Studies on the functional substances from young fruits of Satsumamandarin and Japanese pear.

以20个柑橘品种为试材，分幼果期（单果重2.5g左右）和成熟期（果实成熟期）两个阶段，测定了果实抗坏血酸氧化酶（AAO）活性。在不同品种中，幼果中的AAO比活性范围为47 - 2120单位/mg蛋白，而完全成熟的果实中的AAO比活性范围为18 - 98单位/mg蛋白。不同组织中抗坏血酸（AAO）的活性也存在显著差异，其中以果肉中AAO的活性最高（64-70%），其次是果皮（26-34%）和果肉（2-3%）。结果表明，在0-100 μ g/ml范围内，AAO活性与阿萨浓度呈良好的线性关系。结果表明，该酶测定的阿萨值与黄瓜AAO测定的值相当，说明梨幼果中的AAO可作为测定阿萨的廉价酶源。这些聚烯醇还显示出对亚油酸氧化的抗氧化活性。幼果提取物显示出抗氧化活性约两个月。研究结果表明，日本梨幼果提取物可作为天然抗氧化剂，用于高脂食品。

Twenty cultivars of citrus fruits were harvested two stages of development : young fruit (weight about 2.5 gper fruit) and fully ripe fruit of which the ascorbic acid oxidase (AAO) activities were determined. Among the different cultivars, the specific activities of AAO in the young fruit ranged from 47 to 2120 units per mg protein, while fully ripe fruits had AAO ranging from 18 to 98 unit per mg protein. Significant differences were also found between tissue types in the AAO activity with the higest activity in albedo (64-70%), followed by the flavedo (26-34%) and the pulp (2-3%).AAO obtained from the young fruits of Satsuma mandarin was utilized for the enzymatic determination of ascorbic acid (AsA) based on the difference spectral method as a possible new source of AAO,and the results was compared to cucumber AAO.A linear relationship was observed between AAO activity calculated from the maximum peak height of the difference spectra and the AsA concentration in the ranges of 0-100 ug/ml. The values of AsA determined by the enzyme were also comparable to the valuse obtained using cucumber AAO.Thus, AAO from the young fruit could provide a cheaper source of the enzyme for AsA determination.The crude extract obtained from young fruits of Japanese pear had strong antioxidative activity for linoleic acid oxidation as well as BHA.The extract contained polyphinols such as chlorogenic acid and catechin. These polypenols also indicated antioxidative activity for Jinoleic acid oxidation. The young fruit extract showed antioxidative activity for about two month. These results invesitgated that the extract from young fruits of Japanese pear had been employed for a natural aitioxidant for fatty foods.