Physiochemical Characterization of Soybean Oil Deodorizer Distillate

Increased use of industrial waste and byproducts fits the need of industry to comply with environmental rules. The substitution of natural products for artificial ingredients has gained worldwide attention in the food, pharmaceutical and other industries. These facts justify the study on the utilization of Soybean Oil Deodorizer Distillate (SODD) as tocopherol supplements. Tocopherol, which is physiologically active as vitamin E and a major natural antioxidant, is an especially important player in human and animal nutrition. SODD is a byproduct of the soybean oil refining process that is also rich in free fatty acids (FFA), sterols and hydrocarbons. It has been demonstrated that the use of SODD for vitamin E extraction is not economically viable. However, SODD in the semi-refined form (neutral) can be an alternative for animal and possibly human diet enrichment. The objective of the present study was to evaluate the SODD neutralizing process varying the type, concentration, and excess of alkali, as well as the process temperature and time for homogenization. To verify their potential like vitamin E supplement, SODD was semi-refined (neutral SODD) and characterized physical-chemically. The optimal conditions for the neutralizing process, i.e., in order to obtain the greatest reduction in free fatty acid content, the lowest leaching of tocopherols and the greatest yield, were defined experimentally. In the results FFA content was reduced from 53.4% to 6.1% after neutralization, requiring a second step of neutralization, thus obtaining a FFA content of 1.8% and 11.0% of total tocopherol (TT). Neutral SODD was statistically different from crude SODD regarding the following characteristics: FFA, unsaponifiable matter, saponification number and color. The composition of neutral SODD was 1.8% of FFA, 35.4% of unsaponifiable matter, 130.2 mg KOH/g sample of saponification number, 11% of total tocopherols, 114.8 mEq iodine/g sample of iodine index, 4.8 mEq/kg of peroxide value, 11 mg MDA/kg of TBA value, 0.8% of moisture, 9.7 kcal/g of energetic value and 0.906 g/mL of liter weight. These results suggest the potential use of SODD as a supplement.