Sugars and Organic Acids in Ethanol- and Ethylene-treated Banana Fruits

Ripening of banana was accelerated by 2-3 days with application of 60% ethanol (10ml/12 fruits). However, 1000ppm ethylene induced more rapid ripening changes: in peel color, sugars and organic acid contents. Sucrose, glucose and fructose were identified by high performance liquid chromatography (HPLC). All the three sugars increased with ripening and sucrose was predominant at all stages of ripeness. The increase in sucrose preceded that of glucose and fructose and the ratio of glucose-frucose was almost constant during the course of ripening, that is, from initial (green) until 9 or 14 days of storage. Malic and citric acids were present in almost equal amounts in green fruits (initial). Malic acid increased 2 to 3.6 times the initial level, becoming the predominant acid in ripe fruits. Citric acid increased only in overripe and senescent fruits.