Enhancing the physicochemical performance of myofibrillar gels using Pickering emulsion fillers: Rheology, microstructure and stability

Water loss and lipid oxidation of meat products during processing and storage compromise their sensory qualities, such as flavor, tenderness, juiciness. Herein, surfactant-stabilized emulsions and Pickering emulsions were employed as particulate fillers and fat substitutes in myofibrillar protein-based gels (MPGs). Relatively weak MPGs were formed with the addition of NaCl, which were further enhanced via filling with soy protein isolate nanoparticle-stabilized Pickering emulsions (SNPE) or soy protein isolate nanoparticle-stabilized Pickering emulsions with cinnamaldehyde (SNPE-CA). After thermal treatment at 80 °C, incorporation of SNPE-CA contributed to a highly compact gel network and the highest gel strength, but the minimum moisture content. SNPE resulted in a moderately compact network and the maximum moisture content, MPGs without fillers possessed a looser network and similar gel strength with those containing SNPE. While Tween 80 hindered the aggregation of myofibrillar proteins, causing the presence of Tween 80-stabilized emulsions (TWE) in MPGs generated the loosest network and the lowest gel strength. After further centrifugation or cooking, MPGs with SNPE showed the highest water holding stability, TWE conduced to the moisture stability of MPGs against centrifugation, MPGs with TWE or SNPE-CA or without fillers had a similar water holding stability index during cooking at 100 °C. Additionally, the ability of the three emulsion fillers for improving lipid oxidation stability of MPGs decreased in the following order: SNPE-CA > SNPE > TWE. These findings indicate that Pickering emulsions are potential particulate fillers to enhance moisture stability in meat gels, as well as fat substitutes to protect lipid from oxidation.