Overview
Lukáčová and colleagues compared cadmium, nickel, zinc, copper and iron in raw farm cow milk (3.8% fat) and retail UHT cow milk (1.5% fat) from the Nitra region of Slovakia. Table 1 gives mean, median, SD, CV, minimum and maximum per milk type in mg/kg. UHT milk had slightly higher cadmium, nickel and iron, and raw milk had more zinc and copper.
Key numbers
- Cadmium, UHT 1.5% fat milk: mean “0.33” mg/kg (SD 0.24), range 0.21 to 0.94 mg/kg (Table 1, p. 799).
- Cadmium, raw milk: mean “0.27” mg/kg (SD 0.19), range 0.10 to 0.73 mg/kg (Table 1).
- Nickel: UHT mean “1.01” and raw mean “0.84” mg/kg (Table 1).
- Copper differed significantly between raw (3.90) and UHT (0.95) mg/kg, P<0.01 (Table 1).
Methods (brief)
One gram of milk was digested in perchloric and nitric acid at 120 °C and made up to 25 mL. The methods name both voltammetry and AAS, and AAS wavelengths are listed. No detection limits, reference materials or recoveries are reported, and the number of samples per milk type is not given.
Evidence Fitness
The UHT 1.5% fat milk is a reduced-fat (semi-skimmed) cow milk, so the cadmium results are a direct measurement for reduced-fat-milk; lead, arsenic and mercury were not measured. The cadmium and nickel levels are far above those usually reported for milk, and there is no QA to support them, so treat them with caution. The raw-milk copper SD conflicts with its CV. Peer review is unverified.