Properties of iron-saturated and iron-free lactoferrins from bovine and human milk were compared after digestion in vitro with pepsin at pH 4.5 for 2h followed by trypsin at pH 7.5 for 3h. After digestion, the percentage of 6% TCA-soluble nitrogen, the residual iron-binding capacity, and immunological reactivity were, respectively, 6.0%, 85.0%, and 100% for iron-saturated human lactoferrin, 32.0%, 44.4% and 62.9% for iron-free human lactoferrin, 5.2%, 82.8% and 89.5% for iron-saturated bovine lactoferrin and 35.0%, 39.5% and 34.7% for iron-free bovine lactoferrin. Disc gel electrophoretic and immunoelectrophoretic patterns differed between iron-free lactoferrins from human and bovine milk after the digestion. Bacteriostatic activity against E. coli 0111 was not observed in ironsaturated lactoferrins from human or bovine milk. Iron-free lactoferrins from human or bovine milk retained bacteriostatic activity after digestion with pepsin and trypsin, but this activity decreased with prolonged digestion.

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Fetal death in the last few days of pregnancy or neonatal death were observed in rats fed a 10% soy protein isolate (SPI) diet throughout pregnancy. Among pregnant rats fed a 10% SPI diet supplemented with 0.3% L-methionine or 0.15% L-threonine, 0.2% L-valine and 0.3% L-methionine or fed a SPI diet at a level of 20%, 25%, 35% and 50%, only the 50% SPI diet group showed improved pregnancy and delivery. In the last two or three days of pregnancy, the food intake of the 10% SPI diet group was very small and the biological value was significantly lower after day 15-16 of pregnancy than that in the 10% whole egg protein (WEP) diet group. The free amino acid concentrations in plasma of the 10% WEP and 50% SPI diet groups at day 21 of pregnancy were lower than those at day 7 or 14, while that of the 10% SPI diet group was higher at day 21 than that at day 7 or 14. Pregnant rats fed the 10% SPI diet seemed to have difficulty in utilizing free amino acids in the last one week of pregnancy. It was considered that in the last week of pregnancy, the amino acid composition of the 10% SPI diet was not sufficient for improvement of maternal metabolism and fetal growth, whereas sufficient improvement was observed with the 50% SPI diet.

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Young male rats were fed a low-protein diet (3% casein) for ten days and then their nuclear proteins were compared with those of rats given a control diet (25% casein). The results showed that the total nuclear protein content of the liver was increased 1.4-fold by the low-protein diet. Chromatin was prepared from isolated nuclei and chromosomal proteins were fractionated into histone proteins and non-histone proteins, the latter being further fractionated into urea-soluble non-histone proteins and DNA-binding non-histone proteins. Measurement of the protein content of each fraction showed that the increase of total nuclear protein induced by the low-protein diet was due to an increase of urea-soluble non-histone proteins, without any change in the content of DNA-binding non-histone proteins. On two-dimensional gel electrophoresis, the patterns of urea-soluble non-histone proteins in the two groups were similar, but the amounts of some proteins with moleculars weights of approximately 30, 000 and isoelectric points of around 7, were decreased in rats given the low-protein diet. No specific increase in the amount of any particular urea-soluble non-histone protein was detected in these rats. The two-dimensional gel electrophoretic pattern of DNA-binding non-histone proteins was not affected by the low-protein diet. As many reports have suggested the importance of non-histone proteins in gene regulation, the change of non-histone proteins observed in this study suggests that a low-protein diet might affect gene regulation. Identification of these non-histone proteins will contribute to our understanding of nutrition at the molecular level.

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The major component of green tea tannin, (-) -epigallocatechin gallate (EGCg), has been found to exhibit bio-antimutagenicity in certain bacterial strains or anti-tumor-promoting activity in certain cultured cells. Based on these findings, EGCg and crude catechins (those extracted from green tea and composed mainly of EGCg) were given to animals to see if these test compounds could prevent the growth of inoculated tumors. Tumor cells were inoculated into mice or rats either intraperitoneally (i. p.) to grow ascites tumors or subcutaneously (s. c.) to grow solid tumors. The results showed that both EGCg and crude catechins exhibited appreciable effects when administered (i. p. or s. c.) to the animals after s. c. inoculation of the tumors. No life-prolongation effect was observed among the animals with ascites tumors. Oral administration of crude catechins before tumor inoculation appeared to strengthen the effect of i. p. administration after the inoculation. Furthermore, long-term feeding of crude catechins to mice suppressed the growth of inoculated tumor cells. Moreover, the effect of s. c. administration of crude catechins was clearly enhanced by i. p. injection of lipopolysaccharide (LPS) afterwards, suggesting the induction of a TNF-like substance. From the results of the above experiments, it was assumed that EGCg and crude catechins might suppress the growth of inoculated tumor cells in animals through potentiation of immunological mechanisms rather than working directly on proliferating tumor cells.

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The renin-angiotensin (RA) system is considered to be one of the important factors involved in essential hypertension. Peptides with a molecular weight of 1, 000-2, 000, previously obtained by enzymatic hydrolysis of sardine muscle, have been shown to have in vitro angiotensin I-converting enzyme (ACE) -inhibitory activity. In the present experiment, the blood pressure-reduction and vasodilatory effects of these peptides in vivo were examined. A blood pressure reduction test using SHR rats showed a cleady recognizable effect as a result of intravenous administration. Furthermore, when the peptides (dosages: 0.5, 1.0, 2.0 and 4.0g/kg) were orally administered in 30% vitellinic solution, the blood pressure reduction showed a dose-dependent increase. The rate of reduction increased for about 3h and this effect still continued even beyond 6h after administration. When peptide samples (dosages: 2, 4, 8 and 16g/animal) were orally administered to rabbits, dilation of the aural blood vessels was observed 20min after administration. Even at 120min after peptide administration, persistent vasodilation was observed.

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The hypochalesterolemic effect of a hemicellulose preparation isolated from defatted rice bran (RBH) was compared with that of high-methoxylated pectin (HMP). The serum cholesterol concen tration, cholesterol absorption from the small intestine, liver cholesterol accumulation, and excretion of fecal steroids were determined in rats fed a hypercholesterolemic diet containing either RBH or HMP at the 2% level for 9 days. Both RBH and HMP suppressed the elevation of serum cholesterol levels. The present results indicated that the hypocholesterolemic mechanism of RBH was different from that of HMP, since : 1) RBH did not suppress dietary cholesterol absorption and liver cholesterol accumulation, but facilitated the excretion of acidic steraid rather than neutral steroid. 2) HMP depressed dietary cholesterol absorption and liver cholesterol accumulation, but did not facilitate the excretion of acidic steroid. These results indicate that the mechanism of the hypocholesterolemic effect of RBH involves on increase in excretion of total bile acids, whereas that of HMP is due to the prevention of dietary cholesterol absorption from the small intestine.

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In order to promote the practical utilization of gluten meal, which is a by-product of corn processing for food materials, the optimal conditions for preparation of zein from gluten meal were determined. The most effective extraction of zein from gluten meal was obtained by twice-repeated extraction of the 3% NaCl-extracted residue of the meal with 10 volumes of 60% ethanol at 60°C for 30min. Then the zein was recovered rapidly at a high yield from the ethanol extracts by dropping into more than one volume of 1% NaCl solution. Sephacryl S-200 column chromatography and SDS-polyacrylamide gel electrophoresis revealed that the molecular properties of the zein obtained from gluten meal by the above-mentioned method were almost the same as those of zein extracted from raw corn seeds.

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We clarified the quality and properties of various components and lipids of Taiwan tea seeds (both large and round types) and Japanese tea seeds. The lipids of tea seeds were mainly composed of 90.7-94.4% neutral lipids with 3.6-7.4% glycolipids and 1.6-2.0% phospholipids. Among neutral lipids of tea seeds, the ratio of triacylglycerol was as high as 75.5-80%, whereas acylsterylglucosides were prefatty acids of tea seed lipids were shown ta be C18: 1, C18: 2 and C16: 0. Large amounts of 7-stigmastenol and β-anyrin were recognized in 4-desmethylsterol and 4, 4-dimethylsterol. α-Tocopherol alone was detected among tocopherol analogues.

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Several chromatographic methods have been employed to determine anthocyanins and anthocyanidins, the main compounds responsible for the attractive colors of vegetables and fruits. However, effective methods for separating these compounds have not yet been developed, since their chemical structures are very similar. Therefore in the present study, the isotachophoresis technique was applied for the separation of these compounds and the following results were obtained:
1. When each anthocyanin migrated as a cation in the following electrophoretic system, it was detected as a sharp peak on the chart:
Leading electrolyte: 0.01N HCl+0.5% Triton X-100
Terminal electrolyte: 0.01N Tris
However, the potential unit values for each of the anthocyanins were too close, so that separation from each other was not effective. In some cases, they migrated as a single mixed zone.
2. The formation of complexes of these compounds with aluminum ion resulted in the successful separation of each anthocyanin using the following electrophoretic system:
Leading electrolyte: 0.01N HCl+0.2% Triton X-100
+0.5mM AlCl₃
Terminal electrolyte: 0.01N Tris
3. The extraction of anthocyanins from foodstuffs with 1% HCl-MeOH was thus found to be available as a means for their determination.

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