蓝莓果实外观与糖、酸、酚组成特征

Appearance and Sugar,Acid and Phenol Composition of Blueberry Fruit

以21个蓝莓品种果实为试材,观测外观特点,检测可溶性糖、有机酸营养组成,旨在为育种、栽培、鲜食品种选择提供依据。结果表明,蓝莓果型指数均小于1,大多呈不同程度扁球形,少数近球形和饼形;单果重为0.52 g~2.63 g,其中‘达柔’超过2.5 g,是少有的大型果;果实多呈蓝色且表面附着果粉,‘粉红佳人’为稀有的红色少果粉品种,‘黑珍珠’是罕见的黑色无果粉种质;果实越大果形越扁含水量越高。果实含有果糖、葡萄糖2种可溶性糖和草酸、奎尼酸、苹果酸、莽草酸、柠檬酸5种有机酸以及绿原酸、儿茶素2种酚类物质,3类物质含量依次递减、差异显著。同一品种中两种糖含量相当且葡萄糖含量(48.81 mg/kg)略高于果糖含量(44.41 mg/kg),果糖甜度(7771)显著高于葡萄糖甜度(3661),属于己糖积累型果实,果糖、葡萄糖、总糖含量及甜度变化趋势和幅度极为相似,果糖含量越高,葡萄糖含量越高,果实越甜,‘喜来’、‘日出’是优良的高糖品种。柠檬酸含量最高(6.31 mg/kg),占总酸的76.52%,显著高于其它有机酸,属于柠檬酸优势型果品,不同品种间奎尼酸含量差异巨大,相差1000余倍,‘北卫’是奎尼酸含量极高的品种,‘利博梯’、‘蓝金’是高柠檬酸品种,‘北卫’、‘利博梯’、‘蓝金’是高酸品种。果实风味受总甜度(可溶性总糖含量)影响,由有机酸含量决定,综上所述,‘喜来’、‘日出’、‘比洛克西’、‘N5’、‘黑珍珠’、‘瑞卡’是较好的鲜食品种。

The appearance characteristics of the fruits of 21 blueberry varieties were observed,and the sugars and acids in the fruits were detected,which would provide a basis for the breeding,cultivation,and fresh-eating variety selection of blueberry.The results showed that the 21 blueberry varieties all had the shape index below 1.Most of the varieties had oblate spherical fruits,and a few had nearly spherical or cake-shaped fruits.The vari-eties had the single fruit weight of 0.52 g-2.63 g,among which the variety'Darrow'had the single fruit weight more than 2.5 g.The fruits of most varieties were blue with white powder on the surface.'Pink Lemonade'was a rare variety with red fruit and little white powder,and'Black Pearl'was a rare variety with black fruit and no white powder on the fruit surface.The variety with big and flat fruit generally had high water content.The blue-berry fruit contained two soluble sugars(fructose and glucose),five organic acids(oxalic acid,quinic acid,mal-ic acid,shikimic acid,and citric acid),and two phenols(chlorogenic acid and catechin).The content of the compounds followed the trend of soluble sugars>organic acids>phenols,with significant differences.In the same variety,the glucose content(48.81 mg/kg)was slightly higher than the fructose content(44.41 mg/kg),and the fructose sweetness(7771)wassignificantly higher than the glucose sweetness(3661),which indicated that blue-berry belonged to the fructose-accumulating fruit.The content of fructose,glucose,and total sugar presented similar trends and ranges with the sweetness.The fruit with high fructose content and high glucose content was generally sweet.'Sierra'and'Sunrise'were elite high-sugar varieties.Citric acid presented the content(6.31 mg/kg,76.52%of the total acids)significantly higher than other organic acids,which indicated that blueberry was a cit-ric acid-dominant fruit.The content of quinic acid varied greatly among different varieties,with the difference more than 1000 folds.'Patroit'was a variety with high content of quinic acid,and'Liberty'and'Bluegold'were the vari-eties with high content of citric acid,all of which had rich acids.The fruit flavor was affected by the total sweetness(totalsoluble sugar content)and determined by organic acid content.The results of comprehensive evaluation indi-cated that'Sierra','Sunrise','Biloxi','N5','Black Pearl',and'Reka'were the varietiessuitable for fresh eating.