酯化处理,再应用气相色谱质谱联用技术(GC-MS)分析其脂肪酸组分,同时测定油脂营养成分。[结果]4个品种油棕果肉中脂肪酸种类相同,但成分含量所占比例不同。LS30果肉中棕榈酸含量所占比例最高(53.00%),油酸含量比例最低(22.56%);SJ64果肉中棕榈酸含量比例最低(43.94%),油酸和亚油酸含量比例最高(33.24%和7.10%)。4个品种油棕果肉脂肪酸组分中,棕榈酸平均含量所占比例高达48.47%,变异系数为0.05;其次为油酸,平均含量所占比例为27.90%,变异系数为0.08。脂肪酸组分中,月桂酸与肉豆蔻酸呈显著正相关(相关系数| r |=0.90~1.00,下同),其相关系数为0.90,与其他4种脂肪酸均呈负相关;棕榈酸与油酸呈显著负相关,其相关系数为-0.93,与亚油酸呈较大的负相关性,相关系数为-0.81,与月桂酸和肉豆蔻酸呈负相关,与硬脂酸呈正相关。对油棕果肉油脂各营养成分进行方差分析,发现品种间α-维生素E含量存在显著差异(P<0.05,下同),角鲨烯和β-谷甾醇存在极显著差异(P<0.01)。通过多重比较分析,α-维生素E含量在品种SD60和XJS30间无显著差异(P>0.05),在SJ64和LS30间存在显著差异;角鲨烯和β-谷甾醇含量在4个品种间均存在显著差异。[结论]4个品种油棕果肉中均含有不饱和脂肪酸(油酸和亚油酸),其中SJ64果肉中的油酸、亚油酸,以及油脂营养成分α-维生素E和β-谷甾醇含量均最高,具有较高的营养开发价值,为今后棕榈油品质改良提供材料参考。

【Objective】The fatty acid contents in fruit of four species of oil palm were analyzed,which could provide reference for improvement of palm oil.【Method】According to the national standard of GB/T 14772-2008 and with four species of oil palm as materials,the fatty acid in fresh fruit was extracted. After being methyl esterification catalyzed with potassium hydroxide methanol solution,the fatty compositions were detected by gas chromatography-mass spectrometry(GC-MS),at the same time,the nutrient composition of oil was analyzed and determined.【Result】The fatty acid components of four species of oil palm fruit were the same,but the contents of fatty acids in different species were different. Palmitic acid content in LS30 was the highest,reaching 53.00%,oleic acid content was the lowest(22.56%). Palmitic acid content in SJ64 was the lowest (43.94%),oleic acid and linoleic acid contents were the highest(33.24% and 7.10%). The content of palmitic acid in four varieties of oil palm was the highest,with an average of 48.47% and a coefficient of variation of 0.05,the second was oleic acid with an average of 27.90% and a coefficient of variation of 0.08. There was significant positive correlation between laurel acid and myristic acid(correlation coefficient| r |=0.90-1.00,the same below),with correlation coefficient being 0.90,and negative correlation with the other four acids. There was significant negative correlation between palmitic acid and oleic acid,with correlation coefficient being -0.93,negative correlation with linoleic acid,the correlation was -0.81,negative correlation with laurel acid and myristic acid,and positive correlation with stearic acid. By the variance analysis of palm oil nutrient components, there were significant differences in α-vitamin E among varieties(P<0.05,the same below),and extremely significant difference between squalene and β-sitosterol(P<0.01). By multiple comparative analysis,there was no significant difference between SD60 and XLS30 with α-vitamin E(P>0.05),but significant difference between SJ64 and LS30,there was significant difference in squalene and β-sitosterol among four species of oil palm.【Conclusion】The four species of oil palm fruits all contain unsaturated fatty acid(oleic acid and linoleic acid),among which,SJ64 contains the highest contents of oleic acid,linoleic acid,nutritional value α-vitamin E and β-sitosterol. It enjoys high development value and can provide reference for improvement of palm oil quality in the future.