Metals
Metals are elements that are typically solid at room temperature, with a characteristic luster, malleability, ductility, and good conduction of heat and electricity. In food science they appear in two very different roles. Essential metals such as iron, zinc, and copper are nutrients with defined dietary requirements, while heavy metals such as lead, cadmium, arsenic, and mercury are toxic contaminants with strict maximum limits in foods. Processors must also guard against metal migration from cookware, cans, and processing equipment into acidic or salty foods, and against metal fragments as physical hazards in finished products, which is why metal detection and equipment-maintenance programs are standard in modern plants.