Evaluation of different ripening inducers on the quality, proximate composition and mineral residue in plantain (Musa AAB) fruits

The indiscriminate use of ripening inducers to ripen fruits for domestic markets threatens food safety. Consequently, there is a need to determine the efficacy of inducers used in the industry. Four ripening inducers from plant sources namely; yellow pawpaw leaf, apple, avocado and African bush mango fruits were used to ripen plantain fruits stored in perforated wooden boxes (28-29°C and 77-78% RH). Their effects were compared with those ripened with ethylene glycol or those without ripening inducers (control). The treatment was applied following a completely randomized design replicated four times. Data were collected on fruit colour change, firmness, physiological fresh weight loss, total soluble solids (TSS), total titratable acidity, proximate contents, vitamins A and C and mineral deposit on the ripened plantain fruits. Plantain fruits attained full ripe state on the 4^th day when induced with yellow pawpaw leaf, ethylene glycol, avocado and apple fruits compared to 9 days in the control. Ripening with yellow pawpaw leaves significantly (p<0.05) enhanced vitamin C, TSS, crude protein, fat and fiber contents in plantain fruits at full ripe stage (40.54 mg 100 g^-1, 8.70%, 3.51 g 100 g^-1, 1.67 g 100 g^-1, 6.26 g 100 g^-1, respectively) while least values for these parameters were recorded in plantain ripened with ethylene glycol (38.75 mg 100 g^-1, 7.96%, 3.11 g 100 g^-1, 1.42 g 100 g^-1, 5.43 g 100 g^-1, respectively). Significant residues of heavy metal residue (cadmium – 0.01 µg 100 g^-1, chromium – 0.04 µg 100 g^-1, mercury – 0.13 µg 100 g^-1) were observed in ethylene glycol ripened plantain fruits, while none was observed in fruits ripened with plant materials and control. Yellow pawpaw leaves could serve as cost-effective and safe ripeners for plantain fruits.