Studies on physiological and chemical changes of fresh-cut bananas (Part I). Effect of cutting modes on the changes of physiological activity and deterioration in fresh-cut green tip bananas.

摘要

Fresh-cut green tip bananas were prepared in one of 4 ways: cut longitudinally into sections 10 cm long and 1 cm thick (LCS); sliced into 1 cm thick transverse sections (0 CCS); or sliced obtusely and transversely at 30degree C (30 CCS) or 60degree C (60 CCS). The cut surface area and weight of LCS were the highest, and the weight and cut surface area of sections increased with an increase in the obtuse angle, although this did not alter the ratio of surface area:weight. The concentration of ethylene in polyethylene (PE) bags containing the intact green tip bananas was lowest, whereas ethylene from CCS sections increased with increasing angle of cutting. Ethylene production from LCS was highest after 48 hours at 20deg C. The colour and Hunter L values of the cut surfaces changed during 96 hours at 20deg C. Browning and softening was greatest in LCS, followed by 30 and 60 CCS. Browning and softening was slowest in 0 CCS sections. The respiration rates (CO2 production) of LCS were the highest, and those of the CCS sections did not differ during 96 hours at 20deg C. Ethylene production of all sections increased during storage. The ethylene production rates of LCS were the highest, and those of the CCS sections decreased with decreasing cutting angle. All sections storedat 20deg C under continuous air flow or air including 20 ppm ethylene turned brown and softened. The discoloration and softening rates followed the same pattern as that for colour changes. It is suggested that deterioration rates of sliced tissue from greentip bananas depends on physiological changes associated with cutting direction, and that ethylene does not play a significant role in these processes.