The effect of some nutrients and foods such as dextrin, corn oil, sodium chloride, lemon juice, green tea or Sake on protein digestion in vivo were studied. By use of a stomach tube rats were given egg albumin supplemented with each of the nutrients or foods, and killed after 1 hour. Then the nitrogen contents in the stomachs and small intestines of the rats were measured.
Dextrin, lemon juice and Sake had an effect of increasing the residual nitrogen contents in the stomach and of decreasing those in the small intestine, although the total residual nitrogen contents of the two tracts were similar. Corn oil, sodium chloride and green tea increased the residual nitrogen contents in the stomach only and, therefore, increased the total residual nitrogen contents in the two tracts.
These results seem to show that all the nutrients and foods examined may inhibit the rate of digestion of proteins in the stomach or the rate of passage of protein digests from the stomach to the small intestine.

View full abstract

The inactivation of pepsin by ascorbic acid or ascorbic acid-hydrogen peroxide system was studied with reference to the decomposition of pepsin structure. The following results were obtained.
1. Ascorbic acid or ascorbic acid-hydrogen peroxide system caused the oxidative decomposition of pepsin, which was observed as a slightly lowered viscosity of pepsin solution.
2. From the gel filtration pattern on Sephadex G-25 and G-100, it may be considered that pepsin was decomposed by ascorbic acid or ascorbic acid-hydrogen peroxide system into molecular fragments consisting of trichloroacetic acid-soluble peptides and amino acids.

View full abstract

Three weeks balance studies were carried out in young and adult rats to investigate the effect of three calcium salts (Ca-carbonate, Ca-lactate and Ca-gluconate) on balance of calcium and phosphorus.
All rats received the same levels diet of calcium and phosphorus which contained the 0.49g calcium and 0.33g phosphorus/100g diet.
Calcium absorption was not affected by different calcium source in young stage. But in the case of adult rat, calcium carbonate fed group exhibited higher absorption and retention than the other groups.
In respect to phosphorus metabolism, calcium gluconate fed group exhibited higher absorption and retention in young rat and in adult rat, calcium gluconate and calcium carbonate diet indicated higher absorption and retention than the other groups.
The intestinal uptake and retention of calcium decreased with age and the figures of phosphorus indicate the same results. Moreover, urinary excretion of phosphorus increases with age.

View full abstract

It was suggested that the liquid culture of Saccharomyces cerevisiae had the serum cholesterol-lowering effect. In order to confirm this result, the serum cholesterol level was measured by Sperry-Webb's method on mouse fed the control and experimental diets. The total serum cholesterol level in mouse fed the experimental diet was, on the average, 30% lower than the level in mouse maintained with the control diet. The change of total cholesterol was caused by the change the cholesterol ester. The change on serum cholesterol level by the exchange of the control and the experimental diets was discussed. Upon changing from the control diet to the experimental diet, serum cholesterol level decreased by approximately the same amount of starting. These changes were completely reversible.
Simultaneously, they were discussed the changes on serum protein, lipoprotein, GOT and GPT activities. The serum of mouse fed the experimental diet contained more total protein and less lipoprotein than the control. There were not very much changes on GOT and GPT activities between the control and the experiment.

View full abstract

The rhyzome of ginger (Zingiber officinale) has a high proteolytic activity. The ginger protease was separated by chromatography on DEAE-cellulose into two fractions, GP I and GP II, but they were not distinguishable from each other on sephadex gel-filtration. GP I and GP II were purified to 10- and 13-folds, respectively, by the ammonium sulfate fractionation and the subsequent column chromatography using DEAE-cellulose and hydroxyapatite. The electrophoretic mobilities of the two proteases were different from each other. Their crystal forms were found to be hexagonal plates.
The gel-filtration and electrophoretic analyses indicated the uniformity of the two proteases. Their molecular weights were estimated to be about 22, 500 each, according to the Sephadex G-100 gelfiltration. The general properties of both enzymes were shown to be almost identical with regard to the pH optimum (6.5 to 7.0), the activation by sulfhydryl compounds, the inhibition by heavy metal ions and sulfhydryl reagents such as iodoacetate and iodoacetoamide, and the non-inhibition by dithionitrobenzonate and p-chloromercuribenzonate. The enzymes were not active in the absence of sulfhydryl compounds, but their activities were fully restored by addition of cysteine, β-mercaptoethanol or reduced glutathione. It is noted that the inhibition by heavy metal ions such as Ag⁺ and Ni⁺⁺, and the activation by sulfhydryl compounds were observed more clearly for GP I than for GP II.

View full abstract

Measurement of body fat contents is essential for a judgement of obesity, which is defined as an abnormal increase of the fat content in the body. The fat content estimated from skinfold thickness was compared with the value calculated from the whole body potassium content which was obtained by the counting of whole-body radioactivity. The obese and non-obese women were chosen as subjects for this study. It became clear that the fat value estimated from the potassium content is higher than from the skinfold thickness. The relation between two calculated values were investigated by regression lines. It was obvious that the regression line of obese woman group vary with age, but not of nonobese group.

View full abstract

The ADSA (the American Dairy Science Association) method has been widely adopted for the estimation of the curd tension of milk and milk products. On the other hand, the modified ADSA method has been developed obtaining the accurate findings for the curd tension of soft curd milk.
In the present report, a comparative study between the ADSA method and its modified method were undertaken to estimate the curd tension of medium curd milk. In some cases the values of curd tension estimated by the ADSA method were higher than those estimated by its modified one, whereas reverse results were obtained in other cases. On the estimation of the curd tension of medium curd milk, the modified method was statistically better than the ADSA one; a similar tendency has been observed in soft curd milk.

View full abstract

[in Japanese]

View full abstract