Abstract: The aim of this study was to investigate the effect of smoking time on the heterocyclic aromatic amine content and quality of bacon. Marinated pork belly was smoked for up to 3.0 h at 45–50 ℃. Changes in heterocyclic aromatic amines (HAAs) content and the quality of bacon during smoking were determined. The results indicated that the contents of non-polar HAAs increased significantly with longer smoking time (P < 0.05), while the contents of polar HAAs revealed an initial significant increase (P < 0.05) followed by a decrease, reaching the maximum value after 1 h. The results of color difference analysis suggested that lightness (L*) initially decreased and then increased (P < 0.05), while the opposite trend was observed for redness (a*) and yellowness (b*) (P < 0.05). In addition, water content and water activity decreased significantly, while pH, carbonyl content, and thiobarbituric acid reactive substances (TBARS) content increased significantly with the prolongation of smoking time (P < 0.05). Low field nuclear magnetic resonance analysis confirmed that there was no significant variation in the relaxation time T2b (P > 0.05), but T21 and T22 decreased significantly (P < 0.05). In short, smoking time can significantly affect the HAAs content and quality of bacon.

Key words: smoking, bacon, water distribution, heterocyclic aromatic amines