黄鳍金枪鱼油精制前后对乙酯化及其品质的影响

Effects on ethyl esterification and quality of refined yellowfin tuna oil

为探究原料鱼油品质对乙酯化过程以及对乙酯型鱼油理化特性的影响,该研究使用过氧化值、茴香胺值分别为12.16 meq/kg、21.87的黄鳍金枪鱼油及其精制油作为原料制备乙酯型鱼油,对其理化指标、重金属含量、脂肪酸组成、氧化稳定性以及主体风味成分进行测定,并使用傅里叶红外光谱仪对鱼油加以表征。结果表明,原油酯化油和精制油酯化油得率分别为84.60%、92.69%;乙酯转化率为93.99%、94.84%,理化指标和重金属含量均符合多烯鱼油行业标准(SC/T 3503—2000)。精炼、酯化过程并未改变脂肪酸含量及组成,且提高了其氧化稳定性,使用Rancimat法预测室温25℃下2种酯化油的货架期分别为180.50、176.50 h,说明使用粗鱼油直接制备脂肪酸乙酯具有一定可行性。另外,酯化过程中所产生的(E)-2-己烯醛、庚酸乙酯给予酯化油独特青草香味、果香味,可有效同甘油酯型鱼油挥发性风味进行区分。红外光谱图中1036 cm^(-1)处出现的乙氧基C—O特征峰,可作为快速检测油脂类型的指标;该研究可为乙酯型鱼油的生产和功能研发提供实验依据。

To explore the influence of the quality of fish oil on the physical and chemical properties of fish oil ethyl ester,oil from yellowfin tuna with high peroxide value(12.16 meq/kg)and high anisidine value(21.87)and its refined oil were used inthis study as raw materials to prepare fish oil ethyl ester.The physical and chemical indicators,heavy metal content,fatty acid composition,oxidation stability and main flavor components were measured,and Fourier infrared spectrometer was used to characterize fish oil andethylester.The results showed that the yields of crude oil esterified oil and refined oil esterified oil were 84.60%and 92.69%,respectively.The conversion rate of ethyl esterification were 93.99%and 94.84%,respectively,and the physical and chemical indexes and heavy metal content were in line with the polyene fish oil industry standard(SC/T 3503—2000).The refining and esterification process did not change the fatty acid content and composition,and improved its oxidative stability.The rancimat method prediction of the shelf life of the two esterified oils at room temperature 25℃were 180.50 and 176.50 h,respectively.In addition,the(E)-2-hexenal and ethyl heptanoate produced during the esterification process gave the esterified oil a unique grassy and fruity fragrance,which could be effectively distinguished from the glyceride-type fish oil flavor.In addition,the characteristic peak of ethoxy C—O at 1036 cm^(-1) in the infrared spectrum could be used as an indicator for the rapid detection of oil types.This research provides experimental basis for the production and functional development of fish oil ethyl ester.