Evaluation of pre-heating and extraction solvents in antioxidant and antimicrobial activities of garlic, and their application in fresh pork patties


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The objectives of this study were to screen the optimum conditions for antioxidant and antimicrobial activities of garlic as affected by pre-heating and different extraction solvents, and to evaluate the antioxidant and antimicrobial effects of these extracts in ground meat during refrigerated storage. Methanol extracted garlic had a greater total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging activity and reducing power than water extracted one (< 0.05), whereas the latter had a greater yield and iron chelating ability than the former (< 0.05). Moreover, water extract from fresh garlic (WEFG) and methanol extract from heated garlic (MEHG) produced an inhibition zone against Escherichia coli O157:H7 and Listeria monocytogenes. The addition of garlic extracts (WEFG, MEHG and their combinations WEFMEHG)) to pork patties decreased the pH, hunter a values (redness), thiobarbituric acid substances values and the number of total plate count and Enterobacteriaceae (< 0.05), while the hunter b values (yellowness) increased (< 0.05). Results of this study indicated that the use of the garlic extracts was able to control lipid oxidation and microbial growth in pork patties.