Effects of Microfluidization on the Physical and Storage Stability of Walnut Protein Emulsion and Beverages

Abstract

Walnut meal is a by-product produced during the production of walnut oil and is often treated as a waste.However, the nutrients in walnut meal mean it has signi cant potential for development as a plant-based milk. This study investigated the effect of micro uidization on the stability of walnut protein emulsion (WPE) and walnut protein beverage (WPB) produced from walnut meal, compared with conventional homogenization. The particle size, zeta potential, rheological properties, and stability of WPE all signi cantly improved after micro uidization. The mean particle size and zeta potential of the micro uidized WPE signi cantly decreased (p < 0.05). The rheological properties demonstrated that the viscosity of the micro uidized WPE decreased by 80%, and that the shear force increased 4.5 times as the shear rate increased. This gave the resulting product the characteristics of non-Newtonian uid. LUMisizer stability demonstrated that micro uidization improves stability through protein absorption on the oil-water interface. Micro uidization increased the denaturation temperature (Tm) of WPE from 135.65℃ to 154.87℃. Moreover, micro uidization improved the color, centrifugal precipitation rate, and viscosity in WPB compared to the control at all studied temperatures. The Arrhenius approach was used to establish a shelf-life model, which predicted that micro uidized WPB could be stored for 175 d at 4℃.