The studies on the characterization of lipids, i.e., triacylgcerols, steroids, and naturally occurring sterols, by GC, MS, and NMR were summarized. The relationship between the molecular structures of individual lipids and the chromatographic and spectroscopic data was thoroughly discussed.
A spectrophotometric iodine method was developed to determine peroxide values (POV) of phospholipids. The amount of iodine liberated from iodide by oxidation with the peroxide was determined from absorbance at 360 nm, and POV calculated from absorbance. Deviation in absorbance data due to air oxidation of excess iodide was made minimal by reducing the added volume of potassium iodide solution to 10μL and by conducting a blank experiment at the same time. By this method POV can be easily determined using a small amount of sample, general glasswares, reagents, and spectrophotometer. Good agreement was obtained between POV obtained by this and the JOCS method.
The follwing results were obtained using an ultracentrifuge provided with a rotor of adjustable angle for removing polystyrene-latex particles adhering to a glass substrate. The direction of the removing force could be varied widely by adjusting the rotor angle θ between 0° and 60°. The ratio of the vertical component Fυ to the horizontal component Fh was varied from 1 : 0 to 1 : 1.73 by adjusting this angle. The surface on which the particles adhered was turned between the direction of the centrifugal force Fc and the vertical direction of that of by the centrifugal force (angles θ' of the surface with centrifugal force were 060° and 180240°). 1) The less the contribution of Fυ to the constant Fh, the greater was the extent of removal. Removal was maximum at Fυ=0 or when the resultant centrifugal force Fc=Fh. Also, the greater the contribution of Fh to the constant Fυ, the more was the extent of removal. 2) Fυ acted negatively for particle removal when the surface had been turned to the direction pressed by centrifugal force. In such a case at constant Fc, removal decreased with increase in washing time. Adjusting θ' (θ) so as to turn the surface in the direction vertical to that of the centrifugal force increased removal. That is the contribution of Fυ decreased than the direction of centrifugal force, and removal increased at Fυ>Fh when its force was small. Removal in the former case was about 20% less that in the latter at Fc=Fh even without any contribution of Fυ.
For clarification of the deposition mechanism of dispersed particles onto textile fibers in sodium carboxymethylcellulose (Na-CMC) aqueous solution, the influence of Na-CMC on the deposition of polystyrene (PS) latex particles onto cotton and Nylon-6 fibers was studied from the standpoint of interaction energy between latex particles and fibers. Deposited amounts and the rate of deposition of PS latex particles onto cotton and Nylon-6 fibers in the presence of Na-CMC were less than when Na-CMC was absent. Elimination of the effect of Na-CMC for deposition may thus possibly be due primarily to electrostatic repulsive interactions, since total interaction energy (VT) due to electrostatic and van der Waals forces between latex particles and fibers increases greatly with the addition of Na-CMC. The addition of Na-CMC had virtually no effect on VT for Nylon-6 fiber, and thus possibly steric repulsive interactions due to Na-CMC adsorbed on Nylon-6 fiber may be essential to the deposition of PS latex particles.
Synthesis of macrocyclic lactons (5) having more than 10 members in their rings by intramolecular radical cyclization of the iodoalkyl acrylates (4) using AIBN and n-Bu3SnH was investigated in detail. (4) was prepared as shown in Fig-1. Isolated yields of bromo alcohols (2) were generally 5085%. The conversion of (2) to the iodide (3) and the esterification of (3) occurred in quantitative yields. Products obtained from free radical cyclization reactions of (4) were (5), dilide (6) and acrylic acrylate (7) by simple reduction of the iodide. The addition rate of n-Bu3SnH solution, concentration of (4) in the reaction solution and carbon numbers of (4) were found to influence the formation of (5) seriously. The macrocyclic lactone with a 16 membered ring was formed by the present procedure in excellent yield (95.9%, isolated yield 92.3%). A possible reaction pathway for the formation of (5) is discussed.
Qualitative characteristics of recent products for bakery fat spreads were studied by measuring various chemical and physical parameters of 16 brands (multipurpose type 3; spice containing type 1; sweetened type 7; sweetened milkfat blend type 5). 1) The bakery fat spread contained lipid of 48.174.8% and protein of 0.27% or less, but salt was only slightly present or absent from all brands except one. Sugars including sucrose, glucose, fructose and others were present at about 20% in the sweetened products, which constitute majority of bakery fat spreads in Japan. 2) Analytical results on fatty acid composition indicated the fats to contain hardened fish oil in all brands except two, hardened rapeseed oil with laurin oil in No. 5 and hardened vegetable oil in No. 4. The characteristics of Cruciferae seed oil, probably mustard origin, were found in No. 4, the spice containing type, while that of mikfat was confirmed in all brands of the sweetened milkfat blend type. Nickel was detected at only 0.06 ppm or less in all fat spreads and was somewhat more in brands containing natural materials, such as milk products and mustard. 3) In bakery fat spreads, hardness increased in the order of the spice containing type<multipurpose type≤sweetened type<sweetened milkfat blend type, and depended essentially on the solid fat content of the separated oil, as has also been noted in bakery margarines previously reported. But, hardness appeared to also be influenced by other materials, such as sugars, stabilizers of emulsion and thickeners, Softer fat spreads shed their oil more easily, within the hardness index at about 120 or less. However, beyond this value, this feature was not apparent. Oil was shed with difficulty even at a hardness index exceeding 350. The creaming of sweetened fat spreads varied considerably and was closely correlated to the water-sorption index.
More than seven kinds of phospholipids were isolated from Maitake mycelium and the fruiting body, Glifola frondosa. The positional distribution of fatty acids and compositions of the molecular species were analyzed. Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) in mycelium and PE, PC, phosphatidylinositol (PI), phosphatidylserine (PS) and phosphatidic acid (PA) in fruiting body were found to be the principal types. In mycelium and the fruiting body, fatty acid components of phospholipids were commonly distributed at the C-2 position in palmitic acid, although the C-1 position differed according to the lipid class. It was exclusively occupied by palmitic, oleic and linoleic acids. The representative molecular species of neutral phospholipids were dilinolein, oleoyllinolein and palmitoyllinolein types, while those of acidic phospholipids were palmitoyllinolein and palmitoylolein types.
Globule size analysis for freshly prepared O/W emulsions stabilized by various emulsifying agents was conducted so as to compare the emulsifying capacity of a high pressure homogenizer (H. P. HOMO) with those of the other equipment such as a homomixer (HOMO) and ultrasonic homogenizer (U. S. HOMO). The comparison was also made with a method for providing the fine globule O/W emulsions proposed by Sagitani and his co-workers. The results obtained are as follows : (1) Finer globules with of narrower size distribution could be detected better by emulsification using H. P. HOMO than by any other method. (2) The neccessary amounts of emulsifying agents for obtaining stable O/W emulsions could be reduced by applying the method of H. P. HOMO. (3) This method broadens the scope application of emulsifying agents including certain biological components such as phospholipids and saponins.