Detection of mycotoxins in nuts
Mycotoxins are natural metabolism products of moulds which can have a toxic effect on humans and animals; aflatoxins are the most toxic form of mycotoxins. Some types of food, such as dried fruit, spices and nuts, show an increased risk of aflatoxin release due to fungal infestation. As mycotoxins are temperature-resistant they are usually not destroyed when the food is processed.
For a sufficient extraction of the mycotoxins from the initial product, the sample must be reduced in size and homogenised. As the maximum permissible mycotoxin values range between 0.025 and 15 µg/kg and fungal infestation usually occurs in localised areas, a random sample taken from the bulk must be sufficiently large to allow for the detection of contaminants. The RETSCH Cutting Mill SM 100 facilitates the preliminary size reduction of a representative amount of 1 - 2 kg per ton of nuts to a particle size of 1 - 3 mm. The mill is suitable for the rapid and gentle size reduction of dry materials down to a fineness of 0.25 mm. The sample is then divided into representative sub-samples with the help of the rotary tube divider PT 100 which provides a very high division accuracy. The subsequent fine size reduction is ideally carried out with RETSCH’s Ultra Centrifugal Mill ZM 200. This powerful rotor mill is easy and safe to operate and very versatile due to a wide selection of accessories.
For the processing of hazelnuts, the use of distance sieves, which have been specially developed for grinding temperature-sensitive brittle materials, is recommended. As mycotoxins are lipophilic, the grinding process should be as gentle as possible to avoid the release of fat from the sample. A fineness of 300 µm is sufficient for the subsequent extraction of the mycotoxins from the sample.
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