By a membrane emulsification method, four kinds O/W emulsions with very narrow distribution of droplet size were prepared. The creaming rate of the emulsions for various volume fractions (φ) were measured accurately by the Image-Analysis Method. The obtained creaming rate did not agree with both the values calcurated by using Buscall's equation for monodisper sion of latex and those obtained by Uχ= Uο/ηsys, where Uο is Stoke's value for Newtonian fluid under gravity and ηsys is the viscosity of emulsion determined by Mooney's theoretical equation or Sherman's empirical equation. It was found that the creaming rate of the emulsion could be presented by the equation Uχ=Uο/exp (A [η] φ) for a wide range of φ, where [η] is the intrinsic viscosity of the emulsion and A is a correction coefficient for the individual intrinsic viscosity for emulsions with different radius. Furthermore, this eqation is also applicable to monodispersed hard spheres (latex) from 0 to 0.3 of φ.
For clarification of the nutritional and physiological functions of long-chain trans-monoenoic fatty acids, characteristics of hardened fish oil, weanling male rats were fed diets containing 20 % (by weight) one of the following fats for 5 d and 28 d : soybean oil containing 20 % of trans-or cis-docosenoic acid (TDO and CDO, respectively), a blend of high erucic acid with low erucic acid rapeseed oil (RSO, C22 : 1 20 wt%), or soybean oil (SBO) as the control. A growth, weight and lipid content in the liver and heart, serum lipid and urinary excretion of L-ascorbic acid in the animals were studied comparatively. Boby weight gain in the TDO group exceeded that in the SBO and RSO groups. The same was observed for food intake. Transient increase in liver weight and urinary excretion of L-ascorbic acid in rats fed hardened fish oil could hardly be detected in the TDO group. Slight increase in liver weight was observed in the CDO group. No transient lipid accumulation in the heart in the RSO group could be seen in the TDO group on even the CDO group. Analytical results indicated TDO to be less than CDO on RSO in serum HDL-cholesterol. Total cholesterol level not affected. The low values may passibly have due to SBO used as base oil, and not trans-docosenoic acid.
A sensitive HPLC method was developed for determing acylated sterylglycosides (ASG) in vegetable oil. ASG was concentrated by a silicagel cartridge and subsequently isolated by TLC from other glycosides. Derivatization of ASG with 1-anthroylnitrile was then carried out. Derivatized ASG was separated with HPLC in accordance with carbon number and degree of unsaturation of acyl and steryl groups. Data on an acyl/steryl combination of ASG species were obtained. ASG isolated from commercial soybean phospholipid was used as the standard substance. This method was applicable to extracts from oil seeds with polar solvent mixture. The limit of detection was about 5 ppm for edible oil.
The structural characterization of molecular species in fish oil, a complex mixture of various compounds, was carried out by high performance liquid chromatography/fast atom bombardment mass spectrometry (HPLC/FAB-MS) with a FRIT-FAB interface. Mass chromatograms and mass spectra obtained by HPLC/FAB-MS provided indication of the possible combinations of fatty acid in each triacylglycerol component in fish oil. In this manner, the compositions of polar and labile fractions comprised of polyunsaturated fatty acids such as icosapentaenoic acid and docosahexaenoic acid, were determined. This determination is difficult with GC/MS or HPLC. Differences in molecular species in fish oil and fractionated fish oil at -60°C were also examined by the present methode.
A study was made of trans-fatty acids (trans acids) content in various foods cooked with oils and fats. The products analyzed were doughnuts, potato chips, cereal and other snacks and fast food products. 1) Trans acids, mainly t-18 : 1, were detected in all samples, but their proportion to total fatty acids was lower than 15 % in most samples. Analysis of fatty acids indicated a blend of unhydrogenated oil along with hydrogenated fat had been used for producing these products. Forty-three samples had been prepared using a blend of palm oil, as determined from tocotrienol content, mainly the γ-form. Hydrogenated fish oil was found in one doughnut. 2) A few samples of doughnuts and French fries contained trans acids more than 30 %, suggesting an all-hydrogenated blend had been used, as is commonly the case in the U.S.A.. 3) The intake of trans acids from each sample analyzed was 0.17.7 g per one or two (the small size) doughnuts, 0.10.5 g per 100 g in potato chips, 0.12.9 g per one package of cereal and other snacks, 0.14.6 g per serving of French fries and 0.10.5 g per serving of fried chicken and fish. The intake of total trans acids was estimated as approximately 1.8 g/capita/d in Japan, this amount being markdly lower than that in America, 13.3 g.
Samples were extracted from hop (fresh and dried hop) by ethanol, methanol and ethyl acetate and antioxidative activity was assessed. Extract content, color, α-tocopherol content and absorption were also determined. The following results were obtained : Crude drug extract content in fresh and dried hop was 6.33 % and 7.17 % in the ethanol extract, 5.17 % and 6.16 % in the methanol extract and 2.74 % and 7.32 % in the ethyl acetate extract from 100 g of hop. α-Tocopherol content in 100 g of fresh or dried hop was 4.5 mg and 3.15 mg in the methanol extract and 4.10 mg or 4.20 mg in the ethyl acetate extract, none could be detected in the ethanol extract. The results of thin layer chromatography (solvent chloroform : ether : acetic acid = 97 : 2.3 : 0.5, vol/vol) indicated 5 fractions in the methanol extract and 2 fraction in the ethanol extract, and ethyl acetate extract, respectively. The strongest antioxidative activity from hop was noted for the dried hop methanol extract. Among the fractions in the methanol extract, fractions 1 and 5 showed strong activity.
Determination was made of lipid content and fatty acid compositions of blubber oils from minke whale and dwarf minke whale caught during 1988/89 and 1989/90. Fatty acid distribution and composition of minke whale blubber oils were essentially the same in both seasons. Lipid content of blubber oils was generally higher in dwarf minke whale than in ordinary minke whale. While fatty acid distribution was basically the same in both. Fatty acid composition differed significantly in the two species. Fatty acids such as 16 : 0, 18 : 0, 18 : 1 (n -9), 20 : 1 (n -11) and 20 : 4 (n -3) were at higher levels in dwarf minke whale than in minke whale. The polyunsaturated fatty acids with n -3 structures of 20 : 5, 22 : 5 and 22 : 6 were less in dwarf minke whale than minke whale.