Distribution of aflatoxins in various fractions separated from raw peanuts and defatted peanut meal

The present investigation is the first definitive study of the distribution of aflatoxins in a wet-milling process of raw peanuts. The results show that the majority of the aflatoxins originally present in the peanuts remained in the solid fractions, particularly the protein fraction, during wet-milling. In the protein concentrate preparation, the concentrates carried 81–89% of the total toxin; crude oil, 5–8%; and whey fraction, 3–14%. In the case of protein isolate preparation, 51–56% of the total toxin remained with the isolates, 22–26% with the residue, 11–17% with the whey, and 7–8% with the crude oil. Distribution of aflatoxins in the preparation of protein isolates from defatted peanut meal showed that 55–65% of the total toxin originally present in the meal remained with the protein isolates, 20–28% with the residue, and 10–20% with the whey fraction. Changes in extraction pHs for the preparation of protein isolates either from raw peanuts or defatted meal did not alter the distribution pattern mentioned above. A new approach based upon charge-transfer (electron acceptor-donor) complex formation is suggested to shift this aflatoxin distribution from protein products to disposable whey or residue fraction during the processing of raw peanuts and defatted meal for protein products.