Occurrence of ochratoxin A in fruit molasses

In this thesis, the occurence of ochratoxin A (OTA), which is classified as a "probable human carcinogen" by the International Agency for Research on Cancer and is extremely important in terms of food safety, was comparatively investigated in different fruit molasses (pekmez) produced by both traditional and industrial methods. For this purpose, OTA analysis was performed on a total of 96 pekmez samples, including 73 grape pekmez, 14 mulberry pekmez and 9 carob pekmez, obtained from producers, markets and local bazaars in different regions. OTA analysis in pekmez samples were performed by high performance liquid chromatography technique after extraction and clean-up on immunoaffinity column. OTA was detected in 89 (92,7%) of the 96 pekmez samples analyzed, ranging from 0,11 to 4,65 µg/kg (mean 1,06 µg/kg). Mean OTA concentrations were 1,04 µg/kg, 1,76 µg/kg and 0,25 µg/kg in grape pekmez, mulberry pekmez and carob pekmez, respectively. When compared in terms of production technique, the ratio of pekmez samples in which OTA was detected was 87,5% for those produced by the traditional method and 96,4% for those produced by the industrial method. The mean OTA concentration in these pekmez samples was determined as 0,70 µg/kg in traditionally produced samples and 1,29 µg/kg in industrially produced samples. In addition to OTA in the molasses samples, analyses were also performed for water-soluble dry matter, pH, total acidity, HMF, total phenolics, total flavonoids, antioxidant capacity, and color. Among these analytical properties, HMF levels were found to be significantly affected by the pekmez production techniques, and it was determined that the HMF concentration in pekmez samples produced by traditional methods being approximately seven times higher than in samples produced by industrial method. Carob molasses samples were found to contain lower levels of HMF than other pekmez varieties, but significantly higher total phenolics, total flavonoids, and antioxidant capacity. When examining the relationships between the presence of OTA in the pekmez samples and other analytical properties, a negative but weak correlation was found between OTA concentration and antioxidant capacity.