Comparison of Total Lipids between Normal-"Katsuobushi" and "Shirata-katsuobushi"

Abstract

Comparison of chemical properties and compositions of total lipids between normal-"katsuobushi" (4 samples) and "Shirata-katsuobushi" ("Shirata": phenomena developed in a piece of dried skipjack, 5 samples) was made. The results are summarized as follows: (1) Total lipid contents were 3.0-5.6% (3.7-7.0% as dry matter) in normal-"katsuobushi" and 8.5-11.5% (9.5-12.2%) in "Shirata-katsuobushi". (2) Acid value of total lipids was higher in "Shirata-katsuobushi" than in normal-"katsuobushi", and peroxide value and iodine value were lower in "Shirata-katsuobushi" than in normal-"katsuobushi". (3) Neutral lipid fraction contents of total lipids were 60.6-72.4% (2.1-4.1g in 100g samples) in normal-"katsuobushi" and 75.7-87.9% (6.5-10.1g in 100g samples) in "Shirata-katsuobushi", while compound lipid fraction contents of total lipids were 27.6-39.4% (0.9-1.7g) in normal-"katsuobushi" and 12.1-24.3% (1.4-2.6g) in "Shirata-katsuobushi". (4) Triacylglycerol and free fatty acid contents of neutral lipid fraction in normal-"katsuobushi" were 31.2-49.3% and 28.2-43.3%, respectively, while those in "Shirata-katsuobushi" were 19.4-33.2% and 48.7-60.5%, respectively. (5) Phosphatidylcholine content of compound lipid fraction in normal-"katsuobushi" was 67.9-74.7%, while that in "Shirata-katsuobushi" was 53.2-63.6%. (6) The major fatty acids of total lipids, neutral lipid fraction and compound lipid fraction in both types of "katsuobushi" were 14:0, 16:0, 16:1, 18:0, 18:1, 20:4, 20:5 and 22:6 acids. However, "Shirata-katsuobushi" contained more saturated fatty acids and less highly unsaturated fatty acids than normal-"Katsuobushi".