Abstract: Effects of extraction conditions on properties and fatty acids composition of oil extracted from abdominal adipose tissue of silver carp by diluted alkaline hydrolysis extraction were studied. The results indicated that the extraction ratio and properties of oil from silver carp, such as iodic value, acid value, peroxide value and soapstock content are significantly affected by extraction conditions. The optimal extraction ratio of fish oil 60.5% is obtained by hydrolyzing cracked adipose tissue at 45 ℃ for 5 minutes in pH 9.0 NaOH solution (1:1, W/V) and precipitated in 1.0% NaCl solution for 5 minutes. The oil extracted from silver carp by the optimal conditions is comprised of 16 kinds of fatty acid, i.e. 16:0, 18:1n-9, DHA and EPA, in which ratio of n-3 to n-6 is 2.0 while the content of EPA and DHA are 15.0% and 10.1% respectively.

Key words: fish oil, extraction, properties, fatty acid composition