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.

Effect of food processing on reduction and degradation pathway of pyrethroid pesticides in mackerel fillet (Scomberomorus commerson).

Pyrethroid contamination in fish can contribute to the dietary uptake of pesticides. To mitigate this risk, the effects of frozen storage, thermal treatments (boiling and grilling), and non-thermal treatments (pickling and curing) on the reduction of bifenthrin, cypermethrin, deltamethrin, and permethrin in mackerel fillets were investigated. The curing process was the most effective method that significantly depleted 74.82-79.45% of pyrethroid residues from fish fillets, followed by the synergistic effect of eight weeks' frozen storage and grilling method (69.19-78.31%). Moreover, pyrethroid degradation pathways in processed fish were proposed into three major mechanisms of C1-C3 bond cleavage in cyclopropyl, dehalogenation, and double bond cleavage. These identical pathways incorporated with additional four mechanisms of dimerization, ester hydrolysis, oxidation, and reduction. This study recommended simple and effective processing practices for consumers and/or manufacturers to enhance food safety from the potential risks of consuming pyrethroid-contaminated fish.

Effect of vacuum impregnated fish gelatin and grape seed extract on moisture state, microbiota composition, and quality of chilled seabass fillets.

The effect of fish gelatin (FG) and grape seed extract (GSE) on microbiota composition and moisture state of fish was unexplored. Herein, this study aimed to evaluate the single and combined (FGG) effects on seabass during storage (4 °C) with assistant of vacuum impregnation and to elucidate the underlying preservative mechanism. As suggested by low-field NMR and magnetic resonance imaging, FGG-treated seabass presented higher water holding capacity by controlling transformation from immobilised to free water. Moreover, the total viable count and spoilage bacteria were reduced by > 1 log CFU/g as compared to the control. Changes in microbial flora analysed using high throughput sequencing further indicated that GSE contributed to the notably suppressed growth of Pseudomonas. Also, the accumulation of biogenic amines especially putrescine was decreased (over 0.5-fold) under the combination treatment as compared to the control (P < 0.05). The results suggest that FGG is promising for seabass preservation.

Investigating the migration of pyrethroid residues between mung bean sprouts and growth media.

To study the migration of pyrethroids (cypermethrin, deltamethrin, fenvalerate, and permethrin) from growth media (soil or water) to mung bean sprouts, pyrethroid residues were quantified using polystyrene-magnetic nanoparticles and HPLC-PDA. Pyrethroids reductions in growth media followed a double-exponential decline model (RMSE of 0.0068-0.1845), while the higher accumulation in the vegetable were observed in roots (0.50-6.75 mg/kg) than in sprouts (0.12-2.01 mg/kg). The accumulation was influenced by pyrethroid species, type of growth media, and plant parts. This study contributed a novel prediction method to assess the migration of pesticides from the growth media to the vegetable with the satisfactory sensitivity of the proposed detection method. The recoveries, detection limits (LOD), and quantification limits (LOQ) were 82.9-112.1%, 0.0627-0.1974 µg/L and 0.1892-0.6279 µg/L, respectively, for four pyrethroids. The research provided solid basis for future study of crops that can be used for bioconcentration of chemical hazards in environments.

Inhibitory effects of dietary antioxidants on the formation of carcinogenic polycyclic aromatic hydrocarbons in grilled pork.

OBJECTIVE: The inhibitory effects of dietary antioxidants, diallyl disulfide (DADS) and quercetin, in marinade were investigated on the formation of carcinogenic polycyclic aromatic hydrocarbons (EPA priority 16 PAHs) in grilled pork. METHODS: The formation of PAHs in grilled sirloin pork with different marinades after charcoal-grilling for 2 min/side were evaluated using high performance liquid chromatography with a photodiode array detector (HPLC-DAD). RESULTS: Compared with the control marinade treatment (without antioxidant), the addition of DADS (500 mg/kg meat sample) in marinade significantly decreased benzo[a]pyrene (BaP) (100%) and heavy PAHs (84%) in charcoal-grilled pork, while the addition of quercetin at the same concentration could reduce 23% and 55% of BaP and heavy PAHs, respectively. CONCLUSION: The results of this study suggested that the addition of DADS in the marinade could be important in decreasing the levels of PAHs in grilled meat.