The cold storage of green bananas affects the starch degradation during ripening at higher temperature

The aim of this work was to investigate the starch degradation of bananas stored at low temperature (13 degrees C, cold-stored group) and bananas stored at 19 degrees C (control group) during ripening. The starch granules were isolated during different stages of banana ripening, and their structure was investigated using different techniques. The activities of alpha-amylase and beta-amylase associated to the starch granules were determined, and their presence was confirmed using immunolocalization assays. The increased molecular mobility likely facilitated the intake and action of alpha-amylase on the granule surface, where it was the prevalent enzyme in bananas stored at low temperature. The 10 days of storage at low temperature also influenced the sizes and shapes of the granules, with a predominance of rounded granules and pits on the surface along with superior amylose content, the higher amounts of amylopectin A-chains and the subtle increase in the A-type allomorph content. (c) 2013 Elsevier Ltd. All rights reserved.