Raymond Reiser

When whale oil triglycerides were subjected to pancreatic lipase hydrolysis, eicosapentaenoic and docosahexaenoic acids were found mainly in the di- and triglyceride products, suggesting that they are in the 1,3-positions but resistant to the action of the lipase. Their presence in the 1,3-positions was confirmed. Their resistance to pancreatic lipase hydrolysis was demonstrated by analysis of the products of the enzyme action on: (a) a concentrate of highly unsaturated whale oil triglycerides; (b) the latter after randomization; and (c) synthetic 1,2-di-octadecenoyl-3-eicosapentaenoyl glycerol.Docosapentaenoic acid was also shown to be present in the 1,3-position of whale oil triglycerides but was not lipase resistant. It is postulated that the presence of a double bond near the carboxyl group exercises an inhibitory effect, or that the location of the double bonds in the resistant acids places their terminal methyl groups close to the carboxyl, producing a steric hindrance effect.

ABSTRACT The relationships of marbling level (eight levels from “Moderately Abundant” to “Practically Devoid”) and cooking to cholesterol content of beef longissimus muscle steaks were studied. Only raw steaks with “Practically Devoid” marbling contained significantly less cholesterol (wet basis) than did raw steaks with any of the other seven marbling scores. However, steaks cooked to an internal temperature of 60° or 75°C showed no significant differences in cholesterol content among any of the eight marbling groups. The cholesterol content of cooked steaks was 22–48% higher than that of raw steaks when cooked to 60°C and 38–65% higher when cooked to 75°C; cooking reduced the weight of each steak, thereby increasing the cholesterol content of the steak expressed as a percentage of the cooked weight.

Abstract Comparisons were made of the ratios of the specific activities of stearic acid to oleic acid in adipose tissue and liver triglycerides of rats given methyl stearate-1-14C dissolved in 0.25 ml of corn oil and Sterculia foetida oil. The ratios were about 3 in the corn oil control animals compared to 31 to 43 in adipose tissue and 44 to 246 in liver triglycerides of the S. foetida test animals. When the labeled stearate was administered in 0.5 ml of S. foetida oil almost no label appeared in tissue oleic acid. The inhibition was also shown to be affected by sterculic acid in vitro with rat liver preparations. Evidence was obtained that the mechanism of inhibition is the irreversible binding of enzyme sulfhydryl groups by the cyclopropene group.