adulterate

To debase a food by mixing in inferior, cheaper, or unsuitable substances, whether for economic gain or through careless processing. The verb covers deliberate fraud, such as stretching ground coffee with roasted grain, and also negligent contamination, such as allowing cleaning chemicals to taint a batch. Food law in most countries defines adulteration broadly: a product is adulterated if it contains a filthy or decomposed substance, an unsafe additive, or has had a valuable constituent removed and not declared. Enforcement relies on inspections, laboratory analysis, and traceability records that let investigators follow a suspect ingredient back to its source. For manufacturers, the lesson is that adulteration includes omissions as well as additions, since selling diluted juice as pure juice adulterates just as surely as adding something foreign.