The synergistic antioxidant effects of tocopherol (Toc) with L-ascorbyl palmitate (AP) were investigated by the oven test at 60°C and AOM test using lard, palm oil, stripped safflower oil and fish oil. 1) In the oven test, AP showed a rather prooxidant effect but synergistically enhanced the antioxidant effect of the mixed tocopherols concentrate (m-Toc) on lard. On palm oil, AP inhibited oxidation and enhanced the effect of m-Toc. These effects became more pronounced with at increase in the amount of AP, particularly, AP more than 500 ppm, 0.02 % m-Toc was found markedly effective for inhibiting the oxidation of lard and palm oil. 2) Even the addition of AP with m-Toc essentially failed to inhibit the rapid rise in peroxide content of stripped safflower oil and fish oil rich in polyunsaturated fatty acids. 3) Such effects of AP were also observed in the AOM test, and were basically the same as those of L-ascorbyl stearate (AS). 4) In lard and palm oil, the remnant ratio of Toc after 20 d in the oven at 60°C increased with the amounts of AP and AS suggesting the protective effect of AP and AS on oxidative deterioration of Toc.
Fish oils such as sardine oil, icosapentaenoic acid concentrated oil (EPA-25) and docosahexaenoic acid concentrated oil (DHA-20) were transesterified with polyunsaturated fatty acids (PUFA) prepared from the original oils by low temperature crystallization, in a enzymatic reaction system using immobilized lipase (Lipozyme) originating from Mucor miehei. The optimum reaction conditions were : 6 times PUFA for EPA-25 by molar ratio, 30 % Lipozyme for EPA-25 by weight, 5% water for Lipozyme by weight, 2 h incubation time at 60°C, under which conditions the transesterification ratio reached approximately 32 %. The recovery of triacylglycerol was about 95 %, indicating competitive hydrolysis to be suppressed effectively under the conditions used and PUFA content of the triacylglycerol increased to 62 %. Possibly as a result of the substrate specificity of Lipozyme, the transesterification ratio reached approximately 44% in the soybean oil-myristic acid system, this being 12% higher than that of the fish oil-PUFA system, EPA was more easily incorporated into triacylglycerol than DHA. The preparation of triacylglycerol with high DHA content was thus carried out by additional transesterification in the fish oil-PUFA system and the DHA content of the resulting triacylglycerol was 3.6 times that of the original fish oil. Lipozyme could be recycled more than 20 times under the present transesterification conditions.
The thermal oxidation of the thin film (thickness, 168 μm) of trilinolenoylglycerol (TLNG) on metal plate cells (Pt, Fe, Al, Cu and Ni) in air was carried out by thermogravimetric analysis and elementaly analysis. The weight of TLNG increased in the temperature range of 50°C to 200°C. Compositions of the weight-increased samples were determined by elemental analysis. In the case of TLNG on Pt cell, 2 % and 4 % weight-increased samples (at 94 and 106°C) contained 0.6 and 1.2 radicals of the hydroperoxyl group to 1.0 mol of TLNG, no thermal degradation reaction was observed. The degradation reaction of C-C and C-H bonds in the maximum weight-increased sample (6.1 %) (at 130°C) took place. The oxidation reaction of TLNG and degradation reaction of the oxidative TLNG proceeded similtaneously at over 130°C, corresponding to the maximum weight-increased sample. In the case of TLNG on the Fe cell, the oxidation reaction of TLNG was accelerated by the Fe metal cell. In the case of TLNG on the Al cell, change in the composition of TLNG was similar to that of TLNG on the Pt cell. For TLNG on the Cu cell, the thermal polymerization reaction of TLNG was acceralated by the Cu metal cell. For TLNG on the Ni cell, the catalytic effect of Ni metal for TLNG was similar to that of the Al metal cell.
Inomotosou (Pteris multifida Poiret) [I], Oobainomotosou (Pteris cretica L.) [II] and Hitotsuba (Pyrrosia lingua Farw.) [III] are plants belonging to the Polypodiacea family. The chemical compositions of the essential oils of fresh by ground materials of [I], [II] and [III] were examined by techniques such as capillary GC, GC-MS and IR used in combinations. Compounds 32, 31 and 40 were identified from [I], [II] and [III], respectively. The major common compounds found in oils from [I], [II] and [III] were hexanal, vanillin, 4-hexen-l-ol, 1-hepten-3-ol, 3-hydroxy-2, 2, 4-trimethylpentyl isobutyrate, and those found in both oils from [I] and [II] were carbonyl compounds, alcohols and esters such as heptanal, vanillin, 1-hepten-3-ol, isobutyl isobutyrate, 3-hydroxy-2, 2, 4-trimethylpentyl isobutyrate and ethyl cinnamate. The components included in oils from [II] were quite similar to those from [I]. Both oils from [I] and [II] possessed odor like green and seaweed, and oil from [III] had a greenish and fatty acid-like odor though no odor like that of seaweed.
Two series of new compounds, N, N-bis [2- (N'-acylamino) ethyl] glycines (1) and 4- [2- (N-acylamino) ethyl] 2-piperazinones (2), were synthesized. Both series showed very good antimicrobial properties.
The synthesis and surface active properties of sodium 3-alkoxy-and 3- [alkylmono (di) (oxyethylene) oxy] -2-hydroxy-1-propanesulfonates were investigated. Of all surface active compounds, those with a 2-hydroxypropyl (HP) moiety in the molecules were found more surface-active than the corresponding compounds without it.
Fat stability test on autoxidation based on the conductometric determination method in place of the A.O.M. test was conducted at 9 laboratories. This method was found not to be influenced by sample weights or quantity of water, although the results were affected by temperature. It was necessary to calibrate the temperature of the heating block exactly and to maintain constant air flow during measurement. Compared with the A.O.M. test, this method makes possible laborsaving, cost-reduing and time-reduction. This method has been designated as the C.D.M. (Conductometric Determination Method) test by the auto A.O.M. Committee of the Japan Oil Chemists' Society. It is a novel fat stability test that can be used in place of the A.O.M. test.