The Physicochemical Qualities and Antioxidant Activities of Apple Juices Marketed in Korea

Abstract

국내에서 제조하여 판매되고 있는 사과주스 제품(혼탁형 4종, 청징형 4종)의 이화학적 품질특성과 항산화 활성, 폴리페놀 성분 조성을 조사하였다. 적정산도는 0.299~0.556 범위로 제품형태에 따른 유의적인 차이는 없었다(p<0.05). 가용성 당질 함량은 <TEX>$10.03\sim13.00\;^{\circ}Brix$</TEX>로서 클라우디형이 높았으며 환원당 함량은 40.47~119.17 g/L이었으며 청징형이 높았다(p<0.05). 사과주스의 색도 및 탁도는 혼탁형이 청징형보다 높은 값을 나타내었다(p<0.05). 비타민 C 함량은 0.74~1.22 g/L 범위로 형태에 따른 큰 유의적 차이는 보이지 않았다. 총 페놀 함량은 혼탁주스(1.13~1.42 g/L)가 청징주스(0.12~0.32 g/L)보다 4~12배 정도 많았다. 사과주스의 폴리페놀화합물은 chlorogenic acid, caffeic acid, (-)-epicatechin, quercitrin, phloridzin을 포함하여 9 종이 HPLC로 분리되었으며, 총 함량은 혼탁주스(319.37~985.63 mg/L)가 청징주스(92.88~214.39 mg/L)보다 높게 나타났다. DPPH 방법으로 측정한 사과주스의 항산화 활성은 혼탁주스(<TEX>$1490.92\sim1676.02{\mu}M$</TEX> GAE)가 청징주스(<TEX>$326.22\sim648.28{\mu}M$</TEX> GAE) 보다 강하였으며, FRAP 방법에서도 혼탁주스(<TEX>$3278.52\sim5115.22{\mu}M$</TEX> TE)가 청징주스 (<TEX>$423.86\sim1506.16{\mu}M$</TEX> TE)보다 강한 활성을 보였다. 사과주스의 항산화 활성은 총 페놀 함량과 HPLC로 분석한 폴리페놀화합물의 함량과 높은 상관성(r>0.95)이 있었으며, 색도 또한 항산화 활성과 상관성이 높았다(r>0.95). The physicochemical qualities, antioxidant activities, and polyphenols composition of eight kinds of cloud and clear apple juice products marketed in Korea were investigated. The acidities of eight kinds of cloud and clear apple juice products were in the range of 0.299~0.556 and showed no significant difference (p<0.05). The soluble solid contents of the cloud type were higher than those of the clear type which had higher reducing sugar contents. The color value and turbidity of the cloud type were also higher, but the vitamin c contents showed no significant differences. The total phenolic contents of the cloud type (1.13~1.42 g/L) were four fold to eight fold higher than the clear type (0.12~0.32 g/L). Nine polyphenolic compounds, including chlorogenic acid, caffeic acid (-)-epicatechin, quercitrin, phloridzin, and 5-hydroxymethyl furfural (5-HMF), were isolated by HPLC analysis, and the total amount of the cloud type (319.37~985.63 mg/L) was higher than that of the clear type (92.88~214.39 mg/L). The antioxidant activities, by DPPH and FRAP assays, of the cloud type showed stronger than those of the clear type. The antioxidant activity and the color value were highly correlated with total phenolic content and polyphenols content (r>0.95).