Oil is one of the important nutrients in daily diet, and triglycerides (TAG) are the main components of animal and plant oils. With the improvement of residents' quality of life, excessive intake of oil is the main cause of obesity and a series of chronic diseases. In response to this issue, in addition to reducing the intake of fats, finding more "healthy" edible fats has become a research hotspot for scholars at home and abroad. Since the 1960s, an increasing number of researchers have been focusing on the beneficial functions of diglycerides.

Diacylglycerol (DAG) is a natural oil with a low content, up to 10%, in which edible oils have a DAG content greater than 27.3% to have an effect on human health in reducing blood lipids, inhibiting weight gain, and other aspects. DAG has two isomers, namely 1,3-DAG and 1,2-DAG. Usually, when the composition of fatty acids is the same, the melting point of 1,3-DAG is about 10 ℃ higher than that of 1,2-DAG, and the main factors that have weight loss effects are1,3-DAGDiacylglycerol is a healthier edible oil than triglycerides.

In China, DAG oil was approved as a new resource food in 2008. In 2021, the National Health Commission revised the quality requirements for DAG oil, clarifying that its production process uses soybean oil, rapeseed oil, and other raw materials, with lipase preparations, water, glycerol, and other main auxiliary materials. It is made through lipase catalysis, distillation separation, decolorization, deodorization, and other processes. The DAG content in DAG oil should be ≥ 40%. Researchers from various countries have evaluated the food safety of DAG through extensive animal and clinical trials, including genetic toxicity, teratogenicity, repeated administration toxicity, and carcinogenicity. No significant adverse reactions have been identified, and DAG oil does not pose any safety hazards in daily consumption. Both single dose and long-term intake of DAG oil have no pharmacological effects on the human body and can be consumed for a long time like regular edible oils.

Compared to regular cooking oil, DAGespeciallyIts metabolic pathway enables it to have physiological functions such as inhibiting postprandial blood lipid elevation, reducing body fat accumulation, lowering body weight, and regulating blood sugar. To obtain high-purity DAG products, molecular distillation technology is used to deacidification and purify enzyme catalyzed synthesis of glycerol diesters. Through different experimental studies, it has been shown that molecular distillation technology has a good effect on the preparation of high-purity glycerol diesters and has a wide range of applications.