It is well known that growth retardation of young rats fed a low casein diet is induced when added an essential amino acid mixture lacking histidine (histidine imbalance). Omission of an amino acid (or acids) from the imbalancing amino acid mixture lessened the imbalance phenomenon, especially in the case of lysine.
The lysine omission (-Lys) caused a little increase in free histidine concentration of blood samples from portal vein and heart, which was lowered by the histidine imbalanced diet. Activities of digestive enzymes of the -Lys group were elevated compared with those of the imbalanced group. Though the rate of histidine transport in small intestines was almost the same among the three tested groups, the coexistence of an imbalancing amino acid mixture with histidine in an infused to small intestines tended to reduce the rate of histidine transport, and the lysine omission from the mixture tended to restore it.
Possible contributions of digestive enzymes and intestinal transport of the first limiting amino acid to the amino acid imbalance were discussed.

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This study was undertaken to clarify the reason why the digestibility of Chlorella protein is so very low as already reported.
At first, four kinds of protein samples; soluble protein (SP) and chloroplast (CP) of Chlorella obtained by fractionation, freeze-dried Chlorella (FC), and Chlorella with cells broken by a French Press (BC) were prepared.
The coefficient of in vitro digestibility was determined by the method of trypsin digestion. The values obtained were as follows : FC 70%, BC 75%, SP 86%, and CP 66%. The coefficient of in vivo true digestibility and biological values of the protein samples were determined by the modified Mitchell's method with growing rats fed a 10% level of protein diets for 8 days. The former were obtained as follows : FC 75%, BC 79%, SP 89%, and CP 77%, and the latter as follows : FC 80, BC 80, SP 81, and CP 79. These results suggest that cell walls may influence the action of digestive enzymes, and show that the nutritive value of the chloroplast protein is lower than that of the soluble protein.
Secondly, the chloroplast fraction was further fractionated to obtain chloroplast-soluble protein (CSP), chlorophyll-lipoprotein (CLP), and structural protein (STP).
The coefficients of in vitro digestibility of each fraction were as follows : CSP 87%, CLP 51%, and STP 73%. These data demonstrated that the coefficient of digestibility was raised by removing lipids and pigments such as chlorophyll and carotene. This fact implies the possibility that the action of digestive enzymes is reduced by the existence of lipids and pigments in Chlorella.

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It is feared that Hg should be transfered into sucklings from milk, if their dams take the foods contaminated with PMA. To make clear this point, Hg-203 labelled PMA was administered orally to six lactating guinea pigs for single dose experiment, and to five lactating guinea pigs for repeated dose (five times) experiment. The excretion of Hg into feces and urine, the transfer of Hg into milk and the residue of Hg in some organs and blood, and the transfer into sucklings from dam's milk were studied.
Most of Hg in PMA administered orally was excreted into feces (59.7±2.8% of dose-single dose, 61.7±4.3%-repeated total dose), and urine (13.2±1.7%-single dose, 16.4±3.4%-repeated total dose). On the contrary, the transfer of Hg into milk was small in amount (0.40±0.09%-single dose, 0.40±0.27%-repeated total dose), but continued for experimental term.
The residue of Hg in kidney was larger in amount and higher in concentration than in liver and other organs (kidney-8.5-14.8%, 9.4-28.1 ppm, liver-2.4-2.8%, 0.24-1.5 ppm). However, the small amount of Hg was detected in brain.
The transfer of Hg into the sucklings from milk was 4.85±1.96%-single dose experiment, 5.07±2.78%-repeated dose experiment (100% means the whole amount of Hg in milk sucked by each suckling).
The period in which half amount of orally administered Hg was excreted, was about 2-3 days.

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Blood plasma and tissue free amino acid levels were measured at intervals in rats fasted after they had been fed a 18% casein diet for a week. Most of the plasma free amino acid levels increased remarkably at 4 hours after feeding. Plasma levels of dietary amino acids during the absorptive period were 2 to 6 times as high as those during the postabsorptive period, and the pattern of changes in those appeared to result from a reflection of amino acid composition of dietary protein. Muscle free amino acid levels also increased during the absorptive period. In contrast with these changes, the levels of the branched chain- and aromatic amino acids and also arginine in liver scarcely increased during the absorptive period, although the levels of nonessential amino acids, lysine, histidine and threonine increased. It is considered that the synthesis and degradation of tissue protein and amino acids has a more influence on the free amino acid levels in liver than in blood plasma or in muscle.

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Effective conditions were investigated to remove residual cadmium from rice by treatment with surfactants. Neither fat fraction nor carbohydrate fraction of polished rice contained any significant amount of cadmium. It was found that cadmium occurred mostly in the protein fraction in a chelating state. Both cadmium and protein were efficiently removed from the polished rice when this was treated with each of sodium alkylbenzenesulfonate and sodium alkenylsulfonate. In each case there was a correlation between cadmium and protein in regard to the efficiency of removal. The difference in the alkyl group of the surfactant did not affect the efficiency for removing cadmium and protein. It was considered that each sulfonate-type surfactant had an interaction with the rice protein during washing to form a protein-surfactant complex containing cadmium and, as a result, cadmium was removed along with such a complex. This cadmium-containing complex was found to be formed most favorablly in the pH range of 7-9.

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Soybeans were germinated in dark room at 25°C and the weights of the 3 parts (hull, cotyledon and hypocotyl) in germinated beans and the lipid components of them were determined at various periods up to 7 days. The fatty acids composition of total lipids in each part, triglycerides and polar lipid contents of cotyledon were determined.
The results obtained were as follows :
(1) The lipids content in hull and cotyledon decreased slightly during germination of soybean and gradually increased in hypocotyl, whereas the tocopherol content in cotyledon and hypocotyl was decreased continuously and increased in hull.
(2) Triglycerides of cotyledon lipids decreased markedly during germination of soybeans and free fatty acids and polar lipids of this part were increased. More reduction of unsaturated fatty acids was observed in polar lipids than in triglycerides.
(3) Unsaturated fatty acids of phosphatidyl ethanolamine, phosphatidyl choline and phosphatidyl inositol of cotyledon decreased irregularly during germination of soybeans.

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The quantitative changes of vitamin C, acids and reducing sugars in juices of citrus Unshyu, lemon, grape-fruits, summer orange, strawberry, loquat, peach, grape, prince melon, pineapple, apple and plum during storage at 5°C for 3 weeks were investigated.
More than 40% of vitamin C in fresh juices were still remained in juices of citrus and prince melon after 3 week-storage, but in juices of peach, grape, pineapple and plum, vitamin C decreased to 1020% of original contents.
The contents of reducing sugars in juices of loquat and apple did not change during 3 weekstorage. Those of prince melon and peach increased and those of other fruits showed tendency to decrease.
The contents of acids increased during 3 weekstorage in juices of citrus Unshyu, loquat, peach and prince melon. In other juices no significant changes in acids contents were found.
The increase of amino nitrogen in several kinds of juices in which soluble nitrogen decreased may suggest the production of free amino acids or peptides from protein.

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