Abstract: NaCl is an essential auxiliary material for processing of minced pork products. In this paper, in order to further confirm the role of NaCl in this regard, low field nuclear magnetic resonance and Raman spectroscopy were used to explore the effect of NaCl on cooking yield, hardness, water migration and protein secondary structures in pork batters. The results showed that cooking yield and hardness were signi?cantly (P < 0.05) improved, T2b and T22 relaxation times became shorter, and the peak ratio of T21 (bound water) was increased with the increase in NaCl concentration. Raman spectroscopy indicated that β-sheet content was increased with increasing NaCl concentration from 1% to 2%, while the secondary structure composition was not signi?cantly changed (P > 0.05) with further increase in NaCl concentration up to 3%. With the increase in NaCl concentration, the —OH stretching vibration was shifted to high wavenumbers (3 226 and 3 227 cm-1), and the number of hydrogen bonds in a water molecule was increased. Overall, the addition of a proper amount of NaCl could change the secondary structure of pork proteins and enhance protein hydration, thereby helping improve processing properties of pork batter.

Key words: Raman spectroscopy, low field nuclear magnetic resonance (LF-NMR), water holding capacity, secondary structure, water structure