Acid-modified pea protein isolate and okara cellulose crystal: A co-emulsifier to improve physico-chemical stability of fat-reduced eggless mayonnaise

Mayonnaise, a high fat emulsified food, always contains egg yolk as a source of emulsifier. Lowering fat content and restricting use of egg yolk are promising ways to enhance nutritive profile and attraction to vegan trend. This work aimed to prepare fat-reduced eggless mayonnaise with good physicochemical stability using pea protein isolate (PPI) in combination with cellulose crystals as a co-emulsifier. Emulsifying property of Okara cellulose crystals (OC) and modified OC using gallic acid (OCG) was investigated. The cellulosic materials possessed effective emulsifying property, particularly at increased concentration. The present work suggested that acid-aided hydrolysis could improve emulsifying property of PPI. Then, the acid-modified PPI (aPPI) together with OC or OCG were employed at different ratios as a co-emulsifier for fat-reduced eggless mayonnaise preparation. The co-emulsifier could improve dispersibility and rheological property of the mayonnaise effectively. In addition, the cellulosic materials improved oxidative stability of the mayonnaises, particularly for OCG. This behavior might be expected since a steric hindrance effect of the interfacial films of co-emulsifier, in addition to antioxidant capacity of OCG. Thus, the innovative addition of the dual modes of emulsifying and antioxidant actions could be used to improve physicochemical stability and reduce fat content of eggless mayonnaise.