Antioxidant activity of ultrasound-assisted extracts of elephant garlic and their effects on the quality of pork patties during refrigerated storage

This study investigated the antioxidant activity of elephant-garlic ( Allium ampeloprasum var. ampeloprasum ) ultrasound-assisted extracts obtained with water (APW), 50% ethanol (APE50) and 100% ethanol (APE), and evaluated their effects on the physicochemical properties and microbial counts of pork patties during 14 d of refrigerated storage (4 °C). Total phenolic contents are followed APE > APE50 > APW > unextracted powder (AP) ( p < 0.05). APE exhibited the highest 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power, but the lowest iron-chelating ability relative to AP. Pork patties were prepared by incorporating 0.5% AP, APW, APE50, or APE, while patties without any additive served as the control and those containing 0.1% ascorbic acid (AA) served as the reference treatment. pH and lightness (L*) values did not differ among treatments. APE50 maintained redness (a*), whereas APE reduced it ( p < 0.05). During storage, patties containing AP, APW, APE50 or APE had lower thiobarbituric acid reactive substance (TBARS) and peroxide values than control, with APE showing the greatest inhibition of lipid oxidation ( p < 0.05). Volatile basic nitrogen (VBN) decreased with APW, APE50 and APE, while APE50 or APE also suppressed total plate counts and Enterobacteriaceae ( p < 0.05). These results indicated that APE50 and APE effectively retard lipid oxidation and microbial growth in pork patties which might be better than the typical drying powder.