Mackerel, sardine and lamprey oils, which contain high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were deodorized for 1h with steam under comparable conditions of 280°C and 1mmHg pressure (H-Ma, H-Sa and H-La, respectively). Feeding of these oils at a level of 10% in the diet (CE-2) for one week produced the following effects in male ddY mice; 1) decrease of weight gain, 2) remarkable decrease in the serum triglyceride level, 3) increase of liver weight (about 2.0-fold in comparison with the control group), 4) increase in levels of serum GOT and GPT. It was suggested that the deodorized oils contained strongly biologically active compounds derived from the process of deodorization of long-chain polyunsaturated fatty acids (EPA and DHA) at 280°C. These active compounds may be geometrical isomers, the positional isomers and/or cyclic monomers of EPA and DHA.

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Experiments were conducted to determine the influence of gastrointestinal microflora on nitrogen metabolism in rats, by analyzing the nitrogen and amino acid content of urine from germfree (GF) and conventional (CV) rats fed an 18% casein diet and a protein-free diet. During the casein diet period, significantly greater amounts of nitrogen, urea-N, allantoin and 3-methylhistidine were excreted into the urine, and the ratio of urea-N to urinary nitrogen was greater in the CV group than in the GF group. Total urinary and free amino acid excretions showed significantly opposite trends. During the protein-free diet period, urinary ammonia-N, creatinine, allantoin and 3-methylhistidine were excreted in significantly greater amounts in the CV group than in the GF group. However, urinary nitrogen, urea-N and total amino acids were essentially the same in the two groups, although free amino acid excretion in the GF group far exceeded that in the CV group. Both groups showed essentially the same plasma amino acid concentration. These results suggest that gastrointestinal microflora may accelerate urea synthesis and body protein breakdown in the host.

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The effects of sorghum grain and that sun-dried in winter after being soaked in running cold water for about a month (kanzarashi treatment) on cholesterol metabolism and liver function in rats were examined. The cholesterol level in rats fed a diet containing 55% sorghum was increased significantly in comparison with that in control rats on a rice diet. An increase of serum transaminase activities was also observed in sorghum-fed animals. It was thus proved that “kanzarashi” treatment of sorghum grain prevented the sudden increase in both the serum cholesterol level and transaminase activities in serum. The water extract obtained from sorghum also increased cholesterol levels and transaminase activities.

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We studied the absorption and oxidation of enterally administered medium-chain triglyceride (MCT) and long-chain triglyceride (LCT) in peritonitic rats, and also the effects of carnitine supplementation on these parameters. Peritonitis was produced in rats by the cecum ligation and puncture method described by Wichterman. The necrotic cecum was removed from each rat 16h after the operation to allow recuperation. Peritonitis I or II was present in the rats at 24h and 48h, respectively, after cecum removal. The endotoxin reported by Wichterman was detected in the plasma of rats with either peritonitis I or II. Liver function in the model animals was shown to be deranged in comparison with sham-treated rats, and was more severe in peritonitis I than in peritonitis II. The absorption rate of [¹⁴C] MCT or [¹⁴C] LCT was measured by administering either to rats with peritonitis I and II, and keeping the rats in metabolic cages. The expired ¹⁴CO₂ was trapped continuously for 10h. In rats with peritonitis I, the cumulative ¹⁴CO₂ production from MCT was 66.3±9.2% of the administered dose, whereas that from LCT was only 16.5±3.2%; 87.7±5.1% of MCT and 70.0±12.5% of LCT were absorbed by rats with peritonitis I. In rats with peritonitis II, ¹⁴CO₂ production from MCT and LCT was 73.9±1.2% and 44.5±4.3%, respectively, while the absorption rates of MCT and LCT were 96.8±0.2% and 86.1±11.1%. These results indicate that MCT is more effective than LCT as an energy source under the experimental conditions used. Subcutaneous injection of carnitine into rats with peritonitis I neither increased nor decreased the absorption of LCT and MCT. However, cainitine stimulated ¹⁴CO₂ production from LCT from 16.5±3.2% to 22.6±3.9%, but suppressed that from MCT from 66.3±9.1% to 52.7±11.8%; carnitine stimulated the oxidation of absorbed LCT but suppressed that of MCT under these conditions.

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The hypocholesterolemic effects of cellulose, hemicellulose and lignin were examined in rats fed a 0.5% cholesterol-supplemented diet. 1) To compare these effects, diets each containing 3% added cellulose, hemicellulose or lignin in a cholesterol-supplemented basal diet were prepared, and also a 3% cellulose diet without cholesterol was prepared. These diets were given to male S.D. rats for 4 weeks and the latter diet was fed to a control rat group. Lignin showed a tendency to decrease the plasma and liver cholesterol levels. 2) Organo solve (OS-) lignin, obtained by 90% CH₃COOH treatment, and exploded (EX-) lignin were prepared, and cellulose, OS-lignin or EX-lignin was mixed at 3% with 0.5% cholesterol-supplemented basal diets. These diets were fed to male S.D. rats for 4 weeks. The EX-lignin preparation significantly prevented the elevation of plasma cholesterol. 3) To confirm the relationship between the molecular weight of lignin and its cholesterol-reducing effect, EX-lignin was separated in o three fractions according to molecular size, i. e., high-molecular-weight (HM-), middlemolecular-weight (MM-), and low-molecular-weight (LM-) lignin. Diets, each containing cellulose, hemicellulose, EX-lignin, HM-lignin, MM-lignin or LM-lignin (2% level) were fed for 3 weeks, and to one group, liriodendrin (syringaresinol-diglucoside), extracted from the tulip-tree, was added to the basal diet at 0.5%, as this compound is a derivative of lignin and its molecular weight was smaller than that of LM-lignin. Only LM-lignin showed depression of plasma and liver cholesterols, confirming that molecular size has some relationship to this effect.

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The effects af pH, heat and added salts on the physicochemical properties of pectin solution were investigated. Heating at 100°C for up to 120min decreased the viscosity of pectin at all pH values from 2 to 8. Its viscosity at pH values between 3 and 7 was higher than at other pH values, irrespective of heating. The molecular size distribution of the pectin heated at various pH values was measured using Sephadex G-200 column chromatography. The peak height of the pectin became lower with increased heating time within a pH range of 2-5, suggesting that heating induced acid-hydrolysis of the pectin in this pH range. Heating at a pH above 7 also decreased the molecular size of the pectin mainly due to transelimination. The decrease in the content of methoxyl groups was a slight on heating over an acidic pH range due to rapid saponification caused by the increased heating time. The viscosity of unheated pectin was highest upon addition of 0.5 M Na⁺ or K⁺. Addition of Ca²⁺ also increased the viscosity, whereas no effect of Mg²⁺ addition was observed.

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1-Methyl-1, 2, 3, 4 tetrahydro-β-carboline-3-carboxylic acid (MTCA) and 1-furyl-β-carboline (1-F-BC) in 25 brands of soy sauce were determined by high-performance liquid chromatography. The concentration of MTCA in Koikuchi Shoyu (regular fermented) and Koikuchi Shoyu (semi-fermented) was 486 (mean) and 252 (mean) μg/ml, respectively, and the concentration of 1-FC-BC was 0.159 (mean) and 0.072 (mean) μg/ml, respectively. Although the contents of MTCA were not changed by heating, those of 1-F-BC were increased. Soy sauce was mutagenic to S. typhimurium TA100 without S-9 mixture before and after nitrite treatment. The mutagenic activities of Koikuchi Shoyu (regular fermented) and Koikuchi Shoyu (semi-fermented) were 21, 000 (mean) and 13, 900 (mean) His⁺ revertants/ml, respectively. The mutagenic activities were increased by heating in both cases before and after nitrite treatment. The relationship between the contents of MTCA and 1-F-BC and mutagenicity is also discussed.

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