Safe and targeted detoxification of aflatoxins from contaminated peanut oil by palygorskite infiltrated with Span series surfactant

In this work, using various Span series surfactant (Span 40, Span 60, and Span 80) liquor, three types of newly functional palygorskite adsorbents were developed for removing multiple aflatoxins from peanut oil. The palygorskite infiltrated with Span surfactants all showed excellent detoxification ability in the adsorption of aflatoxins. The removal of AFB 1 by palygorskite infiltrated with Span 40, Span 60, and Span 80 was 94.75 %, 93.85 %, and 91.99 %, respectively. Compared with unmodified palygorskite, the removal of aflatoxins by the three adsorbents was increased by 10.05 %, 9.58 %, and 8.40 %, respectively. What's more, the retention of nutrients in peanut oil was enhanced after treatment with modified adsorbents. Among them, the retention rate of sterols in the oil after Span 40-palygorskite detoxification was increased by 18.71 %, and the tocopherol was increased by 11.20 %. Lastly, the adsorption mechanism was further discussed using kinetic, isothermal, and thermodynamic models. The Freundlich isothermal, Dubinin-Radushkevich model, and the pseudo-second-order rate expression all exhibited a strong association with the test results. The adsorption process mainly involved ion exchange, hydrophobic interactions, and pore-filling effects. Thermodynamic analysis ( ΔG 0  < 0, ΔH 0  > 0, ΔS 0  > 0) denoted that the adsorption effect was spontaneous and endothermic. The composite adsorbents could be a suitable candidate for the elimination of multiple aflatoxins with the merits of high detoxification efficiency, low preparation cost, green, and safety, which may open up new ideas for the creation of novel adsorbents in the fats and oils industry.