Improvement of physical properties of palm stearin and soybean oil blends by enzymatic interesterification and their application in fast frozen food

Abstract

In order to obtain good quality special fats for fast frozen food, blends of palm stearin (PS) and soybean oil (SO) (5 : 5, 6 : 4 and 7 : 3, PS : SO) were subjected to enzymatic interesterification in a fluidized bed reactor. The slip melting point of the interesterified blends thus obtained was 45 °C when the flow rates were 2.24, 1.57 and 0.40 mL min⁻¹, respectively. After interesterification, the contents of SSS- and UUU-type TAGs decreased, whereas the contents of SUU-type TAGs increased. In addition, the β form crystal reduced and β′ form crystal increased due to the change in the type of TAGs. The solid fat content of the interesterified blends was 5–40% at 10–45 °C. The results of sensory evaluation indicated that the special fats prepared from the interesterified blends had better quality when they were applied in the preparation of fast frozen dumplings. Hence, enzymatic interesterification is promising in preparing high-quality special fat for fast frozen food.