旨在为富含多不饱和脂肪酸(PUFA)的中长链脂肪酸甘油三酯(MLCT)产品的应用提供参考,采用脂肪酶Lipozyme TL IM催化精炼桑蚕蛹油(SPO)与三辛酸甘油酯(TRI)进行酯交换反应合成富含α-亚麻酸(ALA)的MLCT(ALA-MLCT),考察了反应时间对ALA-MLCT合成的影响,并对合成的ALA-MLCT的甘油三酯组成、质量指标、氧化稳定性、乳液性能和体外消化特性进行了分析.结果表明:Lipozyme TL IM催化效率高,反应10 h TRI的转化率达到98％以上,反应12 h合成的产物ALA-MLCT中含有ALA的MLCT含量可以达到40.41％,且主要为LnCaCa(10.95％)、PLnCa(7.69％)和OLnCa(6.21％),其质量指标符合中长链脂肪酸食用油标准征求意见稿2022中的一级食用油标准;与SPO和酯交换反应底物物理混合物(SPO与TRI质量比1∶4,SPO+TRI)相比,产物ALA-MLCT氧化稳定性显著提高,其乳液粒径较小且分布均匀,具有更好的物理稳定性;体外模拟消化实验表明,与SPO+TRI相比,ALA-MLCT更快达到消化平衡,但最终二者消化率均可以达到90％以上.综上,合成的ALA-MLCT结构脂有助于提高ALA的生物可及性,有望作为功能性食用油脂.
Enzymatic synthesis and physicochemical properties of medium-and long-chain triacylglycerols rich in α-linolenic acid
In order to provide reference for the application of medium-and long-chain fatty acid triglycerides(MLCT)products enriched with polyunsaturated fatty acids(PUFA),lipase Lipozyme TL IM was employed to catalyze the transesterification of refined silkworm pupa oil(SPO)and tricaprylin(TRI)to synthesize MLCT rich in α-linolenic acid(ALA)(ALA-MLCT).The impact of reaction time on the synthesis of ALA-MLCT was studied,and the triglycerides composition,quality index,oxidative stability,emulsion performance,and in vitro digestion characteristics of the ALA-MLCT were analyzed.The results showed that Lipozyme TL IM had high catalytic efficiency,and the conversion rate of TRI reached more than 98％after 10 h of reaction.The content of MLCT containing ALA in ALA-MLCT synthesized by transesterification reaction for 12 h reached 40.41％,and it was mainly composed of LnCaCa(10.95％),PLnCa(7.69％)and OLnCa(6.21％).The quality indexes of ALA-MLCT complied with the standards of first-class edible oil in the medium-and long-chain fatty acid edible oil standard draft 2022.Compared with SPO and the physical mixture of transesterification reaction substrate(SPO+TRI,in a 1∶4 mass ratio),ALA-MLCT exhibited significantly improved oxidation stability,and its emulsion had better physical stability,with smaller and more evenly distributed particles size.In vitro simulated digestion experiments revealed that ALA-MLCT achieved a faster digestive balance compared with SPO+TRI,but the final digestibility of both could exceed 90％.In conclusion,the synthesized ALA-MLCT can help to improve the bioaccessibility of ALA and is expected to be used as functional edible oil.
NETL
NSTL
万方数据
