Borra de óleo de soja: caracterização físico-química e avaliação da potencialidade econômica

Abstract

In 2015, Brazil was the second largest soybean producer in the world. The main product derived from this oleaginous is crude soybean oil. During the chemical refining of soybean crude oil, at neutralization stage, the formation of the main byproduct of this industry appears called the soybean oil soapstock. The composition of soybean oil soapstock is mostly water and sodium salts of fatty acids (soap). Due to their high content of saponified fatty acids, low value and high availability in soybean oil industry; it is a significant feedstock to obtain a concentrate of fatty acids. The content of total fatty acids determines the commercial valor of this residue. The soybean acid oil obtained from the soybean oil soapstock, can be used as an apatite collector that is a raw material for the production of biodiesel and as a constituent of animal feed. This research had as objective to characterize and evaluate the economic potential of the soybean oil soapstock. The sample used as study has the finality to get viable results of its use as concentrated source of fatty acids. To run the analysis followed the methods proposed by the American Oil Chemists' Society (AOCS), which are applicable to oils, fats and soaps. According to the results, the potential parameters content was obtained: the free fatty acids content on oleic acid (AOCS Ca 5a-40) equal to 12.42 wt%, the total fatty acids content and oxidized fatty acids (AOCS G 3-53) equal to 28.76 e 0.42 wt% respectively, the ashes content (AOCS Ca 11-55) equal to 3.33 wt%, the unsaponifiable matter (AOCS Ca 6a-40) equal to 1.02 wt%, the content of soluble and insoluble matter in alcohol (AOCS Da 3- 48) equal to 31.11 e 1.08 wt% respectively, the neutral oil content (AOCS G 5-40) equal to 7.84 wt%, the pH of the aqueous phase in 25 °C (AOCS G 7-56) equal to 4.02, and the moisture and volatile content (AOCS Ca 2c-25) equal to 65 wt%. Through the results of neutral oil content, unsaponifiable matter content, and oxidized fatty acids content, an d comparing with total fatty acids content, it can be inferred that the largest part of fatty acids contained in soybean oil soapstock studied is in the form of saponified fatty acids. In the other words, the soybean oil soapstock contains significant amount of fatty acids. The amount of free fatty acids in oleic acid reinforces the conclusion about the high quality of the evaluated raw material, since the obtaining of fatty acids as from the soybean oil soapstock is one of the major reasons for the study of its use