REPRINTS, COPIES

1.	Browning in the filtrates of bananas that had ripened for four days was greater than in the filtrates of bananas that had ripened for two days and the difference was highly significant.
2.	Susceptibility to discoloration of bananas upon standing for 30 minutes increased with ripening, but the difference between bananas ripened for two additional days and bananas ripened for four additional days was not significant.
3.	Moisture content of bananas analyzed as purchased averaged 75.2 percent. No significant change in moisture was observed in bananas ripened for an additional two days, but a highly significant increase was found in bananas analyzed after four days of additional ripening.
4.	The protein content averaged 33.8, 39.4, and 51.6 mg/g banana on a dry weight basis for bananas analyzed as purchased, and after either two or four days of additional ripening, respectively and the increase was highly significant.
5.	The specific activity of polyphenol oxidase in bananas decreased with ripening and the difference in the change in specific activity between bananas ripened for four additional days and those ripened for two additional days was highly significant. W-hen the change in activity of polyphenol oxidase was calculated on a basis of dry weight of banana, the difference was not significant.
6.	The dopamine content averaged 236, 175, and 106 micrograms/g banana on a dry weight basis in bananas analyzed as purchased and after two and four days of ripening, respectively, and the decrease was highly significant.
7.	The content of ascorbic acid averaged 20.1, 11.0, and 13.9 mg /100 g banana on a dry weight basis for bananas analyzed as purchased and after two and four days of ripening, respectively. The decrease in ascorbic acid associated with four days of additional ripening was significantly less (5 percent level) than that observed in bananas held to ripen for an additional two days.
8.	As the concentration of dopamine decreased with ripening, the extent of browning and susceptibility to discoloration increased. Doparnine may have been converted to melanin or to the red intermediate, 2, 3-dihydroindole-5, 6-quinone, or to intermediates closer to these compounds, thereby resulting in an increase in brownness of the intact fruit and an increase in susceptibility to discoloration upon standing.
9.	The increase in brownness and the increase in susceptibility to discoloration with ripening were associated with a decrease of ascorbic acid in the fruit. The decrease in doparnine was also associated with a decrease in ascorbic acid.
10.	The specific activity of the polyphenol oxidase did not appear to be the limiting factor for either the brownness of the tissue or for its susceptibility to browning.
11.	Dopamine was located histochemically in the vacuoles of the latex vessels and in a few isolated parenchyma cells of bananas.
12.Polyphenol oxidase appeared to occur throughout the pulp.
13.The concentration of doparnine as influenced in part by concentration of ascorbic acid appears to be the limiting factor in the browning of bananas.

Updated: Wednesday, June 20, 2007.