Effect of freeze drying and oven drying on antioxidant properties of fresh wheatgrass

The effects of freeze drying and hot air drying on total phenolics, total flavonoids and antioxidant properties of flour from seven-day-old fresh wheatgrass (Triticum aestivum L.) were investigated. In the quantitative analysis of antioxidative components, fresh wheatgrass samples had the highest amount of ascorbic acid and chlorophyll, but the lowest amount of total flavonoids and phenolics. In the analysis of ferric-reducing antioxidant power assay (FRAP), ethanolic extract from freeze-dried wheatgrass gave the highest value, while the α-tocopherol gave the lowest value. In the analysis of 2,2-diphenyl-1-picrylhydrazyl scavenging ability, freeze-dried wheatgrass samples exhibited the highest activity among the three samples.