摘要：Crude oils have to be refined before the consumption, in order to remove undesirable accompanying substances; deodorization usually is the last step in the edible oil refining. In a laboratory all-glass deodorizer experiments, degummed, refined and bleached oils from Sclerocarya birrea (SCO), Sorghum bug (SBO), Melon bug water extracted (MBOH2O) and Melon bug solvent extracted (MBOSOL) were deodorized for different periods of times (0.5, 1, and 2 hours) at different temperatures (190, 210, and 250 °C). Quality changes (free fatty acids, peroxide value, tocopherols, sterols and phosphatides) were determined, and also stability against oxidation (Rancimat test) beside the fatty acid composition. It is clear that there was no change in the phosphatides according to deodorization temperature and time, peroxides and free fatty acids content were significantly (P<0.05) reduced in all samples with the increase of deodorization temperature and nearly completely removed at 250°C. Tocopherols were decreased as a result of elevated temperature, and high decrease happened in high temperatures of 210 and 250 °C in all samples except MBOH2O, where tocopherols completely removed during deodorization temperatures. The effect of deodorization on fatty acid composition indicates that, oils did not undergo any changes in the fatty acid compositions during deodorization. The oxidative stability was affected by temperature and time of deodorization, the stability increased as affected by elevated deodorization temperature in all studied samples.
