To obtain soft-ripened persimmons, 'Saijo' persimmons (Diospyros kaki Thunb.) were stored for several weeks at 0℃, treated with 100 or 20 ppm ethylene in sealed containers for 48 h at 20℃, and subsequently kept for 4 days at 10℃ or 20℃. During the ethylene treatment, the containers were left open for 1 h for ventilation, and the effects of the frequency of ventilation on peel color were examined. The persimmons treated with 100 ppm ethylene with or without ventilation reached the soft-ripened stage after 4 days at 10℃ or 20℃. Ventilation during the 100 and 20 ppm ethylene treatments markedly improved peel color of persimmons soft-ripened at 20℃. In summary, ventilation during ethylene treatment improved peel color of persimmons soft-ripened after storage for 4 weeks at 0℃.

　After being stored for several weeks at 0℃, 'Saijo' persimmons were treated with 100 ppm ethylene in sealed containers for 48 hours at 20℃. Immediately after the ethylene treatment, the fruit were packaged in perforated polyethylene film bags and perforated containers and then kept for 4 days at 20℃. Packaging of the individual fruit in the perforated bags that had a perforation area of 39.3 mm² per persimmon significantly decreased the fruit cracking ratio. Packaging of the persimmons in a container that had a perforation area of 42.5 mm² per persimmon or in a container that had a perforation area of 137.8 mm² per persimmon also significantly decreased the fruit cracking ratio. A relatively high calyx abscission ratio and the greatest weight loss were observed in the persimmons packaged in the container that had a perforation area of 137.8 mm² per persimmon. From a practical point of view, packaging persimmons in a container with a perforation area of 42.5 mm² per persimmon or individual packaging of the fruit in a perforated bag with a perforation area of 39.3 mm² per persimmon seems to be the most useful method for inhibiting fruit cracking during the soft ripening of 'Saijo' persimmons.

　The seasonal changes in the quality properties of Shiikuwasha (Citrus depressa Hayata) juice were investigated. In juice at from Shiikuwasha the beginning of the extraction season (October), the concentrations of polymethoxylated flavones (PMFs), such as nobiletin, tangeretin and sinensetin, and the synephrine concentration were higher than those in other months. However, the °Brix/acid ratio was low at 2.20 (°Brix : 9.20，acid : 4.18) in October, indicating the inferior quality of the juice as beverage. The °Brix/acid ratio of the juice at the end of the extraction season (late December) was comparatively high at 5.35～6.09 (°Brix : 9.20, acid : 1.51～1.72), showing high sensory quality. However, the PMF concentration is 1/3 that of the juice at the beginning of the Shiikuwasha season. From these results, juice from Shiikuwasha from the end of November to the beginning of December was considered to be [of well balanced quality] in terms of PMF, and synephrine concentrations and °Brix/acid ratio.

　In this study, we examined the growth inhibition of two heterofermentative lactic acid bacteria, Lactobacillius brevis and Leuconostoc mesenteroides, by the aqueous extracts of 93 species of wild grasses. The aqueous extracts of the 15 species inhibited the growth of the lactic acid bacteria at a concentration of 1% (w/v). The aqueous extracts of evening primrose (Oenothera biennis), shirobanasakuratade (Polygonum japonicum), and agrimony (Agrimonia japonica) had particularly low minimum inhibitory concentrations, being lower than that of green tea.