We prepared Yuzu (Citrus junos) fruit whole paste to analyze its food functionalities and aroma components, and to evaluate its functionality. Nomilin, which is one of the food functional components, was found in the seeds and in the Yuzu fruit whole paste. The Yuzu fruit whole paste from Saitama Prefecture contains vanillin, which is a sweet scent, and eugenol, which is a spicy scent. Additionally, the Yuzu fruit whole paste was found to contain sufficient aroma components. Furthermore, the freeze-dried Yuzu fruit whole paste may affect the lipid metabolism. Importantly, nomillin present in the Yuzu fruit whole paste increased collagen synthesis in the cultured progenitor osteoblasts, thereby indicating that nomillin has the potential to improve the bone metabolism. The use of the Yuzu fruit whole paste including pericarp and seeds made in this study is expected to reduce the industrial waste cost for producers and contribute to the regional industry. Furthermore, the Yuzu fruit whole paste may also have meaningful physiological effects on consumers because of the presence of functional components in the seeds and peels.

　To develop a regression model for the prediction of the physical properties, applicable to peach fruits stored at different temperatures, the respiration rate (CO₂ output rate) and five physical parameters of peach fruits (cv. Kanoiwa-Hakutou) were investigated in the context of storage at 0, 5, 10, 15, 25, and 35℃. The firmness index of the peach fruits was measured using a hand-held firmness tester, whereas the maximum load, spring constant at small and large deformations, and flesh firmness were measured using a universal firmness tester. The changes in the five physical parameters over time showed similar tendencies, and the physical parameters correlated well with cumulative respiration. Consequently, we developed a mathematical model for the prediction of the physical parameters of individual samples based on their cumulative respiration, which followed a sigmoid-type function. The data obtained for these five physical parameters using the model showed a high correlation coefficient (R²＝0.819－0.921), and the spring constant at a small deformation showed the highest value among all parameters. These results indicate that developing a model using cumulative respiration as a variable is feasible and allows the prediction of changes in the firmness characteristics of peach fruits during the postharvest period.

　The phenolic constituents in three sugarcane extracts—bagasse extract (BE), bagasse hydrothermal extract (BHE), and sugarcane juice extract (SJE)—were studied for antioxidant properties using LC coupled to a photodiode array detector and an electrospray ionization mass spectrometer (ESI-MS). The LC-UV/MS chromatogram of the BE showed a signal similar to that of the BHE. Syringic acid (1), 4-hydroxybenzaldehyde (2), p-coumaric acid (3), vanillin (4), syringaldehyde (5), and ferulic acid (6) were detected in the BE and BHE, while the profile of SJE was different; only compounds 4 and 5 were detected in the SJE. In this work, we attempted to elucidate the chemical structure of an unknown peak in the spectrum of the BE. Subsequently, (4E) -3,5-bis (4-hydroxyphenyl) pent-4-enoic acid (7) was identified by a spectral investigation. These seven phenolic compounds were quantified by selective ion mass chromatography (SIM) using LC-MS, and the accumulated contents were 130.3, 105.2 and 1.4mg/g of dry weight in the BE, BHE, and SJE, respectively. Furthermore, each of the seven phenolics and three extracts was examined for antioxidative activity by measurement of the H-ORAC value. These values for the BE, BHE, and SJE were estimated to be 9319, 9417 and 9276 μmol Trolox equivalent/g D.W., respectively. Therefore, the contributions of these seven phenolics to the H-ORAC values were 23.9% for BE, 24.5% for BHE and 0.3% for SJE of the total H-ORAC value.

　We investigated a heat sterilization method for powdered foods such as buckwheat (soba) flour and used a low-oxygen gas heat sterilizer to extend the quality retention period of raw buckwheat noodles. The sterilization instrument incorporated closed circuit flow in which high-temperature, low-oxygen gas (N₂ and water vapor from buckwheat flour) circulated as a heating medium. The low-oxygen gas sterilized the buckwheat flour in a short period without deterioration of the flour quality. Open circuit flow and high temperature air sterilization were also performed using a conventional method. Low-oxygen gas heat treatment significantly reduced bacterial counts, although some characteristics (moisture content, color, flavor, etc.) were altered by the treatment; however, retention of these qualities was better than with the hot-air sterilization treatment. We prepared raw buckwheat noodles from buckwheat flour sterilized with low-oxygen gas and investigated the quality retention period. The bacterial counts of sterilized buckwheat noodles were lower than the prescribed reference value at 10 days. In addition, low-oxygen gas sterilization had little effect on some characteristics (moisture content, water activity, flavor, color, and food texture) or on a sensory evaluation of the buckwheat noodles.

　Low-sugar content plum jams were stored at 24℃ which is equivalent to room temperature, and a microorganism test, physicochemical test and sensory evaluation test of the jam were performed to set the Best-before date. In addition, we preserved jams at high temperatures of 34℃ and 44℃, which were assumed to be accelerated tests. We then derived the Arrhenius equation from the results of physicochemical tests and sensory evaluation tests, and investigated a method for predicting the Best-before date. As a result, the following findings were obtained. (1) The microbial test confirmed that the jam was not spoiled by microorganisms. Therefore, it was found that the microbial test results do not serve as an index for setting the Best-before date when the sterilization treatment is performed properly. (2) The results of sugar content, pH, and water activity measured as physical and chemical tests did not change significantly at any temperature during storage, but the color value (color difference) changed depending on the storage period and temperature. (3) The comprehensive evaluation point of the sensory evaluation test decreased linearly at any storage temperature, and the higher the temperature, the more remarkable the evaluation score decreased. (4) It was clarified that the color difference, which was observed to change during storage, and the comprehensive evaluation point of the sensory evaluation test were indexes for setting the Best-before date. The Best-before date of the plum jam was calculated based on the results, and the color difference was 140.2 days, and the sensory evaluation score was 87.3 days. Since the period obtained from the latter was shorter, this was adopted and further multiplied by the safety factor to determine the Best-before date of the plum jam as 69 days. (5) The color difference showed a change corresponding to the first-order reaction, but it was not possible to predict the time-varying equation only by the Arrhenius equation. On the other hand, the change in the comprehensive evaluation point of the sensory evaluation test corresponded to the 0th-order reaction. The Best-before date estimated by the Arrhenius equation, which was derived from the time-varying equation of the comprehensive evaluation point of the sensory evaluation test at each storage temperature, was close to the measured value.