Masticatory muscle activities of children (60 panelists; 4 to 6 years old) were compared with those of female young adults (54 panelists; 19 to 23 years old) on chewing some food samples with different texture. The texture of food samples was measured by a tensipresser. The food samples investigated were peanut, cooked polished rice, kamaboko (steamed fish paste), cooked unpolished rice, boiled edible burdock, pork chop, octopus boiled and seasoned, takuan (pickled Japanese radish) and surume (dried squid). The chewing frequency and the sum of the proportion of amplitudes for temporal and masseter muscles were calculated from recorded electromyograms. The results obtained were as follows. (1) The chewing frequency was significantly increased in the children compared with in the adults, except for a food sample with low hardness and chewiness. (2) For food samples with higher chewiness, both children and adults showed wide distribution of the sum of the proportion of amplitudes. (3) The sum of the proportion of amplitudes in the children was not significantly different from those in the adults for food samples with higher chewiness.

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To estimate the palatability of rice, DNA analysis based on PCR method was investigated. As template DNAs for PCR, genomic DNAs of sample milled rice were extracted and purified by the cetyltrimethylammoniumbromide (CTAB) method. Rice genomic DNAs were proliferated by PCR with the use of various kind of "sequence-tagged site" (STS) primers. Discriminative DNA bands were binarized as 0 (appeared) or 1 (disappeared) and were subjected to the multi-variate analyses. The results of PCR were used as independent variables and the results of sensory test, "palatability evaluation values" or the results of physical properties of the cooked rice grains were used as dependent variables in the multiple regression analyses. Four kind of palatability estimation equations were developed and applied to the rice samples of the different crop-year. Validation test showed that these four equations can be applied to the unknown rice samples because the multiple regression coefficients were 0.80, 0.91, 0.75 or 0.91, respectively. According to this method, palatability of a single grain of raw rice or cooked rice can be estimated using its DNA as sample. It became possible to develop the various kind of palatability estimation equations based on DNA analysis by PCR method against the data by the sensory test, physicochemical measurements or the spectrophotometric measurements. Palatability estimation equations based on DNA analysis has promising possibility to be applied for the breeding of high-palatability rice or the evaluation of cooked rice palatability of the rice products in the market.

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The antioxidative activity of trehalose on autoxidation of unsaturated fatty acid (UFA) were investigated by a water/ethanol system. The formation of hydroperoxide (HPOD) from linoleic acid (LA) was remarkably inhibited by trehalose. The inhibitory effect on the autoxidation was dependent on the amount of trehalose. Several other disaccharides, sucrose, maltose, and neotrehalose, showed negligible effect on the autoxidation, but maltitol was effective second to trehalose. Similarly to LA, the formation of HPOD from α-linolenic acid (LNA) was inhibited by trehalose and maltitol. On the other hand, when the degradation of LA-HPOD was tested under the same conditions of the autoxidation, it was found that the degradation was not influenced by the presence of all of the saccharides tested, including trehalose. Although volatile aldehydes generated from LA-HPOD was slightly reduced by trehalose and maltitol, the effect of both saccharides seemed to be weak, compared with their inhibitory effect on the autoxidation. Thus, it is clear that trehalose and maltitol inhibit the autoxidation of UFA, but negligibly supress the generation of volatile aldehydes from HPOD.

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The effect of γ-aminobutyric acid (GABA) in yeast extract on blood pressure of stroke-prone spontaneously hypertensive rat (SHRSP) were examined. Two groups of SHRSP were fed 20mg GABA/kg and 40mg GABA/kg respectively, for a month. The systolic blood pressure (SBP) of the two groups were significantly lower, 11mmHg (20mg/kg) and 26mmHg (40mg/kg), compared with the control group after a month. The diastolic blood pressure (DBP) of the two group were also significantly lower, 12mmHg (20mg/kg) and 17mmHg (40mg/kg). Heart rate of the two groups also dropped. Reduction in plasma adrenaline level was observed in 40mg GABA/kg group. These results suggested that GABA in yeast extract had a hypotensive effect.

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The pineapple stem juice-fraction was found to exhibit inhibitory effect against hemolytic activity of venom (hemolysin) prepared from the Deadly Box Jellyfish (Sea Wasp, Habu-Kurage), Chiropsalmus guadrigatus. The antihemolysin was purified to homogeneity from pineapple stem juice by Sephadex G-25 column chromatography, TLC, and HPLC using a MiniQ PC32 2/3 column. The purified antihemolysin had the maximum absorption value at 260nm. It was peptide containing fourteen kinds of amino acids. By the addition of 100μg/ml of antihemolysin, a half of original hemolytic activity of hemolysin was lost.

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The Compactdry CF method was compared with the conventional method (Desoxycholate agar) for 20 type strains and 100 food samples. In the experiment using 20 strain bacteria, there was no significant difference between the compactdry CF method and the conventional method. Total coliforms were determined using 100 food samples, and an adequate correlation was observed between the two methods (r=0.91). These findings suggest that the Compactdry system can be effectively used as a rapid and convenient method for determining total coliforms in foods.

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