ABSTRACT Antioxidant activities of acetylated epigallocatechin gallate (A‐EGCG) and ascorbyl palmitate (AP) were compared using different in vitro assays and food model systems. Both A‐EGCG and AP exhibited DPPH and ABTS radical scavenging activities and reducing power. AP demonstrated greater scavenging efficacy toward both radicals than A‐EGCG ( p < 0.05), while A‐EGCG exhibited greater metal chelating activity ( p < 0.05). Antioxidant activity increased as the concentration upsurged from 0.5 to 10 mg/L. Both antioxidants dose‐dependently inhibited lipid oxidation in β‐carotene‐linoleate and lecithin liposome systems, but AP had higher efficacy. For mackerel mince kept in ice and shrimp oil stored at 30°C, AP more effectively reduced lipid oxidation. FTIR spectra revealed the reduced oxidation peaks at 1745 and 1742 cm −1 . AP efficiently preserved eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents in the stored samples. Therefore, both A‐EGCG and AP were effective natural antioxidants; however, AP had higher efficacy in combating lipid oxidation in fish meat and shrimp oil.
Rajasekaran et al. (Tue,) studied this question.