The changes in the 1,1-dipheny1-2-picrylhydrazyl (DPPH) radical-scavenging activity of eight vegetables popularly consumed in Japan were investigated after different thermal cooking processes such as boiling, simmering, microwave heating, pan-frying and deep-frying. The total phenol and ascorbic acid (ASA) contents of the vegetables were also determined.
The radical-scavenging activity and total phenol content tended to decrease during boiling and simmering, but were retained during microwave heating, pan-frying and deep-frying. However, the ASA content decreased after all cooking processes. The thermal cooking of the vegetables did not significantly affect the radical-scavenging activity in spite of the loss of ASA, since vegetables contain large amounts of phenolic compounds which are stable to heating. These active compounds, however, were partly released into the cooking water during boiling and simmering.

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The physicochemical properties of three kinds of roasted chicken thigh meat were different among broiler (B), Mikawa Red (M) and Nagoya Cochin (K) samples. The reddish color and hardness were greatest in the order of the K>M>B samples, while the free amino acid content of the B sample was higher than that of the M and K samples. The results of the sensory evaluation demonstrated that young people liked the B sample, middle-aged people liked the K sample and old people liked the M sample. The preferred physicochemical properties of roasted chicken thigh meat therefore varied with the age of the consumer.

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We examined the effect of Hon-mirin on the functional components of potatoes during cooking. We analyzed the amount of ascorbic acid and amino acids related to the formation of flavor. We also measured the antioxidative activity by the radical scavenging effect with 1,1-dipheny1-2-picrylhydrazyl (DPPH). The results demonstrate that Hon-mirin controlled the decrease of ascorbic acid in potatoes by heating. It was also apparent that this effect was not caused by the ethanol in Hon-mirin. The amount of amino acids in potatoes was decreased by heating with Hon-mirin or an ethanol solution, and the amount of free amino acids was increased. This result suggests that hydrolysis of the peptide and protein bonds was promoted by heating with Hon-mirin or the ethanol solution. The radical scavenging activity created by Hon-mirin was significantly increased when heating with a little liquid for boiling.

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The concentration effect of collagen-peptide (CP,0-30% w/v) on the physical properties of agar gel (AG,1%w/v) was studied by measuring the rupture properties, textural properties, dynamic viscoelasticity, syneresis and differential scanning calorimetry (DSC). The rupture stress, rupture energy and hardness of AG gel were increased by adding sugar. The rupture stress, rupture energy and hardness of agar and collagen-peptide (AG-CP)gel were increased up to a certain CP concentration and then decreased with increasing CP concentration. CP and sugar prevented the svneresis of AG gel.
A CP solution showed liquid behavior in the temperature range studied (5-30°C) in respect of the frequency dependence of G′ and G″. AG showed an endothermic peak with heating DSC, while CP did not show any exothermic or endothermic peak in the temperature range studied (5-90°C), The rheolegical and DSC changes imply that an increase in the effective concentration of AG from the immobilization of water molecules by adding a certain CP concentration promoted the hardness of AG-CP gel. However, this hardness of AG-CP gel began to decrease with increasing CP concentration, because CP retarded the gelation of AG.

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A study was carried out on the interaction between rutin and alkaline-processed gelatin to improve buckwheat cooking. Gelatin samples containing different amounts of rutin were prepared and gelled under various pH conditions. The rupture property and gel structure of these rutin-containing gelatin samples (rutin-gelatin) were analyzed by a rheometer and scanning electron microscope (SEM), while rutin crystallization in the gel samples was observed by an optical microscope.
The rupture property of the rutin-gelatin samples depended on the amount of rutin crystals appearing and on the pH value of the gel. A slower appearance of rutin crystals was evident when a higher protein and lower rutin concentration were applied. The crystals that appeared were also smaller by this slower crystallization. SEM observation showed, a thick gel structure like an aggregated gelling network in the high-concentration rutin-containing sample, whereas this structure was never apparent in a gel sample without rutin.
The gel structure was therefore changed by the addition of rutin. These results strongly suggest the formation of a rutin-gelatin complex under our experimental conditions.

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Touna is a group of Brassica leaf vegetables, most of which are cultivated locally in various regions of Japan, and is known as one of the traditional Japanese leaf vegetables. This study clarifies the contents of some constituents with nutritional and biological functions in several commercial cultivars of Touna (Meikena, Kawanagare, Osakina and Yairona) in Niigata prefecture. The ascorbic acid content of Touna was 60.4-82.0 mg/100g fresh weight. More than 50% of the total vitamin C content of Meikena remained after boiling for 5 min and after salted pickling for 16-18 h at 4°C. The total polyphenol content of Touna was 8.4-13.1μmol of gallic acid/g fresh weight. Touna is therefore considered to be one of the potent sources of vitamin C and polyphenols.

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The antioxidative capacity of Nikogori made from the collagen of various types of fish and meat was studied. The effects of different types of soy sauce on the antioxidative capacity of Nikogori were also studied. The scavenging activity for peroxyl radicals, which cause particularly severe in vivo damage among the oxygen radicals, was measured by the chemiluminescence method.
Nikogori made from the various types of collagen had as high peroxyl radical scavenging activity as the antioxidative capacity. Soy sauce added to Nikogori markedly increased this antioxidative capacity. Soy sauce (7 kinds with dark color, light color, tamari, and shiro) and fish soy sauce (3 kinds) added to Nikogori made from flatfish markedly increased the peroxyl radical scavenging activity with the exception of shiro soy sauce. In particular, the dark colored and tamari soy sauce samples, the main ingredients of which were soy bean and wheat, markedly increased the peroxyl radical scavenging capability when added to Nikogori.

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Nukaduke (rice bran pickling) is a traditional Japanese method for pickling vegetables in rice bran. Rice bran contains rice bran oil (RBO), the most characteristic bioactive component in RBO, γ-oryzanol, being a mixture of ferulic acid esters of triterpene alcohols or plant sterols. γ-Oryzanol studies have indicated important physiological actions such as a serum cholesterol-lowering effect. The amounts of γ-oryzanol in raw radish and in six commercial rice-bran-pickled radish products were measured by HPLC. The raw radish was pickled in the rice bran, and changes in the amounts of γ-oryzanol, moisture and salinity were analyzed. The distribution of γ-oryzanol fluorescence in the pickled radish was also observed under ultraviolet light irradiation. It was revealed that the ricebranpickled radish accumulated γ-oryzanol during the pickling process. Although the accumulated amount in nukaduke was relatively modest when compared with the physiologically effective amount, a long-term intake of rice-bran-pickled radish might exert the physiological action of -oryzanol.

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It is considered that the taste compounds and vitamin C in edamame (vegetable soybeans) might be eluted or decomposed during the process of boiling because of their solubility in water and instability to heating. This study assesses the effect of boiling time (3-10 min) on the contents of the taste compounds and vitamin C in edamame. The contents of sugar and free amino acids, including the main taste components, sucrose, glutamic acid and alanine, did not significantly decrease during 7 min of boiling. Although the retention of total vitamin C in edamame after boiling for 7 min was more than 90%, that of edamame boiled for 10 min decreased to 85%. These results demonstrate that boiling edamame for 7 min did not significantly affect the contents of the taste compounds and vitamin C.

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The dietary features of Chinese and Japanese food were investigated by comparing the Honzo Komoku and Hontyo Syokkan classifications. Honzo Komoku was compiled by Jitinn Li in 1587, and Hontyo Syokkan was compiled by Hitsudai Hitomi in 1697 after referring to Honzo Komoku.
While fish and shellfish were described in Hontyo Syokkan, they were not in Honzo Komoku; on the other hand, animals and insects were described in detail in Honzo Komoku, but only briefly in Hontyo Syokkan. This by itself demonstrates the difference in dietary features between Chinese and Japanese food.
In addition, the gallbladder and skin of animals, as well as such viscera as the blood and heart were described as medicine in Honzo Komoku, but were not mentioned in Hontyo Syokkan.

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