Significant inhibition of garlic essential oil on benzo[a]pyrene formation in charcoal-grilled pork sausages relates to sulfide compounds

To add garlic more conveniently, the substitute-garlic essential oil (GEO) is wildly applied in meat product for flavor improvement. However, the effects of GEO on chemical hazard formation, such as benzo[a]pyrene (BaP), in meat processing have not been studied. This study focused on the inhibitory effect of garlic (0.05-0.15%, w/w), GEO (0.002-0.006%, w/w) and the active sulfide compounds (0.006%, w/w) on the formation of BaP in charcoal-grilled pork sausages. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of the garlic, GEO and sulfide compounds was also determined. The results showed that the garlic was efficient in the decrease of DPPH free radicals (14.91 23.39%) and BaP content (37.2 62.3%). GEO was also efficient in scavenging DPPH free radicals (14.17-26.20%) and reducing BaP formation (29.1-57.1%). Gas chromatography-mass spectrometer (GC-MS) analysis identified a total of 41 compounds, of which six major sulfide compounds (allyl methyl sulfide, diallyl sulfide, allyl methyl disulfide, diallyl disulfide, allyl methyl trisulfide and diallyl trisulfide) were screened to assess their inhibition of BaP generation. The BaP inhibition of these sulfide compounds were dependent on the number of sulfur (-S-) and thioallyl group (-S-CH2-CHCH2); and allyl methyl trisulfide (AMTS) showed the highest BaP inhibition (63.3%). A significant correlation was found between their BaP inhibition and DPPH scavenging activity (Spearman correlation = 0.91, P < 0.001 ), which indicates that the mechanism of sulfides influencing BaP formation in grilling sausage is related to free radical reaction. Our research gives an insight into the theoretical basis about application of GEO to inhibit BaP during food processing and supports use of GEO as a natural additive in meat products.

Automated summary

The study showed that garlic and substitute-garlic essential oil (GEO) have significant inhibitory effects on the formation of benzo[a]pyrene (BaP) in meat products, with allyl methyl trisulfide (AMTS) being the most effective in inhibiting BaP formation. The mechanism of sulfides influencing BaP formation in grilling sausage is related to free radical reaction, as indicated by a strong correlation between their BaP inhibition and DPPH scavenging activity.