The effect of a high-pressure carbonation treatment on the change in quality of sake during storage was investigated. Measurements of the amino acidity and isovaleraldehyde content of carbonated sake ...(20 MPa pressure at 40, 45 and 50 deg C for 7, 21 and 33 min, respectively) as well as of heat-treated sake (reaching temperature of 65 deg C and immediately cooled) were almost unchanged during storage at 3 and 20 deg C. Glucose in the sake subjected to these treatments was retained at an almost constant under the same storage conditions, except for the sake carbonated at 40 deg C and stored at 20 deg C. In contrast, the amino acidity, and glucose and isovaleraldehyde contents of non-pasteurized (fresh) sake increased during storage at both temperatures. The sake samples subjected to the carbonation treatment and heat treatment both gave better sensory scores than the fresh sake sample after 6 month of storage at 3 and 20 deg C, especially at 3 deg C for the flavor. These results suggest that the high-pressure carbonation treatment is an effective new technique for preserving the quality of sake.
According to conventional views, the rosy bitterling, Rhodeus ocellatus, comprises two subspecies, R. ocellatus kurumeus and R. ocellatus ocellatus, the former being native to Japan whereas the ...latter was introduced into Japan from China during World War 2. To examine the genetic structure of Japanese R. ocellatus, part of the mitochondrial cytochrome b gene from 48 individuals collected from various locations in Japan was sequenced. Three major mitochondrial lineages were found. Based on historical evidence, two of these represent R. ocellatus ocellatus and the third R, ocellatus kurumeus. The existence of two distinct lineages of R. ocellatus ocellatus in Japan suggests at least two colonizations. Some local populations comprised purely R. ocellatus kurumeus, but those from Kashima and Ogori included both subspecies. Because the proportion of R. ocellatus ocellatus in Kashima increased from 1994 to 1995, invasion by R. ocellatus ocellatus into R. ocellatus kurumeus habitats is apparently in progress.
