Levels of heavy metals in local milk and cheese, and phthalate esters in cheese produced by settled Fulani pastoralists in Ogun and Oyo States, Nigeria

Abstract

The quality of milk and cheese produced by Settled Fulani Pastoralists (SPFs) are of food safety concern. This study analysed heavy metals in milk and cheese, and phthalate esters in cheese products in Ogun and Oyo States Nigeria. Purposive sampling technique was used to select 55 equal products samples from 13 communities in the study areas. Milk and cheese samples were analysed for heavy metals (Cu, Ni, Zn, Cd, Cr, and Pb) using Atomic Absorption Spectrometer (AAS) after digestion with standard methods. Phthalate esters in cheese samples were extracted using sonication and analyzed using Gas Chromatography Flame Ionization Detector (GC-FID). The phthalate esters analyzed for in cheese are benzylbutyl phthalate (BBP), di-cyclohexylphthalate (DCHP), Di-2-ethylhexyl phthalate (DEHP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP) and Dimethyl phthalate (DMP). The concentration of Cu, Ni and Zn were higher in cheese samples than in milk samples while levels of Cd and Cr were higher in milk than cheese. The mean concentration of phthalate esters in cheese were BBP (1.49 ± 0.94; 3.55 ± 4.78), DCHP (0.27 ± 0.15; 0.69 ± 1.09), DEHP(1.16 ± 1.93; 0.75 ± 1.06), DEP (1.45 ± 2.28; 1.81 ± 0.66), DiBP (3.27 ± 2.12; 5.75± 2.68) and DMP (1.06 ± 0.56;2.48 ± 1.08) for Ogun and Oyo States respectively. The study confirmed that heavy metals and phthalate esters were presented at high concentrations in milk and cheese samples analyzed.