Enhancing protein content and lubrication behavior of plant-based milk with microparticulated wheat gluten protein via SS-SH interchange

Abstract

The protein fortification and mouthfeel improvement (achieving dairy-like lubrication properties) in plant-based dairy alternatives have consistently been challenging tasks. To achieve this task, we developed a fully plant-based milk product by enhancing lubrication through microparticulated wheat gluten particles. By utilizing a combination of pH shifting, disulfide bond reductants, and high-pressure microfluidization, SH-SS exchange reactions were successfully induced, leading to the preparation of microparticulated wheat gluten particles with a particle size ranging from 1 to 2 μm and excellent dispersion properties. Introduction of a thiol-blocking agent confirmed the dominance of disulfide bonds in particle formation. The findings demonstrated that even at a high protein concentration of 15%, microparticulated wheat gluten sample maintained good flowability. Friction analysis revealed that the micro-particulated gluten protein treated with a disulfide bond reducing agent (GRM) exhibited a lower friction coefficient compared to other samples. Upon the addition of oat milk, GRM effectively reduced the coefficient of friction while increasing the protein content (5 wt%), achieving a lubrication effect similar to that of microparticulated whey protein. This study provides a novel solution for the preparation of microparticulate wheat gluten and enhances its incorporation into plant-based dairy products, offering a new approach to developing high-protein plant-based dairy products with improved mouthfeel and texture.