Surface hydrophobicity has extensively been used as a marker of
protein unfolding (Feng et al., 2015; Li et al., 2012). Although the
NaNO2 treated sausages had significantly lower surface hydrophobicity
on day 0, the loss of surface hydrophobicity was less than11% (200 mg/kg) compared to the control (0 mg/kg) (Fig. 4). The loss
of surface hydrophobicity with increased display time might be
explained by the protein aggregation, which could partially obscure
the protein unfolding. Turbidity measurement can be indicative
of the aggregation of protein. The turbidity of MP significantlydecreased in the NaNO2-treated sausages and decreased with storage
time (Fig. 4). The protein might tightly aggregate to form precipitates,
which may explain the observed decrease of turbidity. These
results are also supported by the decrease of solubility in NaNO2-
treated sausages (Fig. 5).