Effects of Air, Ozone, and Nitrogen Dioxide Exposure on the Oxidation of Corn and Soybean Lipids

This study was conducted to determine the oxidative effects induced by exposure of corn and soybean seeds to air, nitrogen dioxide (NO2), and ozone (O3). Whole, halves, and ground samples of soybean seeds and whole corn kernels were exposed to air, 15 ppm NO2, or 1.5 ppm O3 continuously for 100 h at room temperature. Lipid oxidation was measured by polyunsaturated fatty acid (PUFA) and tocopherol destruction and formation of fluorescent lipofuscin-like pigments. Exposure of whole soybean and corn seeds to air, 15 ppm NO2, or 1.5 ppm O3 was found to induce no PUFA and tocopherol destruction and no formation of lipofuscin-like pigments. Tocopherol and PUFA destruction and lipofuscin-like pigment formation were detected in samples of soybean seed halves exposed to 15 ppm NO2 or 1.5 ppm O3; however, only tocopherol destruction occurred in soybean halves exposed to air. Ground soybean samples exposed to air, 15 ppm NO2, or 1.5 ppm O3 incurred the greatest PUFA and tocopherol destruction and lipofuscin-like pigment formation.