The Influence of Particle Size and Protein Content in Particle-Filled Myofibrillar Protein Gels

Abstract

The addition of glass microspheres as a model insoluble, hydrophilic filler in comminuted meat gels was investigated. The influence of protein content (9, 11, and 13%), filler size (∼4 μm, 7 to 10 μm, and 30 to 50 μm), and volume fraction filler (ϕf) on the microstructure, cooking losses, and large deformation/textural properties were evaluated. Microstructural analysis indicated the glass microspheres did not strongly interact with the gel matrix. For all protein levels investigated, cooking losses decreased with increasing ϕf, and this impact was more pronounced with smaller filler particles. The textural attributes of the 9 and 11% protein gels exhibited a similar dependence on filler size. When incorporating the 4 μm and 7 to 10 μm particles at increasing ϕf, the Hardness, Resilience, Cohesiveness, and Springiness all displayed a sharp increase to a plateau. The larger 30 to 50 μm particles exhibited no increase in any of the textural properties until higher ϕf were employed. In the 13% protein gels, the influence of the particles were diminished, and the effect of particle size was substantially reduced. The influence of these insoluble model filler particles was attributed to their ability to decrease the mobility of the aqueous phase, which explains their minor impact on more stable formulations. Through this work, it has been demonstrated that micrometer-sized hydrophilic particles have the potential to improve the stability and enhance the textural properties of comminuted meat gels. These findings suggest that micrometer-sized inert particles might function as an effective stabilizer in comminuted meat batters at low concentrations.