著者

ONO Tomotada CHOI Myoeng Rak IKEDA Ako ODAGIRI Satoshi

出版者

社団法人日本農芸化学会

雑誌

Agricultural and Biological Chemistry (ISSN:00021369)

巻号頁・発行日

vol.55, no.9, pp.2291-2297, 1991-09-23

被引用文献数

8 42

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The protein particles in soymilk were fractionated in size by differential centrifugation. Particles of more than 100 nm in diameter (LSP) constituted 40% of the total protein in raw soymilk, 70% of the protein components being 11S globulin. LSP was not formed in the presence of 2-mercaptoethanol and sodium ascorbate. LSP was decreased by heating, and particles of 100-40 nm in diameter (MSP) were increased. The formation of MSP was not due to any degradation of LSP but to the combination of supernatant proteins of less than 40 nm in diameter with each other. MSP formed by heating contained the βsubunit of 7S and the basic subunit of 11S as main components. The particles of more than 40 nm in diameter (LSP+MSP) constituted 50% of the total protein in both raw soymilk and soymilk.

著者

菅原 悦子 伊東 哲雄 米倉 裕一 櫻井 米吉 小田切 敏 SUGAWARA Etsuko ITO Tetsuo YONEKURA Yuichi SAKURAI Yonekichi ODAGIRI Satoshi

出版者

日本食品科学工学会

雑誌

日本食品工業学会誌 (ISSN:00290394)

巻号頁・発行日

vol.37, no.7, pp.p520-523, 1990-07

被引用文献数

1

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Bacillus natto was cultured in the chemically defined liquid medium which contain various amino acids as nitrogen source, and effects of amino acids on the formation of pyrazines were examined. The amino acids which are related to glutamic acid on metabolism, L-glutamic acid, L-aspartic acid, L-arginine and L-proline, promoted the best growth. Yields of pyrazines produced in the culture broth were not always parallel to cell growth. In the case of L-serine, L-aspartic acid, L-alanine and ammonium citrate, whole pyrazines were yielded about 10mg/l and above, and mostly consisted of tetramethylpyrazine. Pyrazines which have a characteristic side chain corresponding to the amino acid present in the medium were not detected.各種アミノ酸を添加した合成培地で納豆菌を培養し,ピラジン化合物の生成量を比較検討し,ピラジン化合物生成に対する納豆菌の役割について考察した.(1) 各種アミノ酸を添加した合成培地での納豆菌の増殖は代謝上, L-グルタミン酸と関連の深いアミノ酸(L-グルタミン酸, L-アスパラギン酸, L-アルギニン, L-プロリン)で良好であった.(2) 培養液からのピラジン化合物の抽出方法として,加熱条件の有無を考慮して, LIKENS-NICKERSON型連続蒸留抽出装置を用いる方法とPorapak Q吸着剤を用いる方法を比較したが,連続蒸留抽出法でピラジン化合物が二次的に生成している可能性は薄かった.(3) 納豆菌の増殖の良否とピラジン化合物の生成量には相関はみられず, L-セリン, L-アスパラギン酸, L-アラニン,クエン酸ニアンモニウムで, 10mg/l前後,あるいはそれ以上のピラジン化合物を検出し,その大半はテトラメチルピラジンであった,(4) 各種アミノ酸の特徴的な側鎖をもつピラジン化合物は確認できなかったので,この化合物はアミノ酸から直接生合成されず,より簡単な中間体をへて生成される可能性が高い.(5) 納豆菌が関与するピラジン化合物生成はその前駆体を多量に生成することによる可能性は高いが,最終段階まで酵素的に進むことも考えられ,さらに検討が必要である.