One of the components in the proximate analysis of biological materials, consisting mainly of salty, non-organic constituents. Ash is essentially all the compounds that are not considered organic or water. It includes metal salts which are important for processes requiring ions such as Na+ (Sodium), K+ (Potassium), Ca+ (Calcium). It also includes trace minerals which are required for unique molecules, such as chlorophyll and hemoglobin.

For instance, the analysis of Honey shows:

Typical Honey Analysis

• Fructose: 38%
• Glucose: 31%
• Sucrose: 1%
• Water: 17%
• Other sugars: 9% (maltose, melezitose)
• Ash: 0.17%

Source: Sugar Alliance

In this example the Ash would include all the vitamins and minerals in honey.

Also see:

• oxides, e.g. Al₂O₃, CaO, Fe₂O₃, MgO, MnO, P₂O₅, K₂O, SiO₂
• carbonates: Na₂CO₃ (aka soda ash),
• bicarbonates, e.g. NaHCO₃ (aka baking soda),