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

以20个柑桔品种为研究对象，在果实发育的两个阶段分别收获幼果（每果重约2.5克）和成熟果实，测定其抗坏血酸氧化酶（AAO）活性。在不同品种中，幼果中AAO的比活性在47 ~ 2120单位/ mg蛋白质之间，而成熟果实中AAO的比活性在18 ~ 98单位/ mg蛋白质之间。不同组织类型的AAO活性也存在显著差异，反照率活性最高（64-70%），其次是黄酮类（26-34%）和果肉（2-3%）。采用差谱法对柑橘幼果中提取的AAO进行酶解测定，并与黄瓜中的AAO进行了比较。在0 ~ 100 ug/ml范围内，差谱最大峰高计算的AAO活性与AsA浓度呈线性关系。该酶测定的AsA值与用黄瓜AAO测定的AsA值相当。因此，来自幼嫩果实的AAO可以为AsA测定提供更便宜的酶来源。日本梨幼果粗提物对亚油酸和BHA具有较强的抗氧化活性。这种提取物含有多酚，如绿原酸和儿茶素。这些多酚还显示出抗氧化活性。幼果提取物的抗氧化活性持续约2个月。研究结果表明，日本梨幼果提取物可作为高脂肪食品的天然抗氧化剂。

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.