基于人乳脂肪组成的酶法人乳脂肪替代物的构建

为了开发新型高相似性人乳脂肪替代物，依据中国人乳脂肪的脂肪酸组成和甘油三酯结构，以巴沙鱼油、樟树籽仁油、亚麻籽油、微生物油（富含ARA）及DHA藻油(质量比为153.81∶ 15.16 ∶ 62.33∶ 7.89 ∶ 1081)为原料油脂，以固定化脂肪酶Lipozyme RM为催化剂，在60 ℃下酯交换反应8 h 制备人乳脂肪替代物，测定其脂肪酸、sn-2位脂肪酸及甘油三酯组成及含量，分析其红外光谱图、熔融性质、结晶性质及流变学性能。结果表明，构建的人乳脂肪替代物中链脂肪酸含量为12%、亚油酸和亚麻酸总含量为19.53%且比例约为1∶ 1.5，ARA含量为1.17%，DHA含量为111%，其 sn-2位富含棕榈酸（43.10%），结构甘油三酯含量高（58.75%），无反式脂肪酸生成，熔融温度低于人体温度且在20 ℃下仍能保持18.7%的固体脂肪含量，结晶形态细腻且流变性能优异。制备的人乳脂肪替代物具有应用于婴幼儿配方奶粉、婴幼儿米糊和婴幼儿饼干等各种婴幼儿食品的潜力。 For the development of new high-similarity human milk fat substitutes， based on the fatty acid composition and triglyceride structure of Chinese human milk fat, five kinds of oils, including basha fish oil, Cinnamomum camphora seed kernel oil, linseed oil, microbial oil(rich in ARA), DHA algae oil, with mass ratio of 153.81∶ 15.16∶ 62.33∶ 7.89∶ 10.81 were used to prepare the human milk fat substitutes (HMFS) catalyzed by immobilized lipase Lipozyme RM at 60 ℃ for 8 h，and its fatty acid, sn-2 fatty acid and triglyceride compositions and contents were determined, as well as the infrared spectra, melting properties, crystalline properties, and rheological properties. The results showed that the HMFS contained 12% of medium-chain fatty acids, 19.53% of linoleic acid-linolenic acid with ratio 1∶ 1.5, 1.17% of ARA and 1.11% of DHA, and its sn-2 position had high content of palmitic acid (43.10%), and it had high content of structured triglycerides(58.75%)，and no trans fatty acid were formed. The melting temperature of HMFS was below body temperature and the solid fat content of HMFS at 20 ℃ was 187%. In addition, the crystals form of HMFS were fine and uniform, the rheological properties of HMFS were excellent. The HMFS obtained has potential application in various infant foods such as infant formula, infant rice cereal and infant biscuits.