Enea has developed a diagnostic kit for dairy farms and analysis laboratories to trace toxic substances in milk. Enea explains that the kit is able to detect the presence of aflatoxin M1 in raw milk in a rapid, effective and low-cost way, a substance considered carcinogenic to humans that comes from animals fed with contaminated feed. The results of the research carried out in collaboration with the University of Turin have been published in the scientific journal Toxins. “Because of the harmful effects on human and animal health, the European Union has set a maximum concentration of aflatoxin M1 of 50 nanograms/litre in raw milk, heat-treated milk and milk intended for cheese production. It has further lowered this threshold value in foods intended for infants and children (25 ng/l), who are among the largest consumers of this food” recalls Enea.
The analysis technique developed by the Enea researchers involves, for the first time, the use of monoclonal antibodies produced by a plant of the same genus as tobacco (Nicotiana benthamiana), to ‘intercept’ the toxins present in milk even at very high concentrations low – well below the limits set by law – as demonstrated by the experiments conducted on raw milk samples containing different concentrations of aflatoxin M1 (25, 50 and 75 nanograms/L). Marcello Catellani of the Enea Laboratory of Bioproducts and Bioprocesses, explains that “this is the ‘green’ version of Elisa – one of the best and most widespread rapid screening methods for the detection of toxins in food and animal feed – which allows the analysis accurate, fast and low cost of large numbers of samples”.
For the production of antibodies, the researchers made use of an alternative and economic production system offered by Plant Molecular Farming (Pmf), a system that uses plants to produce complex molecules such as antibodies. Catellani underlines that “it is a biotechnological approach that can ‘free’ the production of antibodies from the classic and more expensive systems based on animal cell cultures, which require dedicated structures and environments, specific reagents and tools for their growth in sterility, such as bioreactors and incubators”.
The PMF, continues Enea, allows you to operate in non-sterile conditions (greenhouse, water, electricity, soil) with costs reduced to a minimum. For this work, the agroinfiltration technique was used which involves the use of a particular bacterium called Agrobacterium tumefaciens which carries the genetic information of interest in the plant tissues of the Nicotiana benthamiana plant. “This process – indicates Cristina Capodicasa of the Enea Biotechnology Laboratory – is advantageous in terms of speed and yield: it requires only 1-2 days for the growth of agrobacteria, which have the task of conveying the genetic information in the plant, and after about a week it is possible to collect the leaves from which to extract up to 1.6 g/kg of antibodies”.
“Therefore, the scale-up of this production is immediate, easily modulated and inexpensive, when compared with in vitro cell cultures, because it simply requires an expansion of the cultivation space dedicated to the plants,” Capodicasa further states.
Lastly, Enea indicates that “aflatoxins are mycotoxins produced by fungi belonging to the genus of aspergilli which usually develop when foodstuffs are stored at temperatures between 25 and 32°C and with ambient humidity rates of over 80 percent. They are invisible to the naked eye, have no taste and, above all, show high stability during heat treatments such as, for example, pasteurization of milk.”
