The oil content of the silkworm, Bombyx mori, in the pupal stage was 4.8% for the male and 9.0% for the female (wet basis), respectively. Total lipid (TL) extracted from silkworm pupae mainly consisted of triacylglycerol (TG), phosphatidylethanolamine, and phosphatidylcholine. TL and TG contained approximately 40% α-linolenic acid as the predominant fatty acid. 20:3n-3 was also present in the pupa, but the quantities were very small. Total tocopherol in TL was 125.2 μg/g lipid for the male and 224.1 μg/g lipid for the female, respectively. The oxidative stability of TL was confirmed by measuring the decrease in oxygen in the headspace. The oxidative stability of TL from silkworm pupae was very high and no difference between sexes was appeared. It has been suggested that a synergistic effect between phospholipids and tocopherol in silkworm pupa plays an important role in protecting the lipids against oxidation. Furthermore, the silkworm pupa contained carotenoids such as lutein and neoxanthin. These carotenoids may act as antioxidants in TL. The silkworm pupa would be a good source of the functional fatty acid, α-linolenic acid, and of the functional pigments, lutein and neoxanthin.
We classified the volatile components of roasted sesame seed oils into three groups, namely, the nitrogenous components (NC), the sulfur components (SC), and the triacylglycerol decomposition products released upon heating (TDP), by head space sampler gas chromatography- mass spectrometry (HSS-GC-MS) analysis, and the results of sensory evaluation were compared with the composition of the three volatile component groups described above in various roasted sesame seed oils. The results revealed that there was a positive correlation between the amount of SC, and negative correlation between the amounts of TDP as determined by HSS-GC-MS analysis, and the aromatic quality of the oils. Furthermore, we analyzed the volatile component composition of three roasted sesame seed oil products obtained commercially at supermarkets in Japan for one year. There were no significant differences in the amounts of NC, SC, and TDP among the three commercial products. Our study suggests that the analysis of volatile components by HSS-GC-MS is highly effective and convenient for the quality control of roasted sesame seed oils.
Examination was made of the effects of edible oils containing medium-chain fatty acids (MCFA) on the body fat weight and blood lipid concentrations of rats fed a mixture of randomly interesterified rapeseed oil (87%) and medium-chain triacylglycerols (13%) (MLCT), and a physical mixture of rapeseed oil (87%) and medium-chain triacylglycerols (13%) (MIX). Wistar male rats were randomly divided into three groups and fed diets containing 7% rapeseed oil, MLCT and MIX for 6 weeks. Although the body fat weight and blood cholesterol concentration of rats fed MLCT and MIX diets were significantly lower than those of rapeseed oil diet, those of rats fed MLCT and MIX diets were not significantly different. The result suggests that the lowering effects of MCFA in the diet on body fat accumulation and blood cholesterol concentration in rats are similar to those caused by MLCT and MIX. It is of particular interest that the effective suppression of body fat accumulation in rats has been observed in the diet with a relatively small amount of MCFA (0.9% in experimental diet) when it is compared with the amounts of MLCT and MIX in diets.
We studied formation of chiral aggregates of optical active N-lauroyl-L-valine (L-LVA), N-lauroyl-L-glutamic acid (L-LGA) and methylester of L-LVA (L-LVMe) in various solvents such as acetonitrile, 1,4-dioxane, tetrahydrofuran and 1,2-dichloroethane through the measurements of circular dichroism (CD), NMR chemical shift of N-H proton and vapor-pressure osmometry (VPO). The above acylamino acids and L-LVMe showed CD bands at 212-215 nm, whose intensities depended on temperature. The CD bands have been believed to come from the formation of chiral aggregates. However, by means of NMR and VPO analyses, the acylamino acids and L-LVMe were found to be present mostly as monomers in relatively polar solvents such as acetonitrile, 1,4-dioxane and tetrahydrofuran. On the other hand, L-LVA in 1,2-dichloroethane forms chiral aggregates; the mean aggregation number of L-LVA increases with increasing in its concentration.
The micellization and adsorbed film formation for an aqueous binary mixed system of anionic top-heavy type surfactants: sodium salt of α-sulfonatomyristic acid isopropyl ester (α-SMy·iPr) and sodium 1-oxo-1 [4-(tridecafluorohexyl) phenyl]-2-hexanesulfonate (FC6-HC4), were studied by means of surface tension measurement (drop volume method). The surface tension (γ) was precisely measured for the solutions of the respective single and eleven mixed systems at 30.00 ± 0.03°C in order to determine critical micellization concentrations (CMC) and surface excesses (Γ) as a function of net mole fraction of FC6-HC4 (XFC6-HC4). The effect of added NaCl on CMC was examined for each single system to determine the degree of counterion binding (βi) from the Corrin-Harkins plot. Using the data of CMC and βi, we estimated the micellar composition (YFC6-HC4), activity coecients (fi) of the two surfactants in mixed micelles, and the interaction parameter (ω0), the calculation of which was made on the basis of our own theoretical equations taking into account of mutual counterion effect in binary ionic surfactant mixtures. From the CMC-YFC6-HC4 curve, markedly positive and slightly negative deviations from ideal mixing micelle formation were found, i.e. the positive deviation at the range of 0 < XFC6-HC4 < ca. 0.3 and the slightly negative deviation at the range of ca. 0.3 < XFC6-HC4 < 1. On the other hand, the composition of adsorbed film (ZFC6-HC4) was also estimated as a function of XFC6-HC4 using the surface tension data from below CMCs. In addition, Γ was determined as functions of XFC6-HC4 and ZFC6-HC4 and the partial molecular area (PMA) was evaluated from the plot of mean molecular surface area (Am) vs. ZFC6-HC4. All the data obtained showed without exception that an addition of 10 to 20% α-SMy·iPr to FC6-HC4 results in a marked enhancement of surface activity and micelle formation ability, accompanying a favorable packing in two-dimensional or three dimensional structuring by the two top-heavy type surfactants, and that the two or three dimensional structures are thermodynamically more stable due to higher FC6-HC4 content.
Detergency with new type automatic washing machines placed on the market in 2000 by five companies were evaluated with regard to removal of four soil types and several types of artificial test cloths and the factors involved in detergency evaluation are discussed. Detergency was found to differ considerably according to the machine, a finding not disclosed in test conducted in 1997. The particular washing mechanism of new models and less mechanical impact on clothing were considered the reason for this. These factors will remain appreciable and thus a detergency index should be specified for each machine for the consumer. This parameter is based on soil removal capacity according to soil type. An equation for detergency determination along with mechanical impact data are presented in this paper.
Cerebrosides, the representative sphingolipid in mushrooms, were isolated and purified from seven fruiting bodies of basidiomycetes, and their principal sphingoid base was confirmed to be 9-methyl-4-trans,8-trans-sphingadienine (9-methyl base). The 9-methyl base was also present in free ceramide, diglycosylceramide (diglucosyl type) and the acidic sphingolipid (phosphorylinositol-containing sphingolipid) fraction from the Maitake mushroom (Grifola frondosa), although usually in small amount. Examination was also made of the effects of fungal cerebroside on the fluidity of phospholipid liposomes by fluorescence depolarization of the hydrophobic fluorescence probe (1,6-diphenyl-1,3,5-hexatriene). The 9-methyl branched chain in fungal cerebroside molecules, as also with cis double bond in sphingoid base or fatty acid moieties, was found to effectively inhibit decrease in liposome fluidity as a result of cerebroside (30%) addition. The 9-methyl base in fungal cerebroside should thus have the same physiological functions as 8-cis unsaturated sphingoid bases in plants.