Occurrence and control of biogenic amines in plant-based fermented foods

Biogenic amines (BAs) are microbial-derived compounds that may exert adverse effects in humans when present at high concentrations. They are mainly formed by amino acid decarboxylation and can be produced by various microorganisms, including lactic acid bacteria, enterobacteria, staphylococci and Bacillus spp. While high BA levels in non-fermented foods indicate spoilage, their presence in fermented foods is often unavoidable, making process control essential to limit their accumulation. Plant-based fermented foods are gaining global interest, but their production frequently relies on spontaneous fermentation, which may lead to uncontrolled BA formation. This review evaluates BA occurrence in plant-based fermented foods, focusing on products fermented by bacteria and fungi: (i) Brassicaceae vegetables (e.g., sauerkraut and kimchi), (ii) soy-based products (e.g., soy sauce, miso, tempeh), and (iii) olives and other pickles. Mitigation strategies are also discussed, including the reduction of microbial aminobiogenic potential and BA degradation through microbial metabolism or the addition of food-grade ingredients with BA-degrading activity, such as diamine oxidase (DAO). BA levels are highly variable and influenced by raw materials, ingredients and processing conditions, occasionally reaching potentially harmful concentrations, particularly for histamine. This review provides a critical overview of risks and strategies to improve the safety and quality of plant-based fermented foods.