The Effect of Different Concentrations of Activated Carbon with Bleaching Earth During Bleaching Process on Physicochemical Properties of Soybean Oil

Document Type: Research Paper


1 M. Sc. Graduated of the Department of Food Science, Science and Research Branch, Islamic Azad University, Tehran, Iran.

2 Associate Professor of Research Center of Food Industries and Agriculture, Standard Research Institute-ISIRI, Iran.


Considering the importance of bleaching earth with activated carbon in reduction of impurities in vegetable oils, this study was conducted to investigate the effects of bleaching process on physicochemical properties of the bleached soybean oil. The bleaching process was carried out with bleaching earth (1 % w/w) containing different concentrations of activated carbon (0.1 % up to 0.5 % w/w). The results indicated that bleaching process did not affect the structure of the oil while the percentage of free fatty acids (FFA) of the oil samples after bleaching was increased as compared to the blank. During bleaching, peroxide values of the samples and color were decreased. Since the vegetable oils have been shown to be the major sources in the diet therefore the refining particularly the bleaching process plays a decisive role in the production of high quality oil. Therefore this step is one of the critical control points (CCP) in ensuring the quality of the final product.


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