Assessment of Anthropogenic Influence in Kurmi Cocoa Farmlands and Cocoa Beans using Heavy Metals as Indicators, and the In-vitro Bioaccessibility in Locally Produced Cocoa Based Beverages to Public Health

Abstract

This study was conducted to assess the level of anthropogenic-influence across cocoa farmland soils, to cocoa beans and the locally produced cocoa-based beverages (CBB) from cocoa producing communities of Kurmi, Taraba State using heavy metals (Cr, Cu, Zn Pb, Cd, Mn, and Fe) as indicators. The results show Cr, Zn, and Pb in soil samples from Abong, Gidan Makeri, and Asha on the average detected to have values above the permissible limit (PL) set by the FAO/WHO. The further assessment shows only 23%, 39% and 4% of their total concentrations are from anthropogenic-related activities (Apn%) and of low ecological risk to the environment with potential ecological risk (Er) ˂40 and Ri≤10. The level of heavy metals in the cocoa beans samples analyzed were observed to be above the PL set by FAO/WHO. Compared to the values detected in the cocoa beans samples, the mean concentrations for Cr (6.25±1.88), Cu (7.78±2.87), Zn (19.73±7.19), Pb (18.10±6.59). Cd (4.78±2.07), Mn (8.26±4.92), and Fe (33.79±4.07) were observed to be significantly higher in the locally produced CBB samples. The in vitro digestion of the CBB samples shows mean bioaccessibility concentrations range from 0.67-3.38 mg/kg, with Fe, Cu, Cd, and Pb showing the highest mean concentration values of 3.38±2.64, 2.68±3.51, 1.84±1.82, and 1.65±1.27 mg/kg.The results revealed Cu and Cd with mean in vitro concentrations of 2.68±3.51, and 1.84±1.82 to be highly extracted in the gastrointestinal fluids showing a percent bioaccessibility of 34%and 39%. The estimated daily intake (EDI) of the metals were observed to be above the oral reference dose (RfD) values with average contributions rates (ACR) to RfD >100%.