Products of technological and biotechnological modification (acid and enzymatic hydrolyzates and hydrothermal extracts) of the holothurian Cucumariajaponica from the Far East region are the complex multicomponent systems containing biologically active agents of a sea origin that has to provide them biological activity. The research objective consisted in quantitative studying of anti-radical properties of acid, enzymatic hydrolyzates and hydrothermal extracts from soft fabrics of a holothurian from the Far East region (Cucumaria japonica) and their influence on oxidation of lipids in fat emulsion products. The reaction with stable free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical was used as a model system. Radical relating activity of hydrolyzates and extracts from Cucumaria japonica varied over a wide range from 48 to 78%. The maximum radical binding activity was noted for acid hydrolyzates. The activity of the hydrolyzate from a nimbus and feelers of Cucumaria japonica was comparable with activity of ionol. It has been defined that levels of manifestation of anti-radical activity depended on a way of technological and biotechnological processing of raw materials. Studying of fractional composition of melanoidins of hydrolyzates and extracts from Cucumaria japonica established that they can be divided into fractions--with molecular masses about 10,000 and 1000 Da. The maximum content of melanoidins has been defined in fraction weighing about 1000 Da. Introduction of acid, enzymatic hydrolyzates and hydrothermal extracts from Cucumaria japonica in the composition of oil-fat emulsion systems allowed to slow down processes of lipid oxidation and triglyceride hydrolysis in mayonnaise. Introduction of hydrolyzates and hydrothermal extracts from Cucumaria japonica in an oil-fat emulsion product allowed to reduce peroxide value by 22-45%, acid value by 12-35% on the 90th days of storage. Acid hydrolysates of Cucumaria Japonica most significantly reduce the rate of oxidation and hydrolysis.