Chemistry of formation and elimination of formaldehyde in foods

Formaldehyde can be produced in raw food materials through a multitude of biochemical pathways, as well as in thermally processed foods via the degradation of lipids, sugars, amino acids, and vitamin C. This compound is highly toxic and can contribute to the progression and onset of various diseases, including nasopharyngeal cancer and leukemia. Aside from its inherent toxicity, formaldehyde also serves as a vital precursor for the synthesis of other toxins. These include heterocyclic aromatic amines, 4 (5)-methylimidazole, and advanced glycation end products. This review provides a discussion of the formation pathways of formaldehyde in raw food materials and during food processing, especially thermal processing. It also highlights the elimination of formaldehyde through interaction with other food components during food processing and cooking. While raw food materials, like potatoes, do contain a significant amount of formaldehyde, and this compound can be produced through various pathways in thermally processed foods, the content of formaldehyde in processed foods remains low. This is primarily due to the interactions between formaldehyde with amino acids, proteins, and polyphenols. Other deleterious aldehydes, including acrolein and methylglyoxal, also engage in the reactions with formaldehyde, leading to the creation of numerous new compounds. The safety of these resulting components is currently not fully understood, necessitating systematic and comprehensive research for their potential health impacts.