Presence of Fusarium emerging mycotoxins in tiger-nuts commercialized in Spain

Tiger-nuts are tubers from the plant Cyperus esculentus which are commercialized in some regions of West and Central Africa, USA and Spain. These tubers have a high microbial charge such as bacteria, moulds and yeasts which could remain until the finished product. In this study we examined 47 samples of tiger-nut tubers purchased from Spanish supermarkets for contamination with the emerging Fusarium mycotoxins: Enniatins ENs (EN A, EN A1, EN B and EN B1), beauvericin (BEA) and fusaproliferin (FUS). The extraction of the samples was carried out with methanol using an Ultraturrax homogenizer. Mycotoxins were analyzed with a liquid chromatography (LC) coupled to a diode array detector (DAD). The percentage of contaminate samples with one or more emerging mycotoxins was 21.3%. EN A1 result the most common EN found with the highest prevalence of 17% with levels ranging from 32.3 to 4400 μg/g. EN B1 and BEA were present simultaneously in 5 samples, whereas the maximum contamination observed of the EN B1 was of 346 μg/g. The lowest incidence were observed for the ENs A and B evidenced only in one sample of the total studied. Only one emerging mycotoxin, fusaproliferin (FUS), has not been detected in any sample studied. The present work is the first one ever drafted on the presence of the emerging Fusarium mycotoxins in Spanish tiger-nuts.