Gelation of recombined soymilk and cow's milk gels: Effect of homogenization order and mode of gelation on microstructure and texture of the final matrix

Abstract

The present study examined the development of the gel network as well as the final structure obtained from mixed soymilk–cow's milk gels recombined with cream. An understanding of the structural changes occurring as a result of different process manipulations may aid with understanding the reported texture differences in these matrices. Results showed that changing the mode of homogenization, the composition of the fat globule surface changed. When both milk and soymilk were homogenized with the cream, the resulting gel had the highest gel stiffness at the end of fermentation. Confocal microscopy demonstrated that as long as milk was homogenized with cream (regardless of the presence of soymilk during homogenization), the resulting gel showed finer protein aggregates. On the other hand, without homogenization or when soymilk was homogenized with cream before milk addition, a coarser gel structure was noted. The composite gels where both casein micelles and soy proteins aggregated simultaneously appeared homogeneous compared to the gels formed by the gelation of caseins before soy proteins. This work clearly demonstrated that by modulating the timing of casein and soy protein aggregation, as well as the composition of the fat interface, it was possible to modify the gel structure and affect texture properties.