Ochratoxin A (OTA) represents one of the most widespread mycotoxins in agricultural commodities in the world and is considered a possible human carcinogen with its potent nephrotoxicity. Since OTA is stable under most food processing conditions, OTA has been detected in a wide range of cereal grains and their processed products as well. Puffed cereals are commonly used as baby snacks or as ingredients in snack formulations. We investigated the explosive puffing process effect on reduction of OTA in rice and oat. The rice and oat grains were adjusted the moisture content at 16% wet weight basis (wb) and spiked OTA (100 μg/kg), and then puffed by the explosive puffing machine at 5, 7, and 9 kgf. The temperature of chamber was 200°C and the duration times for 5, 7, and 9 kgf were 5, 6, and 9 min, respectively. The reduction of OTA in puffed rice and oat snacks were in the range of 15 – 28% and 38 – 52%, respectively, and the reduction of OTA in puffed rice and oat snacks were decreased with increasing explosive puffing pressures. The moisture content of puffed rice and oat snacks were in the range of 5 – 8% wb and 6 – 10% wb, respectively, and the moisture content in puffed rice and oat snacks were decreased with increasing of explosive puffing pressures. A decrease in bulk density of puffed rice and oat snacks was observed with increased explosive puffing pressure. In addition, increased values of degree of redness (a) in puffed rice and oat samples were observed with increasing explosive puffing pressure. These results suggest that OTA in rice and oat may be reduced significantly by explosive puffing process.

Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.