Italy is the second leading hazelnut producer after Turkey, covering 13% of the global production. Hazelnuts (Corylus avellana L.) - Tonda Gentile Trilobata cultivar - are widely cultivated in Piedmont, where they adapt well to the continental climate and reach excellent quality. The confectionery industry processes 90% of the domestic production, while the remaining 10% is consumed fresh, both in-shell and shelled. The former are generally used for fresh consumption, while the latter are used as a raw material by the food and cosmetic industries.
Hazelnuts can be contaminated by fungal species, part of the Aspergillus genus, that can produce aflatoxins. In particular, A. parasiticus can produce four aflatoxins (B1, B2, G1, G2), while A. flavus can only produce B1 and B2.
Researchers from Agroinnova and Disafa (University of Turin), in cooperation with Tecnogranda Spa, have assessed the effectiveness of cold atmospheric plasma for mycotoxin detoxification. They developed a cold atmospheric plasma system generated by dielectric barrier dishcharge (DBD) and adjusted the parameters so as to reduce the presence of aflatoxins on shelled hazelnuts.
The effects of different gases (N2, 0,1% O2, 1% O2, 21% O2), power (400, 700, 1000, 1150 W) and exposure times (1, 2, 4, 12 min) were assessed.
Preliminary tests on aflatoxin standard solutions showed that using high power for a few minutes led to a complete decontamination.
On hazelnuts, in similar conditions (1000 W for 12 mins), the cold plasma treatment reduced the concentration of total aflatoxins and aflatoxin B1 by over 70%. Aflatoxins B1 and G1 were more sensitive to plasma treatments with respect to aflatoxins B2 and G2, respectively. During the plasma treatment, aflatoxin B1 were shown to be more sensitive even compared to aflatoxin G1. In addition, at the highest power and for the longest time, the maximum increase in temperature was 28.9°C.
"The cold atmospheric plasma treatment has the potential to be a promising method of aflatoxin decontamination. Not only is it effective, but it could contribute to maintaining organoleptic qualities intact. The possibility of adjusting power, gas composition and exposure time, means this technology can be adapted to naturally contaminated food matrices and could be installed on hazelnut processing lines."
"This treatment takes longer than microwave-induced argon plasma, but it looks more promising, as it does not significantly increase the temperature of the matrix. The study will now continue to assess the safety (quantity and toxicity of degradation products), quality (physio-chemical properties), structural chances and organoleptic properties of the product after the treatment."
Source: Ilenia Siciliano, Davide Spadaro, Ambra Prelle, Dario Vallauri, Maria Chiara Cavallero, Angelo Garibaldi, Maria Lodovica Gullino, 'Use of Cold Atmospheric Plasma to Detoxify Hazelnuts from Aflatoxins', 2016, Toxins 2016, Vol. 8, 125
On hazelnuts, in similar conditions (1000 W for 12 mins), the cold plasma treatment reduced the concentration of total aflatoxins and aflatoxin B1 by over 70%. Aflatoxins B1 and G1 were more sensitive to plasma treatments with respect to aflatoxins B2 and G2, respectively. During the plasma treatment, aflatoxin B1 were shown to be more sensitive even compared to aflatoxin G1. In addition, at the highest power and for the longest time, the maximum increase in temperature was 28.9°C.
"The cold atmospheric plasma treatment has the potential to be a promising method of aflatoxin decontamination. Not only is it effective, but it could contribute to maintaining organoleptic qualities intact. The possibility of adjusting power, gas composition and exposure time, means this technology can be adapted to naturally contaminated food matrices and could be installed on hazelnut processing lines."
"This treatment takes longer than microwave-induced argon plasma, but it looks more promising, as it does not significantly increase the temperature of the matrix. The study will now continue to assess the safety (quantity and toxicity of degradation products), quality (physio-chemical properties), structural chances and organoleptic properties of the product after the treatment."
Source: Ilenia Siciliano, Davide Spadaro, Ambra Prelle, Dario Vallauri, Maria Chiara Cavallero, Angelo Garibaldi, Maria Lodovica Gullino, 'Use of Cold Atmospheric Plasma to Detoxify Hazelnuts from Aflatoxins', 2016, Toxins 2016, Vol. 8, 125