Abstract
In order to investigate the new aspects of processing properties of banana, the changes of the contents of sugars, starch and pectic substances, of acidity in banana harvested from the three different places during ripening was observed. That were samled every other day.
In respect of the determination of pectic substances, at first, the pulp and peel of banana were boiled in 70% ethylalcohol so as to remove sugars, then dried. Thus, by the fractional extraction the obtained dried materials were successively fractionated into three parts which were soluble in water at 30°C (W-S), 0.4% sodium hexametaphosphate at 30°C (P-S), and 0.05 N hydrochloric acid at 85°C (H-S). The pectic contents (Ca-pectate) of the fraction were quantitatively determined.
As the results, while the sugar was increased, the starch was decreased. Especially they were increased or decreased markedly after seven days. The total amount of suger in Philippine banana was comparatively large quantity. The acidity and pH showed small peak on the five or seven days. The total amount of pectin was gradually decreased, especially the decrease was significant in the latter half of ripening. The total pectin contents of banana pulp on the nine days of ripening, expressed as Ca-pectate on the fresh basis 0.55 % in Ecuadore banana, 0.66% in Philippine banana and 0.68% in Taiwan banana.
As for the ratio of the extracted fractions, P-S and H-S fractions decreased through ripening, while W-S fractions increased.
This is shown that the banana pulp was gradually softend.
The pectin amount in the banana peel was comparatively small and the changes through ripening were not markedly.
