this is how it works
when bananas are green they are starches(break open one and you'll see), as they ripen they are actually getting oxidized and this process converts the starch to a simple sugar
Starch-Sugar Transformation During Banana Ripening: The Behavior of UDP Glucose Pyrophosphorylase, Sucrose Synthetase and Invertase
N. N. TERRA 1 , E. GARCIA, 1 F. M. LAJOLO 1
1 Authors Terra, Garcia, and Lajolo are affiliated with Depto. de Alimentos e Nutricão Experimental, Faculdade de Ciências Far-macêuticas – USP'(Bloco 14), Caixa Postal – 30786, 01000, São Paulo, SP, Brasil.
This Research was sponsored by a Grant from FINEP (Brazil).
Copyright 1983 by the Institute of Food Technologists
ABSTRACT
Abstract REFERENCES
Starch concentration, sequence of appearance of sucrose, glucose and fructose and activity of some enzymes of sucrose synthesis were followed during ripening of preclimacteric bananas (Musa acuminatd). As starch was degraded sucrose content increased and preceded formation of glucose and fructose. At the same time, while UDP-glucose pyrophosphorylase activity remained constant, activity of sucrose synthetase and invertase increased. The observed sugar and enzyme changes indicated that starch to sucrose transformation via glucose-1-phosphate-UDP-glucose may be an important mechanism for starch disappearance during ripening. The hypothesis was confirmed with thin banana slices infiltrated with [14C(U)]glucose-1-phosphate: the label was incorporated into sucrose three times faster for climacteric than for preclimacteric fruits. Pyrophosphorylase activity and climacteric induced activation of sucrose synthetase could be inhibited by protein and nucleic acids synthesis inhibitors.
Ripening changes were studied in plantains of three cultivars, two Horn types and one French type, and compared with those in bananas ripened under the same conditions. Bananas contained 1% starch when fully ripe and none when overripe, whereas plantains contained about 9% starch when fully ripe and 3% when overripe (composition expressed as percentage fresh weight). Total sugar content was 23% in fully ripe and overripe bananas but in plantains it increased from 20% when fully ripe to 27% when overripe. The ratio of glucose:fructose was approximately unity for bananas and plantains at all stages of ripeness. Sucrose comprised more than 70% of the total sugars in fully ripe bananas and plantains and about half of the total sugars in overripe fruits.
this link will actually show you how to test for sugar and starch, it's a basic test that most people can do
http://www.curriculumsupport.educati...ipe_fruits.pdf
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Originally Posted by wack
