Assessment of Some Mineral and Heavy Metal Contents of Samples of Edible Chalk (NZU) Produced in Mbaise, Imo State, Nigeria

The incidence of consumption of food materials with high doze of heavy metals is common. The main purpose of this work was a comparative analysis of mineral and heavy metal of four samples of edible chalk (nzu) produced and in Mbaise, Imo State, Nigeria. Four different samples of edible chalk—ike nzu, ogbake nzu, akuru aku,apiri nzu or apiriaka and oru (pink edible chalk) were selected and purchased from the market of area of study. Calcium and potassium contents were determined by flame photometry, while heavy metals—chromium, lead, nickel and cobalt; magnesium and phosphorus contents were determined by spectrophotometry. Results indicated that calcium contents ranged from 2.52-6.30mg 100-1g, each significantly different (p<0.05) from each other; potassium was 0.016-0.02 mg 100-1g, magnesium, 0.22-0.37 mg 100-1g,with a significant difference, and phosphorus,10.74-98.48 mg 100-1g, each significantly different from each other. Heavy metal contents revealed 14.50-25.0 mg 100-1g for chromium, with a significant difference; lead, 5.25-17.50 mg 100-1g, each significantly different from each other; nickel was detected in only akuru aku and apiri api, which ranged from 1.0-1.5 mg 100-1g.No cobalt was detected in the samples. It showed that akuru aku had the greatest value in calcium (6.30mg 100-1g),whereas ike nzu (ogbake nzu) had the greatest values in magnessium (0.37 mg 100-1g),potassium (0.02 mg 100-1g), and phosphorus (98.48 mg 100-1g).Ike nzu also had the greatest values in chromium (25.0 mg 100-1g) and lead (17.50 mg 100-1g), whereas akuru aku had the greatest value (1.5 mg 100-1g).