Effects of Calcium Chloride Treatment on the Photosynthetic Capacity and Intensity of Banana Fruit during Ripening

Abstract

The general objective of this work was to highlight the physiological phenomenon of photosynthesis that underlies ripening in banana fruits and to follow its bioindicators evolution. To achieve this goal, pigment content, protein content and the amount of oxygen released were determined at different stages of ripening of bananas fruits. The determination of pigment content was carried out by spectrophotometric assay after extraction in pure acetone. Protein content was determined using a known albumin concentration calibration curve. Moreover, photosynthetic intensity was evaluated by measuring the oxygen released by the banana peels by means of an oximeter. Results showed that there was a gradual decrease in pigment levels, while at the same time there were increases in carotenoid and protein levels. Photosynthetic intensity and capacity also decreased significantly. The treatment of bananas with calcium chloride helped to slow the fall of photosynthetic activity. Also, calcium chloride treatment induced a reduction of the decrease in chlorophyll content, photosynthetic intensity and increase in proteins content. Positive correlations were found between photosynthetic intensity and levels of chlorophyll a and total chlorophylls. The intensity of photosynthesis was negatively correlated with carotenoid and protein levels. The change in photosynthetic intensity during ripening was proportional to the variation in chlorophyll a and total chlorophylls content, but inversely proportional to variations in total carotenoids and proteins contents.