桃果实不同发育时期细胞内糖酸分布对甜酸风味的影响

为了解桃果实发育过程中细胞内糖酸的分布、变化规律对果实甜酸风味的影响,采用区室分析方法研究了‘白凤’桃(Prunus persica‘Hakuho’)果实不同发育时期细胞内糖酸组分、含量及其分布对甜酸风味的影响。结果表明,成熟果实中(花后100 d)可溶性糖(蔗糖、葡萄糖、果糖和山梨醇)在液泡、细胞质和细胞间隙中的含量分别为27.3、11.6、9.0 mg/g,有机酸(苹果酸、柠檬酸、奎宁酸和莽草酸)含量为2.09、0.94、0.35 mg/g;未成熟果实中(花后60 d)可溶性糖在液泡、细胞质和细胞间隙中的含量分别为0.97、2.2、2.3 mg/g,有机酸含量为0.25、0.44、0.82 mg/g。‘白凤’桃果肉细胞内不同的糖酸分布对成熟果实的甜酸风味具有显著影响,而对未成熟果实影响较小。成熟果实中糖酸在液泡、细胞质和细胞间隙三者之间的分布差异可能是导致果实甜度变化的主要原因。

Effects of Intracellular Distribution of Sugar and Acid at Different Developmental Stages on Sweetness and Sourness of Peach Fruit

To understand the distribution and changes of sugars and acids in peach fruit during the growing stages, their distribution and concentrations in vacuoles, cytoplasm, and free space in fruits of Prunus persicae ＇ Hakuho＇ at different growing stages were studied by compartmental analysis, and their contribution to fruit sweetness and sourness was assessed. Results showed that the concentration of sugars （sucrose, glucose, fructose and sorbitol） and acids （malate, citrate, quinate and shikimate） in vacuoles, cytoplasm and free space of mature fruits was 27.3, 11.6 and 9.0 mg/g, and 2.09, 0.94 and 0.35 mg/g, respectively, and was 0. 97, 2. 2 and 2. 3 mg/g, and 0. 25, 0. 44 and 0. 82 mg/g in immature fruit, respectively. Sweetness and sourness was less affected by the different distribution of sugar and acid in cells in immature fruit than that in mature fruit. There was an obvious concentration gradient between the vacuoles, cytoplasm and free space for sugars and acids, and the differences in the intracellular distribution of sugar and acid may be responsible for the changes of fruit sweetness.