Carotenoids are known to be superior quenchers of singlet oxygen. Thus, carotenoids, which are present in various vegetables, are widely thought to exert many health benefits and anti-aging effects. This study investigated the health effects of carotenoid and carotenoid-rich vegetable intake at each stage of life. Among carotenoids, the use of lycopene can be cost-prohibitive. Thus, attempts were made to extract lycopene from tomato skin using SC-CO₂ (supercritical-carbon dioxide). Further, the carotenoid content, a potential antioxidant source, of 70 vegetables in Japan was determined by reversed-phase HPLC. These results were applied to the development of carrot juice and space food. Additionally, a new assay method to quantify the singlet oxygen absorption capacity (SOAC) of antioxidants, including carotenoids, and vegetable extracts was proposed.

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Many dipeptides have unique physiological functions such as antihypertensive effects and taste enhancing effects. In this study, we focused on the taste of dipeptides and conducted screening for dipeptides as salt taste enhancers. Dipeptides were synthesized using TabS, an _L-amino acid ligase (Lal) from Pseudomonas syringae NBRC14081. Six kinds of amino acids, which were easily released by the hydrolysis of proteins or peptides, reacted with 20 proteogenic amino acids, and the reaction mixtures were evaluated using sensory evaluation. In the first screening, the reaction mixture or _L-Leu-_L-Ser, a known salt taste enhancing dipeptide, was added to a salt solution containing ATP and panelists judged the salt taste intensities. In the second screening, the reaction mixture or residual substrate amino acids was added to a salt solution containing ATP and subjected to sensory evaluation. _L-Met-Gly was identified as a candidate salt taste enhancer. In addition to sensory evaluation, the salt taste enhancing effect of _L-Met-Gly was evaluated using a taste sensor. Taste sensor analysis showed that _L-Met-Gly had a salt taste enhancing effect, and the relative sensor response for _L-Met-Gly was equal to or higher than that for _L-Leu-_L-Ser. This is the first report that _L-Met-Gly is a salt taste enhancing dipeptide. Furthermore, we propose that the screening method using reaction mixtures of Lal is applicable for the taste evaluation of other dipeptides.

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The present study aimed to clarify the effects of soluble tannins from astringent persimmon on the qualities (color and texture) of Japanese wheat noodles (udon). We investigated the addition of the untreated paste or juice of astringent persimmon, which are abundant in soluble tannins and highly astringent, to flour during the production of Japanese noodles. The resulting noodles were dark in color and reddish. Also, the values of elasticity modulus and repture stress of boiled noodles were increased by the addition of the untreated astringent paste or juice from astringent persimmon. It is concluded that the qualities of udon noodles were highly influenced by the addition of soluble tannins from astringent persimmon.

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Shio-koji is a gruel-like fermented rice seasoning that is obtained from the digestion of rice under high-salt conditions. The average chemical composition of 14 commercially available shio-koji products was analyzed and determined as : 11.0% NaCl, 21.9% reducing sugar, 0.07% formol nitrogen, and 50.2% water. Amylolytic and proteolytic enzyme activities were detected in the majority of the shio-koji products, although they were not detected in others. It is currently accepted that maturation at 60°C for more than 6 hours is required for sufficient digestion of starch and proteins. However, maturation at either 50°C or 60°C for 6 hours resulted in increased formol nitrogen levels without loss of enzyme activity. Upon comparison of shio-koji and amazake, in a solution of 10% NaCl-containing koji extract, here we report that a 10% NaCl solution led to the decreased thermal stability of α-amylase while that of proteases was augmented.

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The functional properties of a Japanese wheat cultivar were evaluated to improve the sensory and quality attributes of the grain. The functional properties of wheat flour milled from Triticum aestivum L. cv. Yumechikara grown in Hokkaido (Sample B) was compared to commercial bread flour milled from imported wheat (Sample A). Although the dough expansion of both samples was similar, the final bread product made from sample B showed a slightly decreased bread volume. In sensory evaluations performed using 48 panels, final products made using sample B had a higher overall preference, possibly due to the higher protein content and lower amylose content of the Yumechikara cultivar. The characteristics of Sample B appeared to be shown using the straight-dough procedure. Thus, while processing Yumechikara flour was more difficult, products made from this flour may achieve higher functionality for bread processing if the Yumechikara cultivar is used as the maternal line in breeding.

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The ultimate objective in the research and development of rice flour bread is “The creation of ‘delicious’ bread by ‘skillfully’ preparing it with ‘superior’ rice flour.” The milling of rice flour involves a milling machine, which employs various, different milling principles for the milling of hard, granular, polished white rice. Besides roller milling, the percussive method, which crushes grains through collisions with pins, hammers, etc.; high-speed rotation; and air-flow jet milling, where rice grains mutually collide in air streams, are available methods for the milling of rice flour. The different milling principles have spawned diversity in rice flour, while grain size and the proportion of damaged starch have become indices for the characteristics of rice flour. The surface state of rice flour varies greatly according to the water absorption rate, and has an influence on flour characteristics in subsequent secondary processing. Characteristics as measured by farinograph and extensograph, amylose content, and the rice flour milling method affect the quality of the bread dough. Methods for evaluating texture distinctive to rice flour bread have been proposed. In a puncture test of rice flour bread, determining the extensibility past the rupture point is considered a promising candidate among such methods. The evaluation of water content dynamics in rice flour bread through magnetic resonance imaging (MRI) is also a promising method for evaluating characterizing bread quality.

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