The effects of low salt concentrations on the mechanism of adhesion between two pieces of pork semimembranosus muscle following tumbling and cooking

•We investigated the mechanisms of adhesion of pork semimembranosus muscle.•Protein bonding in the exudate tended to weaken with decreasing salt content.•The in-gel bonds were stronger than the gel-to-muscle surface bonds.•Breaking stress increased between non-salted meat and 0.8%-salted meat.•Meat surface modification did not impact breaking stress.

The aim of this research was to gain deeper insight into the effect of salt content on the adhesion between pieces of semimembranosus pork muscle bound by a tumbling exudate gel. Hydrophobic site number, free thiol and carbonyl content were measured in tumbling exudate and meat protein to evaluate the protein-protein interactions involved in the adhesion process. Proteins were far more oxidized in exudate than in meat, and under our experimental conditions, salt content increased protein bonding in the exudate but not in the meat. Breaking stress increased between non-salted meat and 0.8%-salted meat but did not depend on the protein physicochemical properties of the tumbling exudate. Modifying the meat surface by tumbling alone, tumbling and salting, or scarification had no effect on breaking stress. It is suggested that the break between the meat pieces occurred between the tumbling exudate and the meat surface due to weaker chemical bonds at this location.