Various novel fragrance and flavor compounds have been synthesized day by day. The inevitable demands on exploitation of new synthetic methods for these compounds are gradually increasing in response to the intense competition in worldwide. This review deals mainly with the recent trend of Japanese market and progress on interesting fragrance and flavor compounds.
Analysis of alkyl poly (oxyethylene) ethers was carried out by HPLC. Nonionic surfactants were well separated regardless of the distribution of the adducted number of ethylene oxides to give chromatographic peaks according to alkyl chain length under certain rigidly controlled eluent conditions. Moreover, the analytical sensitivity of nonionic surfactants with solvent extraction became 20 times without solvent extraction. This method should thus prove particularly suited for the analysis of nonionic surfactants in aqueous solution because in view of its simplicity and rapidity of performances.
The critical composition of a lecithin (containing 1.3 wt% H2O) -hexadecane-ethanol system (20°C) was studied. Lecithin is insoluble in hexadecane but swells considerably in hixadecane (99wt% of hexadecane in lecithin). The vapor pressure of a lecithin-ethanol solution was also studied. From the deviationof Raoult's law, lecithin was found to form aggregates in ethanol. These findings indicate distinct features of lecithin, rarely observed in other surfactants.
Theeffects of phospholipids on the oxidative decompositionand dimerization of d-γ-tocopherol (γ-T) or d-δ-tocopherol (δ-T) during the autoxidation of methyl linoleate (Me-Li) or methyl laurate (Me-La) were investigated. The fatty acid methyl esters, which contained tocopherol (0.5 %) and one of following additives (0.01-0.5 %) were oxidized by air under A.O.M. conditions. The additives used in the experiments are as follows : phosphatidylcholine (PC) and phosphatidylethanolamine (PE) as phospholipids, tri-n-butylphosphate (TBP) as a model component of phosphate ester, and tri-n-octylamine (TOA) as that of a nitrogenous base. The amounts of tocopherol and its dimers formed in a reaction mixture were determined by HPLC. PC and PE improved the stability of the tocopherol monomer in Me-Li (Figs.-1 and 7) and suppressed the formation of its dimers (Figs.-2, 3, 8 and 9). The total amount of the tocopherol monomer and its dimers was constant regardless of the presence of phospholipids (Figs.-4 and 10). It is thus evident that phospholipids suppress the initial stage of the oxidation of tocopherol, in which tocopherol changes to its dimers, and that they also contribute to the regeneration of the tocopherol monomer from its dimers. TBP, by which the stability of tocopherol under the condition of the thermal oxidation was improved, promoted the oxidation of tocopherol (Figs.-1 and 7) and suppressed the dimerization of tocopherol (Figs.-2, 3, 8 and 9) under the autoxidative conditions of Me-Li. The oxidation of tocopherol in Me-Li was promoted by TOA at low concentration (0.01 %). The oxidative decomposition of tocopherol decreased with the concentration of TOA. However, TOA eventually suppressed the oxidation of tocopherol (Figs.-1 and 7) and formed mainly diphenylether type dimed (Figs.-2 and 8).
The effect of supplementing linoleate as safflower oil was investigated in rats to determine the minimal requirements for amelioration of essential fatty acid deficiency caused by feeding hardened fish oil (HFO). Male rats were fed diets containing 20% HFO for 4 weeks. A portion of HFO was replaced stepwise with safflower oil (1, 3, 5 and 10%). The influence of the oil addition on the physical properties of HFO was also studied by measuring the melting point by 4 different methods and solid fat content (SFC) at 540°C. 1) The melting points remained unchanged by the addition of safflower oil to ITFO at 10% or less, and the SFC at 540°C did not change essentially addition of the vegetable oil at 3% or less. 2) The reduction of body weight gain in the HFO group may primarily have resulted from reduction of food intake since no significant change in food efficiency (weight gain/food intake) occurred even when safflower oil was supplemented.
(+) -2- (4-methyl-3-cyclohexenyl) propionaldehyde (2) as a component of bulgarian rose oil and (+) -2- (4-methyl-3-cyclohexenyl) allyl alcohol (3) were obtained by the oxidation of (+) -limonene (1) with lead tetraacetate. Using (2) and (3), new aromatic chemicals were synthesized. The reaction of (2), (+) -2- (4-methyl-3-cyclohexenyl) acrylaldehyde (5) with 1, 1-dimethyl-hydrazine gave (+) -2- (4-methyl-3-cyclohexenyl) propiononitrile (6a) and (+) -2- (4-methyl-3-cyclohexenyl) acrylonitrile (6b), respectively, with lds of 7275%. Acetals (9 a), (9 b), (9 c) and (9 d) were also obtained from (2) or (5) and trimethyl orthoformate or triethyl orthoformate. α, β-Unsaturated carboxylic acid (10) was synthesized via the condensation of aldehyde (5) with malonic acid. Alcohol (11) and esters (12 a), (12 b) (carbon numbers are C10C15) were synthesized from aldehyde (5) with C2C3 alcohols, and reduction with lithium aluminum hydride, Thesecompounds were evaluated on the basis of their odor : (6 a), (10), (12 a) emitted an odor that would qualify them for use as flavor materials.
Microemulsions solubilizing large amounts of water and hexadecane were found present in a water/alcohol/lecithin/hexadecane system (20°C). The addition of ethanol and propanol lessened the hydrophobic effect between hydrocarbon chains of lecithin and water by changing the solvent properties of water and promoted the migration of lecithin molecules. Therefore, lecithin can easily swell in water and hexadecane, leading to the formation of a microemulsion (Organized one phase).
The thermal weight reduction characteristics of household margarines were investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC). 1) The weight reduction behavior of margarines with aqueous vaporization was observed to vary with the type of sample. In particular, aqueous vaporization in the type of margarine containing gas, or high content of water and protein was noted to start at lower temperature than that of the other types. 2) The pyrolysis behavior of margarines after dehydration varied with the type of sample. In the case of the high linoleic soft type, weight gain with absorption of oxygen was observed and weight reduction in temperature range from 300°C to 400°C was slower than that of other types. TG curve of butter fat containing fat spread was more simple than those of the above samples. However, weight reduction appeared essentially the same in common soft and carton hard margarines since their fatty acid compositions were similar. 3) The rate of weight reduction by the end of the isothermal step at 110°C was correlated to moisture content. From 250°C to 350°C, it was also correlated to the iodine value.