Effects of Different Ripening Regimes of Musa Acuminata (Banana) on Albino Rats used as Risk Assessment Model

Abstract

Fruit ripening is a natural process in which a fruit goes through various physical and chemical changes and gradually becomes sweet, colored, soft and palatable. The use of artificial ripening agents to enhance fruit ripening has become prevalent mostly due to the commercial purposes. People consume fruits ripened with chemicals such as calcium carbide, these can pose great health risk to the consumers. Therefore, the study was aimed to investigate the effect of different ripening regimes of Musa acuminata on albino rats used as risk assessment model. Two ripening agents namely calcium carbide and African bush mango were used and compared with a control with no ripening agent. Results showed that banana ripened with 30g calcium carbide (RB4) was the first to ripen in 3days followed by banana ripened with 7g calcium carbide (RB3) and banana ripened with African bush mango (RB2) with naturally ripened banana (RB1) ripening on the 10th day. Proximate composition result of the fruit showed an increased moisture from 77.77% in RB1 to 85.15% in RB4, carbohydrate content reduced from 18.16% to 12.94%, Fibre, protein, fat and Ash content were found to decrease with the use of ripening agents in the following range 1.10-0.50, 1.24-0.35, 0.73-0.30 and 1.05-0.77. A total of twenty-five (25) adult female albino rats were divided into five (5) groups (1, 2, 3, 4 and 5), with five (5) animals in each group. Group 1 received distilled water only, group 2 received 20g of naturally ripened banana, group 3 received 20g of banana ripened with African bush mango while groups 4 and 5 received 20g each of banana ripened with 7g and 30g calcium carbide respectively for 30days. Heavy metals result showed a significant increase (p < 0.05) in the levels of Lead (Pb) and Arsenic (As) for groups 2, 3, 4 and 5 when compared with group 1. However, group 4 and 5 for Chromium were significantly higher when compared with group 1 while group 2 and 3 showed no significant difference (p < 0.05). Results from human health risk assessment model for Estimated Daily Intake showed an increase above the tolerable daily intake for heavy metals such as Pb (for group 2, 3, 4 and 5) and As (for group 5). There was also a fall in the Tolerable daily intake for Cr (all groups were below the TDI) and As (for group 1, 2, 3 and 4). Toxic Hazard Quotient showed increased values above the standard THQ (0<x<1) for an acceptable human such as Pb (for group 2, 3, 4 and 5) and As (for group 5), whereas values for Cr and As (for group 1, 2, 3 and 4) were below the standard THQ. Carcinogenic Risk (CR) values showed that all values estimated were within the value of United States Environmental Protection Agency (USEPA) incremental lifetime carcinogenic risk (ILCR > 10-3) while Arsenic for group 5 was otherwise. Antioxidant enzyme activities showed a significant increase (p < 0.05) in catalase activity for group 2 when compared with group 1, while groups 3, 4 and 5 recorded no significant change. Glutathione Peroxidase and Glutathione Reductase activities for all the groups were not significant (p < 0.05). Likewise, Superoxide Dismutase activity for groups 4 and 5 were significant (p < 0.05) when compared with group 1 but recorded no significance for group 2 and 3. Liver Function Test (LFT) result for Aspartate aminotransferase (AST) and Alkaline phosphatase (ALP) activities showed no significant (p < 0.05) difference. Alanine amino (ALT) transferase activity was significantly increased across the groups when compared with the control group (Group 1). The observed results showed that calcium carbide contains traces of potential toxic elements (heavy metals) and that its use in fruit ripening will pose a potential health risk on the consumers.