The effect of storage temperature and water activity on aflatoxin B1 accumulation in hull‐less and hulled spelt grains

BACKGROUND In concomitance with shifts in climate conditions in recent years, an increasingly frequent emergence of Aspergillus flavus and aflatoxins in cereals has been observed. In this study the effects of temperature (15, 23, 30 and 37 °C) and water activity (aw) (0.85, 0.90, 0.95 and 0.99) on aflatoxin B1 (AFB1) production by A. flavus isolate inoculated on hull‐less and hulled spelt grains were investigated. RESULTS The optimal conditions for AFB1 biosynthesis were reached at 30 °C and aw value of 0.99 in the all tested samples (hull‐less grains, dehulled spelt grains and hulls). The AFB1 accumulation was significantly higher in hull‐less than in dehulled grains, that implicated a protective effect of spelt hulls. The levels of AFB1 were about 10–170 times higher in hulls than in grains. In order to determine the possibility of predicting the occurrence of AFB1 under different storage conditions mathematical models [second order polynomial (SOP) and artificial neural network (ANN)] were applied. CONCLUSION The achievement of such estimation facilitates further decisions on continuous monitoring of the potential hazard related to AFB1 contamination of stored spelt‐based food. The knowledge of the storage temperature and aw effects on the AFB1 content in spelt during the postharvest phase is of great practical importance. © 2019 Society of Chemical Industry