The effects of sodium phytate or phytin administration on several mineral utilizations in rats were examined. Eighteen male 4-week-old Wistar/ST rats were divided into 3 groups. One group (control group) was fed a basal AIN93G diet, the other two groups (SP group and phytin group) were fed the basal diet containing sodium phytate (1.0wt%) or rice bran-derived phytin (1.0wt%), respectively, for 4 weeks. Because the phytin used contained magnesium, zinc, and manganese, the phytin group consumed more of these minerals than the other two groups. The SP group excreted more magnesium in their feces and had a lower apparent absorption than the control group, which had a similar magnesium intake. In addition, the SP group had lower zinc concentrations in the serum and several organs than the control group. There was also a trend toward lower serum and organ zinc concentrations in the phytin group compared to the control group, but the only significant difference was in the femoral zinc concentration. The phytin group had lower apparent iron absorption and lower serum and organ iron concentrations than the other two groups. The serum phosphorus concentrations and urinary phosphorus excretion were increased in the SP and phytin groups. These results indicated that 1) phytic acid inhibits the absorption of magnesium and zinc, 2) minerals bound to phytin, possibly manganese, inhibit iron absorption, 3) phytic acid is partially hydrolyzed in the digestive tract, phosphoric acid and the minerals bound to phytic acid are released and utilized.

To clarify the nutritional availability of iodine in seaweeds, the solubility and molecular species of iodine in several edible seaweeds were examined. The extraction rate of iodine from dry powdered seaweed samples by water or protease treatment was almost 100% for four species of kombu (Saccharina japonica, S. angustata, S. ochotensis, S. diabolica),but 37-88% for seaweeds other than kombu. In seaweeds other than kombu, some of the iodine may be either physically unextractable due to the cell walls or bound to insoluble substances. When the extracts obtained by protease treatment were analyzed by HPLC-ICPMS, iodide ions and iodoamino acids, monoiodotyrosine (MIT) and diiodotyrosine (DIT),were detected in all of them. In kombu, hijiki (Sargassum fusiforme),arame (Eisenia bicyclis), and wakame (Undaria pinnatifida, leaflike part),more than 90% of the iodine were iodide ions, whereas the proportions of MIT and DIT were relatively high in susabi-nori (Neopyropia yezoensis),hitoe-gusa (Monostroma nitidum), and mekabu (Undaria pinnatifida, root portion). In particular, more than 60% of iodine was iodoamino acids in susabi-nori which contains about 40% protein. In addition, several edible seaweeds contained unknown iodine compounds, although the amount ratios were small. These results indicate that iodine in powdered kombu is easily absorbed and effectively utilized.

The sales amount of commercially available baby food products is increasing in Japan. Although babies and toddlers are vulnerable to iron deficiency, hijiki seaweed (Sargassum fusiforme) is regarded as effective iron source in Japan. Hijiki seaweed however contains excessive amount of inorganic arsenic. The provisional tolerable weekly intake (PTWI) of inorganic arsenic had been withdrawn by the World Health Organization (WHO) after once established, because the Joint FAO/WHO Expert Committee on Food Additives (JECFA) concluded that the current PTWI for inorganic arsenic was no longer protective for health. Attention to the use of hijiki seaweed for babies and toddlers is necessary. Therefore, we examined changes in the number of babyfood products containing hijiki seaweed in the market in Japan. Our study found that babyfood products were increased from 560 to 574, but babyfood products containing hijiki seaweed decreased from 24 (4.3%) to 17(3%).

Oysters (Crassostrea gigas) are a highly nutritious shellfish that are widely consumed worldwide, and their polysaccharides have been confirmed to have prebiotic properties through in vivo digestion. It has been demonstrated that polysaccharides derived from oysters greatly increases Lactobacillus reuteri. We have previously reported on the antioxidant activity of paeonol (2'-Hydroxy-4'-methoxyacetophenone),which has the chemical structure of hydroxyacetophenone in this compound, and its oral administration showed therapeutic effect on ulcerative colitis in rats. The absorption kinetics of paeonol in rat intestines has also been investigated. On the other hand, paeonol has been reported to have an antibacterial effect, so we tried to examine the effect of this compound on lactic bacteria (Lactobacillus plantarum) in vitro when used in combination with oyster powder extract or adenosine. Adenosine was used as a component confirmed in the oyster powder extract tested. As a result of this study, we found that the combined use of paeonol and oyster powder extract was effective in restoring the growth of lactic bacteria. Specifically, the recovery rate of the growth was 92 % in the 1 % oyster powder extract containing 25 mM paeonol group compared to the 5 % DMF control group. We also confirmed the effect of the combination with paeonol and adenosine on lactobacillus proliferation, but the recovery rate of the combination with 0.125 mM adenosine containing 25 mM paeonol was only 69 %. Therefore, it is suggested that oyster powder extract may include something ingredients other than adenosine, indicating that can be expected to have the effect of increasing the growth of Lactobacillus plantarum.

It is well known that folic acid intake during pregnancy prevents developing neural tube defect. Folic acids are able to take from various foods such as green and yellow vegetables and supplements. This study investigated the effect of folic acid intake from green and yellow vegetables and supplements on serum folic acid concentration. Study subjects were 12 female students. The subjects were divided into 4 groups, each group was administered folic acid-rich foods; green and yellow vegetables (120 g/day),rice boiled in folic acid containing water, or folic acid supplements (gummies or tablets). Serum folic acid levels measured 30 days after administration of the vegetables or supplements were significantly increased compared with basal levels. Next, we evaluated the effects of long-term intake of green and yellow vegetables. Nine female students were ingested 100 g of the vegetables for 90 days, at least three times a week. Serum folic acid levels were measured before and after ingesting the vegetables. Significant increase in serum folic acid was observed 60 days after ingestion. This study revealed that taking folic acid-rich foods and supplements increased serum folic acid levels. To reduce neural tube defect, it was suggested the importance of education of females about folic acid intake from the time of non-pregnancy.

Udon dashi soups (soup for thick wheat noodles) are specially prepared and served at each restaurant chain. To clarify the difference in taste depending on the restaurant chain, the taste of udon dashi soup by the taste sensor and the high-performance liquid chromatography (HPLC) was scientifically evaluated in this study.

Udon dashi soup (A) is a concentrated dashi, which is diluted and utilized for udon dashi soup served at the restaurant chain. Udon dashi soups (B, C, D) are Kansai-style dashi served in the restaurant chain in Hyogo prefecture, and udon dashi soups (B, C) are served in the restaurant chain in the same family. These udon dashi soups are generally made from shaved fishes, such as dried sardine shavings and dried kelp. After diluting these udon dashi soups to 4% Brix, Taste Sensing System (TS-5000Z) with the taste sensor was used to quantify eight different taste components: sourness, bitter stimulus, astringent stimulus, umami, and saltiness as the initial taste, and general bitterness, astringency, and umami richness as the aftertaste. Free amino acids in the udon dashi soups were also determined using the HPLC analysis.

Three types of udon dashi soups (B, C and D) had less sourness and astringent stimulus than udon dashi soup A, but had a stronger umami and saltiness. However, no difference in the aftertaste (general bitterness, astringency, and umami richness) was detected. The taste of udon dashi soup D was significantly different from that of udon dashi soups B and C. In particular, the sourness and astringent stimulus were suppressed, and both saltiness and umami became stronger in udon dashi soup D. From the determination of free amino acids, udon dashi soups A, B and C showed high values for glutamic acid, aspartic acid and histidine, while no serine and arginine were not detected in udon dashi soup C. Very high levels of taurine and histidine in udon dashi soup D were contained. Anserine and carnosine were also characteristically found in udon dashi soup D. Therefore, udon dashi soups B, C and D may be mixed by the different processing methods using the different ingredients respectively.

From these findings, it was suggested that scientific evaluation of taste characteristics of udon dashi soup is possible by using the taste sensor and amino acid analysis.

To examine the potential of downy cherry (Prunus tomentosa) as an edible fruit, the organic acids, sugar, and vitamin C concentrations were compared with those of several kinds of conventional fruits including cherries and raspberries. In addition, the amount and stability of the red pigments contained in Prunus tomentosa were also examined. The vitamin C concentration was very low, less than 1 mg/100 g fresh weight. The concentration of red pigments was similar to that of raspberries. The organic acid content was similar to that of other fruits compared, and like other rosaceous fruits such as cherries and plums, it contained more malic acid than citric acid. Brix sugar content was low, about half that of cherries. The taste of Prunus tomentosa was light due to its low sugar content. Therefore, it is expected that Prunus tomentosa will be processed into jam, juice, fruit wine, etc., rather than eaten raw.

Physiological function of nickel as an essential nutrient for reproduction is discussed. Nickel deficiency induces abnormality in reproduction. In goats, nickel deficiency decreases the success rate of the first insemination and increases the abortion rate. In minipigs, nickel deficiency causes a retardation in pregnancy and delivery of offspring. In rats, nickel deficiency causes a decrease in epididymal sperm density, spermatozoa motility, epididymal transit time, and testicular sperm production rate, as well as weights of seminal vesicles and prostates. Since cyclic nucleotide-gated (CNG) cation channel subunits A3 and B1 distribute in the sperm flagellum, potentiation of CNG channels by Ni²⁺ may be responsible for reproductive abnormality induced by nickel deficiency. Since Ni²⁺ stabilizes the C3-convertase C3b-Bb complex in the alternative pathway of the complement system and seminal plasma contains a relatively high level of nickel, nickel may have a role in preventing male reproductive tract infection.