Estudo das alterações na cadeia de ácidos graxos após o refino do óleo de Salvia hispanica L. para redução do índice de acidez

Abstract

The chia (Salvia hispanica L) seed is gaining prominence in the market, and its consumption is increasing due to its composition rich in proteins, fibers, antioxidant compounds and fatty acids. Its oil, the largest source of Omega 3 of vegetable origin, is one of the most consumed forms. However, the characteristics of this oil vary according to the planting conditions of the seed, the time between harvesting and the extraction of the oil and the way in which it is extracted. Because of this variation, the acid value of the product is often higher than those accepted by the Brazilian Health Regulatory Agency (ANVISA), then a refining process is necessary to reduce this value. Because there is no published research on alkaline refining applied on chia oil, this study aimed to examine if this process results in changes in fatty acid composition and in physicochemical properties with standards regulated by ANVISA, verifying if the use of alkaline refining can be used for chia oil. Gas chromatographic analyses were performed to determine the composition of fatty acids and titration tests to obtain the acid and peroxide values. The experiments of this paper showed that the refining decreases the acidity of the oil without a significant drop in the concentration of Omega 3 and 6; however, it leads to a significant increase in the peroxide value, thus facilitating the oxidation of the oil.