The results from the preceding study promoted on investigation of the effects of linoleate supplementation in dietary hardened fish oil (HFO) on rats fed HFO, safflower oil (SFO) and the mixtures of these two oils, 1 : 1 and 5 : 1 mixture by weight for 8 weeks. Weight gain and fatty acid profiles of liver, heart and adipose tissue lipids along with those of fecal lipids were compared. 1) Complete recovery from the unfavorable effects of HFO on the body weight gain was noted to occur with the addition of SFO as a source of linoleic acid, indicating the lowering of rate of weight gain to possibly not be due to trans fatty acids in HFO but to essential fatty acid deficiency. 2) The percentage of 20 : 4 n-6 in liver lipids markedly increased by partial substitution (20%) of SFO for HFO, but further addition failed to have such effect. In contrast, the addition of SFO failed to significantly increase heart lipid content due to the relatively high pre-existing level of arachidonic acid in the HFO group. Small amounts of trans fatty acids were found in the liver, heart and adipose tissue lipids from rats fed SFO, but only small amounts of trans fatty acids of 20 : 1 and 22 : 1 could be detected in these tissues of rats fed HFO, as was also noted in the preceding study. 3) Analysis of fatty acids in fecal lipids indicated trans acids, especially 20 : 1 and 22 : 1, to be preferentially discharged into the feces, while linoleic acid to be excreted when administered in excess though in rats, resumption of the level of this polyunsaturated fatty acid occured easily. Furthermore, the positional isomers of cis and trans monoene fatty acids, absent from dietary fats and tissue lipids, were detected at considerably high levels in the feces.
Linear type, novolak type and cyclic type phenol-aldehyde oligomers were prepared and their antioxidant effects on autoxidation of lard were evaluated by oven tests at 60°C. Their antioxidant effects were affected both by their molecular weights and structures. The most effective molecular weight and ratio of ortho methylene linkage for acyclic oligomers was from about 6001000 and 91 % respectively. The introduction to a methyl group to the methylene linkage weakened the antioxidant effects. In this case, intramolecular hydrogen bonding between hydroxyl groups is essential to the expression of antioxidant effects, and the introduction of the methyl group to the methylene linkage apparently prevents the hydrogen bonding. Cyclic oligomers did not exert antioxidant effects on the autoxidation of lard. Such effects by oligomeric phenolic compounds arise possibly from cooperative intramolecular hydrogen bonding with adjacent aromatic hydroxyl groups and stabilized phenoxy radicals in oligomeric chains (Cage effect).
Synergistic antioxidant effects of tocopherols (d-Tocs) and essential oils from several spices on lard and palm oil were investigated by oven and AOM tests. The antioxidant effects of essential oils were also studied in the same manner. 1) As its major constituent, linalol was detected from the essential oil of sage, α-pinene from that of nutmeg, cineol from that of rosemary, cinnamic aldehyde from that of cinnamon, eugenol from those of allspice and clove and thymol from that of thyme. 2) On lard, each essential oil of allspice, cinnamon, clove and thyme clearly showed antioxidant effects when added in the amount to 1 000 ppm, and somewhat enhanced the effect of a mixture of d-Tocs (m-Toc). However, such effects were not observed by the addition of each essential oil of sage, nutmeg or rosemary. 3) On palm oil, none of the essential oils showed antioxidant effect, but that of cinnamon showed a synergistic effect with in a m-Toc. This synergistic effect was observed following the addition of each essential oil of thyme and rosemary along with a mixture of d-Tocs in the oven test.
In a (W/O)/W emulsion, the dispersion behavior of (W/O) droplets was observed following sudden reduction in impeller speed. The rates of both coalescence and breakup of (W/O) droplets were quantitatively estimated, and then the dependence of coalescence and breakup rate constants on operating conditions such as impeller speed and droplet diameter was determined. As the impeller speed increased, coalescence and breakup also increase. As (W/O) droplet diameter increased, coalescence decreased and breakup increased. Leakage of the inner aqueous phase into the outer aqueous phase was found to occur mainly as a result of (W/O) droplet breakup.
The relative activity of lipase, solubilization of Yellow OB and removal of triolein were determined to clarify the effects of hydrolysis by lipase and solubilization on the removal of triolein in the lipase-surfactant system. Three kinds of lipases from Candida cylindracea, Fusarium sp. and Chromobacterium viscosum were used. In the lipase-SDS or LAS system, lipase activity gradually reduced with increase in surfactant concentration. At low concentration of the latter, the activity was well maintained and removal of triolein was promoted by hydrolysis. At high concentration, the activity was inhibited and triolein was removed by solubilization. Removal of triolein by hydrolysis was noted to be more efficient than by solubilization. In the lipase-AOS or AE2S system, triolein was removed very much at both high and low surfactant concentrations. This was due to the effective maintenance of lipase activity and solubilization resulting from surfactant cmc.
Dodecyl oligo(oxyethylene)carboxymethyl ethers (1 )and 2-[oligo(oxyethylene)]octadecanoic acids (2) were prepared by the method shown in Scheme-1. They were examined for their capacity to function as cariers for the active and competitive transport of alkali (Li+, Na+, and K+) and alkaline earth (Mg2+, Ca2+, and Ba2+) metal cations in chloroform membrane systems. Simple alkanoic acid, i.e. dodecanoic acid failed to mediate the transport of any cation in the present systems, but (1) and (2) with an appropriate number of oxyethylene units (m) effectively transported the cations, confirming the validity of introduction of the oligo (oxyethylene) chain into alkanoic acids. For the transport of alkali metal cations, carriers with m≥4 were effective, and those with m≥5 were superior in K+-selectivity to those with m=4. All (1) and (2) transported Ca2+ and Ba2+ with higher efficiency but lesser ion-selectivity than in the case of alkali metal cations. The results are discussed based on “host-guest” relationship between the cavity size of pseudocyclic oligoethers and cation diameter, and on lipophilicity and rigidity of complexes formed from carrier molecules and cations.
The effects of thiodipropionic acid (TDPA) in preventing decomposition of tocopherol (Toc) in each oil (soybean, olive, palm and hardened palm oils), and changes in the peroxide values of soybean oil with different degrees of oxidative rancidness with TDPA during the oven test at 60°C were investigated. Toc content and peroxide values were determined by HPLC and the JOCS official method 2.4.12-71, respectively. TDPA suppressed the oxidation of each oil and decomposition of Toc in each oil during the oven test at 60°C. The ratio of the decomposition of peroxide in oxidative rancid oil (POV10130) increased with the concentration of TDPA. The decomposition of Toc in peroxide from which oxidative rancid oil had been removed during storage at 60°C was observed. Peroxide may thus be concluded not to bring about the composition of Toc in oil. These results indicated the decomposition of Toc in oil to possibly be due to secondary products from peroxide.