Effect of drying methods and extraction solvents on the antioxidant properties of cooked and raw spinach leaves
Adnan Amjad, Muhammad Sameem Javed, Mohibullah Shah, Aneela Hameed, Muhammad Shahbaz, Shabbir Ahmad
Owing to substantial loss of nutrients during food processing, there is a dire need to explore various processing techniques to retain maximum antioxidant potential of green leafy vegetables. The current study was aimed to evaluate the effects of various drying techniques on the physicochemical and antioxidant properties of raw and cooked spinach leaves. Extraction was carried out by using different solvents (methanol, ethanol, acetone and water were used for extraction purpose). Oven dried sample were significantly different with sun dried samples in terms of Free Radical Scavenging Activity (90.63±2.52, 83.2±6.55), total phenolic contents (937.04±48.45 mg GAE/100g DW, 1251.78±110.05 mg GAE/100g DW) and ferric reducing antioxidant power (7452.27±245.5 µmol Fe²/100g, 8780.27±184.4 Fe²/100g). Similarly, raw and cooked spinach leaves showed distinct extraction rate with significant free radical scavenging activity (1199.8±212.92), total phenolic contents (1199.8±212.92 mg GAE/100g DW, 1034.39±423.55 mg GAE/100g DW) and ferric reducing antioxidant power (8169.47±336.5 Fe²/100g, 5635.53±452.3 Fe²/100g).