A study was carried out to examine the effects of the levels of dietary protein and supplemented sulfur-containing amio acids, such as methionine, cystine, cysteine, homo-cystine, S-methyl-_L-cysteine, cysteic acid or taurine, on plasma cholesterol levels in growing rats fed a low-soy protein diet containing cholesterol. Hypercholesterolemia was produced by feeding rats a 8.1% soy protein isolate (SPI) diet containing 0.5% cholesterol and 0.25% sodium cholate. An increase in the level of dietary SPI resulted in decreased plasma and liver cholesterol levels and an increase in the level of plasma HDL-cholesterol. Supplementation of methionine, cystine, cysteine or homo-cystine had an effect of reducing body weight loss, and at the same time significantly decreasing the plasma cholesterol level. Supplementation of S-methyl-_L-cysteine, cysteic acid or taurine had little effect on either the plasma cholesterol level or body weight. Supplementation of methionine to the low-SPI diet had little effect on the level of plasma HDL-cholesterol. These results indicate that hypercholesterolemia caused by a low-SPI diet containing cholesterol may be due to a deficiency of dietary methionine.

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The effects of processing of oats (whole grains, cut type) and defatted oats with a twin-screw extruder were examined with regard to both compositional changes in the dietary fiber fraction and hypocholesterolemic activity in cholesterol-fed rats. The insoluble and soluble dietary fiber contents of raw materials and extruded products were separately measured using an enzymatic-gravimetric method. All of the extruded products contained more soluble fiber than the corresponding raw material, suggesting that some of the water-insoluble fibers were transformed to soluble ones during extrusion cooking. Male Sprague-Dawley rats, aged 5 weeks, were fed diets containing extruded or steamed oats respectively, at a 55% level for 9-11 days. The oats extruded at a maximum temperature of 177°C tended to reduce the serum cholesterol level in comparison with the steamed material, although there was no significant difference between defatted oats extruded at 139°C and the steamed material. Both extruded products, however, showed a tendency to decrease the apparent accumulation ratio of ingested cholesterol in the liver.

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Experiments were carried out to clarify the different effects of two types of soybean phospholipid, i. e., a phospholipid mixture (PLmix) and phosphatidylcholine (PC), on hematological parameters and concentrations of various lipids in serum of rats. These phospholipid concentrates had similar fatty acid patterns. Male Sprague-Dawley rats were separately fed a 20% casein diet containing 10% soybean oil as a control, 2.5% PLmix or PC+7.5% soybean oil, 5% PLmix or PC+5% soybean oil, and 9% PLmix or PC+1% soybean oil for 30 days. Weight gain and food intake were almost the same in all groups, except for a reduced weight gain in the 9% PLmix group relative to the control group. The erythrocyte and platelet counts tended to increase in both the PLmix and PC groups, and platelet aggregation tended to be elevated in the PC groups. However, there were no differences in hemoglobin concentration and hematocrit between any of the groups. Concentrations of serum total cholesterol and HDL-cholesterol in rats fed the PLmix diets but not the PC diets were markedly decreased relative to those of the control group. On the other hand, the concentration of serum triglyceride was significantly decreased in the PC groups, but only a slight reduction was observed in the PLmix groups. Hepatic p-450 was increased in both the PLmix and PC groups. These results suggested that the effects of phosphatidylcholine on various serum lipids were markedly different from the effects produced by the phospholipid mixture, although some of the effects of the two treatments were similar.

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The purpose of this study was to investigate the effects of three dietary fiber sources, cellulose, apple pulp and guar gum, on tocopherol and major lipids in plasma lipoprotein fracions in pregnant rats, and on fetal tocopherol. The pregnant rats were fed either an experimental diet containing 10%, dietary fiber, or a fiber-free diet (ad libitum-fed or pair-fed to the guar gum group) during the gestation period. The increment of lipids or α-tocopherol in plasma due to pregnancy was not suppressed by feeding with the above dietary fiber except for guar gum. In rats fed the guar gum diet, only fetal α-tocopherol was lower than in pair-fed rats, although plasma α-tocopherol levels were not different among the groups. As compared with the pair-fed rats or any other pregnant rats, the distribution of α-tocopherol in plasma lipoproteins in rats fed the guar gum diet was significantly lower in the low-density lipoprotein (LDL) fraction and significantly higher in the very-low-density lipoprotein (VLDL) fraction. Therefore, the present study demonstrated that the reduced fetal α-tocopherol content produced by feeding with guar gum may be related to the low level of LDL-α-tocopherol.

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Two water-soluble arabinogalactan proteins (A-I and A-II) were isolated from 13 different vegetables and their molecular weight distribution and chemical properties were comparatively investigated. The molecular weights of A-I and A-II were in the range of 20-60×10⁴ and 9-13×10⁴, respectively. The contents of carbohydrate and protein of A-I were in the range of 75-85% and 15-25%, respectively, and the carbohydrate contents of A-II were slightly higher than those of A-I. In both A-I and A-II, the galactose/arabinose ratio varied from 0.5 to 2.0 among the various vegetables tested. The amino acid compositions of A-I and A-II were characterized by appreciable amounts of hydroxyproline and serine, both peculiar to arabinogalactan proteins, and high proportions of glycine and alanine. However, their hydroxyproline contents differed widely among the tested vegetables. It was found that 13 vegetables examined could be classified into three types depending on the contents, ratios and molecular weight distributions of A-I and A-II: Type A (stalk, fruit and light-colored leafy vegetables, shells of beans, and root vegetables), Type B (seeds of beans and Japanese butterbur stalk), and Type C (green-colored leafy vegetables). Comparative examination of the three different types of vegetables suggested that the arabinogalactan protein profile was primarily determined by the degree of tissue hardening (fiberization) and greening, or by a combination of their effects.

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In order to clarify the foods that contain condensed phosphates (CP), a newly simplified analytical procedure was adopted. Orthophosphate (OP) and CP were extracted from each sample with ice-cold 10% trichloroacetic acid. Two columns of ion-exchange resin per sample were prepared. The extract was loaded on both columns and OP was eluted with 0.2 _M potassium chloride (KCl). OP in the eluate was extracted as a molybdenum complex and measured photometrically. From one column, CP were eluted with 20 ml of 2 _M KCI. Qualitative analysis of CP was carried out with this eluate. Whenever CP were detected, subsequent fractionation was carried out using the remaining column. Color development of CP in each fraction as molybdenum blue was done in order to estimate their contents photometrically. OP was detected in all samples analyzed, but CP were sometimes not present. CP were found in the following foods; mashed potato, soybean products, boiled vegetables, frozen shellfish, cuttlefish products, canned crab, dried fish, fish paste, ham, sausage and cheese. The types and contents of CP varied from one food to another. It is suggested from these findings that intake of CP would result from consumption of these foods.

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The effect of prolonged vinegar feeding on postprandial blood glucose response was examined in totally gastrectomized and untreated rats. A basal diet and a vinegar diet were used for this experiment. The vinegar diet was prepared by the addition of powdered vinegar to the basal diet at a level of 7% (about 1% as acetic acid). The animals were fed with the basal or the vinegar diet for 10 weeks, and then orally administered 250mg of glucose per 100 g body weight as 20% glucose solution. Among untreated rats, the postprandial blood glucose level was significantly lower in rats fed the vinegar diet than in those fed the basal diet. On the other hand, prolonged feeding with the vinegar diet produced no effects in the totally gastrectomized rats. These results suggest that prolonged feeding with vinegar changes the postprandial blood glucose response by delaying the gastric emptying rate.

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We developed a simplified everted gut assay for iron absorption, involving preincubation of pancreatin and bile. This method is convenient and effective, especially when radioactive authentic materials are difficult to obtain. We applied this method to the measurement of iron absorption of hemoglobin and heme iron compound (HIP). HIP is an iron-rich compound derived from hemoglobin by utilizing endo-proteinase and an ultrafiltration membrane. It was found that the iron absorption of HIP was almost the same as that of hemoglobin, although the HIP was 4-5 times richer in iron than hemoglobin. Despite the presence of phytin (iron/phytin=1/3 as mol), the iron absorption of HIP did not decrease. It was suggested that the iron of HIP was not inhibited by other food components.

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To determine whether Euglena gracilis z can accumulate vitamins, it was grown for 6 days at 27°C under light illumination in Koren-Hutner medium supplemented with an excess of each of the following water-soluble vitamins: B₁, B₂, B₆, B₁₂, C, biotin, folic acid, pantothenic acid, nicotinic acid, p-aminobenzoic acid. None of the added vitamins affected the growth of E. gracilis z; the cell number reached a maximum (20-23×10⁶ cells/ml) after 5 days in each case, as in the control cells without vitamin supplementation. E. gracilis z took up and accumulated vitamins B₁ and B₁₂, and nicotinic acid, but did not accumulate other vitamins. The maximum intracellular contents of the vitamins under the present experimental conditions were: vitamin B₁, 7.9±0.3 (mg%; dry basis); vitamin B₂, 3.5±0.2; vitamin B₆, 7.5±0.6; vitamin B₁₂, 1.4±0.1; vitamin C, 27.2±0.4; folic acid, 1.7+0.5; pantothenic acid, 12.9±0.1, nicotinic acid, 41.0±0.2; biotin, 4.6±0.3.

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Japanese and Korean food composition tables were compared for 51 food items, and 13 of the 51 items were purchased in Korea and brought to Japan for mineral (Ca, Mg, P, Fe, Na, K, Zn, Mn and Cu) analysis by inductively coupled plasma atomic emission spectrometry and fluorometry (for Se only) after ashing with concentrated HNO₃ in high-pressure Teflon vessels. Energy content, protein, lipid and carbohydrate in both food composition tables were not significantly different from each other. The extents of discrepancy between the two tables were rather large with regard to minerals; Fe showed an especially large discrepancy. Upon comparison of measurements with food composition table values, Fe was also unique, i. e., many of the measured values were smaller than the Korean table values, while some of them were higher than the Japanese table values. These results suggest that 1) some Korean foods actually have a high Fe content and/or 2) Korean table values may overestimate the Fe contents of foods.

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A study was performed to investigate the lipid characteristics of commercially available meat products (loin rolled ham, LRH; bacon, BCN; pressed ham, PRH; chopped ham, CPH; frankfurter sausage, FFS; chilled hamburg steak, CHS). The lipid levels in these foods were found to be reduced year by year, especially in the case of LRH, BCN and PRH. In each of the meat products, the lipid content was significantly correlated with the amount of saturated and monounsaturated fatty acids, but not with the amount of cholesterol. However, the cholesterol content was found to be higher in BCN, FFS and CHS which contain more lipids than in LRH, PRH and CPH which contain less lipids. The polyunsaturated fatty acid (PUFA) levels were markedly dependent upon the meat materials examined, with PRH, CHS, CPH and FFS containing higher percentages of PUFA. The 2-thiobarbituric acid (TBA) values suggested that CHS and FFS were more susceptible to lipid peroxidation than CPH and PRH, which in turn were more susceptible than LRH and BCN. No significant relationship was found between the α-tocopherol content and the TBA value in any of the meat products, whereas the TBA value for CHS was negatively correlated with the amount of α-tocopherol per gram of PUFA.

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