A correlation was performed to establish links between all
parameters measured in this study. Certain physicochemical and
structural parameters were highly correlated with NaNO2 content
(Table 1). NaNO2 had a significantly negative correlation with carbonyl
levels and positive correlation with free amine levels
(Table 1). This implies an anti-oxidative effect of NaNO2 on MP in
sausages, which could also explain the negative correlation between
surface hydrophobicity and NaNO2 (Table 1). However, NaNO2 had
significantly negative correlation with the –SH levels and positive
correlation with S–S levels (Table 1), thus indicating that NaNO2 increased
protein oxidation. The redox potential of sausages as influenced
by a certain level of NaNO2 might reach a certain balance
between the protective effects against carbonylation and promotive
effects on formation of disulfide cross-linkings. Table 1 showed that
3-NT had significant negative correlations with carbonyls, –SH, surface
hydrophobicity and turbidity, but had a significant positive
correlation with S–S. These factors indicate that 3-NT could be a
promising marker for protein oxidation.