A small field search on the effects of hand sorting process on aflatoxins and sterigmatocystin occurrence in raw hazelnut kernels

Presence of aflatoxins in hazelnut paste in Turkey and a risk assessment study

Two hundred and two hazelnut paste samples from various hazelnut processing plants in the Black Sea Region of Turkey were analysed for the incidence of aflatoxins (AFs) by liquid chromatography coupled with fluorescence detection (LC-FLD). All 202 (100%) hazelnut paste samples were contaminated with various AFs ranged from 0.17 to 12.96 µg kg^-1. AF contamination level of four (1.98%) samples exceeded legal limits. Risk assessment for hazelnut paste was determined by using AF incidence results, and the margin of exposure (MOE) and hepatocellular carcinoma (HCC) risk approach were applied. For the adult Turkish population (15+ years age group), the average lower bound (LB) and upper bound (UB) exposure levels for aflatoxin B1 (AFB1) and total aflatoxins (AFT) were 0.0106-0.0107 ng kg^-1 body weight (bw) per day and 0.0250 ng kg^-1 bw per day, respectively. MOE estimates for mean and 95th percentile exposures to AFB1 for hazelnut paste were higher than 10,000, which indicates no potential health concern for Turkish adults. HCC for the Turkish population was 0.00023 cases per 100,000 people per year. The study indicates that Turkish population is not under this toxicological risk when consuming hazelnut paste containing food products.

Fungi Occurrence in Ready-to-Eat Hazelnuts (Corylus avellana) From Different Boreal Hemisphere Areas

The present study evaluated the fungal contamination of ready-to-eat dried hazelnuts considering for the first time the application of the same condition drying process of several hazelnut cultivars from different boreal hemisphere areas. Fifty lots of hazelnuts (Corylus avellana), belonging to eight cultivars from seven regions in four countries, were analyzed for fungal microbiota, describing both load levels and species diversity. For this purpose, a polyphasic approach consisting of morphological examination (optical and scanning electron microscope observation) and molecular characterization [PCR-DGGE analysis and sequence analyses of the internal transcribed spacer (ITS)] was performed. The results show that different fungal populations occur in dried hazelnuts regardless of their geographical area of production. Although some varieties appear to be relatively less susceptible, species related to Aspergillus, such as A. commune and A. ochraceus, Penicillium, including P. commune, P. solitum, and P. expansum, and Rhizopus, for instance, R. stolonifer and R. oryzae, have generally been found. A related character "hazelnut cultivar-fungi" was found for species related to the genera Trichoderma and Fusarium, including F. oxyxporum, F. solani, and F. falciforme. All 14 species found are known to host pathogenic strains. Therefore, their presence in a ready-to-eat product, such as dried hazelnuts, can pose a real danger to the consumer. Based on these considerations, the development of new protective strategies seems highly desirable. The species-level description of the contaminating fungal community acquired through this study is the starting point for the development of tailor-made protective biotechnologies.