ISOBE Yuka Mie University, Faculty of Education, Associate Professor, 教育学部, 助教授 (80218544)
MATSUI Hiroki Mie University, Faculty of Bioresources, Associate Professor, 生物資源学部, 助教授 (30346001)
|Budget Amount *help
¥3,800,000 (Direct Cost : ¥3,800,000)
Fiscal Year 2004 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 2003 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Narezushi produced in Mie Prefecture were investigated for microbial ecology, changes in components during maturing process, and function of isolated lactic acid bacteria(LAB). The study was conducted to inherit the traditional food positively.
In the case of Sammazushi, viable counts of bacteria were 8.9X10^8 and 1.8X10^8 cells/g for fish meat and rice, respectively. Three LABs isolated from the Narezushi were identified as Lactobacillus sakei, Leuconostoc lactis, and Lactococcus lactis, respectively, based on nucleotide sequences. Several general bacteria were also isolated.
Molecular ecological analyzes of microbiota of Sammazushi and Sabazushi were carried out. For Sammazushi, 13 species were detected from 89 clones. Five LABs,Lb.sakei, Leuc.gelidum Leuc.mensenteroides, Lc.lactis subsp.lactis MR17,Lc.piscium were included. Lb.sakei was considered as major LAB according to abundance of clone. For Sabazushi,23 species were found from 93 clones. Eleven LABs,Lb.sakei, Pediococcus pentosaceus, Lc.piscium, Leuc.gelidum etc.were included.
Changes in components during maturing process were investigated. Moisture of fish meat portion was increased after maturation in Narezushis tested. While ash content of fish meat was decreased, that of rice portion was increased. Change in protein content was small during maturing process. Almost all amino acids were decreased in Ayuzushi. Several amino acids were increased in Sabazushi, and many of amino acids were increased in Sammazushi. Changes in contents of free amino acid were varied among Narezushis tested. Kinds of amino acids changed during maturing were also varied among Narezushis. Lactate was major organic acid among Narezushis. Several LAB isolates were tested for tolerance against acid, however, none of the isolate tolerated for treatment at pH2.