PETボトル詰柑橘果汁の光増感オフフレーバー

摘要

透明容器詰柑橘果汁のクロロフィル類による光増感劣化オフフレーバーについてまとめた．蛍光灯照射に よりテルペン類が酸化して柑橘特徴香が失われると共に，金属様臭または油臭い特徴を有する種々脂肪族カ ルポニル化合物が生成した．最も寄与度が高いと考えられた成分として1－オクテンー3－オンを同定した．異 臭は蛍光灯照射1日で急激に進行した．クロロフィル類はオフフレーバーの前駆体である脂質の光劣化を促 進し，その促進作用はpHが低いはど強くなった．ビタミンCの添加や酸素バリア性ボトルの使用など，酸 化対策がオフフレーバーの抑制には有効であった．%Off-flavor development in clear bottled citrus juices by photosensitized oxidation of chlo rophylls during storage under the fluorescent light exposure was summarized. The citrus-like aroma was decreased due to oxidation of terpenoid while various odor-active aliphatic carbonyl compounds which smell metallic or oily were observed by fluorescent light exposure. The major compound con tributing to the light-induced off-flavor was identified as l-octen-3-one. The light-induced off-flavor was rapidly developed by the fluorescent light irradiation 1 day. It was proven that the photosensi-tivity of the chlorophylls promoted the oxidation of lipid, which was precursor of l-octen-3-one, and the chlorophyll photosensitivity was increased at low pH. Antioxidation treatment such as the addi tion of vitamin C and the use of oxygen barrier plastic bottles are effective for the control of off-flavor development.