Plant Diamine Oxidase (DAO) Obtained from Pisum Sativum: Biochemical and Technological Characterization and Safety Profile for Its Application in Food Supplements

The histamine present in fermented foods, cheeses, fish and sausages can cause adverse reactions in people with deficiency or low activity of the enzyme diamine oxidase (DAO), responsible for their degradation. Plant-derived DAO supplementation, specifically Pisum sativum extract, represents a natural and safe alternative to restore this function in individuals sensitive to dietary histamine. This study examines the biochemical and technological characterization of plant DAO, as well as its safety profile supported by preclinical, clinical, and regulatory data. DAO is an amine oxidase containing copper, with copper-dependent catalytic activity. Its structure is made up of a dimer of identical subunits, each with an approximate molecular weight of 85 kDa and a copper atom essential for its function. The enzymatic activity, calibrated by specific spectrophotometric methods, remains stable and reproducible in commercial batches. The analysis by SDS-PAGE electrophoresis and UV-vis spectroscopy showed a pure enzyme, structurally intact and with reversible dependent activity of copper, confirming the identity and functionality of the ingredient. The production process of the Plant DAO includes rigorous stages of receiving, conditioning, sieving, mixing, forming tablets or capsules, and thorough quality controls at each stage. Only batches that meet all quality criteria are released for marketing, thus guaranteeing the safety and efficacy of the final product. Toxicological studies in animal models indicated no adverse effects at doses much higher than those recommended for humans. Clinical trials in healthy volunteers confirmed a good tolerance and safety profile for oral intake of DAO. The wide commercialization and use in several countries have not reported significant adverse events, highlighting its safety in the general population. This plant enzyme, certified according to international standards and approved by regulatory bodies, represents an effective option for the management of histamine intolerance, contributing to the improvement of associated symptoms and the quality of life of patients.