Effects of cluster dextrin encapsulation on the properties and antioxidant stability of fractionated Riceberry protein hydrolysate powder prepared by bromelain

In this work, the biological properties of fractionated Riceberry bran protein hydrolysate obtained by ultrafiltration (URBPH) were evaluated and the possibility of using cluster dextrin to produce hydrolysate powder by spray-drying was investigated. Fractionation into peptides < 3 kDa was observed to improve antioxidant activity. URBPH < 3 kDa was then freeze-dried (FD-URBPH) and spray-dried (SD-URBPH) at different inlet air temperatures of 100–160 °C. The water solubility and antioxidant activity of FD-URBPH were higher than those of SD-URBPH. Nevertheless, encapsulation of hydrolysate with 10% cluster dextrin and an inlet temperature of 120 °C was also successful in maintaining protein qualities, which showed high 2,2′-azino-bis 3-ethylbenzthiazoline-6-sulfonic (ABTS^•+) scavenging activity (89.14%) and water solubility index (92.49%) and low water activity (a_w = 0.53). Moreover, encapsulation preserved the antioxidant activity of peptides during gastrointestinal digestion better than the free form. URBPH and its spray-dried microcapsules could be used as bioactive ingredients in functional drinks or foods.