This study determined the total phenolic content and antioxidant capacity of garlic (Allium sativum L.) and leek (Allium ampeloprasum L.), as well as evaluated their anticholesterol oxidation potential in fish burgers. The total phenolic contents were 1.1 ± 0.1 mg GAE/g FW to garlic and 1.3 ± 0.4 mg GAE/g FW for leek. Leek extract showed antioxidant activity index (1.3 ± 0.01) in DPPH and β-carotene/linoleic acid assay (66.5 ± 1.6%); however, in ORAC assay, no statistic differences were observed (P > 0.05). Besides that, bioactive compounds of garlic and leek extracts were identified by ultra-high performance liquid chromatography-electrospray by ionization-mass spectrometry (UHPLC-ESI-MS). Fish burgers were prepared using different concentrations of leek and garlic and stored at -18 °C for 90 days. Thus, at days 0, 30, 60, and 90, the samples were grilled and analyzed as to their cholesterol and cholesterol oxidation products contents. Storage and grilling led to an increase in cholesterol oxidation products; however, addition of garlic and leek minimized cholesterol oxidation products formation. After 90 days, samples containing 3% leek + 0.5% garlic ware the most effective in inhibiting the cholesterol oxides formation during storage and showed the lowest increase in cholesterol oxidation products content (21.16%). Thus, the findings of this research indicate the potential application of garlic and leek as natural inhibitors of cholesterol oxidation in food. PRACTICAL APPLICATION: Garlic and leek have a set of bioactive compounds with a wide antioxidant capacity when used in meat foods such as fish burgers. Garlic and leek used as natural antioxidants perform well in the shelf life of fish burgers and can be substitutes for synthetic antioxidants in this type of product. The presence of both vegetables reduced the formation of prejudicial products to human health generated during the shelf life of the food.
Keywords: Allium ampeloprasum L.; Allium sativum L.; cholesterol oxidation; fish burgers; natural antioxidants.
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