A NIR spectral imaging apparatus was developed to obtain information on spectrally discriminated images and the location of material to be measured. The apparatus consisted mainly of a CCD camera, a liquid crystal tunable filter and a spectral illuminator, which consisted of a xenon lump as well as a grating spectrometer. The sample surface image could be captured at any wavelength from 400nm to 1100nm. To investigate the performance of the apparatus, it was employed in the measurement of sugar content distribution at the surface of a fresh green melon cut in half and in the detection of foreign materials among blueberries. The absorbance at 676nm was found to be highly correlated with the sugar content in fresh green melons. Next, the intensity of each pixel of the images was converted into sugar content. By assigning the sugar content to a linear color scale, the sugar distribution of the melon was visualized. The plant organs could be detected by the second derivative absorbance image at 680nm, which is an absorption band of chlorophyll. The second derivative absorbances for blueberries and plant organs were determined in the image. The positions of pixels judged as plant organs in the detection image were in good agreement with the actual locations where plant organs had been placed. The apparatus demonstrated that plant organs contaminating the raw blueberry materials could be detected using the proposed methodologies.
Japan has a wide variety of commercial beverage products compared to the rest of the world. Tea (green, black, oolong, etc.), coffee, and fruit juice (especially citrus) beverages are the main product groups. For beverages providing a mellow and attractive flavor, aroma is one of the most important factors affecting quality and thereby product value. Generating a product with high quality aroma and good palatability poses significant challenges during product quality improvement. Therefore, to create attractive beverage products, fundamental knowledge of the key aroma constituents (potent and off-flavor odorants), as well as their chemical and sensory behaviors, in beverages has been strongly needed. In this article, our research about potent and off-flavor odorants and their characteristics in teas (Sen-cha, pan-fired green tea, and Ceylon black tea), coffee, and citrus fruit juices, based on the Aroma Extract Dilution Analysis (AEDA) technique, is described.
近年，高齢者における誤嚥性肺炎の発症者数が増加している．誤嚥性肺炎の予防には，口腔細菌叢の改善が重要と考えられている．例えば，選択圧により口腔の細菌の割合を増加させたりする．そこで，in vitroで種々の食品成分が口腔細菌や誤嚥性肺炎の起因菌などの増殖に及ぼす影響を調べた．15μg/mlの（−）-Epigallocatechin Gallate (EGCg）液は，口腔に常在の細菌（S. mitis, S. oralis, S. salivarius）の増殖率をおよそ50％抑制した．しかし，そのEGCg液はS. pneumoniae, S. sanguinis, S. mutans, E. faecium, P. aeruginosaおよびE. coliなどの増殖は抑制できなかった．10mg/mlのXylitol液は，レンサ球菌の増殖率を50％前後抑制した．しかし，グラム陰性菌種の増殖率は，抑制できなかった．5mg/mlのCaffeine液は，口腔に常在の細菌の増殖率をおよそ50％抑制した．この時，誤嚥性肺炎の起因菌の増殖率は，口腔に常在の細菌よりもより強く抑制された．