Drying Effects on Phytochemicals and Antioxidant Properties of Ginger Powder Undergoing Different Drying Techniques

Abstract

The objective of this study was focused on drying techniques including oven, mechanical, sun and shade drying on changes in phytochemicals and scavenging antioxidant capacity of ginger powder. The dry ginger had highest phenolics content (487.87±2.63 mg GAE/g) and flavonoids (322.63±3.74 mg RE/g) on weight basis. The highest DPPH antioxidant scavenging capacity in (78.13±1.02%) and highest FRAP assay in (38.64±0.76 mmol Fe(II)/mg). Oven drying technique had a positive effect on retaining flavonoids content. Shade drying technique had a positive effect on retaining phenolics content, ascorbic acid and DPPH antioxidant scavenging activity assay. On the other hand, sun drying technique had a positive effect on retaining FRAP antioxidant assay. The changes in antioxidant scavenging activity due to the drying techniques were positively correlated with phytochemicals content.
 Drying techniques caused a significant change in phytochemicals and antioxidant activity in dry ginger. However, it can be recommended that special technique should be taken for processing that phytochemicals and antioxidant scavenging capacity remain in processed ginger powder.