In vitro digestibility of proteins, peptidomic analysis and antioxidant ability of sodium-reduced pork sausage with partial substitution of NaCl by KCl.

High salt (NaCl) consumption can impact on human health, and KCl is the most widely used replacement salt in meat products. This study investigated the effects of 0% NaCl (NS), 3% NaCl (HS), 1.95% NaCl (RS), 1.95% NaCl+1.05% KCl (RS + K) on protein digestibility of pork sausage in vitro. The results indicated that RS + K showed the highest gastrointestinal digestibility (GID) because of the structure of looser cross-linked strands and uniform cavities, while HS exhibited the lowest GID. RS + K released more peptides (2499) during gastrointestinal than NS (2301), RS (2130) and HS (2235), with a higher proportion of peptides with molecular weights <1000 Da, and more unique peptides. Meanwhile, the digestion product of RS + K exhibited excellent radical scavenging activity and improved the antioxidant abilities to reduce oxidative injury which was induced by HO in HepG2 cells. These results demonstrated that partial substitution with KCl can be an effective strategy for improving the digestibility of sodium-reduced gel-type meat products.