METHODOLOGICAL ASPECTS OF LIPID EXTRACTION FROM BIOLOGICAL MATRICES

The paper presents the studies on the degree of raw fat extraction from meat systems by various methods. Relative differences in extraction methods are shown depending on the polarity of solvents used. Fat was extracted using the classical Soxhlet method, as well as two-step extraction. Specially prepared model systems were used as test samples including both simple and multicomponent mixtures in the form of meat-and-bone meal, bone meal, and meat-and-plant meal. It was found that when using non-polar solvents, a large amount of polar lipids was lost. The influence of the solvent on the degree of extraction for glycerides, phosphatides, free fatty acids and oxidation products was shown. A number of experiments are presented and the results are given on the degree of fat extraction using mixtures of organic solvents with mineral acid. The studies allowed to choose the best extraction method for each type of meat and meat-containing raw materials. Based on the results, methodical recommendations are proposed on the use of hydrophobic and hydrophilic solvents and their mixtures. Methods of lipid extraction from food products after alkaline and acid hydrolysis are considered. Examples of fat determination by instrumental methods (refractometry) are given. Classical methods for fat content evaluation are described (Randall method, Twisselmann method, and Rushkovsky method).