Aflatoxin decontamination in tree nuts: a scoping review of physical, chemical, and biological methods

Aflatoxin (AF) contamination in tree nuts poses a serious threat to global food safety, public health, and international trade due to the potent carcinogenicity of aflatoxin B₁ (AFB₁). Although traditional mitigation strategies exist, their industrial implementation is constrained by a strict "technological filter," in which high detoxification efficacy must be carefully balanced against the preservation of the nutritional, structural, and sensory quality of the food matrix. This scoping review systematically mapped and critically synthesized recent scientific advances (2005-2025) in physical, chemical, and biological decontamination methods, evaluating their operational effectiveness, underlying mechanisms, and qualitative impacts on tree nuts. Guided by the question, "What physical, chemical, and biological methods are most effective for AF decontamination in tree nuts, and to what extent are they feasible regarding quality preservation and industrial applicability?", the study strictly followed the Joanna Briggs Institute (JBI) Manual for Evidence Synthesis and was reported according to PRISMA-ScR guidelines. A total of 41 eligible original studies were selected after comprehensive screening of the PubMed, Scopus, Web of Science, and ScienceDirect databases. Physical approaches, particularly cold atmospheric plasma and UV-C radiation, achieved robust reduction rates ranging from 70% to 95%; however, these highly energetic treatments often induced lipid oxidation, evidenced by linear increases in malondialdehyde (MDA) levels in matrices such as pistachios. Among chemical methods, ozonation and the use of organic acids achieved degradation rates close to 100% for the most toxic forms, but significant technological trade-offs were identified, including up to a 29% loss of α-tocopherol in hazelnuts. Inorganic selenium emerged as a promising alternative by combining efficacy with matrix preservation. Biological strategies using microorganisms such as Bacillus subtilis, Bifidobacterium lactis, and Lactobacillus kefiri demonstrated substantial sustainable potential, with detoxification efficiencies exceeding 80% through dual mechanisms of active biosuppression and physical adsorption. No single universal method is currently sufficient to handle contamination safely. The future of commercial AF management depends on the development of "hurdle technology," integrating multi-stage synergistic interventions with automated optical sorting and intelligent packaging, supported by further technical advances, studies of practical applicability, and industrial-scale validation to ensure absolute consumer safety and commercial viability.