Mycotoxins Contaminating Nuts: A Review

Abstract

The main mycotoxins in nuts: (Aflatoxins): The most toxic and widespread, produced by the fungi Aspergillus flavus and A. parasiticus, and considered to be highly carcinogenic. Found in high levels in walnuts, pistachios, almonds, and hazelnuts. Ochratoxins: These pose a risk to the kidneys, nervous system, and immune system, and are found in almonds, Brazil nuts, and hazelnuts. Fumonisins: These are relatively rare in nuts, but their chronic toxicity is under study. Patulin: Its presence in nuts is limited, but it is the subject of regulatory discussions.

The most important sources and routes of contamination are: Pre-harvest: Climatic conditions (humidity, temperature) and genetic factors in the crop play a major role in fungal infection and toxin production. Post-harvest: Inadequate drying and storage in warm, humid conditions (relative humidity >50%) are critical factors that stimulate fungal growth and toxin production. Processing: Common roasting, baking, and frying processes do not significantly reduce aflatoxin levels or may be ineffective.

Several methods are used for detection and analysis: Traditional analytical methods include (HPLC), (LC-MS/MS), and (ELISA). Emerging technologies such as biosensors and hyperspectral imaging supported by artificial intelligence show great potential for rapid, field-based detection.

The review emphasizes that mycotoxin contamination of nuts is an ongoing global challenge that requires an integrated “farm-to-table” approach. Successfully controlling this problem depends on combining good agricultural practices, appropriate storage conditions, accurate detection methods, and effective mitigation strategies, all within a strict regulatory framework to ensure the safety of these highly nutritious foods.