In order to determine the relationship between color development and the nutritive value of food protein subjected to non-enzymatic browning, browned casein was examined biologically and biochemically. Development of the brown color (420nm) of a casein-glucose mixture (liquid state) during autoclaving (121°C, 10-60 min) increased as the ratio of glucose to casein increased to surpass that of a casein-glucose mixture (solid state) stored at 37°C (RH 58%, 1-4 week). Inversely, in vitro digestibility by trypsin and the growth of Tetrahymena pyriformis W were decreased to a greater extent in medium containing casein stored with glucose than in that containing casein autoclaved with glucose. These tendencies were also reflected by the changes in FDNB-reactive lysine content. Rat growth was completely suppressed by feediag a diet containing 10% casein stored with glucose. However, the diet containing 10% casein autoclaved with glucose suppressed rat growth only slightly. Supplementation of L-lysine (0.48%) to diets containing browned casein restored the growth of rats completely to normal. These findings suggest that the difference in protein quality between the two types of browned casein might be dependent on the content of available lysine, rather than that of the substance related to browning intensity.

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The preventive effects of a hemicellulose preparation isolated from corn bran (CBH) against lipid accumulation in the liver were examined in male rats (4-week-old) fed a diet cantaining 1% orotic acid. ln experiment I, the serum and liver lipid concentrations were determined in rats fed the orotate diet supplemented with 2% CBH or 4% cellulose (KC flock) for 1-3 weeks. In rats fed both the orotate diets, the concentration of serum lipids began to decrease during the first week and bottomed out in the second. Thereafter it increased rapidly and had almost recavered by the final week. Ligid aecumulatian in the liver was observed in the orotate diet-fed rats. However, the rats fed CBH showed a significantly lower elevation of liver lipid in the first week in comparison with rats fed cellulose. In experiment II, the concentration of serum and liver lipids and excretion of fecal orotic acid were determined in rats fed the orotate diet containing different types of cereal dietary fiber (DF) for 10 days. The following DF were used: 2% CBH or high-methoxylated pectin (HMP), and refined wheat bran (RWB) or refined corn bran (RCB) at 4% NDF. The orotate diet-fed rats developed obvious hepatomegaly, but the animals fed the CBH diet showed less accumulation of liver ligid and a decrease in the level of fecal orotic acid. From these results, we considered that the protective effect of CBH against lipid accumulation in the liver induced by dietary orotic acid is not due to its inhibitory action against the intestinal absorption of orotic acid.

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The immunopotentiating effects of Bifidobacterium longum SBT 2928 (BL2928) were studied in model animals with experimental tumors. BL2928 was selected by mitogenic assay as a potent immunomodulating strain from many food microorganisms including Lactobacillus and Bifidobacterium. When BL2928 was administered systemically, it exhibited marked anti-tumor activity in both allogeneic and syngeneic tumor models. In contrast, administration of carrageenan, an anti-macrophage agent, inhibited the anti-tumor activity of BL2928. Feeding of cultured milk fermented with BL 2928 slightly but significantly prolonged the life span of ICR mice that had been inoculated intraperitoneally with Sarcoma 180. haddition, intragastric incubation of heat-killed BL2928 significantly suppressed the growth of subcutaneously inoculated Sarcoma 180, and also enhanced the delayed-type hypersensitivity responses to sheep erythrocytes in CDF₁ mice. Although the degree of anti-tumor effect differed according to the route of administration, BL2928 modified the host immune responses in both the systemic and oral routes.

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Male weanling rats of the Fischer 344/DuCrj strain were fed for 8 weeks on feed supplemented with 20, 100, 500 or 1, 000mg of d-α-tocopherol (Toc) /kg diet, and female rats were fed similarly with 100 or 1, 000mg d-α-Toc/kg diet. α-Toc concentrations in plasma and RBC were the lowest among the tissues examined. In the control groups (100mg/kg diet), α-Toc concentration was highest (>300 μg/g) in the adrenals in both sexes, and in the ovaries of females. An approximately linear relationship between α-Toc concentration in the liver and the dietary d-α-Toc level was observed. α-Toc concentration in the lives of males gives the 1, 000mg Toc diet was the highest (861μg/g), whereas in females the level was lower (284μg/g). α-Toc distribution in subcellular fractions of the liver in male rats gives the 1, 000mg d-α-Toc/kg diet (D) was compared with that of the 100mg α-Toc group (B). α-Toc concentrations in the microsomal fractions of both groups were highest (B: 0.31, D: 1.74μg/mg protein). α-Toc concentrations in each subcellular fraction increased in the order of nucleus, cytosol, mitochondria and microsomes as a result of excess doses. Biochemical parameters of plasma in each group remained within the normal ranges. The level of plasma lipids thus showed a very close correlation with dietary d-α-Toc level.

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The major green tea polyphenolic component, (-) -epigallo catechin gallate (EGCg), has been shown to exhibit noticeable inhibition of angiotensin I-converting enzyme (ACE) activity. A study was conducted to determine whether this effect in vitro is reflected in the blood pressure of animals following oral feeding. Crude catechins (extracted from green tea and composed mainly of EGCg) were fed in the diet to spontaneously hypertensive rats (SHR) or stroke-prone SHR (SHRSP), and their blood pressure was measured by the tail cuff method. The mean systolic blood pressure of SHR fed a diet containing 0.5% crude catechins from the age of 5 weeks increased with time, but remained significantly lower than that in the control group (p<0.05). At the age of 16 weeks, the diets of the two groups were exchanged. As a result, the blood pressure curves of the two groups crossed in 2 weeks, and this situation persisted. In SHRSP given 1% saline as drinking water, addition of 0.5% crude catechins to the diet not only tended to suppress the blood pressure to a non-significant extent relative to the control group, but also clearly prolonged the survival period before death due to stroke.

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In. order to determine the influence of different sources of rat serum on the activities of heart and adipose tissue lipoprotein lipase (LPL), serum from hypothyroid, euthyroid and hyperthyroid rats fed either a high-carbohydrate or high-fat diet, and that from fed and fasted rats were used for assay of LPL activity. Heart LPL activity was increased in the presence of serum from high-fat-fed rats in the assay mixture compared with that assayed in the presence of serum from high-carbohydrate fed rats. Similarly, when serum from rats made hyperthyroid by intraperitoneal injection of L-thyroxine was used to activate the assay substrate, the activities of heart LPL from these animals or the enzyme obtained from hypothyroid animals were increased to levels exceeding those when normal rat serum was used to activate the substrate. In the case of adipose tissue LPL, serum from high-fat-fed or hyperthyroid rats did not stimulate the enzyme activity, although the enzyme activity of rats fed a high-carbohydrate diet was slightly increased in the presence of serum from fasted rats.

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Effects of several iron compounds on iron bioavailability were estimated. The compounds were ferrous sulfate, ferric orthophosphate and colloidal and powdered ferric pyrophosphates, supplied in experimental diets. Anemic rats were fed each diet for 2 weeks, and the hemoglobin value, hematocrit, serum iron concentration, liver and spleen iron concentrations, and total iron binding capacity were analyzed. The following results were obtained: 1) Bioavailability was highest for ferrous sulfate and ferric orthophosphate, followed by colloidal ferric pyrophosphate at a comparable level whereas powdered ferric pyrophosphate had the lowest value. 2) Lower bioavailability was observed for powdered ferric pyrophosphate showing 19.5% weight loss on ignition, than for that showing 21.4% or 22.9% weight loss. 3) The bioavailability of powdered ferric pyrophosphate was greatly improved when dextrin or dextrin with vitamin C was added to the salt solution before drying.

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Daily vitamin intake was estimated by a total diet (market basket) study using highperformance liquid chromatography. Food samples covering 181 items were categorized into 13 groups based on the statistical values presented in “The National Nutrition Survey”. Each group was analyzed with reference to 10 kinds of vitamin. Estimated daily intakes of vitamins were 2, 264 IU for retinol, 1.16mg for thiamin, 1.10mg for riboflavin, 4.8mg for niacin and 6.27mg for α-tocopherol equivalent. Compared with the daily intakes presented in “The National Nutrition Survey”, the daily intakes investigated in this experiment were low for thiamin and riboflavin.

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