Production, characterization and spray-drying encapsulation of date (Phoenix dactylifera L.) seed protein hydrolysates for bread fortification

Abstract

The extraction of health-promoting compounds from waste biomaterials and delivery of them into food and pharmaceutical products is of growing importance. In this study, date seed protein hydrolysate (DSPH) was produced through enzymatic hydrolysis using alcalase (30–180 min), and characterized. The hydrolysate was then microencapsulated via spray-drying and incorporated into pan-bread formulation. Enzymolysis time significantly influenced the degree of hydrolysis (1.5–26.5%), free amino acid content, and antioxidant activity of DSPH. DSPH obtained after 120 min of hydrolysis (DSPH-120) was found suitable for microencapsulation. Among the microcapsule powders produced with various carriers (i.e., maltodextrin, gum Arabic, whey protein concentrate (WPC), and pectin), the maltodextrin-WPC-based one was selected for bread fortification, due to its high production yield and favorable physicochemical, functional, and morphological properties. The fortification level (1–5% w/w) impacted the moisture content, water activity, firmness, specific volume, porosity, color indices (for crust and crumb), antioxidant activity, and sensory attributes (especially bitterness) of the fortified breads. Overall, breads fortified with up to 3% microcapsule powder exhibited acceptable physicochemical and sensory characteristics. These findings demonstrate the potential of DSPH as a valuable source of bioactive compounds and antioxidants for fortification of food products, like bread, after microencapsulation.