To remove the odors from four types of milk protein hydrolysates, a continuous distillation column system was used. The solutions of milk protein hydrolysates were distilled under a reduced pressure with steam injection and the removed odors were evaluated by gas chromatography (GC), gas chromatographymass spectrometry (GC/MS) and gas chromatography-olfactometry (GC-O). Undesirable odors from four types of milk protein hydrolysates were efficiently removed under the appropriate conditions in the distillation column. In GC/MS analysis results, the removal efficiency of alkylbenzenes in the milk protein hydrolysates was more than 80%. In GC analysis results, especially dimethyl trisulfide and methional responsible for undesirable odors were removed at an efficiency of about 40% and 70%, respectively. Characteristic odors of the milk protein hydrolysates were detected by a sniffing test method using GC.

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We evaluated the effects of transglutaminase (MTG) treatment on the texture of Chinese noodles. When MTG was added to wheat flour at 1-10 units per gram of protein, the shear strength of boiled noodles increased with improvements in their resistance to bite. The mechanical properties of noodles were improved by the addition of both MTG and protein degradation products in combination compared with MTG alone. Moreover, when noodles were stored in a refrigerator after boiling, changes in the mechanical properties of noodles with time after boiling and loosening of the texture were also reduced by the addition of MTG. MTG also improved the anti-acid and anti-retort properties of noodles that should have a long shelf life. These improvements in the noodle texture were related to the quantity of G-L bond.

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Anthocyanin-soybean protein complexes were prepared from the mixture of autoclaved defatted soybean extract and methanol extract of various plants containing anthocyanin. All anthocyanin-soybean protein complexes contained anthocyanin and showed reddish or purple coloration. The maximum concentration of anthocyanin (0.23% dry weight as cyanidin equivalent) was observed in the complex prepared from black soybean. Anthocyanin-soybean protein complexes showed large radical-scavenging activities which levels were higher than that observed in soybean protein precipitate containing some isoflavones. The largest radical-scavenging activity was observed in the complex prepared from the extract from red leaves of Sapium sebiferum. The highest radical-scavenging activity was presumed to be originated from tannin constituents (geraniin and chebulagic acid) as well as anthocyanin. Anthocyanin-soybean protein complexes also have good potential to be as a new functional material valuable in food industries.

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A relationship between the evaluation of fried materials and the amount of polar compounds was investigated. Fresh oil and the used oil with three degrading degrees (Acid value: about 1, 2 and 4.5) were used in this study. The fried materials (fried batter, maitake tempura and croquette) and frying oil itself were sensory evaluated by the Ranking Method. There were significant differences among the evaluation scores of the oils and of the fried materials prepared with different degrading oils (Kruscal-Wallis test, n=40, P<0.01). In proportion as the oil was degraded the flavor of the fried materials fell off. Sensory evaluation panelists distinguished the quality of fried materials prepared with different degrading oils, but it tended to be difficult to distinguish highly deteriorated oils containing higher than 15% polar compounds (Turkey's method, P<0.05). Fried batter and maitake tempura fried with the oil containing less than 15% polar compounds and the oils themselves were evaluated to be good by the panel. Croquette was rated high when it was fried with the oil containing about 24% polar compounds. When the polar compound content increased higher than 15% level, the evaluation scores of the fried materials tended to lower and the acid value exceeded the standard value to discard the used oil. Therefore, it is our opinion that the measurement of polar compounds is useful in judging whether deep-frying oil is usable or not.

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To test the digestibility of galactooligosaccharides (GOS) prepared from lactose through the transgalactosylation reaction of Sporobolomyces singularis cells and β-galactosidase from Kluyveromyces lactis, hydrogen gas in the exhalation of sixteen healthy subjects given GOS was analyzed. Hydrogen excretion following ingestion of GOS was substantially greater than that following ingestion of placebo. This fact shows that GOS was a mixture of non-digestible saccharides. Furthermore, to clarify non-digestible ingredients in GOS, we separated transgalactosylated di-, tri- and tetra-saccharides from GOS by Bio-Gel P-2 column, respectively. Then, resistance of these saccharides to the digestive enzymes was studied in vitro. The samples which contain di-, tri-, and tetra-saccharides were not digested in vitro by α-amylase of human saliva, the artificial gastric juice, and α-amylase of hog pancreas, but di-saccarides were partially digested by the enzymes of rat intestinal acetone powder. These results show that hydrogen excretion following ingestion of GOS was associated with bacterial degradation of tri-, and tetra-saccharides and some of di-saccarides in GOS after passing undigested through the small intestine into the large bowel.

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It has been reported that Royal Jelly (RJ) treated with protease N (ProRJ) contained three ACE inhibitory peptides (IY, VY and IVY) and that three peptides have an antihypertensive effect on spontaneously hypertensive rats (SHR). We examined the mechanism by which ProRJ decreased blood pressure in SHR. In single oral administration of ProRJ at a dose of 2.0g/kg in SHR, the systolic blood pressure was significantly decreased 6 hours after administration. And the angiotensin I converting enzyme (ACE) activities in the abdominal aorta and lungs of SHR administration of ProRJ were decreased compared to those of control at 6 hours after administration. IY, VY and IVY were detected in the abdominal aorta and lungs of SHR, and also in plasma by the HPLC method. The amount of aldosterone in plasma was significantly decreased from 1 hour to 4 hours after administration of ProRJ in SHR. According to these results, it was suggested that the antihypertensive effect of ProRJ in SHR is responsible for ACE inhibitory activity of IY, VY and IVY in ProRJ.

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In order to examine the differences on dietary fibers: soluble (SDF), insoluble (IDF), and total (TDF), protein, and oil contents, and weight of 100 seeds on soybeans, 7 soybean cultivars were cultivated in upland, drained paddy field and late-seeding time at Tohoku National Agricultural Experiment Station in 1995. The drained paddy field culture, as compared with the upland culture, gave no different of SDF, IDF, TDF contents, high protein and low oil contents and heavy weight of 100 seeds. Significant differences were observed in protein and oil contents and weight of 100 seeds. From the contribution ratio of the field condition and cultivar, cultivar was higher than field condition in dietary fibers, protein, oil contents and weight of 100 seeds. The late-seeding time culture, as compared with normal-seeding time culture, gave slightly high IDF content, low oil content, and light weight of 100 seeds. As to the variation of IDF content, it was presumed that increased IDF content was influenced by reduced weight of 100 seeds. The low oil content was influenced by low temperature during ripening. Significant differences were observed in IDF, oil contents and weight of 100 seeds. From the contribution ratio of the seeding time and cultivar, cultivar was higher than seeding time in dietary fibers, protein and oil contents and weight of 100 seeds. However, slightly high contribution ratio was also observed in oil content in seeding time.

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The aged mash (fermented moromi) in soy sauce brewing was pressed to separate into liquid soy sauce and soy cake (soy sauce lee). The major quantity of free isoflavones in the mash remained in the soy cake. The remaining rate of 8-hydroxydaidzein (8-OHD), 8-hydroxygenistein (8-OHG), daidzein and genistein in the soy cake were 65.2%, 82.9%, 88.5% and 95.0%, respectively. These potent antioxidative o-dihydroxyisoflavones (ODI) in various soy cakes, which were obtained from the brewing makers, were also present in rich enough amounts to utilize these cakes as antioxidant materials. The extracted preparations with ethanol and ethyl acetate, in addition to a highly concentrated ODI fraction separated by Amberlite XAD-2 column chromatography, showed strong antioxidative effects against fish oil in both oil and lipid/aqueous systems. In particular, the ODI fraction exhibited higher antioxidative activity than α-tocopherol in these model systems. It also showed higher DPPH radical scavenging activity and stronger inhibition of lipid peroxidation in a liposome system. From these results, it was suggested that the soy cake dealt with as industrial waste could be well used as antioxidant materials.

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