Effect of undernutrition on development of cadmium (Cd) poisoning was investigated in rats with a long experimental period ranging from 7 to 12 months. In a group, fed on low protein (10%), low Ca (0.04%), low P (0.06%) diet containig Cd 200 ppm, marked growth retardation was observed with the following patho-physiological characteristics :
1) Reduced feed-intakes (one-third of normal) and loss of hair on the skin were observed with a concomitant change of eating behavior.
2) Progressive increase of Cd output in the urine was observed during the whole experimental period (the maximum level of Cd was 2.6 μg per ml of the urine).
3) Tubular type of proteinuria due to Cd poisoning was ascertained both by immunological determination of retinol-binding protein (RBP) in the urine and by histological examinations of the kidney. Tissue level of Cd was found to be about 200 μg per g of the kidney.
4) The bone was found to be fragile and thin with marked atrophy of bone cortex by fluoroscopic examination. Significant decreases of plasma Ca, P and Ca X P with a concomitant increase of serum alkaline phosphatase activity were compatible with the changes in osteomalacia, although histological examination will be required, particularly focusing on changes of osteoid tissue. In contrast, no tubular proteinuria as well as bone atrophy were detected in rats fed on Cd containing normal balanced diet, regardless of the significant accumulations of Cd in the kiney and the bone.
These results clearly demonstrate that nutritional factors play an important role in early development of Cd poisoning in rats. These patho-physiological consequences due to Cd induced malnutrition were discussed, particularly focusing on a role of the intestine (Cd enteropathy).

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In order to investigate the differences of the nutritive value between bovine and human milk proteins, young male rats of Sprague-Dawley strain (body weight of 50-60 g) were fed for 14 days on the diets with the content of 8% proteins which were prepared from human normal milk, human colostrum and bovine milk, respectively. The PER (protein efficiency ratio) values of human normal milk, human colostrum and bovine milk were 4.08, 3.37 and 3.40, respectively.
The PER for human normal milk was the highest of all with significance (p<0.01).
The amino acid mixtures which were simulated to human normal milk or bovine milk protein gave quite the same results as these protein diets.
The concentration of urea in the blood plasma of the rats fed on human normal milk protein was lower than that of bovine milk protein.
From the results of the experiments on the supplement of various amino acids to skim milk, it was shown that the difference of the PER values between human and bovine milk proteins was not derived from the difference of the essential amino acid content but mainly from the difference of the cystine content of each milk.
_L-Cystine, when supplemented to bovine milk protein, increased PER and decreased the concentra tion of urea in the blood plasma of rats as compared with those for the milk protein.
The diets having the same content of total cystine as human milk, were prepared by mixing casein and milk serum protein at various ratios, with addition of _L-cystine if necessary. There were no significant differences in PER among these diets.
Amino acid composition of casein or milk serum protein were similar in both human and bovine milk.
Then it was concluded that the PER for bovine milk protein can be raised to the same value as human milk protein in the rat by adding cystine and/or bovine milk serum protein.

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For the purpose of obtaining the fundamental data of the appropriate cooking and processing of pectin, the effects of pH and salts on the texture of low-methoxyl pectin jelly were examined.
The standard mixture ratio of low-methoxyl pectin jelly is as follows : 1% of commercial low-methoxyl pectin, 20% of sucrose and calcium chloride equivalent to 25mg per one gram of pectin as calcium.
The characteristic value of the texture from the pH2 to 6.5 was measured. It has been said that the gel of low-methoxyl pectin jelly is formed by cross-linkage of polyvalent cations, however, it was not so sensitive to the pH in comparison with high methoxyl pectin jelly.
The texture and preference were examined by use of calcium chloride, calcium phosphate and milk as calcium salts, and magnesium chloride and magnesium sulfate as magnesium salts.
The jelly by use of calcium salts showed generally higher characteristic value of the texture than that by use of magnesium salts. The hardness of jelly increased in proportion to the increase of calcium concentration from 25mg to 50mg per one gram of pectin, and however, it significantly decreased in the higher concentration of calcium salts than the above.
In the case of using magnesium salts in the concentration of 150mg per one gram of pectin, the hardness curve shows peak.
It is estimated that the above result is caused by the existence of the most suitable amounts of polyvalent cations for the cross-linkage among pectin molecules and that the gel formation is inhibited by the existence of the more amounts of polyvalent cations.
The sensory evaluation by ranking test is conducted on the four kinds of low-methoxyl pectin jelly of different salts as coagulants.
As the result, the jelly by use of milk is significantly preferred.
The jelly by use of magnesium salts is not preferred. The sensory evaluation by seven point-test of both side scale showed the high correlation to the overall acceptable evaluation in order of taste, adhesiveness, cohesiveness, elasticity and softness in the preference parameters.

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The protein levels of casein diet (CA), soy protein diet (SP) and protein mixture diet (PM, mixture in equal portions of casein and soy protein as a protein source) were 10%, respectively.
1. Similar tendencies on feed intake, body weight gain, feed efficiency and N efficiency were obtained from the three groups.
2. The apparent N digestibility and ratio of N retention were CA>PM>SP. The differences of mean values between CA and SP on the apparent N digestibility and between CA and other two groups on the ratio of N retention were significant.
3. The apparent Ca digestibility, and the quantity and the ratio of Ca retention were SP>CA>PM. Significant differences of mean values were found between CA and PM on the apparent Ca digestibility and the ratio of Ca retention, and between SP and PM on the quantity of Ca retention.
4. The quantity of Mg retention was SP>PM>CA, and the difference of mean velues from SP to CA was significant.
5. The apparent P digestibility and the quantity of P retention were SP>CA>PM. Significant differences of mean values were found between SP and PM on the apparent P digestibility, and be tween PM and other two groups on the quantity of P retention. The ratio of P retention was CA>SP>PM, and the difference of mean values from CA to PM was significant.
6. In the femur and the tibia with fibula, the P content in the bones, and Ca and P % in the moisture and fat-free bones were SP>PM>CA. A significant difference was found between SP and CA.

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A lactase from Escherichia coli was immobilized to DEAE-Sephadex A-25 and to porous glass beads and each bound enzyme evaluated for its applicability to hydrolysis of lactose in milk and whey. By coupling 20-40 mg of lactase to 1 g of DEAE-Sephadex A-25 at pH 7.0, 18-24 mg of lactase were immobilized. When 1 g of porous glass beads was substituted with Sephadex, 3-6 mg of lactase were immobilized. The lactase from Escherichia coli showed a pH optimum of 7.0. Behavior was the same when the enzyme was immobilized by either DEAE-Sephadex or porous glass. Hydrolytic activity of immobilized lactase column was determined by running a 4% lactose solution (pH 7.0, 0.02 M phosphate buffer) through the column at 37°C for 30 days. These column still maintained about 50% of the initial activity. The rate of hydrolysis of lactose in skim milk and acid whey was about 50% of the rate with pure lactose for immobilized lactase. However, the DEAE-Sephadex-lactase column significantly released lactose into milk, rendering this process unsuitable. This study indicated that porous glass beads were better carriers for an immobilized enzyme such as lactase.

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The in vitro digestion of lysozyme and casein roasted at 180-250°C was investigated by use of pancreatin, trypsin, papain and pronase. Lysozyme roasted at 180°C for 20 min was digested completely by proteases within 24 hr. On roasting lysozyme over 210°C for 20 min, however, the residue became water-insoluble in a ratio over 70% and the digestibility extremely decreased. Similarly, on roasting casein over 210°C its digestibility decreased to almost the same degree as in the case of lysozyme. It is considered that such decreases in the digestibility are partially based on the decomposition and racemization of amino acid residues on lysozyme and casein.

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1) When B₂-butyrate was added to fish oil or linseed oil fatty acid methyl ester, maximum peroxide value was lower than when B₂-butyrate was not mixed.
2) When B₂-butyrate was added to autoxidized ester, peroxide value went lower in proportion to the amount of the addition.
3) It seems that active oxygen contained in autoxidized ester made B₂-butyrate decompose and at the same time, peroxide of autoxidized ester decomposed itself.

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It has so far been believed that firming (the process by which the tissues of vegetables become to be unable to be macerated by heating) is promoted by calcium and other metal ions. In the present study, however, the firming of Japanese radishes and beets was found to be retarded by calcium ion.
It is considered that firming prevents the excessive disintegration, together with the maceration, of vegetables.

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