Changes in physicochemical properties of proteins in Kayserian Pastirma made from the M. semimembranosus muscle of cows during traditional processing

In the current study, we examined the effects of beef processing to produce pastirma on the physicochemical properties of proteins in M. semimembranosus (SEM) muscle. Protein concentrations significantly increased in pastirma muscles (P < 0.01), as a result of the salting and curing process. The surface hydrophobicity values of processed samples were higher than those without processing at all guanidine-HCl concentrations, suggesting hydrophobicity increased, which may attribute to the new generated peptides during the traditional pastirma-making process. The metmyoglobin content greatly increased (by as much as 89%) in pastirma samples compared with the unprocessed samples. The images of histology also demonstrate that the pastirma processing had no negative impact on the structure of the muscle. The results from this study suggest that the traditional pastirma-making process catalyzed the enzymatic digestion of muscle proteins, and the differences in some physicochemical parameters between the control and pastirma samples were thus likely to be contributable to protein digestion. Thus, the traditional pastirma-making process results in the degradation of many proteins into peptides, which might then be obtainable as functional components to treat human diet- and lifestyle-related diseases such as hypertension, hyperglycemia syndromes or to be used as nutraceuticals.