The Faculty of Agriculture, Yamagata University
Because it is an area that takes pride in a wide variety of indigenous crops in Tsuruoka, Yamagata Indigenous Crops Preservation Center was founded in 2004 to ensure the preservation of the indigenous crops. In this Center, the indigenous crops are cultivated and exhibited while being preserved and the crops are employed by the students as educational materials.
Institute for Advanced Biosciences, Keio University (IAB)
The IAB is currently engaged in state-of-the-art research on sake in Tsuruoka. In collaboration with the Tsuruoka Sake Brewers Council, the institute clarified, by means of metabolomics, the scientific mechanism of jukusei, or aging of Japanese sake, which is a process of preservation for a certain period of time and, as a result, the flavor and smoothness of sake being enhanced.
Through this research, the institute tracked changes in the composition of namazake, or sake before heat treatment, and hiirezake, or heat-treated sake, made by eight sake breweries based around Tsuruoka, after four months of preservation. The result was that in namazake, glucose, the main component of sweetness, and the peptides, which are related to sourness and bitterness, increased and the amino acids decreased over time. In heat-sterilized hiirezake, on the other hand, no increase in glucose or the peptides was detected but the decrease in the amino acids was found to be faster than in namazake. This demonstrated a difference in transition between namazake and hiirezake.
This technology has caught worldwide attention since it may potentially be applied to management and evaluation of the quality of sake as well as to the optimization of preservation methods. In addition, the technology is increasingly expected to have the potential for use with other alcoholic beverages, including wine and shochu.