Critical steps in the production of oil from oilseed to reduce heterocyclic aromatic amines

Abstract Contamination by the heterocyclic aromatic amines (HAAs) norharman and harman is one of the risks in vegetable oil production, so oil producers strive to decrease their content in the end products. In this study, the effects of production conditions—specifically, two pretreatment methods (roasting and microwaving), four extraction methods (two pressing and two solvent extraction) and adsorption refining (four absorbents)—of five oils (flaxseed, peanut, rapeseed, sesame, and sunflower seed) were evaluated. The results showed that microwaving as a pretreatment produced significantly fewer HAAs than roasting (P<0.05). After two pretreatments, the HAA content of oils was ranked from high to low as follows: sunflower oil, sesame oil, flaxseed oil, rapeseed oil, and peanut oil. Solvent-extracted oils (9.16–316.73 µg/kg) had fewer HAAs than pressed oils (26.61–633.93 µg/kg). Using adsorbents reduced HAAs in oils from the initial 21.77–484.22 to 0.31–41.58 µg/kg, and the removal rate reached 99.28%. This study provides critical HAA reduction strategies for application in the oil production process to obtain safe final products.