Effect of woodchip types on heterocyclic aromatic amine formation and quality characteristics of smoked bacon

The impact of different woodchips (beech, oak, pear, and apple) on the contents of heterocyclic aromatic amines (HAAs) and quality characteristics of smoked bacon was investigated. The results indicated that the contents of total HAAs and non-polar HAAs in beech- and oak-smoked bacon were lower than that in pear- and apple-smoked bacon (P < 0.05). There were no HAAs detectable in control (non-smoking) sample. The smoking process promoted the formation of free amino acids (FAA) in the smoked bacon. The total contents of FAA in beech- and oak-smoked bacon were higher than these in the pear- and apple-smoked bacons (P < 0.05). The beech-smoked bacon had the highest L*-value (P < 0.05), and oak-smoked bacon had the lowest thiobarbituric acid-reactive substance (TBARS) value and carbonyl content (P < 0.05). Additionally, woodchip types had no significant influence on a*-value, b*-value, moisture content, a(w), T-20, T-21 and T-22 (P > 0.05). PCA of the HAA contents and quality characteristics could effectively differentiate that were unsmoked and smoked bacon. Therefore, woodchip types had a great influence on HAA contents and quality of smoked bacon.