Abstract: The experimental material used to prepare Chinese-style bacons by dry salting and following air-dried ripening was pork belly pieces in this study. A 9-run, 4-factror, 3-level orthogonal array design was employed to investigate the effects of four process parameters, namely salting time, air-dried ripening temperature, relative humidity, repeated time of chitosan coating on physico-chemical and quality indices and proteolysis in bacon. Results indicated that proteolysis index (PI) and total free amino acids (TFAA) significantly increased (p＜0.05) with the increase of temperature during processing. The PI and TFAA in the treatment group of 17－32 ℃ increased 20% and 28%, compared with those in the treatment group of 13－28 ℃, respectively. TBARS was significantly correlated with temperature during preparation processing (r = 0.93, p＜0.01), and the maximal value of TBARS was (0.65 ± 0.26) mg/kg. The products with water content of (59.75 ± 1.89)% and salt content of (3.49± 0.49)% exhibited a better sensory quality. The TFAA and total scores of sensory evaluation as target functions revealed that the optimal processing conditions were air-dried ripening time of 5 days, drying temperature of 17 ℃, repeated coating number of 2 and salt addition amount of 1.5%.

Key words: pig belly, air-dried ripening, proteolysis index, free amino acid, sensory quality, processing optimization