Influences of Illumination Pretreatment on Soybean Oil Activated Clay Bleaching Effects and Soybean Oil Quality Evaluation.

Visible light has been widely studied for possible applications in food industry as being a kind of clean energy. Presently, the influences of illumination pretreatment on soybean oil quality followed by conventional activated clay bleaching, including the oil color, fatty acid composition, oxidation stability, and micronutrient content, were investigated. Results demonstrated that the illumination pretreatment increased the color differences between the non-illuminated and illuminated soybean oils, which indicated that the light exposure could improve the decoloring effects. The fatty acids composition and the peroxide value (POV) and oxidation stability index (OSI) of the soybean oils showed little changes during this process. Although the illumination pretreatment affected the content of lipid-soluble micronutrients, including phytosterols and tocopherols, no significant differences could be observed ( p > 0.05). Moreover, it showed that the illumination pretreatment showed significant effects for decreasing the following activated clay bleaching temperature, indicating the energy saving potential of this novel soybean oil decoloring process. The present study might provide new insights for developing eco-friendly and efficient vegetable oil bleaching technology.