Quality Characteristics of Jeju Beets Treated by Various Drying Conditions

다국어 초록 (Multilingual Abstract)

Beets (Beta vulgaris) contain a lot of betalains, a type of natural pigment, so they are known to be red and have strong antioxidant abilities. This study was conducted to compare the physicochemical properties of Jeju beets processed by hot air drying and combined drying. Beets were sliced to 3 mm and dried by hot air drying (13 hours at 50°C, 6 hours at 60°C, or 4.5 hours at 70°C) or combined drying (hot air and infrared radiation). Appearance, water activity, moisture content, pH, color, rehydration ratio (RR), total polyphenol content (TPC), FRAP value, DPPH radical scavenging ability, and ABTS radical scavenging ability were determined. In hot air drying, as the drying temperature increased, water activity, moisture content, and b* value were decreased while L*, a* value, RR, TPC, FRAP value, and ABTS radical scavenging ability were increased. The combined drying had lower water activity and pH value; moreover, it had a higher L*, a* value, RR, TPC, FRAP value, DPPH radical scavenging ability, and ABTS radical scavenging ability. In this study, it was found that the combined drying was more suitable than hot air drying to maintain the antioxidant ability of beet.