Postmortem changes in the concentrations of amino acids, adenosine triphosphate-related compounds and other compounds in chicken breast muscle stored at 0 and 10°C were examined in relation to the taste intensity of chicken soup prepared from the stored muscle. The concentrations of most of the free and combined amino acids, ammonia, inosine and hypoxanthine increased, but that of inosine 5'-monophosphate (IMP) decreased during storage.
The concentrations of IMP and glutamic acid changed almost linearly during storage, so that the taste intensity value in Yamaguchi's equation (S. Yamaguchi : J. Food Sci., 32, 473 (1967)) could be written as a function of storage time. The equation shows that the taste intensity of chicken soup must reach a maximum value when the muscle has been stored for 7.86 days at 0°C. From a sensory evaluation using Scheffe's method, chicken soup prepared from the muscle stored for 7-8 days at 0°C confirmed this hypothesis by showing the highest taste intensity.

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The formation and possible derivation of volatile acids in the production of fish sauce were investigated. Low molecular weight volatile acids, C₂-C₆, were detected in the study. An addition of amino acids in different mixtures with varied concentrations to fish mixtures used for the production of fish sauce did not increase the concentrations of volatile acids. When fish left at room temperature for a number of days without any addition of salt was added to fresh fish containing specific mixtures of amino acids, incubation for a specified time caused the concentrations of all the volatile acids present to rise to a high level, this increase possibly having been due to microbial action. Furthermore, an increase in the concentrations of acetic, isobutyric and isovaleric acids in the long-chain fatty acid-added samples was observed. This phenomenon suggests that certain volatile acids detected in this study might have been produced from the lipid fraction, and particularly the breakdown of long-chain fatty acids. With 48 hr of incubation after amino acids had been added to fish mixtures, no increase in the concentration of volatile acids was detected. It appears that under the experimental conditions in this study, no positive information could be derived for the role of amino acids in the production of volatile acids.

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The effect of sheet dehydration on the color of veal, pork, beef and tuna muscle was studied. A positive linear relationship between the percentage of weight decrease and iron level was found in all the samples during dehydration, the iron content in all samples being concentrated as a result of the removal of water. There was a corresponding increase in the redness and iron content of the veal, pork and yellowfin tuna samples, in which the iron content was in the range of 0.93-1.09, 0.88-1.16 and 0.62-0.93 mg%, respectively. However, this phenomenon was not observed in the bigeye tuna samples, in which the iron content ranged from 0.50-0.78 mg%, nor those of bluefin tuna (1.29-1.62) and nor those of beef (1.82-2.51).
The color changes to veal and pork were perceptible when the iron content varied in the range of 0.9-1.2 mg%, while significant change in the color of yellowfin tuna muscle appeared in a lower range of iron level.

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Gel formation by polysaccharides was found by transmission electron microscopy to involve particularly strong molecular association. Gels of the Na-forms of κ-carrageenan, alginate, gellan gum and low-methoxyl pectin formed in the presence of a specific cation contained much wider or longer microfibrils than aqueous solutions or gels of the polymers in the absence of the cation. The gel formed by mixtures of two polysaccharides with similar backbones had certain forms depending on the association of the different molecules.

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Burdock roots were found to contain a comparatively large amount of pectic polysaccharides (about 993 mg of uronic acid/100 g of tissue). These pectic polysaccharides were fractionated with three reagents, a uronic acid composition of HCl-soluble pectin (pA), acetate buffer-soluble pectin (pB), and sodium hexametaphosphate-soluble pectin (pC), at 39.4%, 53.9% and 6.7%, respectively. The degree of esterification of pB was 38.3%, and with the addition of CaCl₂, pB formed precipitates. The DEAE-cellulose column chromatograms of pA, pB and pC were different. The main neutral sugar composition of the pectic polysaccharides was arabinose and galactose. After cooking for 1 hr, the percentage of pA in the cooked tissues increased, and that of pB and pC decreased; however, a large amount of the pectic polysaccharides remaining in the tissue were of high molecular weight. The burdock roots contained a large amount of pB (low methoxyl pectin) which was difficult to break down in a hot neutral solution by trans-elimination, and was consequently difficult to soften during cooking.

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Research on the dietary habits of those 85 and over living on some of the outlying islands of Okinawa was conducted, and it was found that certain seaweeds are frequently consumed. A second study was then performed to ascertain the influence of those frequently eaten Okinawan seaweeds on the lipid and sugar metabolism of hypercholesterolemic rats and diabetic rats. The energy and protein intakes of the aged were 82-87% of the required dietary allowance, but the intake rates of vitamins B₁ and C were higher. Salt intake was low for both men and women at 6 g and 5.8 g, respectively; the Na/K ratio was 1.8 for men and 2.3 for women. Their blood pressure, hemoglobin (Hb), total protein (T-Prot), total cholesterol (T-Chol), and HDL-Chol showed normal adult values. The addition of 5% freeze-dried and pulverized Okinawa-FutoMozuku (Mozuku) to the feed of hypercholesterolemic rats significantly raised the serum HDL-Chol, and lowered the concentrations of serum and liver cholesterol. It was noted that physical exercise by the diabetic rats improved the sugar metabolism and, with the addition of Aosa to the diet, there was a synergistic improvement. The oral glucose tolerance test (OGTT) showed that, for both the Control and Aosa diet groups, the physically active group had the most improvement, with the Aosa-exercise group having the lowest values. Concerning the serum lipid concentrations, Aosa and physical activity showed the most conspicuous effect on all types of Chol.

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Nylon 6 films with a molecular weight of 2.4 × 10⁴ were prepared by molding from the melted state. The resultant melt films were elongated under various conditions to study the drawing characteristics from morphological aspects. The storage modulus of the resultant film with a maximum drawing ratio of 4 times reached 5.2 GPa at 20°C when the specimens were elongated in a hot oven at 50°C and annealed at 180°C for 15 min. This was the highest value among the drawn specimens, although it is much lower than the crystal lattice modulus (183 GPa). The reason for the poor mechanical properties was investigated by using wide-angle X-ray diffraction, small-angle X-ray scattering, small-angle light scattering and birefringence. It transpired that there was a preferential orientation of the crystal axis with respect to the stretching direction, which lead to the rotation of crystallites and subsequent tautly tied molecules.

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[in Japanese]

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