基于酶促酯交换的含亚麻酸巧克力的制备及其性质研究

利用固定化脂肪酶Lipozyme TLIM催化质量比为38∶3的天然可可脂与亚麻籽油进行酯交换反应,得到熔点为(36.52±0.34)℃的油脂(称为酯交换可可脂)。酯交换可可脂中亚麻酸的含量由反应前0.64%±0.01%升高至3.10%±0.28%,主要甘三酯POP、POS和SOS的含量由84.52%降至62.72%,低熔点甘三酯UUU和SUU含量分别由0.92%和6.85%增加至10.94%和16.60%。酯交换可可脂的固体脂肪含量(SFC)在5~30℃时低于天然可可脂的SFC,但其随温度变化的趋势与天然可可脂的相一致,当温度高于34℃时,酯交换可可脂的SFC略高于天然可可脂的SFC,37℃时酯交换可可脂的SFC为1.64%。以酯交换可可脂为原料制备的含亚麻酸巧克力表面光滑,口感细腻,具有可可和亚麻籽油独特的香味。加速氧化实验结果表明该巧克力20℃时的货架期为428 d,约61周,具有良好的贮藏稳定性。 

Preparation of chocolate containing linolenic acid by enzymatic interesterification and its properties

The interesterification of cocoa butter and flaxseed oil with mass ratio 38∶ 3 was catalyzed by immobilized lipase Lipozyme TLIM and the melting point of the resulting lipid( named as interesterified cocoa butter) was( 36.52± 0.34) ℃. The linolenic acid content of the interesterified cocoa butter increased from 0.64% ± 0.01% before reaction to 3.10% ± 0.28%,but the content of major triacylglycerols of POP,POS and SOS decreased from 84.52%to 62.72%.The content of low melting point triacylglycerols of UUU and SUU increased from 0.92% and 6.85% to10.94% and 16.60%,respectively. In the range of 5 ~ 30 ℃,the solid fat content( SFC) of the interesterified cocoa butter was lower than that of natural cocoa butter,however,its variation trend of SFC with temperature was consistent with that of natural cocoa butter.When the temperature was above 34 ℃,the SFC of interesterified cocoa butter was a little greater than that of natural cocoa butter and the SFC of interesterified cocoa butter was 1.64% at37 ℃. The chocolate containing linolenic acid prepared by the interesterified cocoa butter had fine and smooth surface,good taste with special flavor of cocoa butter and flaxseed oil. The results of accelerated oxidation test indicated that the shelf life of the resulting chocolate was 428 days at 20 ℃,approximately 61 weeks,which had good storage stability.