Ash content testing determines the total mineral residue remaining after a food sample is incinerated at high temperature, indicating refinement level, mineral load or potential contamination in products such as flour, sugar and dried fruit.
In trade practice
Laboratories incinerate a weighed sample in a muffle furnace at a defined temperature until a constant weight is reached, then express the residue as a percentage of the original sample. In wheat flour, ash content is a key grade indicator and is referenced in legal standards for certain flour types. For dried fruit and honey, unexpectedly high ash values can signal soil contamination or adulteration and should prompt further investigation. Buyers should confirm that the test method and reporting basis match those used in the applicable standard.
In a specification
A specification should state the maximum ash content, the method reference, the incineration temperature and whether the result is expressed on a dry-matter or as-received basis.