Effects of sodium nitrite addition optimized by Lactate-NAD-LDH model on the quality of minced meat gel and Chinese sausage

In this study, we investigated the dose-effect relationship between sodium nitrite and myoglobin reaction (10 mg myoglobin consumes 0.204 mg sodium nitrite) using the Lactate-NAD-LDH model established in the previous stage. This model was applied to the processing of minced meat gel and Chinese sausage to validate the optimal sodium nitrite addition of 30 mg/kg, as deduced by the Lactate-NAD-LDH model. The results showed that the addition of 30 mg/kg sodium nitrite effectively inhibited protein oxidation of minced meat gel, promoted the formation of nitrosomyoglobin (NOMb), reduced the residual nitrite levels, significantly increased the a∗ value, and reduced the hardness ( P < 0.05), making the minced meat gel show a relatively uniform and compact network structure. Meanwhile, this concentration inhibited lipid oxidation of Chinese sausage, contributing to the development of a good color. 44 volatile compounds (VOCs) were detected in sausages of different levels of sodium nitrite (CK: 0 mg/kg, CN30: 30 mg/kg, CN150: 150 mg/kg). Notably, the content of esters and alcohols in the CN30 was significantly higher than in the other groups. OPLS-DA analysis revealed that 19 VOCs (VIP>1) could be considered discriminative compounds, including ethyl 2-methylbutyrate, 4-methyl-1-pentanol, (Z)-2-pentenol, and 4-nonanone, etc. Collectively, the results of this study provide a theoretical reference for the development of healthy meat products with low sodium nitrite. • N30 significantly increased the a∗ value and reduced the hardness of minced meat gel ( P < 0.05). • N30 significantly inhibited protein oxidation in minced meat gel ( P < 0.05). • CN30 inhibited lipid oxidation of chinese sausage, contributing to the development of a good color. • The content of esters and alcohols in the CN30 was significantly higher than in the other groups ( P < 0.05). • 19 volatile compounds are screened as flavor markers to distinguish varied groups.