Post-harvest Treatment of Banana with Artificial Ripening Agent Influences Its Nutritional Quality and Antioxidant Potential

Abstract

Bananas are widely consumed fruits that are often subjected to artificial ripening to accelerate their marketability for economic gains. Calcium carbide (CaC2) is most commonly used as ripening agent, particularly in developing countries, due to its low cost and effectiveness. However, the use of CaC2 has raised concerns about its potential impact on the safety and nutritional quality of the treated fruits. Assessment of the impact of this practice on the nutritional value of banana is key to improving its functionality and maximize its nutriture. This study was undertaken to examine the effect of post-harvest treatment of banana with calcium carbide agent on nutrient composition and antioxidant enzymes of the pulp. Mature green bananas were separated into fingers of the same size and divided into 4 groups. Group I was untreated and unripen while groups II and III were CaC2-treated at 4g/kg and 8g/kg of fruit respectively. Group IV underwent natural ripening. Proximate composition, sensory evaluation and antioxidant enzyme analyses were carried on the samples after the treatment period following standard procedures. The results show that calcium carbide used at 4g/kg and 8g/kg tilted sensory properties of banana pulp towards low values but not significantly (p > 0.05). On the other hand, there was significant difference (p < 0.05) in the proximate composition of the artificially ripened banana compared to control bananas. Similarly, the levels of essential minerals decreased significantly (p < 0.05) in treated groups II and III compared with group 4. Furthermore, the results of antioxidant enzyme activities indicated that calcium carbide treatment compromised the levels of all the antioxidant enzymes analysed as their concentrations significantly decreased (P < 0.05) from 3.42 to 1.65 U/mL; 32.79 to 22.73 U/mL and 0.68 to 0.28 U/mL for peroxidase, ascorbate peroxidase and catalase respectively. These findings have shown how the nutritional composition as well as antioxidant potential of banana could be compromised if the use of chemical ripening agents such as calcium carbide continues unabated.