The fatty acid composition in platelet phospholipids and in the plasma lipid esters as well as the serum lipoprotein lipid concentrations were determined in 67 healthy male subjects in order to establish the relationships between blood lipids and platelets. A positive correlation was found between the concentrations of the triglyceride rich serum lipoprotein lipids and the relative percentage of saturated and monounsaturated fatty acids in plasma. The correlations were also positive between the serum high density lipoprotein-cholesterol concentration and the relative content of linoleic acid in the plasma cholesterol esters and phospholipids. Negative correlations were found between the relative percentage of saturated and monounsaturated fatty acids in the plasma lipid esters versus linoleic acid in plasma and in the platelets. On the other hand there were positive correlations between linoleic acid in the plasma lipid esters and in the platelet phospholipids. These results indicate a direct dietary influence on the platelet phospholipid fatty acid composition. The correlations between the fatty acids of the n-6 series within plasma and platelets as well as between plasma and platelets indicate that a high linoleic acid content is not associated with an increased arachidonic acid concentration. The results also indicate that the limiting metabolic step in the conversion of linoleic acid into arachidonic acid may be located at different levels in plasma and in the platelets.

The content of 4-demethyl-, 4-monomethyl-and 4,4-dimethylsterols in 13 vegetable oils was found to vary between 0.10-1.4%, 0.01-0.08% and 0.02-0.29%, respectively. The largest amount of demethylsterols was found in maize and wheat germ oils, whereas the largest amounts of the dimethylsterols were found in olive and linseed oils. The predominating demethylsterols were sitosterol, campesterol, stigmasterol and AS-avenasterol. Among the 4-monomethylsterols, obtusifoliol, gramisterol, cycloeucalenol and citrostadienol predominated, but usually more than 10 components were found in this fraction. The composition of the 4,4-dimethylsterol fraction was a/so rather complex, with the 9,19cyclopropanesterols together with a-and #-amyrin predominating. In most of the oils, characteristically high or low percentages of some sterols were found, and a few specific sterols were also noted. A scheme useful for characterization is presented.

ByL.-B. C r o o n , Astn'Rogstad, T L e t h andT.Kiutamo *Four quick-test methods (the Foodoil sensor, RAU-Test,Fritest' and Spot test) and two ordinary laboratory methods (the free fatty acids and GLC determination of triglycerid h e r s ) were compared to a standard method (column chromatographic determination of polar compounds). One hundred samples collected from fast food shop and restaurants were included in the investigation. The Foodoil sensor showed the highest correlation to the standardmethod(c.f.= 094).TheRAU-Test,Fritest'andSpottestwerealso wellcorrelated to thestandardmethod.1t waseasiertocompare thecolourof the reaction mixtures to the colour scale of the RAU-Test than to that of the Fritest'.The amount offreefattyacids were found tobeanunreliableindicatorofdeteriorated fryingfat.The triglyceridedimers couldnotbequantified, but assessment by visual comparison of the peak pattern in the chromatc gram corresponded well with the results of the standard method.

No abstract

Three groups of rats were maintained on diets containing different proportions of trans fatty acids (0, 18.3 or 36.6% of the total fatty acids) for eight weeks. No differences in body weight were observed among the three groups, but the fat cell size, determined in epididymal fat, differed significantly between the controls and the rats fed diets containing trans fatty acids. The supernatant obtained by centrifuging homogenates of liver from the rats at 9000 X g (S-9 fraction) was used as an activator in a bacterial test for mutagenicity of 2-aminofluorene and aflatoxin B1 using Salmonella typhimurium strains TA 98 and TA 100, respectively. The mutagenicities of 2-aminofluorene in strain TA 98 and of aflatoxin B1 in strain TA 100 were significantly lower with the liver S-9 fraction from rats fed a diet containing 36.6% trans fatty acids than with the liver S-9 fraction from rats fed a control diet with no trans fatty acids.