Surface Modification of Okara Cellulose Crystals with Phenolic Acids to Prepare Multifunction Emulsifier with Antioxidant Capacity and Lipolysis Retardation Effect

Abstract

Emulsion-based foods are widely consumed, and their characteristics involving colloidal and oxidative stabilities should be considered. The fabrication of the interfaces by selecting the emulsifier may improve stability and trigger lipolysis, thereby reducing energy uptake from the emulsified food. The present work aimed to develop Okara cellulose crystals (OCs) as a multifunction emulsifier to preserve the physical and chemical stability of a Pickering emulsion via surface modification with phenolic acids. The modification of OC was performed by grafting with the selected phenolics to produce OC–gallic acid (OC-G) and OC–tannic acid (OC-T) complexes. There was a higher phenolic loading efficiency when the OC reacted with gallic acid (ca. 70%) than with tannic acid (ca. 50%). This trend was concomitant with better antioxidant activity of the OC-G than OC-T. Surface modification based on grafting with phenolic acids improved capability of the OC to enhance both the colloidal and oxidative stability of the emulsion. In addition, the cellulosic materials had a retardation effect on the in vitro lipolysis compared to a protein-stabilized emulsion. Surface modification by grafting with phenolic acids successfully provided OC as an innovative emulsifier to promote physico-chemical stability and lower lipolysis of the emulsion.