Effects of plant polyphenols and α-tocopherol on lipid oxidation, residual nitrites, biogenic amines, and N-nitrosamines formation during ripening and storage of dry-cured bacon

Effects of plant polyphenols (green tea polyphenols (GTP) and grape seed extract (GSE)) and α-tocopherol on physicochemical parameters, lipid oxidation, residual nitrite, microbiological counts, biogenic amines, and N-nitrosamines were determined in bacons during dry-curing and storage. Results show that plant polyphenols and α-tocopherol significantly decreased pH, lipid oxidation (formation of thiobarbituric acid reactive substances) and residual nitrite content compared with control (P < 0.05) at the end of ripening. Microbial counts, biogenic amines, and N-nitrosodimethylamine (NDMA) contents in dry-cured bacons were significantly affected by plant polyphenols or α-tocopherol (P < 0.05), with GTP being the most effective in reducing aerobic plate counts (APC), Enterobacteriaceae, and biogenic amines (putrescine, cadaverine, histamine, tyramine and spermine), as well as in inhibiting the NDMA formation (P < 0.05). Principal component analysis indicated that there were positive correlations between physicochemical factors, biogenic amines (putrescine, cadaverine, histamine, tyramine and spermine), NDMA and APC, and between the TBARS and sodium nitrite. There was a negative correlation between NDMA and nitrite. These findings suggest plant polyphenols, especially GTP, could be utilized for processing dry-cured bacons to improve quality, shelf life, and safety of finished products.