Dao (Diaminoxidase) Purification from Natural Sources and Enzyme-Enriched Food Production
Articles > Article · 2025
Authors: Burak Durmaz, Erhan Canbay, Ş.Ö.Baykan, Hatice KALKAN YILDIRIM, Eser Y. Sözmen
Applied Food Research, Journal Indexed in ESCI, International, Emerging Sources Citation Index (ESCI), 2025, vol 5, pp 1-8
DOI: 10.1016/j.afres.2025.101155
Summary
Histamine intolerance, affecting approximately 1–3% of the population, is linked to elevated histamine levels that can mimic allergic reactions. Diamine oxidase (DAO) plays a key role in histamine degradation. This study aimed to purify a plant-derived DAO enzyme with higher specific activity than commercial supplements and to apply it in fermented foods, specifically pickles, widely consumed in Turkish cuisine. DAO was extracted from wheatgrass produced from a local cultivar registered by the Aegean Agricultural Research Institute. The enzyme was purified using ammonium sulfate precipitation and dialysis. Enzyme activity and histamine levels were quantified using LC/MS-MS. Wheatgrass DAO showed a specific activity of 10.18 U/mg in the crude extract and increased to 207.6 U/mg after dialysis. To assess its functionality, DAO (both commercial and plant-derived) was added at various concentrations during pickle fermentation. After three weeks, herbal DAO reduced histamine levels in pickle juice by up to 96%, significantly outperforming the commercial enzyme in most cases. This is the first reported application of wheatgrass-derived DAO in food fermentation (Patent No: P-201710). The findings suggest a promising natural solution for reducing histamine in fermented foods, offering a dietary alternative for individuals with histamine intolerance.