Influence of protein and solid fat content on mechanical properties and comminution behavior of structured...

Recently an approach has been developed to structure plant-based lipids with the intention to mimic animal fat tissue in processed meat products or analogues. This study investigated the comminution behavior in a bowl chopper of such structured lipids with varying mechanical properties. For products like salami-type sausages these systems need to withstand comminution to yield particles for inclusion in product matrices. Therefore, samples were prepared from protein suspensions with 6%, 8%, 10%, and 12% soy protein isolate (SPI) and 70% (w/w) total fat with varying solid fat contents (0-30%, w/w). The hardness of samples prepared with 6% and 8% SPI varied between 4.5 and 35.9 N. When comminuted in a bowl chopper, these structures had insufficient mechanical strengths to facilitate the formation of small particles and yielded a coarse paste. Higher concentrations of protein increased hardness (15.9-76.2 N and 15.6-96.1 N, for 10% and 12% SPI, respectively). These samples retained their structural integrity upon comminution yielding individual intact particles. The size of these particles increased with sample firmness, i.e. with increasing amount of protein. The shape of the particles was more elongated the higher the solid fat content as indicated by a higher aspect ratio. Taken together, results show that structural characteristics of the gelled emulsions can be tuned to yield desired fat particles after comminution.