FATTY-ACID COMPOSITION, EXTRACTION, FRACTIONATION, AND STABILIZATION OF BULLFROG (RANA-CATESBEIANA) OIL

The oil extracted from the fat-storage organ (fat body) of the bullfro g (Ran catesbeiana) was characterized for its fatty acid composition. The main fatty acids were palmitic (18.1%), stearic (4.1%), myristic ( 2.7%), oleic (31.7%), and linoleic (12.9%) acids. Long-chain polyunsat urated fatty acids were also present in significant amounts, i.e., eic osapentaenoic (1.5%) and docosahexaenoic (4.7%), and were probably der ived from the fish meal content of the diet. A partially fractionated oil was extracted from the homogenized and frozen fat body with an ole ic acid content of 43.2%. The natural alkaloid boldine, added at 0.5 m g/g oil level, improved the oxidative stability by a factor ranging fr om 1.7 to 2.4, as assessed by the Oil Stability Index method between 9 0 and 110 degrees C. The stabilization effect of boldine was higher th an that of naringenin, morin, and quercitin and for the synthetic anti oxidant butylated hydroxytoluene at the same concentration level.