Stearic Acid State in Soybean Protein-Isolate/Carboxymethyl Cellulose Composite Films

Abstract

The thermalgravimetric and differential scanning calorimetry analysis were used to evaluated the state of stearic acid in the soybean protein-isolate/carboxymethyl cellulose composite films. The stearic acid lose its weight rapidly in 210~280 oC, while no significant weight loss presented among 210~280 oC in the profiles of the control and the composite films dried at 90 oC. Hence, the stearic acid was well interacted with the other ingredients. Moreover, the stearic acid was distributed as the free state and bound state in the composite films. The free stearic acid ratio of the composite films dried at 90 oC was the lowest among the tested films. The temperature of 90 oC effectively enhanced the interaction of the SA with the other ingredients.