The internode cavities of bamboo were utilized as storage chambers for keeping fruit fresh during the Ming dynasty in China. It was reported that fruits could be kept for a long time due to the antiseptic action in the internode cavities. In order to confirm this, we compared the quality of fresh fruits stored in the internode cavities of bamboo with that in plastic chambers as a control and investigated the trace gas component in the internode cavities. The experiments were conducted with Phyllostachys heterocycla as a bamboo species and used sweet peppers as the fresh fruit. The concentrations of O₂ and CO₂, temperature and relative humidity in the internode cavities of bamboo were similar to those in the plastic chambers during the experiment. Hydrocarbons including C₈H₁₄O and C₁₃H₂₂O with antiseptic action were detected as trace gases in the internode cavities of bamboo. Surface color change, injury damage and weight loss of fruits were more significant in the plastic chambers than in the internode cavities of bamboo. It was comfirmed that the fruits of sweet pepper can be kept for a longer time in the internode cavities than in the plastic chambers.

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In this study, a convenient and stable measurement method of cell concentration of Amphidinium sp. growing in culture solution was developed and it was applied to investigation of effects of different light property on growth rates of the algae. As cell clusters of the algae were observed when the concentration was high, the cell concentration measured with a conventional hemocytometry was underestimated. However, high linear relationships were observed between cell concentration and chlorophyll fluorescence intensity excited at 470 nm light and measured at 680 nm in spite of high concentrations. The relationships were represented as the two regression lines. The one belonged to the algae in the white, blue and red-blue light LED conditions and the other belonged to it in the red light LED conditions. The growth rate of the algae cultured under blue light was much larger than that under red light, and that under red-blue light (red:blue = 4:1) was larger than that under blue light. These results imply that blue lights are necessary for the algae to proliferate rapidly, and even a bit of blue light has the effect of propagate the algae, and chlorophyll fluorescence measurement could be applied to estimation of normally-developed algae cell concentration.

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Chlorophyll fluorescence measurement technique is widely used as a powerful tool in obtaining dynamic information on photosynthetic activities in non-destructive and non-invasive way. And, it has been reported that electron transport rate (ETR), one of the most popular chlorophyll fluorescence parameters, can be used as a relative index of photosynthetic rate in C₄ plant leaves because of their photorespiration is negligible. In this study, we applied for the first time ETR to assess photosynthetic rate of turf grass (Zoysia matrella Marr.) canopy. As a result, we observed a direct correlation between relative ETR (rETR: rETR=PPF×Φ_PSII) defined in this study and gross photosynthetic rate under the artificial light condition in our lab. Furthermore, based on the lab data, we tried to diagnose the effects of water-stress on turf grass canopy under the sun and then successfully detected a significant decrease in gross photosynthetic rate of turf grass canopy by measuring its rETR.

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By using rice grains as an example of the application of XYZ chemiluminescence to food products, we analyzed factors that affected the photon emission. The X photon emission curve of rice consists of primary emission, with a peak immediately after mixing, and persistent secondary emission. It is similar to the XYZ standard photon emission curve and requires continuous measurement after the reagent is injected. The results of the analysis showed that maximum photon emission intensity and the emission curve were changed markedly by changing the grain size of the rice. The results of the analysis also showed that solid samples such as rice needed to be ground into an uniform size to achieve accurate measurements. The maximum intensity of the primary photon emission was comparable in air and nitrogen gas. Under air, after the intensity had peaked it decreased and then increased again. We inferred that, after the primary emission, secondary emission was sustained by the reaction of the Y reagent (gallic acid) with remaining concentration and oxygen in the air in the presence of the Z reagent (catalyst). This suggests that air should be replaced with nitrogen gas for accurate measurements. A strong correlation between fat acidity (the deterioration index of rice) and photon emission intensity was observed. This indicates that X photon emission shows the level of lipid peroxides and that integrated photon emission is an appropriate analysis index for solid samples. The approach used here, which requires only a small sample, has a low level of environmental impact and is quick and effective in measuring deterioration in the quality of rice grain.

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