건조방법에 따른 사과꽃 5종의 항산화 활성 및 HPLC를 활용한 정성·정량분석

Abstract

The present study comprised a comparison of the effectiveness of hot air drying versus freeze drying to determine the antioxidant activities of five types of apple blossoms-i.e., from apple varieties ‘Hongno’, ‘Aori’, ‘Fuji’, ‘Jonathan’, and ‘Myanmar’. Comparisons were made between the total polyphenol content, the total flavonoid content, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging ability, and the fluorescence recovery after photobleaching (FRAP) activity of each type of apple blossom. Qualitative and quantitative analyses were carried out on 11 phenolic substances (caffeic, cinnamic, m-coumaric, p-coumaric, ferulic, 4-hydroxybenzoic, salicylic, sinapic, syringic, vanillic, and gallic acids) and six flavonoid substances (apigenin, isoquercitrin, luteolin, quercetin, quercitrin, and rutin) by high-performance liquid chromatography (HPLC). Freeze-drying resulted in total polyphenol content, total flavonoid content, DPPH radical-scavenging ability, FRAP activity, phenolic acid substances content, and flavonoids content values that were 3.6, 2.7, 3.8, 3.4, 2.4, and 5.7 times higher, respectively, than those resulting from hot air drying. However, hot air drying resulted in higher content values among the following phenolic acids: gallic, sinapic, and ferulic acid. The freeze-dried ‘Aori’ apple blossoms exhibited the highest antioxidant activity, phenolic acid content, and flavonoid content. They had total polyphenol content of 500.6 mg GAE/g, total flavonoid content of 123.8 mg QE/g, DPPH radical-scavenging ability of 83.3%, FRAP activity of 117.4 mg TE/g, total content of the 11 phenolic acid substances of 737.9 mg/kg, and total content of the 6 flavonoid substances of 105.8 mg/kg. Therefore, among five types of blossoms investigated in the present study, freeze-dried ‘Aori’ apple blossom was the most suitable for use as natural antioxidant materials, such as functional health foods and cosmetics.