Abstract: The effect of lowering levels of NaCl addition (2.5%, 2.0%, 1.5%, and 1.0%) on the physicochemical and quality characteristics of Harbin dry sausages was investigated by measuring moisture content, water distribution, salt content, color, shear force, thiobarbituric acid reactive substances (TBARS) and total bacterial count as a function of fermentation time. Our aim was to produce reduced salt sausages. The results showed that the moisture content, water activity (Aw), L* value, TBARS value and total bacterial count of the sausages with lower levels of NaCl addition were significantly higher (P < 0.05) during the initial fermentation (0–6 d), whereas a* value, pH value and shear force were significantly lower (P < 0.05). During the late fermentation stage (6–12 d), the moisture content, Aw, pH value and L* value of the sausages with lower levels of NaCl addition were significantly lower (P < 0.05) while the shear force, TBARS value and total bacterial count were significantly higher (P < 0.05). There was no significant difference in a* value among all sausages (P > 0.05). Additionally, low field nuclear magnetic resonance (LF-NMR) analysis showed that the relaxation time (T21) of immobilized water in all sausages were faster with fermentation time, and the relaxation time of sausages with lower levels of NaCl addition was significantly faster (P < 0.05). Finally, sensory evaluation showed that the sausage with 2% NaCl presented the best overall acceptance with a moderate salinity. To sum up the optimal level NaCl addition to Harbin air-dried sausages was 2.0%.

Key words: Harbin air-dried sausages, NaCl addition level, physicochemical characteristics, water distribution