Aflatoxin levels in hazelnut samples obtained from exporter companies were monitored over a 3-year period. A total of 3188 samples of raw and processed hazelnuts were analysed using an HPLC method. The total aflatoxin content of the contaminated samples was in the range of 0.02–78.98 µg kg⁻¹ for hazelnut kernels, 0.07–43.59 µg kg⁻¹ for roasted hazelnut kernels, 0.02–39.17 µg kg⁻¹ for roasted sliced hazelnut kernels, and 0.02–11.20 µg kg⁻¹ for hazelnut purees, respectively, showing that the variations of aflatoxin contamination were very high. The results of aflatoxin analysis revealed that the aflatoxin contamination in the hazelnut samples was at a tolerable level. A total of 3147 samples were contaminated with aflatoxins, although below the legal limits. However, the aflatoxin contents of 41 samples exceeded the legal limits. Therefore, aflatoxin contents of hazelnuts should be monitored regularly to minimise the risk of aflatoxin hazard, and pre- and post-harvest strategies should be developed to prevent aflatoxin formation.

The aim of this study was to evaluate the effect of the dried sourdoughs produced with two different fermentation methods [Spontaneous fermentation(SPF) and starter of lactic acid bacteria-added fermentation(STF)], and three different drying methods (Drying in oven;DO, Freeze drier;DFD, and Spray drier;DSD) on various quality properties of the wheat bread. The bread samples prepared by addition of the dried sourdoughs at the rates of 3%, 6% and 12%, and control bread prepared without sourdough were compared in terms of bioactivity, shelf life, physicochemical and sensory properties. The addition of the dried sourdough affected the specific volume, pH and acidity of the bread samples significantly (p < 0.05), and a slow down moisture loss occurred during shelf life. The a* value of crust, antioxidant activity, and sensory properties were improved compared to the control bread. The use of dried sourdough at the rate of 12% gave the most effective results. When the fermentation and drying methods were evaluated together, the combinations of SPF/DO, SPF/DFD and STE/DSD gave the best results.