Abstract:

In this study, fruits from the red apple cultivars ‘Starking’ and ‘Pink Lady’, the green cultivars ‘Granny Smith’,
and the yellow cultivars ‘Golden Delicious’ were analyzed by HPLC for changes in the kinds and amounts of soluble sugars
and anthocyanins after bag removal during coloration and correlation between these two components. The results showed
that the kinds of anthocyanins in apples varied among the different cultivars. Three anthocyanins, cyanidin 3-galactoside,
cyaniding 3-glucoside chloride and cyaniding 3-arabinoside were identified in the skin of the red apple cultivars after the
completion of coloration and two anthocyanins, cyanidin 3-galactoside and cyaniding 3-arabinoside in both green and
yellow cultivars in different amounts. Various anthocyanins were identified in significantly different amounts in the fruit
and cyanidin 3-galactoside was the most abundant in the skin. All the different apple cultivars contained the same soluble
sugars in different amounts, with fructose being the most abundant followed by sucrose, glucose and the smallest amounts
of galactose and sorbitol. Our analysis found that during the process of coloration, the changes in anthocyanin content,
especially cy-3-gal had an extremely significantly positive correlation with sucrose content. This study speculates that
sucrose might be responsible for the regulation of cy-3-gal biosynthesis in apple skin.

Key words: apple, soluble sugar, anthocyanin, high performance liquid chromatography (HPLC)