Relationship between Flavonoid Chemical Structures and Their Antioxidant Capacity in Preventing Polycyclic Aromatic Hydrocarbons Formation in Heated Meat Model System

The relationship between the chemical structures of six flavonoids and their abilities to inhibit the formation of polycyclic aromatic hydrocarbons (PAHs) in a heated meat model system was investigated. The PAH8 forming in samples was analyzed by using QuEChERS coupled GC-MS. Inhibitory effects of PAHs were myricetin (72.1%) > morin (55.7%) > quercetin (57.3%) > kaempferol (49.9%) > rutin (32.7%) > taxifolin (30.2%). The antioxidant activities of these flavonoids, assessed through (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity assay (DPPH), [2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid)] free radical scavenging activity assay (ABTS) and ferric ion reducing antioxidant power assay (FRAP) assays, exhibited a significant negative correlation with PAH reduction. Notably, myricetin that contained three hydroxyl groups on the B-ring, along with a 2,3-double bond in conjugation with a 4-keto moiety on the C-ring, demonstrated strong antioxidant properties and free radical scavenging abilities, which significantly contributed to their ability to inhibit PAH formation. However, rutin and taxifolin, substituted at the C-3 position of the C-ring, decreased the PAH inhibitory activity. The ABTS assay proved the most effective in demonstrating the correlation between flavonoid antioxidant properties and their capacity to inhibit PAH formation in heated meat model systems. Thus, the inhibition of PAHs can be achieved by dietary flavonoids according to their chemical structures.

Assessment of High-temperature Refined Charcoal to Improve the Safety of Grilled Meat Through the Reduction of Carcinogenic PAHs

This study presents mitigation strategies for reducing carcinogenic polycyclic aromatic hydrocarbon (PAH) contamination levels in grilled meat using high-temperature refined charcoal (HTC) prepared by Iwate kiln, also known as high-quality charcoal. Four different types of HTC were investigated for their properties in conjunction with their potential to reduce PAHs in grilled meat, including high-temperature Eucalyptus charcoal (HTEC), Leucaena charcoal (HTLC), Acacia charcoal (HTAC), and bamboo charcoal (HTBC). The results showed that all HTCs had higher fixed carbon, higher heating value, and lower volatile compounds (83.07-87.81%, 7,306-7,765 Kcal/g, and 6.98-11.97%, respectively) than commercial low-temperature refined charcoal (LTC) (65.33%, 6,728 Kcal/g, and 22.22%, respectively). The current high fixed carbon content and heating value responded to the rising maximum temperature of charcoal up to 500-600°C, providing heat source stabilization to control the radiant energy exposure of charcoal during grilling, thereby shortening grilling time. The PAH16 value of the LTC-grilled sample (144.41 μg/kg) was significantly higher than that of the HTEC, HTLC, and HTAC-grilled samples (98.21, 80.75, and 79.56 μg/kg, respectively). However, PAH16 levels in the sample grilled with HTBC were unexpectedly high (265.75 μg/kg), and cooking loss was not significantly different between samples grilled with all charcoals. Overall, the findings indicated that using HTC prepared from Eucalyptus, Leucaena, and Acacia woods could reduce PAH contamination in grilled pork by up to 45%. However, more research is needed to determine the best preparation method for high-quality charcoal made from bamboo.