The objective of this study was to evaluate the effect of ultrasonic pretreatment on diacylglycerol (DAG) synthesis by lipase-catalysed glycerolysis of lard and to analyse the physicochemical properties of lard-based DAG. The optimal ultrasonic pretreatment conditions were: Rhizomucor miehei (Lipozyme^® RMIM)-to-lard ratio 4:100 (W/W), 45 °C for 5 min, and power 250 W. The lard-based DAG samples for 4 h of glycerolysis reactions with ultrasonic pretreatment (named DAG-U) and 11 h of glycerolysis reactions without ultrasonic pretreatment (named DAG-N) had similar DAG contents and were used for further analysis. The major FA compositions and iodine value of lard, DAG-U and DAG-N were similar. Fourier transform infrared spectroscopy analysis proved that enzymatic glycerolysis with and without ultrasonic pretreatment did not change the structure of the lard. Differential scanning calorimetry analysis showed that the crystallization onset of DAG-U and DAG-N shifted to higher temperatures than that of lard, which indicated that DAG oils accelerated nucleation and crystal growth. X-ray diffraction analysis revealed that both DAG-U and DAG-N contained β′ crystal and a substantially lower amount of β crystal. Overall, ultrasonic pretreatment promotes diacylglycerol production from lard through lipase-catalysed glycerolysis, and DAG-U and DAG-N have similar physicochemical properties.

这项研究的目的是评估脂肪酶催化猪油的甘油分解对超声波预处理对二酰基甘油（DAG）合成的影响，并分析基于猪油的DAG的理化特性。最佳超声波预处理条件为：黑根毛霉（的Lipozyme ^®RMIM）与油比4：100（W / W），45°C持续5分钟，功率250W。基于猪油的DAG样品经过超声预处理（命名为DAG-U）进行4小时的甘油分解反应，未经超声波预处理的11 h甘油分解反应（命名为DAG-N）具有相似的DAG含量，并用于进一步分析。猪油，DAG-U和DAG-N的主要FA组成和碘值相似。傅里叶变换红外光谱分析证明，有和没有超声预处理的酶促糖酵解都不会改变猪油的结构。差示扫描量热分析表明，DAG-U和DAG-N的结晶起始温度比猪油更高，这表明DAG油加速了成核和晶体生长。X射线衍射分析表明，DAG-U和DAG-N均含有β'晶体和明显较少量的β晶体。总体而言，超声预处理通过脂肪酶催化的甘油分解促进猪油中的二酰基甘油生成，而DAG-U和DAG-N具有相似的理化特性。