In the cytosol, the maltose released from the starch degradation was assumed to be attacked by an α-glucosidase, followed by a conversion of the resulting glucose to glucose 6-phosphate via hexokinase. However, another enzyme called disproportionating enzyme (DPE 2, a glucanotransferase) seems to participate on this process, converting, by a transglucosylation reaction, a molecule of maltose in glucose and transferring the other glucose to a cytosolic carbohydrate molecule. The DPE 2 activity in bananas (Musa accuminata AAA cv. Nanicão) during the starch degradation was followed by using native PAGEs. To check if it had any relation with the ethylene hormone, the fruits were treated both, with ethylene and by its antagonists, the 1-MCP (100nL/L). Several ripening parameters were also measured such as: ethylene and CO₂ production (by gas chromatography), starch concentration (enzymatic method) and soluble sugars (glucose, fructose, sucrose and maltose - by HPLC-PAD). A burst in the soluble sugar level was observed concomitant to the activity increased in the native PAGE, for all different treatments. As the 1-MCP delays the starch degradation and modify some enzymes activities profiles, like the β-amylase one, witch seems to be the main enzyme that releases maltose from the starch degradation process, it was also possible to notice a reduction on the DPE 2 activity. In the ethylene treated fruits this phenomenon was accelerated. As maltose is probably the main product of starch degradation and no maltase activity was detected, the DPE 2 should be the main protein involved in maltose metabolism.