海洋深層水が清酒酵母に与える影響(Effect of Deep Seawater on Sake Yeast)
- 標題
- 海洋深層水が清酒酵母に与える影響(Effect of Deep Seawater on Sake Yeast)
- 作者
- 上東 治彦, 加藤 麗奈, 杉山 洋, 上神 久典, 中尾 みか, 佐見 学(Haruhiko UEHIGASHI, Reina KATOH, Hiroshi SUGIYAMA, Hisanori UWAGAMI, Mika NAKAO, Manabu SAMI)
- 文件屬性
- 日本研究
- 知識分類
- 食品應用
- 出版年
- 2006
- 刊名
- 日本醸造協会誌
- 卷
- 101
- 期
- 2
- 頁
- P 117-124
- 點閱數
- 6907
摘要
高知県室戸市では水深320mの海中から海洋深層水(DSW)を取水している。DSWはその清浄性および多くのミネラルを含むことから, 様々な発酵食品に応用されている。今回, 清酒発酵に与えるDSWの影響を調べることを目的として, 小スケールでの清酒発酵試験(1-2L)を行った。従来からDSWを発酵中に添加することにより, 清酒の香気成分すなわち酢酸イソアミル, カプロン酸エチルおよびカプリル酸エチルの生成を亢進することが知られている。この現象のメカニズムを探る目的で, DSWを添加して発酵させた場合の酵母の遺伝子発現をcDNAマイクロアレイを用いて解析した。その結果, DSWの添加により高級アルコーレおよび脂肪酸の代謝, 生合成に関連する遺伝子の発現上昇が認められた。これらの発現上昇が清酒の香気成分の生成量を増加させたものと推察された。また, DSWを添加した清酒の小仕込を行い, 官能検査を実施したところ, NaClやDSWの主要ミネラルを添加した場合に比べて総合評価が有意に高いことが明らかとなった。さらに興味深いことに, NaClを単独添加した場合, ストレスに関連する遺伝子の発現が上昇することが見出された。一方, DSWを添加した場合, このストレス関連遺伝子の発現上昇は抑えられた。以上の結果からDSWを清酒醸造に応用することの重要性が示されたものと思われる。
Deep Sea Water (DSW) can be pumped up from a depth of 200 meters at Muroto in Kochi. Since DSW is known to be unspoiled by pollution and contain various minerals, it is used for a variety of fermented foods. To investigate the effects of DSW on sake production, we carried out small-scale (1-2L) fermentation tests. As a consequence, the addition of DSW led to elevated levels of aroma components, including isoamyl acetate, ethyl caproate and ethyl caprylate. To elucidate further the mechanism underlying this phenomenon, we used cDNA microarray for studying yeast gene expression during fermentation. As a result, the addition of DSW substantially increased the transcript levels of several genes known to be involved in higher alcohol and fatty acid biosynthesis. It is therefore suggested that the rise in transcription of these genes caused the increased aroma production. Sensory evaluation revealed that the addition of DSW to fermentation resulted in a significantly superior flavor profile of final products compared with the addition of NaCl, a major component in seawater. Interestingly, the microarray analysis demonstrated that the addition of NaCl by itself induced stress during fermentation as indicated by mRNA levels in sake yeast. The addition of DSW appeared to ameliorate the negative effect induced by NaCl. Taken together, these results indicate that addition of DSW to the fermentation processes provides unique advantages for sake production.
Deep Sea Water (DSW) can be pumped up from a depth of 200 meters at Muroto in Kochi. Since DSW is known to be unspoiled by pollution and contain various minerals, it is used for a variety of fermented foods. To investigate the effects of DSW on sake production, we carried out small-scale (1-2L) fermentation tests. As a consequence, the addition of DSW led to elevated levels of aroma components, including isoamyl acetate, ethyl caproate and ethyl caprylate. To elucidate further the mechanism underlying this phenomenon, we used cDNA microarray for studying yeast gene expression during fermentation. As a result, the addition of DSW substantially increased the transcript levels of several genes known to be involved in higher alcohol and fatty acid biosynthesis. It is therefore suggested that the rise in transcription of these genes caused the increased aroma production. Sensory evaluation revealed that the addition of DSW to fermentation resulted in a significantly superior flavor profile of final products compared with the addition of NaCl, a major component in seawater. Interestingly, the microarray analysis demonstrated that the addition of NaCl by itself induced stress during fermentation as indicated by mRNA levels in sake yeast. The addition of DSW appeared to ameliorate the negative effect induced by NaCl. Taken together, these results indicate that addition of DSW to the fermentation processes provides unique advantages for sake production.