Property changes in three varieties of starch (normal corn, waxy corn and wheat) heated in three varieties of monoglycerides (glycerin monostearate (MS), glycerin monooleate (MO) and glycerin monolinolate (ML)) were investigated. The starches were heated at 150°C for 1 h under open-air conditions. The heated starches were thoroughly washed with chloroform and dried. Little change in the shape of starch granules in all samples was observed on SEM images. Differential scanning calorimetry patterns were different among the starch and monoglyceride varieties with the decrease in enthalpy ratios compared to the control being 31% for normal corn starch in ML ; 20% for waxy corn starch in ML ; and 8% for wheat starch in ML. Rapid visco-analyzer patterns were different among the starch and monoglyceride varieties with the maximum viscosity peak ratio compared to the control being 2% for normal corn starch in ML ; 0% for waxy corn starch in ML ; and 8% for wheat starch in ML. The extent of amylose degradation was different among starch samples : 65% for normal corn starch in ML and 43% for wheat starch in ML. Gel permeation chromatography using a Toyopearl HW-65 column showed only one sharp peak in all the patterns of starch samples heated in ML, indicating amylopectin decomposition products with an average molecular weight of 1800. In contrast to the results of ML, changes in starch properties were small in the samples heated in MS. These results suggest that monoglycerides might easily penetrate into starch granules, forming radicals in an unsaturated fatty acid moiety with heating, and these starch components might be directly and/or indirectly attacked by these radicals and decompose to a dextrin-sized product.

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As okara ingestion suppresses the increase in plasma cholesterol level in rats, we attempted to effectively use okara as a functional food. Soymilk containing okara (okara/soymilk) fermented by lactic acid bacteria showed higher in vitro bile acid-adsorptive capacity than unfermented okara/soymilk. Lactic fermentation increased the alkali-stable polysaccharide content of okara/soymilk. Fecal bile acids and cecum content of rats fed fermented okara/soymilk were also increased. Moreover, lactic fermentation increased the propionic and butyric acid contents in the cecum. Alkali-stable polysaccharides generated by lactic fermentation were assumed to increase short-chain fatty acids in rat intestines and fecal bile acids. Alkaline treatment could extract bile acid-adsorptive compounds from fermented okara/soymilk, but decreased the adsorptive capacity of the extract. Protein was the main bile acid-adsorptive compound separated from fermented okara/soymilk, but no increase in bile acid-adsorptive capacity in the separated proteins was observed after lactic fermentation. Therefore, the increase in bile acid-adsorptive capacity appears to depend on alkali-stable insoluble polysaccharides generated by the lactic fermentation process.

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We studied the antihypertensive effect of an octapeptide (Gly-Ala-Hyp-Gly-Leu-Hyp-Gly-Pro), which is derived from chicken collagen hydrolysates and has strong angiotensin I-converting enzyme (ACE)-inhibitory activity, on spontaneously hypertensive rats (SHRs). 6h after a single oral administration of the octapeptide (4.5mg/kg SHR body weight), the systolic blood pressure was significantly reduced. The octapeptide was not digested by digestive enzymes from the epithelia of the porcine small intestines in vitro. These results suggest that this ACE-inhibitory peptide is absorbed by SHRs in the peptide form and that it lowers blood pressure.

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‘Shibukiri mizu’ (SM) is the supernatant containing astringency components obtained from azuki beans that have been boiled in water for 6 min and then allowed to stand. Even though this supernatant is expected to contain many bioactive components, such as polyphenol glycosides, oligosaccharides and saponins, SM is currently disposed as a food-processing waste. In this study, we examined the antibacterial effects of SM on food-poisoning bacteria, plant pathogens, and plant growth-promoting bacteria. SM showed high antibacterial activity to Staphylococcus aureus 209P and Pseudomonas solanacearum MAFF 03-01418, and very minor activity to Pseudomonas fluorescens MAFF 01-06351. These results indicate that the food processing waste SM may be effectively re-utilized as an antibacterial material against food-poisoning bacteria and plant pathogens.

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Hypsiziprenol A₉ is a polyterpene isolated from the fruiting body of the Japanese edible mushroom Buna-shimeji (Hypsizigus marmoreus). Although our recent studies revealed that hypsiziprenol A₉ has strong anti-tumor activity against tumor-bearing mice, its mechanism of action remains unclear. To elucidate further its anti-tumor action, we examined in detail hypsiziprenol A₉-induced apoptosis in human cancer cell lines.
We observed that hypsiziprenol A₉ strongly inhibited the growth of human promyelocytic leukemia HL-60 cells and several other cancer cell lines in a dose-dependent manner. Hoechst 33342 staining showed DNA fragmentation and condensation of chromatin in HL-60 cells treated with hypsiziprenol A₉. DNA laddering, a hallmark of apoptosis, was detected using agarose gel electrophoresis. In addition, flow cytometric analysis confirmed that hypsiziprenol A₉ increased sub-G₁/G₀ populations in a time-dependent manner. Hypsiziprenol A₉ also increased activities of caspase-2, -3, -8 and -9 in a dose-dependent manner in the apoptotic HL-60 cell. Furthermore, JC-1 fluorescent staining determined that hypsiziprenol A₉-induced apoptosis was associated with a loss of mitochondrial membrane potential.
These results suggest that hypsiziprenol A₉ inhibits the growth of HL-60 cells by inducing apoptosis that is mediated through mitochondrial membrane potential loss and caspase activation.

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In Japan, deep seawater has been a valuable resource for food industries ; in particular, deionized deep seawater is widely used for bottled mineral water. However, concentrated deep seawater, a byproduct of the deionization process, has no current applications. In this study, we produced highly concentrated deep seawater using a novel membrane distillation system and cultivated the well-known halotolerant microalga Dunaliella salina, which is a rich source for β-carotene, using the distillation products. The proposed membrane distillation system consisted of two glass compartments (feed and permeate sides) and a polytetrafluoroethylene (PTFE) membrane. NaCl concentration from 5.2 to 12.3% was effectively achieved by maintaining the feed side at 36°C and the permeate side at 15°C ; the water flux through the PTFE membrane was 0.4 t/day/m². The highly concentrated deep seawater produced from the distillation system was used to cultivate D. salina by adding only nitrogen and phosphate sources. These results suggest that this membrane distillation system is useful in manufacturing highly concentrated deep seawater that can be used as a medium for D. salina cultivation.

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We conducted a placebo-controlled, double blind study to evaluate the effects of Lactobacillus plantarum strain No. 14 (No. 14) on the Japanese cedar pollen allergy. The study was carried out between January and March 2005 during the Japanese cedar pollination season. A total of 28 female students were given 0.5 g (2.0×10¹⁰CFU) of No. 14 for 3 weeks. We observed no significant differences in blood constituents between the placebo and No. 14 groups. However, the total serum IgE level significantly decreased due to No. 14 intake. After the 3-week duration, increases in the total serum IgE level and the eosinophil counts were also observed in the placebo group, but were suppressed in the No.14 group. The occurrence of the subjective symptom (a runny nose) was significantly less for the No. 14 group than for the placebo group between week 1 and week 3. Moreover, percent body fat was significantly decreased after No. 14 intake. These results show that a daily oral intake of No. 14 suppresses Japanese cedar pollinosis and decreases percent body fat.

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DNA not only stores genetic information, but it also provides important nutrients for our body. DNA is thought to improve the hepatic function during alcohol consumption. We studied the effect of consuming DNA-Na obtained from chum salmon milt on alcohol metabolism. Five healthy male subjects were given DNA-Na (500mg) or placebo tablets 30min before drinking beer (633mL ; alcohol content, 5%), and then alcohol, acetaldehyde and acetic acid levels in blood were measured at regular intervals (0, 1, 2, and 4h). The results showed that DNA-Na significantly suppressed elevation of the blood acetaldehyde level, suggesting that the mechanism of DNA-Na digestion may be related to the oxidation-reduction cycle of coenzyme NAD.

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A study on discriminating imported pumpkins by the composition of their inorganic elements was conducted to develop a scientific technique for identifying their geographic origin for import clearance. Seeds of pumpkins produced in Mexico, New Zealand and Tonga were used. A linear discrimination model was created for identifying pumpkins from Mexico, which are free of customs duty, and pumpkins from other countries, which are subject to customs duty. The effectiveness of this model was evaluated by cross validation. It had a high hit ratio of 95% (39/41) of all samples. This result suggests that discriminating by inorganic element composition may be useful in identifying the geographic origin of pumpkins for import clearance.

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Goishi tea, a post-heating fermented tea, is produced in Otoyo town in Kochi Prefecture, Japan. Two natural fermentation steps by aerobic and anaerobic fungi and microorganisms participate in the production of Goishi tea. To investigate the effects of the manufacturing process on the functionality of Goishi tea, changes in superoxide anion scavenging activity and catechin content in hot water extracts of Goishi tea were examined. Superoxide anion scavenging activity and catechin content drastically changed in the two fermentation steps. In addition, high levels of (-)-catechin and (-)-gallocatechine were observed in the final product of Goishi tea. However, the contribution of catechin and gallic acid determined in this study to the superoxide anion scavenging activity of Goishi tea was low. These results suggest that some other component generated during the two steps of fermentation is the main contributor to the superoxide anion scavenging activity of Goishi tea.

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[in Japanese]

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