The concentration of potentially toxic elements (PTEs) in the coffee products: a systematic review and meta-analysis

Coffee is one of the most consumed products globally, and its contamination with potentially toxic elements (PTEs) occurs throughout the production chain and production. Therefore, the current meta-analysis study aimed to estimate the concentration of essential elements (Cu and Co) and the contamination of PTEs (Ni, Cr, Pb, As, and Cd) in coffee. The recommended databases, including PubMed, Scopus, and ScienceDirect, were investigated to collect data regarding the contamination of PTEs in coffee products from 2010 to 2021. Among 644 retrieved citations in the identification step, 34 articles were included in the meta-analysis. The pooled mean concentration of essential elements in coffee products is much higher than that of toxic elements (Co (447.106 mu g/kg, 95% CI: 445.695-448.518 mu g/kg) > Ni (324.175 mu g/kg, 95% CI: 322.072-326.278 mu g/kg) > Cu (136.171 mu g/kg, 95% CI: 134.840-137.503 mu g/kg) > Cr (106.865 mu g/kg, 95% CI: 105.309-108.421 mu g/kg) > Pb (21.027 mu g/kg, 95% CI: 20.824-21.231 mu g/kg) > As (3.158 mu g/kg, 95% CI: 3.097-3.219 mu g/kg) > Cd (0.308 mu g/kg; 95% CI: 0.284-0.332 mu g/kg)). Results showed high differences between pooled concentrations of all PTEs in coffee products of different countries.