Short-term nitric oxide gaseous treatment of post-rigor pork: Multidimensional impacts on meat quality, protein oxidation and proteolysis, and microstructure.

This study investigated the effects of short-term nitric oxide (NO) gaseous treatment on the quality and underlying mechanisms of post-rigor chilled pork. Samples were subjected to either NO exposure (117 μL/L) or pure N2 (control) for 41 min prior to 7-day vacuum storage. Results showed that NO treatment significantly improved the redness without elevating residual nitrite, whereas shear force and purge loss increased relative to controls. NO accelerated protein oxidation, evidenced by increased S-nitrosothiols, carbonyls, disulfide bonds, and Schiff bases with decreased sulfhydryl, leading to increased surface hydrophobicity, reduced solubility, and altered microstructure. This NO-induced oxidative cross-linking inhibited proteolysis, as evidenced by lower MFI and troponin-T degradation. Volatile profiling indicated that the overall flavor profile was affected by storage duration rather than NO treatment, with less off-odor generation. These findings provide a theoretical basis for determining the optimal industrial application window for NO in fresh meat processing.