Komatsuna was grown in normal soil, soil enriched with chemical fertilizers and soil enriched with organic fertilizers to study the changes with cooking in the mineral, nitrate nitrogen and amino acid contents.
The mineral content was highest in komatsuna grown in organically fertilized soil, followed by that grown in chemically fertilized soil and then in normal soil. Cooking tended to reduce the residual Ca and Fe contents in komatsuna grown in all three types of soil. The reduction by cooking of nitrate nitrogen was less in komatsuna grown in organically fertilized soil than in the other two soil types. Cooking tended to increase the contents of flavorrelated amino acids, especially in komatsuna grown in the organically fertilized soil. The sweetness-related and bitterness-related amino acid contents tended to be decreased by cooking.

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Sensory tests and textural measurements were made of komatsuna grown in normal soil, soil enriched with chemical fertilizers and soil enriched with organic fertilizers. Uncooked komatsuna grown in normal soil achieved the highest overall score, while komatsuna grown in soil enriched with chemical fertilizers and soil enriched with organic fertilizers achieved lower scores because of the grassy smell and harsh taste. Significantly more energy was required for chewing komatsuna grown in soil enriched with chemical fertilizers (p<0.05), suggesting high consistency. Uncooked komatsuna grown in normal soil was most favored. No difference was apparent among the komatsuna samples grown in different soil types after cooking by hitashi (parboiling and pressing). Ni-bitashi (boiled and seasoned) komatsuna grown in soil enriched with organic fertilizers was significantly favored (p<0.05)in its overall evaluation. Stir-fried komatsuna grown in soil enriched with chemical fertilizers was slightly more favored than the samples grown in the other two types of soil according to the overall evaluation and results of tests on tastiness and texture.

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The components contained in the cooking water and in an extract from the surface of rice cooked with acetic acid were examined to clarify the mechanism for the textural change due to the addition of acetic acid. Compared to rice cooked only with distilled water, the water absorption rate above 60°C was higher in the rice grains cooked with acetic acid. The amounts of solids and total sugar extracted from the surface of cooked rice were also increased by acetic acid, indicating that this contributed to the increase in the stickiness, transparency, and glossiness of the cooked rice. It was found, however, that the fine structure of starch in the extract from the surface of the cooked rice was unaffected by the addition of acetic acid. It is suggested that there was hardly any degradation of starch by acetic acid under the cooking conditions used in this study.

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A series of investigations has been conducted to enable the development of palatable vinegared dishes for the aged. In the present study, a sensory evaluation of various kinds of vinegary dressing was carried out by a panel of female college students who were divided into three groups depending on the degree of liking for vinegared dishes: the “like”, “neutral” and “dislike” groups. The like group gave the grain-vinegar dressing high scores among the three vinegary dressings prepared with grain vinegar, rice vinegar and whole-rice vinegar. In contrast, the dislike group gave the rice-vinegar dressing high scores, while a 3-fold-diluted vinegary dressing (containing 10% vinegar) attracted a high evaluation by the same group. Vinegary dressings with varying concentrations of sugar from 5% to 13% attracted increasingly high scores from all the groups as the sugar concentration was increased. The results of a correlation analysis suggested that the smoothness had a strong positive correlation with the all taste attributes except for sourness, and also indicated that the sourness was alleviated by sweetness and umami.

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The stability of ascorbic acid(AA) at 100°C in the presence of soybean oil or rapeseed oil was investigated with a cooking model. The residual AA level with 5% soybean oil was significantly lower than that without the oil up to 30 min heating, while the addition of rapeseed oil did not significantly affect the ascorbic acid stability. The addition of soybean oil resulted in lipid peroxide being accumulated at an early stage, and AA loss was initially correlated with a decrease in a-tocopherol, a sensitive indicator for lipid peroxidation. These results suggest that lipid peroxidation affected the stability of AA in the aqueous phase in the presence of dissolved oxygen.

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A questionnaire survey was conducted to identify the regional variety of Japanese New Year's dishes and how they are prepared.
Questionnaires were sent out to students of universities and colleges throughout Japan in December 2001 and 2608 questionnaires were collected in January 2002.
Japanese soba was eaten by 74.8% of Japanese on New Year's eve, while Okinawa soba was eaten by 58.8% in Okinawa. Osechi dishes were eaten by 79.6% during the New Year period, most being homemade although some were bought from shops. Kuromame was most commonly eaten, followed by boiled fish paste, cooked herring roe, cooked sweet-potato paste, cooked vegetables, cooked sardines, fried eggs, rolled kombu and vinegared dishes. The cooked vegetables and vinegared dishes were mostly homemade, while fried eggs and boiled fish paste were mostly purchased from shops. The popularity of Japanese New Year's dishes varied according to the region although it has decreased compared to that of 23 years ago.

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[in Japanese]

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[in Japanese]

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