Abstract: To provide a novel and stable protein composition, and a method for stabilizing the protein composition. A composition that contains protein and water containing ultra-fine air bubbles having a mode particle size of 500 nm or less, and a method for stabilizing a protein composition that involves mixing protein and water containing ultra-fine air bubbles having a mode particle size of 500 nm or less.

Abstract: The present invention provides an extraction method that either does not use emulsifiers, organic solvents, and the like or can reduce the amount used of emulsifiers, organic solvents, and the like. In addition, the extraction method of present invention can also efficiently extract various components from various materials to be extracted, and can highly maintain potency and the like of the extracted components, in particular if the components are active agents. Furthermore, the extraction method of present invention has excellent safety. The extraction method of present invention is achieved by bringing materials to be extracted into contact with liquid containing ultra fine bubbles for extraction treatment. The ultra fine bubbles utilized during the extraction process preferably have a mode diameter of 500 nm or smaller and a concentration of 1,000,000 or more per 1 ml of liquid.