脂肪酶Lipozyme TL IM水解金枪鱼油工艺优化 及其脂质分析Porcess optimization of lipase Lipozyme TL IM hydrolysis of tuna oil and its lipid analysis

旨在为Lipozyme TL IM在鱼油脂质改性及相关功能性产品的研发和应用提供参考，以金枪鱼油为原料，采用固定化脂肪酶Lipozyme TL IM对其进行水解，并分离改性水解甘油酯。采用单因素试验研究了pH、水油比（质量比）、水解温度和水解时间对金枪鱼油水解度的影响，确定了适宜的水解工艺参数，并分析了不同水解度下（20%~50%）改性水解甘油酯的脂肪酸组成、结构、热稳定性和氧化稳定性。结果表明：Lipozyme TL IM水解金枪鱼油的适宜工艺参数为pH 6.0、水油比 3∶ 1、水解温度40 ℃、酶添加量5%（以鱼油质量计），在此条件下水解30、60、80、120 min可分别得到水解度为20%、30%、40%和50%的改性水解甘油酯；随着水解度的增加，所得改性水解甘油酯的多不饱和脂肪酸含量增多，饱和脂肪酸含量减少，结构改变，热稳定性和氧化稳定性变差。综上，可采用Lipozyme TL IM对金枪鱼油进行水解以富集多不饱和脂肪酸，为后续产品开发提供特异性底物。In order to provide a reference for the research and application of Lipozyme TL IM in the modification of fish oil and related functional products, tuna oil was used as raw material, and the immobilized lipase Lipozyme TL IM was used for hydrolysis, and the modified hydrolyzed glycerides were separated. The effects of pH, water-oil ratio (mass ratio), hydrolysis temperature and hydrolysis time on the degree of hydrolysis were studied by single factor experiments, and the appropriate hydrolysis process parameters were determined. In addition, the fatty acid composition, structure, thermal stability and oxidation stability of the modified hydrolyzed glycerides under different degrees of hydrolysis (20%-50%) were analyzed. The results showed that the suitable process parameters for hydrolysis of tuna oil by Lipozyme TL IM was pH 6.0, water-oil ratio 3∶ 1, hydrolysis temperature 40 ℃ and lipase dosage 5% (based on mass of tuna oil). Under these conditions, after hydrolysis for 30, 60, 80 min and 120 min, the modified hydrolyzed glycerides with hydrolysis degrees of 20%, 30%, 40% and 50% were obtained, respectively. With the increase of the hydrolysis degree, the polyunsaturated fatty acid content of modified hydrolyzed glycerides increased, the saturated fatty acid content decreased, the structure changed, and the thermal stability and oxidation stability deteriorated. In conclusion, Lipozyme TL IM can be used to hydrolyze tuna oil to enrich polyunsaturated fatty acids, and provide specific substrates for subsequent product development.