Estudo da proteção de ácidos graxos de cadeia longa presentes em subproduto da agroindústria visando aplicação em nutrição animal

Abstract

Ruminant diets are characterized by low levels of lipids and these may be supplied by different sources, such as by-products of oil industries. The soapstock is the main by-product of the vegetable oils refining industry. To make use of this by-product in ruminant diets, aiming for a efficient result, the fatty acids must be protected. The protected fat is a source of unsaturated fat wich reacts with calcium to form a salt widely known as calcium soap. The present research evaluated the content and fatty acid composition by gas chromatography and also the concentration of the following analytes: Na, Ca, K, Mg, P, S, Fe, Zn, Mn, As, Cd, Co, Hg, Pb, Se and Cu (ICP OES), in four different origins of lees (A Soybeans soapstock, C Soybeans soapstock, B cotton sead soapstock and D flaxseed soapstock). The logistics was also considered for selection of the material, once it is extremely important in assessing the costs/benefits of the best lees source. To evaluate the process of fat protection it was applied the factorial design (24 e 22), and the final product was characterized by the same parameters of the raw. The lipid content for the four samples was approximately 51%. The fatty acid composition relative to oleic, linoleic and linolenic acids proved to be more favorable to the lees of A, C and D. The content of As, Cd, Co and Pb of the four samples of soapstock were below the LOD. Therefore, logistics was was determinant for the choice of A soapstock. Total fat content and fatty acids composition did not change significantly when compared with the raw material. It is possible to scale-up the process. The evaluation of costs for the fat protection process showed that about 93% more viable than the commercial protected fatty acids. It follows that the lees chosen presented high potential for the required use.