Abstract

The effect of banana treatment with traditional kerosene smoking and ethrel released ethylene were investigated to determine their efficacy on ripening, shelf life and physicochemical quality attributes. Fruits at full maturity stage that are light green and three quarter full were used. The study was consisted of three factors namely ripening techniques (conventional kerosene smoking and Ethrel), exposure times (that is, 18, 24 and 30 h), and cultivars (Williams I, Poyo and Giant Cavendish).  Fruits were conventionally treated with kerosene smoke released from kerosene burners and ethylene released from 10 ml of ethrel solution (2-chloro ethyl phosphonic acid). They were equally treated under airtight conditions over three sets of exposure times inside locally standard 3 m × 2 m × 3 m sized six separate commercial banana ripening chambers. Fruits were then sequentially withdrawn from the chambers on the basis of their respective exposure times and studied under ambient conditions (23±1°C and 73±1% RH). All parameters tested were invariably and progressively affected by treatment combinations over the experimental period. Significant differences (p ≤ 0.05) in mean values were also recorded in all parameters at different stages of the ripening period. A three way significant (p ≤ 0.05) interaction effect of the three factors was revealed on the 7^th day of the ripening period on the major quality parameters, starch, TSS, and TSS/TA. Sensory quality evaluation results conducted on the 7^th day of the ripening period also showed a similarly highly significant interaction effect among the treatment factors on all quality attributes tested. Ethrel treated fruits demonstrated higher sensory quality mean score values in color (3.85), flavor (3.89), taste (3.80), aroma (3.66) and total acceptability (3.67), other than mouth- feel (3.37) and degree of ripening (3.49). Fruits treated with all treatment combinations of the kerosene smoking system equally completed their maximum ripening stage on the 7^th day of the ripening period. However, at this stage, fruits were found developing some off ripening effect black scars on the peel in addition to the relatively low quality attributes recorded upon them through the sensory evaluation panel. Fruits treated with ethrel completed their ripening stage on the 7^th day only at the exposure time of 30 h. Those exposed to 18 and 24 h exposure times took more time and extended their ripening stage to up to the 11^th day. Thus, in terms of ripening efficiency, the kerosene smoking system can be used at the lowest exposure time of 18 h under the conditions tested. The ethrel-based ripening system can similarly be used for equal ripening efficiency and better sensory quality attributes but only at the highest exposure time of 30 h.

Key words: Banana, ripening, shelf life, physicochemical quality, kerosene smoking, ethrel.