The amount of pentane in the breath of rats in a vitamin E (VE) -deficient group was found to be significantly higher than that in a VE-supplemented group. The activities of antioxidative protective enzymes from the lungs of VE-deficient animals were found to be lower than those of VE-supplemented animals. By addition of selenium to the diet, the amount of pentane in the breath showed a decreased tendency, as compared with that in selenium-unsupplemented groups. From the results of these experiments, the amount of pentane exhalation, TBA value and the amount of VE in tissues or blood plasma were found to be significantly related to each other. In humans, a significant relationship between plasma VE value and pentane exhalation in breath was confirmed. Since administration of antibiotics to rats did not affect the amount of pentane in the breath, it is assumed that this exhaled pentane is not produced by the action of enterobacteria.

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The mean dietary zinc intake of 25 young adult women was calculated to be 6.5+1.4mg/day (0.125±0.030mg/day/kg body weight) from the results of a 7-day food consumption survey and our own data-base on the zinc contents of food. Zinc intake showed high positive correlations with intake of protein (γ=0.800), phosphorus (γ=0.799) and iron (γ=0.736). The low zinc intake in these subjects was attributable to their low level of food consumption (mean daily energy intake, 1, 648±281kcal) and their preferred consumption of low-zinc foods such as beverages, vegetables, milk and fruit. The mean plasma zinc concentration was 749±94pg/l, and mean daily urinary excretion of zinc was 366±107μg. There were no significant correlations between zinc intake (per kg body weight) and plasma zinc level, or between zinc intake and urinary zinc level.

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The effects of a urea supplement to a low-protein diet on growth rate, nitrogen balance, and plasma free amino acid concentration were investigated in growing rats. Rats fed 20% casein, 5% casein, or 5% casein supplemented with urea for about 5 weeks were compared. In rats fed the 5% casein diet supplemented with urea, the growth rate was higher, the nitrogen balance was more positive, and the retention of nitrogen was greater than in rats fed the 5% casein diet without the supplement. Of the plasma free amino acids, essential amino acids were increased by the supplement, and the essential/non-essential amino acid ratio was higher. The supplementation of a low-protein diet with urea thus caused a favorable change in the pattern of amino acid metabolism to one of synthesis of body protein.

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Some analytical conditions were investigated in order to develop a more appropriate analytical method for the fractionation and determination of carnitines in milk and milk products. On fractionation into acid-soluble and acid-insoluble carnitines, a 6% concentration of perchloric acid was selected to obtain a clear milk supernatant, since concentrations of 2-6% perchloric acid made no significant difference to the recovery of acid-soluble and acid-insoluble carnitines. The acid-soluble fraction yielded, most of the octanoyl-, about half of the decanoyl-, a small part of the lauroyl- and none of the myristoyl carnitine. The effect of potassium hydroxide concentration on the hydrolysis of carnitine in milk was investigated, and 2.3N potassium hydroxide was found to be most suitable for the acid-soluble fraction of milk, while 3.5N was the most suitable concentration for insoluble milk fractions. Acetyl CoA with a high specific radioactivity of at least 0.05 pCi/5 nmol in the reaction mixture was required for determination of small amounts of carnitine in milk. It was found that phosphate buffer was superior to Tris buffer, since the radioactive noise resulting from the use of Tris in the reaction mixture caused a higher blank value. In this analytical method, thelower detection limit of carnitine in milk was 0.05 nmol, and the coefficients of variation were estimated to be 1.0% for total carnitine, 1.6% for free carnitine, 1.0% for acid-soluble carnitine and 6.2% for acid-insoluble carnitine.

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Carnitines in milk and milk products were analyzed and the changes in their distribution during the manufacturing process were investigated. Raw milk contained 166nmol/g total carnitine, pasteurized milk contained 164nmol/g, and UHT sterilized milk contained 159nmol/g. The carnitine contents of yoghurt and cream were almost the same as in milk, twice as high in evaporated milk, about ten times higher in powdered milk, and markedly lower in butter or cheese. Carnitine contents of five commercially available infant formulas varied from 590 to 1, 300nmol/g. The major proportion of carnitine in milk and milk products, except for butter and cheese, consisted of free- and short-chain acyl carnitines, while butter and cheese contained appreciable amounts of long-chain acyl carnitine. With regard to the heat treatment of milk or cream, a marked increase of free carnitine and a decrease of acyl carnitine were observed after holding for 15 min at 115°C, while no change was observed after heating for 2s at 120°C. A small increase of free carnitine was observed by heating for 2 s at 140 or 150°C. Short-chain acyl carnitine was hydrolyzed by heating more easily than long-chain acyl carnitine. In the process of cream separation, a significant decrease in the contents of free- and short-chain acyl carnitines was observed in cream, while no significant change was observed in skim milk. The low carnitine content of butter was due to the low content of carnitine in butter oil, although butter serum contained almost the same amount of carnitine as milk. No visible change was observed in the distribution of carnitine during the manufacture of whole milk powder or lactic fermentation of yoghurt.

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The effects of oxidized products (OP) and gallic acid (GA) on the decomposition of tocopherol (Toc) in soybean and hardened rapeseed oils during autoxidation at 60°C were investigated. OP are fatty substances insoluble in petroleum ether, that are separated from fatty acids after saponification of heated oils. Oils (10g) with or without OP. GA and a mixture of these substances were placed in glass beakers and allowed to oxidize in an incubator at 60°C. Then, the Toc and peroxide values of the oils were determined by both HPLC and the JOCS official method 2. 4. 12-71, respectively. Increases in peroxide values and decomposition of Toc in oils were apparently promoted by the added OP, and decomposition of Toc increased with the increased concentration of OP. Also, decomposition of ethanolic Toc by added OP was observed during storage at 60°C. Therefore, decomposition of Toc by OP may be attributable to the oxidative reaction of OP. On the other hand, GA showed remarkable suppression of Toc decomposition by OP.

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Hitoegusa (Monostroma latissimum WITTROCK), a kind of greenish seaweed, is widely used as a food, “Nori no tsukuda-ni, ” in Japan. The aim of this study was to examine its antioxidative activity and antitumor effect. Hitoegusa was collected at different stages in its life cycle. Strong antioxidative activities were observed in both dichloromethane and methanol extracts of Hitoegusa at several growth stages. Both types of extract obtained from seaweed in January demonstrated especially strong activities. A homogenized suspension of Hitoegusa was intraperitoneally injected into mice implanted with Sarcoma 180. Seaweed collected in March and May seemed to be therapeutically effective against Sarcoma 180, while January weed had no effect.

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