In chemistry, describing substances without the carbon-hydrogen frameworks characteristic of living matter. Nutritionally, the inorganic components of food are the minerals: sodium, potassium, calcium, iron, zinc, and others the body needs for bones, fluid balance, nerve function, and enzyme activity, plus water itself. Fertilisers and some food additives are described as inorganic to distinguish them from carbon-based organic compounds. Analysts measure a food’s inorganic fraction as ash, the mineral residue left after burning away all organic matter. The inorganic-organic distinction organises both chemistry teaching and practical work in food analysis.