Enhancing stability of diamine oxidase via alginate encapsulation: Plant-derived (Pisum sativum L.) vs commercial animal-derived enzymes

ABSTRACT Plant-derived diamine oxidase (DAO) has emerged as an alternative to animal-derived DAO for managing dietary histaminosis. While it is currently used as a dietary supplement, its incorporation into foods has also been proposed as a strategy to reduce histamine content prior to consumption. However, its enzymatic activity may be affected during food processing and storage, making stabilization approaches such as encapsulation particularly relevant. This study aimed to evaluate the effect of spray-drying encapsulation with alginate on the activity and stability of DAO extracted from yellow peas ( Pisum sativum L.) under various food-relevant conditions, including storage temperatures (-18, 4, and 25 °C), pH values (3, 5 and 7), and thermal treatments (60, 70 and 80 °C). Animal-derived DAO was used as a reference. The results showed that plant-derived DAO exhibited 2.44-fold higher specific activity than the animal-derived enzyme. In addition, spray-drying encapsulation achieved a 98.2% activity retention, maintaining enzymatic activity. Encapsulation significantly improved storage stability over 2 months, particularly at low temperature, and at pH 5 and 7. Under thermal stress, encapsulated plant DAO retained more activity than the free enzyme at 60 and 70 °C. These findings suggest that encapsulated plant-derived DAO may provide improved activity and stability compared to animal-derived DAO under several food-relevant pH and temperature conditions, supporting its potential use in fermented beverages, such as wine, fish products, and dairy matrices, where histamine control during processing is particularly important.