Thermodynamic and frying application properties of DAG and LML structured lipids.

With diacylglycerol (DAG) and long-medium-long (LML) structured lipids as research object and soybean oil as the control, the physicochemical properties, thermodynamic properties and frying application properties of 50%DAG, 90%DAG were studied. The results showed that the viscosity, density, acid value (AV) and peroxide value (POV) of 50%DAG, 90%DAG and LML structured lipids were consistent with soybean oil, and the aniside value (AnV)of the three lipids were all higher than that of soybean oil. In addition, the triglyceride composition and fatty acid composition of the three oil in the experiments were only different because of the structure change and the middle chain fatty acids. Both the --OH in 50%DAG and 90%DAG, and the medium chain fatty acids in LML structured lipids would decrease the initial weight loss temperature, and the melting curves of the 50%DAG and 90%DAG would have a large temperature span. The differences of 50%DAG, 90%DAG and LML structured lipids in 3470 cm-1, 1400~1100 cm-1 and 722 cm-1 were caused by structural change. After continuous frying at high temperature, the acid value, peroxide value, chroma, moisture content, anisidine value of 50% DAG, 90%DAG and LML structure lipids and the texture of potatoes after frying with different fats did not change significantly. The AV, POV, chroma, moisture content, AnV and glyceride composition of 50%DAG, 90%DAG and LML structured lipids, and the texture properties of potato chips after high-temperature continuous frying demonstrated good stability. In summary, 50%DAG, 90%DAG, and LML structured lipids maintained good stability during high-temperature continuous frying, meeting the national frying oil standards, and could be used as daily frying oil. [ABSTRACT FROM AUTHOR]