Characterization of orange peel extract-cross linking whey protein nanoparticles and their influences on the physical and sensory properties of orange juice

Abstract

This work explores the characterization of orange peel extract (OPE)-cross-linked whey-protein nanoparticles for enhancing the physical and sensory properties of orange juice. Three methods were employed to cross-link particle-forming peptides with citric acid, i.e., OPE charging–cross-linking–desolvation (A), cross-linking–OPE charging–desolvation (B), and OPE charging–desolvation–cross-linking (C). B method produced smaller particles (229 ± 11.53 nm) with higher encapsulation efficiency (67.16 ± 1.75%). Kinetic studies indicated predominantly diffusion-based release of OPE from the particles, B express the lowest diffusion rate with 10.20 ± 1.23% after 6 h incubation in NaCl. Using citric acid as a cross-linking agent enhanced the encapsulation efficiency. Moreover, functional orange juices were formulated using OPE and B capsules (500 mg/L). Under simulated in-vitro gastrointestinal conditions, the antioxidant activity was higher in B capsule supplemented juice comparing to OPE supplemented juice at oral, gastric, and intestinal phase which recorded of 69.43 ± 0.750, 85.66 ± 1.12 and 94.53 ± 2.00 mg ascorbic acid/100g respectively by DPPH and 80.91 ± 1.37, 132.01 ± 0.50 and 153.47 ± 2.63 mg ascorbic acid/100g respectively by ABTS. Sensory evaluation demonstrated the acceptability of OPE and cross-linked nanoparticles by the panelists. Cross-linking–OPE charging–desolvation provides high encapsulation efficiency with palatable physico-sensorial attributes in orange juice and offers a promising strategy for creating a nutritious beverage.