Rice bran protein (RBP) has shown good nutritional and biological values. The present study aimed to determine the functional properties of rice bran crude protein (RBCP) and apply RBCP to a rice jelly recipe to improve the jelly quality and make it an acceptable product for consumers. The design used in the jelly formulation was a central composite design. The freeze-dried crude protein of Sung Yod (SY; 0.00-0.50%) and Hom Rajinee (HR; 0.00-0.50%) rice brans were applied to the rice jelly recipe. The crude protein extract significantly influenced the physicochemical, sensory, and angiotensin I converting enzyme (ACE)-inhibitory activity of the developed jellies (p < 0.05). The optimized jelly contained 0.11% SY and 0.50% HR crude protein extract. The rice jelly fortified with lyophilized RBCP presented a high content of bioactive compounds (phenolic and flavonoids) with antioxidant activity and ACE-inhibitory activity. Therefore, the crude protein extract of rice brans is a potential raw material that can be used in jelly products as a cheap material to improve the jelly's nutritional quality without affecting consumer acceptability. The outcome of the present investigation confirms that rice bran extracts may have the potential to be further exploited as ingredients in foods.
Keywords: ACE-inhibitory activity; Innovative food; bioactive activities; crude protein extract; jelly fortification; rice bran by-product.