What You Need to Know
High concentrations of NaCl create a surface salt layer that lowers water activity (a_w) below 0.85, inhibiting psychrotrophic bacteria. The osmotic dehydration also denatures surface proteins, forming a firm, dry crust that protects the interior. Over extended storage, lipid oxidation generates aldehydes and ketones, contributing to rancidity if not properly controlled.
The Science
Primary Reaction
Osmotic dehydration and protein denaturation due to high NaCl concentration