Essential and non-essential metals in coconut milk: Determination, chemometric analysis, and risk assessment study

Due to the widespread metal contamination in plant-based foods, food safety is a major global public concern. The growing demand for plant-based beverages in the market has emphasized the need to conduct research on the metal composition of these products. This study aimed to examine the concentrations of essential and non-essential metals in coconut milk collected from a commercial market located in Lahore-Punjab, Pakistan. Twenty samples (10 commercial milk and 10 extracted milk) were analysed using inductively coupled plasma-optical emission spectrometry (ICP-OES) after ultrasound-assisted extraction (UAE). In addition, the current study investigates the distribution, correlation, and chemometric assessment of 13 metals (Mg, Ca, Mn, Fe, Co, Cu, Zn, Al, Cr, Ni, Cd, Pb and Ba). The concentration ranges of essential metals vary over a wide range for Mg (43.8-687.5mg/L), Ca (127.7-606.5mg/L), Mn (0.64-22.3mg/L), Fe (12.4-91.6mg/L), Co (1.2-5.5mg/L), Cu (1.9-10.8mg/L), and Zn (1.3-9.9mg/L). While, the concentration ranges of non-essential metals vary over a range for Al (0.016-0.093mg/L), Cr (0.19-0.91mg/L), Ni (0.11-0.99mg/L), Cd (0.01-0.02mg/L), Pb (0.01-0.02mg/L), and Ba (0.13-0.93mg/L). Tolerable dietary intake (TDI) values for Cr, Ni and provisional tolerable monthly intake (PTMI) value for Cd were higher than the value established by World Health Organization (WHO) and European Food Safety Authority (EFSA). The higher values of TDI and PTMI indicate that these metals might be harmful to human health through the consumption of coconut milk. The computed values of the target hazard quotient (THQ < 1), the hazard index (HI < 1), and the cumulative cancer risk (CCR) ranged from 8.2 ×10⁻⁵ to 1.0 ×10⁻⁴ which indicated low risk of exposure to metals through consumption of coconut milk. From a dietary and food safety perspective, the study is important for users of plant-based beverages.