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.