Study of quality indicators of fatty acids obtained during soapstock pro-cessing by three-stage technology

Fatty acids were obtained from soapstocks by a combined three-stage technology, which includes three consecutive stages: the first is saponification of the feedstock with a sodium hydroxide solution, the second is salting out with sodium chloride; the third is a two-stage hydrolysis and decomposition with a solution of sulfuric acid with a concentration of 10–12%, and then with sulfuric acid with a concentration of 80–92%. The organoleptic, physicochemical and other quality indicators of the fatty acids obtained under the rational conditions identified were determined. It was found that the fractional composition of the fatty acids obtained corresponded to the characteristics of fatty acids in first-grade light oils, indicating their high quality. The fatty acids have the following indicators: mass fraction of moisture and volatile substances – 1.8%, mass fraction of total fat – 97.1%, depth of oleic acid cleavage – 64.3%. Comparative analysis of the physicochemical indicators of fatty acids obtained by three methods: decomposition with sulfuric acid, saponification and decomposition with sulfuric acid and saponification, salting out and decomposition with sulfuric acid showed that the concentrations of the main fatty acids (stearic, oleic, linoleic acid) obtained by the third method (saponification, salting out and decomposition with sulfuric acid) were higher than those obtained by the first two methods.