JP2004313032A

JP2004313032A - Method for producing functional raw material

Info

Publication number: JP2004313032A
Application number: JP2003108595A
Authority: JP
Inventors: Sadaji Yokoyama; 横山定治
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-04-14
Filing date: 2003-04-14
Publication date: 2004-11-11

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing γ-aminobutyric acid, to provide a food, feed, fertilizer, agrochemical or the like, containing the γ-aminobutyric acid, to provide a food, feed, fertilizer, agrochemical or the like, obtained by the method, and to provide a method for economically and efficiently preserving a raw material selected from various food raw materials in a lactobacillus fermentation process, various un-used food raw materials, or their post-treated products, characterized by treating the preservation target by a decarboxylation enzyme reaction of lactobacillus in an anaerobic condition to prevent contamination with various bacteria. <P>SOLUTION: This method for producing γ-aminobutyric acid is characterized by treating a food raw material which contains ≤20 w/v% of glutamic acid and/or its salt or to which the ≤20 w/v% of glutamic acid and/or its salt is added, with a lactobacillus having a glutamic acid decarboxylation enzyme-producing ability. In order to prevent nutritive substances, functional substances contained in the raw material, a heating temperature in a process for thermally treating the food raw material may suitably be adjusted, or the food raw material may not be heated. The formation of an anaerobic state due to the generation of carbon dioxide in the decarboxylation enzyme reaction of the lactobacillus fermentation can be utilized to achieve the practically sufficient preservation of the food and food raw material even in a non-closed container (opened container). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、γ―アミノ酪酸の製造方法、γ―アミノ酪酸を含有する食品、飼料、餌料、肥料、又は農薬等の製造方法、及び当該方法で得られる食品、飼料、餌料、肥料、又は農薬等に関する。本発明は、又、乳酸菌の脱炭酸酵素反応により保存対象物を嫌気状態にして雑菌による汚染を抑制することを特徴とし、当該乳酸菌発酵過程により各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料の経済的、効率的な保存方法を提供するものである。
【０００２】
【従来の技術】
近年の我が国に於ける食の欧米化に伴う動物性脂肪の過剰摂取、ファーストフード、スナック菓子、清涼飲料からの甘味料の過剰摂取等の栄養バランスの偏りによって、若年層から老年層にわたり癌、心疾患、肥満、アレルギー性疾患、動脈硬化等の生活習慣病が急増している。更に、病原性大腸菌Ｏ―１５７、黄色ブドウ球菌等による食中毒、規制外食品保存薬の添加、輸入農産物中の残留農薬問題等食品の保存に関しても深刻な問題が発生している。又、男女ともに平均寿命が世界最高になるなど、国民の高齢化が急速に進展し、国民医療費の高騰、高齢者の健康維持、老化防止等への対策が求められている。又、高度情報社会でのストレスの高い職場環境、生活環境で過ごす為のリラックス機能、抗ストレス作用のある食品の開発が求められている。
【０００３】
上述の現在人の直面する食生活への不安を解消する方策として、最近、農水産物及びそれらに含まれる機能性成分（ファイトケミカルズ）、及び各種発酵生産過程を利用した疾病予防、健康維持・増強作用等の機能性を持つ新しい加工食品、医薬品素材、機能性食品素材等の新規研究開発が注目されている。
【０００４】
大豆は、納豆、味噌、醤油等の伝統発酵食品の原料であり、これらの食品が日本人の長寿に関与していることが最近の研究で科学的に実証されてきている。大豆サポニンには抗癌作用、抗動脈硬化作用、コレステロール低減作用が、大豆蛋白、不飽和脂肪酸にはコレステロール低下作用、イソフラボノイドには更年期障害、骨粗鬆症に効果が証明されている。しかしながら、大豆に含まれるｎ−ヘキサナールの青臭さ、大豆蛋白の苦み、イソフラボノイドに起因する収斂味が大豆の消費拡大に対して問題となっている。
豆腐等の生産に際しては大豆の乾燥重量の約４０％が粕に相当する為に、全国で副成する豆腐粕いわゆる御殻（おから）の量は膨大なものとなっている。御殻は蛋白質を４．８％，脂肪を３．６％程度含み栄養成分は比較的豊富であるが水分が約８０％と高い為に、腐敗し易く運搬、保存、利用上の問題となっている。
御殻は一部が“卯の花”等として食品分野で利用される他は大部分が家畜飼料、焼却処分となっている。
甘藷はβ―カロテン、食物繊維、ビタミン、アントシアニンに富み、肝機能改善作用、活性酸素除去能、高血圧抑制作用、便通改善等の機能性を有している。
又、オレンジ色、紫色の色素を多く含む高色素系甘藷は、ペーストフレーク、天然色素、飲料、チップス、パウザー等へも利用が検討されている。又，鹿児島県に於いては澱粉生産に年間約２１万トンの甘藷が使用され、毎年約６万トン（水分８０％換算）の甘藷澱粉粕が排出されている。澱粉粕は澱粉以外の甘藷の有する機能性成分の大部分を含有し、非常に有用なものであるが、非常に腐敗し易く、一部が家畜飼料に使用されているに過ぎない。
【０００５】
又、甘藷を原料とする芋焼酎の生産に際して副成する芋焼酎粕も毎年多量（約２０万トン／年）に副成するが、近年処理方法に窮している。芋焼酎粕も甘藷の澱粉の大部分がアルコール酵母の作用でエタノールに変換したものであり、その他の甘藷に元来含まれていた機能性成分の大部分はアルコール蒸留残渣である焼酎粕中に残存している。焼酎粕はこの様に非常に栄養豊富な機能性に富む有用食品素材であるが、非常に腐敗し易く、又特有の味及び臭いが食品としての利用に際して障害となっている。現状では一部が家畜飼料として利用されているに過ぎない。
【０００６】
食品製造時に副成する粕、廃液はこれまでは海洋投棄、焼却処理される場合が多かったが平成１３年５月に食品リサイクル法が施行され、大量消費、大量廃棄の高度経済成長を基盤とした社会と決別して、食品廃棄物、副成物の有効利用、削減、再利用を基本とするゼロエミッション（循環型）社会の構築が必須事項となった。数値目標として、平成１９年度程度には各企業はその廃棄物の少なくとも２０％をリサイクルする義務が発生する。
【０００７】
以上の状況から、各種農水産物、未利用食品素材及び工場副成物等の有効利用を達成する為には、原料の特異味、特異臭の改善、及びこれらの各種農水産物、未利用食品素材及び工場副成物の保存安定性の向上が最も重要と考えることが出来る。更に、上記の保存過程を通して機能性物質の回収又は／及び生産が出来れば非常に有益である。
【０００８】
抗高血圧作用、アルコール代謝促進作用、抗肥満作用、抗ストレス作用、抗老化作用、学習能力向上効果等を示す機能性物質にγ―アミノ酪酸があり、これはグルタミン酸脱炭酸酵素の作用によりグルタミン酸から生成される。グルタミン酸脱炭酸酵素は微生物、植物及び動物組織に広く分布しており、これらのグルタミン酸脱炭酸酵素を利用した各種のγ―アミノ酪酸を高含有する食品の製造方法が報告されている。
【０００９】
トマト、カボチャ、ニンジン等の植物由来グルタミン酸脱炭酸酵素を用いたγ―アミノ酪酸生産方法がこれまでに提案されている（特許文献１、特許文献２参照）。乳酸菌を用いたγ―アミノ酪酸生産法は特許文献３及び特許文献４に提案されている。クモノスカビ（Ｒｈｉｚｏｐｕｓ）を蒸煮大豆に生育させて高濃度のγ―アミノ酪酸を含む発酵製品を生産する方法も報告されている（非特許文献１参照）。又、グルタミン酸ナトリウムを添加したＧＹＰ（グルコース、酵母エキス、及びペプトン等を含む）培地に乳酸菌を培養して３ｗ／ｖ％以上のγ―アミノ酪酸が生産出来たとの報告もある（非特許文献２参照）。
【００１０】
しかしながら、各種食品素材、各種未利用食品素材、又はそれらの後処理物より、特にそれらの原料を加熱工程等の殺菌処理を行わずに、又は／更に、非密閉容器（解放型容器）等を用いてγ―アミノ酪酸を生産する方法、及びこれらの原料を経済的、効率的に保存する従来技術は現在まで見られない。又、高額の設備投資が不要な、従来設備で対応可能である経済的、効率的、かつ安全な食品、飼料、餌料、肥料、又は農薬等の製造方の開発が求められていた。又、各種食品素材、各種未利用食品素材、又はそれらの後処理物に特有の特異味、特異臭がそれらの食品、飼料等への利用に際して障害となっており、経済的、効果的な改善方法の確立が求められていた。
【特許文献１】
特開平０３―２２４４６７号公報
【特許文献２】
特開平０３−２４４３６６号公報
【特許文献３】
特開２０００−１４３４６号公報
【特許文献４】
特開２０００−２１００７５号公報
【非特許文献１】
日本農芸化学学会誌、第７５巻、臨時増刊号、第２６９頁（２００１年）
【非特許文献２】
日本農芸化学学会誌、第７５巻、臨時増刊号、第２７１頁（２００１年）
【００１１】
【発明が解決しようとする課題】
本発明の目的は、２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料に、グルタミン酸脱炭酸酵素生産能を有する乳酸菌を作用させることを特徴とする抗高血圧作用等を有する機能性物質であるγ―アミノ酪酸を製造する方法、当該方法で得られた高濃度のγ―アミノ酪酸を含む乳酸菌発酵液をその製造過程に使用する食品、飼料、餌料、又は農薬等の製造方法、及びγ―アミノ酪酸を含有する食品、飼料、餌料、肥料、肥料、又は農薬等を提供することにある。
【００１２】
又、本発明の目的は乳酸菌を作用させるに際して、当該原料に含まれる栄養物質、機能性物質が加熱処理等で変質する場合にはその変質を防止する為に栄養物質、機能性物質の安定性に応じて乳酸菌発酵過程等の前後の当該食品素材原料の加熱処理温度を適当に調整するか又は非加熱で行っても良く、更に、本発明方法に使用する、乳酸菌発酵を実施する容器には密閉容器を使用しても良いが、非密閉容器（解放型容器）でも実用上充分な保存効果が達成出来、実用的、経済的、かつ効率的な各種食品素材の保存方法を提供するものである。
【００１３】
【課題を解決する為の手段】
本発明を概説すると、第１の発明は２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料にグルタミン酸脱炭酸酵素生産能を有する乳酸菌を作用させることを特徴とするγ―アミノ酪酸の製造方法。第２の発明は第１の発明の結果として達成出来る各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料の実用的、経済的、かつ効率的な食品素材の保存方法。第３の発明は第１の発明を製造工程に含む食品、飼料、餌料、肥料、又は農薬等の製造方法。第４の発明は第３の発明により得られる食品、飼料、餌料、肥料、又は農薬に関する。第５の発明は第１〜第３の発明を実施するに際して原料の加熱処理を実施、又は非加熱処理のいずれでも行えること、及び第１から第３の発明の実施を密封系容器、又は非密封系容器いずれでも行える経済的、効率的な製造方法の提供である。
【００１４】
本発明者は２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料に、各種微生物を作用させて有用機能性物質を生産する研究を鋭意実施した。その結果２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料にグルタミン酸脱炭酸酵素生産能を有する乳酸菌を作用させることにより機能性物質であるγ―アミノ酪酸を多量に生産出来ること、更に当該原料に含まれる栄養物質、機能性物質が加熱処理等で変質する場合にはその変質を抑制する為に栄養物質、機能性物質の安定性に応じて乳酸菌発酵操作の前後の当該食品素材原料の加熱処理過程での加熱温度を適当に調整するか又は非加熱で行っても良く、更に、本発明方法に使用する、乳酸菌発酵に使用する容器には密閉容器を使用しても良いが、非密閉容器（開放型容器）でも実用上充分な保存効果が達成出来、経済的、かつ効率的に各種食品素材を充分保存出来ることを見いだした。
本発明はこれらの新規事実に基づいて成されたものである。
【００１５】
【発明の実施の形態】
以下に本発明について具体的に説明する。本発明には２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料を用いる。
具体的には豆乳、牛乳、脱脂粉乳、昆布エキス、果物ジュース、果物ジュース、又は野菜ジュース等の食品素材、及び、チーズホエー、大豆煮汁、豆腐廃水、御殻、鰹煮汁、缶詰（パインナップル、オレンジ、モモ等）ジュース、又はアルコール蒸留廃液（芋焼酎粕、米焼酎粕、麦焼酎粕等）、甘藷澱粉粕、ジャガイモ澱粉粕等の未利用食品素材、又はそれらの後処理物より選択した原料等を用いる。本発明に用いる豆乳とは大豆に限らず緑豆、小豆、エンドウ、落花生、刀豆、隠元豆等、一般的に人、家畜に摂取されている豆類から得られたものであれば特に限定は無く、例えば、すり潰したままの、固形分を含んだ状態でも良く、又固液分離して得られる上液を用いても良い。家畜乳としては牛乳が供給量、コスト等の点で使用に適しているがその他の家畜乳、例えば、山羊、羊等の乳も良好に本発明の原料に使用することが出来る。又、脱脂した各種動物の乳、例えば脱脂粉乳を使用することも出来る。海草エキスとしては、供給量、コストの面、及び、品種によれば３ｗ／ｗ％を超える（海草の乾燥物中のグルタミン酸含有量）グルタミン酸を含むところから昆布エキスが本発明には適しているが、他の海草、例えばワカメエキス、ひじきエキス等も使用出来る。果物ジュースとしてはミカン、パインナップル、レモン、モモ、梨、リンゴ等一般的な果物を使用可能であり、野菜ジュースとしてはトマト、キャベツ、白菜、大根等一般的な野菜を使用可能である。
これらは、破砕してそのままのものを使用しても良いが、例えば固液分離した後に使用しても良い。又、鰹節、鯖節等の魚肉エキス等を使用することが可能である。大豆、トーモロコシ、小麦、米等の蛋白質を醤油麹、米麹又はプロテアーゼ等の酵素剤を用いて酵素分解により可溶化、及びアミノ酸化して多量のグルタミン酸を含んだ分解液も本発明の原料に使用することが出来る。
本発明には以上の様な食品素材の外に、未利用、又は廃棄物と見なされている食品素材を使用することが出来る。チーズ生産時に副成するチーズホエーは非常に栄養豊富な食品素材であるが、乳製品の消費拡大と共にその処理に困っている。豆製品の製造時に副成する大豆煮汁、小豆煮汁等の各種豆煮汁も大量に排出され各企業はその処理に困窮している。又、豆腐生産に於いて大量に副成する御殻、豆腐排水もその処理が大きな問題となっている。鰹節生産時に排出される鰹煮汁、各種魚の缶詰生産時に副成する魚煮汁もその処理方法が問題となっている。食品生産企業に於いては各種缶詰原料を使用した際にのこる缶詰ジュースの処理が問題となっている。各種澱粉の生産に際して大量に副成するトーモロコシ澱粉粕、甘藷澱粉粕、馬鈴薯澱粉粕、葛澱粉粕、かたくり澱粉粕、タピオカ澱粉粕等の処理方法の検討が求められている。又各種アルコール製造過程で副成する廃液、例えば醪を蒸留することにより副成するアルコール蒸留廃液は現在その処理に困っている。例えば、乙類焼酎、泡盛、甲類焼酎、ラム酒、ウオッカ、ジン、テキーラ、ブランデー等の蒸留酒製造に際して副成する残渣、廃糖蜜、トーモロコシ等を原料とするアルコール生産で副成する大量アルコール蒸留残渣等の処理方法の提案が求められている。本発明に於いてはこれらの未利用食品素材を使用することが出来る。
使用に際して、これらの未利用食品素材は、固液分離を行わずにそのまま用いることも可能である。又、固液分離をして、固形分を除去した上清、又は固液分離を行って得られた固形分を再度水等に縣濁して用いることも可能である。更に、これらを減圧濃縮装置等で濃縮して使用することも出来る。酒粕、味醂粕等はアルコール含有量が高い為にそのまま使用するのは困難となる場合がある。その場合は、例えば、酒粕を原料にして粕取り焼酎を生産し、その際に副成する焼酎蒸留廃液（焼酎粕）を用いるのが良い。攪拌、縣濁、濃縮、固液分離等は定法による行うが、この操作が本発明における後処理の一例である。
上述の食品素材の内、例えば昆布エキス、蛋白質酵素分解液の様に３〜１０ｗ／ｖ％のグルタミン酸を含む原料は例えば、グルタミン酸又はその塩を添加せずに乳酸菌発酵をすることが可能であるが、その他の原料の場合は一般的に２０ｖ／ｗ％以下の範囲でグルタミン酸及び／又はその塩を添加して乳酸菌発酵を行う。更に、本発明に於いては、上記の食品素材は単独で乳酸菌発酵の培地としても良いが、適当に複数個の原料を混合して用いても良い。例えば、牛乳と豆乳を等量混合したものにグルタミン酸ソーダを添加して乳酸菌発酵を行うことにより、γ―アミノ酸を高濃度に含んだ高機能性のヨーグルトタイプの食品を得ることが出来る。同様のことは、例えば焼酎粕と御殻、野菜ジュースとオレンジジュース、チーズホエーと脱脂粉乳、焼酎粕と豆腐排水とチーズホエー、米焼酎粕と麦焼酎粕と芋焼酎粕と豆乳という様に多様に組み合わせることが可能である。
本発明で用いる乳酸菌としてはグルタミン酸脱炭酸酵素生産能を有する乳酸菌であれば特別に限定は無い。使用可能な乳酸菌例としてはラクトバチルス（Ｌａｃｔｏｂａｃｉｌｌｕｓ，以下Ｌｂ．と略称する）、ラクトコッカス（Ｌａｃｔｏｃｏｃｃｕｓ）、ストレプトコッカス（Ｓｔｒｅｐｔｏｃｏｃｃｕｓ），ロイコノストック（Ｌｅｕｃｏｎｏｓｔｏｃ），ペディオコッカス（Ｐｅｄｉｏｃｏｃｃｕｓ）属等に属するものを挙げることが出来る。これらの中でもラクトバチルス属の乳酸菌が最も適している。例としてはラクトバチルスブレビス（Ｌｂ．ｂｒｅｖｉｓ），ラクトバチルスプランタールム（Ｌｂ．ｐｌａｎｔａｒｕｍ），ラクトバチルスデルブリッキ（Ｌｂ．ｄｅｌｂｒｕｅｃｋｉｉ），ラクトバチルスブルガリカス（Ｌｂ．ｂｕｌｇａｒｉｃｕｓ），ラクトバチルスヘルペティカス（Ｌｂ．ｈｅｌｖｅｔｉｃｕｓ）等を挙げることが出来る。これらの中でも好適な菌としてはラクトバチルスブレビスＩＦＯ−１２００５，ラクトバチルスブレビスＩＦＯ−３３４５，ラクトバチルスブレビスＩＦＯ−１２５２０，ラクトバチルスブレビスＩＦＯ−３９６０，ラクトバチルスプランタールムＩＦＯ−１２５１９，ラクトバチルスプランタールムＩＦＯ−３０７０，ラクトバチルスプランタールムＩＡＭ−１０４１等を用いることが出来る。
乳酸菌はあらかじめ種培養した培養液を用いるのが好ましい。種培養に使用する培地は乳酸菌が良好に増殖する培地であれば特に限定されるものでは無いが、菌の増殖程度を測る為には、薄い着色の透明な培地で種培養を行うのが好ましい。例えば、酵母エキス、グルコースを各１ｗ／ｖ％、ポリペプトンを０．５ｗ／ｖ％、酢酸ソーダを０．０２ｗ／ｖ％、硫酸マグネシウム、硫酸鉄、食塩を０．００１ｗ／ｖ％含有してｐＨを６．８に調整したＧＹＰ培地を用いることが出来る。
種培養した乳酸菌培養液はそのまま使用しても良いが、使用する前に集菌、洗浄、濃縮、縣濁等の前処理を加えても良い。
通常は、各種食品素材、未利用食品素材等にグルタミン酸及び／又はその塩を添加して乳酸菌発酵を行う。グルタミン酸脱炭酸酵素の基質濃度を高めることにより高濃度のγ―アミノ酪酸を生産することが出来る。グルタミン酸の添加は乳酸菌発酵の初期段階で添加しても良いし、又は乳酸菌発酵の途中での２段階、３段階、又は４段階に分割して添加しても良い。添加濃度には特に厳密な制限は無いが、２０ｗ／ｖ％以下が良く、特に０〜１０ｗ／ｖ％が最適である。又、上記原料に乳酸菌の栄養素としてビタミン、無機塩、窒素源等を添加しても良い。
食品素材はグルタミン酸及び／又はその塩を添加した後に、乳酸菌種培養液を接種前にｐＨを３．０〜７．０に、好ましくは４．５〜５．５に調整する。ｐＨが３．０より低いと乳酸菌の生育が抑えられ、７．０より高いと同じく生育が阻害されると共に、雑菌の汚染が発生し易く、所期のγ―アミノ酪酸生産が達成出来ない。
【００１６】
乳酸菌発酵前の食品素材原料は滅菌処理を行っても良いが、この操作は必須では無く、状況に応じて滅菌操作を行わずに直接乳酸菌発酵を行っても良い。当該原料に含まれる栄養原料、機能性原料が加熱処理等で変質する場合にはその変質を防止する為に栄養物質、機能性物質の安定性に応じて乳酸菌発酵操作の前後の当該食品素材原料の加熱処理過程での加熱温度を適当に調整するか又は非加熱で行っても良い。本発明方法に使用する、乳酸菌発酵を実施する容器には密閉容器を使用しても良いが、非密閉容器（解放型容器）でも実用上充分な保存効果が達成出来る。容器上部の開口部は出来るだけ狭くなっている方が、脱炭酸酵素反応で発生する炭酸ガスによる乳酸菌発酵液、及び容器液面部位の脱酸素が充分行われ、充分な嫌気状態の形成により、雑菌の汚染はより効果的に防止される。しかしながら、開放型容器であっても上部に蓋等をすること等で充分に所期の目的は達成出来る。このことにより、経済的、かつ効率的に各種食品素材を充分保存出来る。乳酸菌発酵を行う為に接種する菌体数に特に限定は無いが、接種量が少ない場合は雑菌汚染が起こり易く、接種量を多くした場合には、種培養液生産のコストが増加する。そのため初発菌体数は１ｍｌ当たり１ｘ１０^５から１ｘ１０^９個になるように接種するのが好ましい。乳酸菌発酵の培養条件としては、温度は２０〜４５℃、好ましくは３０〜３７℃が良い。通気、攪拌、静置のいずれの培養法でも良いが、経済性から考えて、静置培養が最も適している。発酵時間は数時間〜１０日の間でγ―アミノ酪酸の生成量を勘案しながら適当に設定すれば良い。
グルタミン酸ソーダが原料中に存在する場合、グルタミン酸脱炭酸酵素反応によるグルタミン酸分子のカルボキシル基の脱離に伴うナトリウムイオンの遊離で乳酸菌発酵液のｐＨが上昇する。乳酸菌は通常は自身の生産する乳酸、酢酸等によるｐＨ低下により発酵の後期に死滅するのが一般的であるが、本発明の実施形態であるグルタミン酸ソーダ存在下での発酵では例外的現象としてｐＨが中性又はそれ以上に迄上昇する。このことは乳酸菌自体の生存には適しているが、反面雑菌汚染の可能性も増大する。そのために、本発明に於いては乳酸菌が充分量に増殖する培養１日以降は菌体内に生産されたグルタミン酸脱炭酸酵素の安定領域であるｐＨ３．０〜６．０に、好ましくはｐＨ３．５〜５．５の範囲に酸又はアルカリで乳酸発酵液のｐＨを調整することを特徴とする。グルタミン酸脱炭酸酵素分子は乳酸菌の細胞膜外層に局在しており、菌体は何らの特別な処理を必要とせずに、菌体そのものが酵素蛋白分子（固定化酵素）の様に触媒反応を行う。
食品の保存中に頻出する腐敗細菌の多くは酪酸菌であり酪酸生成により嗜好性の面で食品価値が激減する。酪酸菌の繁殖を抑えるには溶存酸素を減少させてｐＨを下げることが重要である。本発明に於いては、グルタミン酸脱炭酸酵素反応での炭酸ガス発生により溶存酸素を系外に追い出し、ｐＨを酸性状態に維持することで酪酸菌の増殖が抑えられていると考えることが出来る。又、バチルス属菌等の好気性菌も本発明の酸性下嫌気性条件では生育出来ない。更に、酸性条件下で頻繁に食品を汚染する黴類も本発明の嫌気性条件下では発育は困難である。本発明の条件に於いて容器の液上面が充分な嫌気状態になっていることは着火したマッチを容器内に入れた場合にただちに消火されたことによっても確認された。
乳酸菌発酵液中のグルタミン酸及びγ―アミノ酪酸の定量は測定試料をｐＨ２．２のクエン酸緩衝液で希釈した後、日立アミノ酸自動分析装置Ｌ−８５００Ａ｛（株）日立製作所製｝で行った。
乳酸菌発酵でγ―アミノ酪酸を生産した後は、発酵液をそのまま食品、飼料、餌料等として用いても良く、又はこれから単離精製操作、後処理操作を行っても良い。単離操作の為には、固液分離、クロマトグラフィー、脱色、塩析、電気透析、精密濾過、逆浸透等の操作を組み合わせて実施する。後処理操作は遠心分離、濃縮、膜分離、活性炭処理等を組み合わせて行う。又、精製されたγ―アミノ酪酸は濃縮液の状態で製品としても良いが、噴霧乾燥機によりデキストリン、マルトース等と共に乾燥して粉末状の製品としても良い。これらの製法は通常の方法により行うことが出来る。
この様な操作で天然物である食品素材から高濃度のγ―アミノ酪酸を含有する乳酸菌発酵物を生産することが出来る。例えば消費拡大に問題点であった豆乳の青臭さ、収斂味、野菜ジュースの青臭さ、芋焼酎粕の特異臭等は乳酸菌発酵により低減された。
【００１７】
乳酸菌は食品衛生の点で最も安全な微生物であり、乳製品を初め多くの加工食品の風味の改善、保存性の向上、異臭の除去などの目的に数多く利用されている。
人類は紀元前に羊、山羊、牛等を家畜化したのちに、乳酸菌を利用して積極的のそのミルクを利用してきた。その間、有史以来現在まで、乳酸菌は人類が発酵食品を通じて体内に摂取してきた微生物であり、経験的に観て非常に安全性の高い細菌、いわゆるＧＲＡＳ（ＧｅｎｅｒａｌｌｙＲｅｃｏｇｎｉｚｅｄＡｓＳａｆｅ）と言える。乳酸菌、及び乳酸菌を利用した発酵食品には免疫力増強作用、抗菌性、血中コレステロール抑制作用、整腸作用、乳糖分解作用、膣炎防止、歯槽膿漏予防、抗腫瘍作用等があり、そのいずれについても多くの研究、試験により確認されている。近年予防医学の重要性が強調されており、腸内の微生物とりわけ乳酸菌叢を利用して、宿主である人の疾病予防や改善を目指すプロバイオティックス（ｐｒｏｂｉｏｔｉｃｓ）の概念が注目されている。
【００１８】
γ―アミノ酪酸は人に対して抗高血圧作用、アルコール代謝促進作用、抗肥満作用、抗ストレス作用、抗老化作用、学習能力向上効果等を示す機能性物質である。植物に対する抗ストレス様効果を示す物質としては、植物に耐塩性を付与する化合物として、ジベレリン、サイトカイニンそしてクロロフィルの前駆物質である５−アミノレブリン酸（ＡＬＡ）がある。人及び動物に対して抗ストレス活性を呈するγ―アミノ酪酸が植物に対しても何らかの抗ストレス作用を示す可能性が期待され、実際にγ―アミノ酪酸による植物への耐塩性付与効果の研究も行われている。これらのことは、本発明で得られる乳酸菌発酵液がある種の農薬（植物栄養剤）として使用される可能性を示している。
本発明に於いて対象とする食品としては特に限定は無いが、例として、健康食品、健康酒、調味料、飲料、漬け物等を示すことが出来る。
健康食品として用いる場合には、本発明で得られる乳酸菌発酵液をそのまま摂取することが可能である。又、必要に応じて固液分離、濃縮、精製、粉末化等の操作を行い、更に、各種の造粒化装置により粒状固形物とし、又、場合によれば糖衣錠とすることも出来る。更に、目的に応じて、ゼリー状、シロップ、顆粒、粉末、又はドリンク剤の形の製品とすることも可能である。これらは、この分野で一般に実施されている技術及び設備を用いて実施することが出来る。
健康酒は本発明で得られる乳酸菌発酵液又は後処理物に味醂、香料、及び、ケイヒ、コウカ、ジオウ、シャクヤク、チヨウジ、ニンジン、ボウフウ、ウコン、ヤクモウソウ等の生薬を混合して、必要に応じて加熱処理、澱下げ、膜濾過、充填等の処理をして得ることが出来る。
調味料は、大豆、小麦、大麦、米等の調味料原料と本発明で得られる乳酸菌発酵液又は後処理物に、醤油麹、米麹、又は酵素製剤、そして食塩、アルコール等を添加して、分解及び熟成を行い、その後に必要に応じて、固液分離、澱下げ、活性炭処理、精密濾過、加熱、充填を行って生産することが出来る。
飲料は本発明で得られる乳酸菌発酵液又は後処理物に香料、酸味料、糖分を加え、又必要に応じて、リンゴ、ブドウ、ミカン、レモン等のジュースの濃縮液を添加した後炭酸ガスを吹き込んで充填することにより生産することが出来る。
【００１９】
漬け物の製造には、製造時に使用する調味液、添加物等を加える際に本発明で得られる乳酸菌発酵液又は後処理物を同時に添加すれば良い。
上記の操作をすることにより得られた食品は抗高血圧作用、アルコール代謝促進作用、抗肥満作用、抗ストレス作用、抗老化作用、学習能力向上効果等を示す機能性物質であるγ―アミノ酪酸を多量に含むと共に、各種農水産物原料が元来有する機能性も有している。更に、乳酸菌発酵液を固液分離せずに用いた場合には、乳酸菌体自体が有する免疫賦活化能、消化酵素分泌活性化、日和見感染の防止等の機能性も有している。
本発明で得られた乳酸菌発酵液は肥料として田畑に散布しても良く、又、養殖魚類の餌としても充分に使用することが出来る。
【００２０】
本発明で言う飼料には特に限定は無いが、大麦、カラス麦、藁等に本発明で得られる乳酸菌発酵液又は後処理物を適当に配合して与えれば良い。酪農分野ではこれまでも乳酸菌体は幼獣の病気、とりわけ下痢防止の為に飼料に添加されている。又、牧草を保存して家畜の嗜好性に富む良質の長期間の保存性を有するサイレージを得る為に、乳酸菌の増殖は非常に重要である。サイレージの目的は酪酸発酵を阻止することにある。酪酸菌はｐＨ７．０で最も活発に増殖する。乳酸菌が草の糖分を原料に乳酸を生成し、その酸により酪酸菌などの雑菌の増殖を抑制し、サイレージの変敗を防止する。乳酸菌が作る乳酸により、牧草が酢漬けの様な状態となり不良発酵を抑制する。ｐＨを４．２以下に抑えることが良い飼料を作る為に重要である。本発明は、例えば言えば、各種食品、食糧素材にサイレージ化の処理をした様なものであり、各種未利用食品素材を飼料として利用する際に不都合成分と言われていた特異臭、特異味等は乳酸菌発酵により低減され、牛、馬、鶏等の家畜類に対して非常に嗜好性の高い飼料となる。更に、乳酸菌の増殖効果によって、雑菌の繁殖が抑制され、非常に保存性を高めることが出来る。
本発明で得られる乳酸菌発酵液又は後処理物を用いて、γ―アミノ酪酸を有する酒類を生産することが出来る。目的とする酒類には特に限定は無いが、清酒、ワイン、ビール、ブランデー、ウイスキー、味醂、本直し、雑酒等の酒類を例示することが出来る。これらの酒類を生産する為には、その製造過程中に少なくとも１回、本発明で得られる乳酸菌発酵液又は後処理物を適当量添加すれば良い。この様にして得られる酒類はγ―アミノ酪酸を高濃度に含み、機能性、香味に富んだ製品である。
この様にして、本発明により各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料より乳酸菌発酵で抗高血圧作用等を有する機能性物質であるγ―アミノ酪酸を製造する方法、高濃度のγ―アミノ酪酸が得られる当該乳酸菌発酵を製造過程に含む食品、飼料、餌料、肥料、又は農薬等の製造方法、及びγ―アミノ酪酸を含有する食品、飼料、餌料、肥料、又は農薬等を得ることが出来る。更に本発明により２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料での当該乳酸菌発酵の脱炭酸酵素反応での炭酸ガス発生による嫌気状態の形成を利用した各種食品素材の経済的、効率的な保存方法を提供することが出来る。
【００２１】
【実施例】
以下、本発明を実施例によって更に具体的に説明するが、本発明はこれらの実施例によって限定されるものでは無い。
実施例１
市販の豆乳４５０ｍｌにグルタミン酸ソーダを５０ｇ添加してｐＨを５．２に調整した後に全量を５００ｍｌにして１リットル容三角フラスコに入れた。これを、加熱殺菌操作を行わずに以下の乳酸菌発酵に使用した。使用した豆乳の成分値は１００ｇ当たり蛋白質３．７ｇ、脂質３．７ｇ、炭水化物２．６ｇ、ナトリウム８５．５ｇ、ビタミンＥ１ｍｇ、カルシウム５５ｍｇ、マグネシウム２２ｍｇ、レシチン１３０ｍｇ、コレステロール検出せず、イソフラボン２９ｍｇである。種培養培地としては、酵母エキス、グルコースを各１ｗ／ｖ％、ポリペプトンを０．５ｗ／ｖ％、酢酸ソーダを０．０２ｗ／ｖ％、硫酸マグネシウム、硫酸鉄、食塩を０．００１ｗ／ｖ％含有してｐＨを６．８に調整したＧＹＰ培地を用いた。ＧＹＰ培地を１２０℃、１５分高温高圧滅菌した後、乳酸菌としてラクトバチルスブレビスＩＦＯ−１２００５を１白金耳接種して３０℃で２日間培養した。本培養操作は種培養液を接種後、３０℃で静置培養した。培養１日以降、経時的にｐＨを測定してｐＨを３．５〜５．５の間になる様に酸を添加して調整した。乳酸菌発酵途中で培養液を濾過してアミノ酸分析計によりγ―アミノ酪酸の生成量を測定した結果を次表１に示した。
【００２２】
【表１】

グルタミン酸脱炭酸酵素反応により、グルタミン酸１分子のα―カルボキシル基が脱炭酸されて１分子のγ―アミノ酪酸が生成する。又、使用したグルタミン酸ソーダ（１水塩）の分子量は１８７．１であり、γ―アミノ酪酸の分子量は１０３である。これらから計算すると、培養７日後のγ―アミノ酪酸生成量５．２％の場合にはグルタミン酸からγ―アミノ酪酸への生成モル収率は９５％であった。培養途中、及び７日培養後に於いても乳酸菌以外に雑菌の汚染は見られず香味良いものであった。
実施例２
市販の豆乳４．５リットルにグルタミン酸ソーダを５００ｇ添加してｐＨを５．２に調整した後に全量を５リットルにして１０リットル容ガラス製濾過瓶（ブフナーロート濾過瓶）に入れた。これを未加熱でそのまま乳酸菌発酵に使用した。
あらかじめ培養しておいた乳酸菌種培養液５０ｍｌを添加した。使用した豆乳の成分値は１００ｇ当たり蛋白質３．８ｇ、脂質２．５ｇ、炭水化物４．７ｇ、ナトリウム６０ｍｇ、ビタミンＥ０．４ｍｇ、カルシウム４０ｍｇ、マグネシウム２０ｍｇ、レシチン１００ｍｇ、コレステロール検出せず、イソフラボン２５ｍｇである。種培養培地としては、酵母エキス、グルコースを各１ｗ／ｖ％、ポリペプトンを０．５ｗ／ｖ％、酢酸ソーダを０．０２ｗ／ｖ％、硫酸マグネシウム、硫酸鉄、食塩を０．００１ｗ／ｖ％含有してｐＨを６．８に調整したＧＹＰ培地を用いた。ＧＹＰ培地を１２０℃、１５分高温高圧滅菌した後、乳酸菌としてラクトバチルスブレビスＩＦＯ−１２００５を１白金耳接種して３０℃で２日間培養した。種培養液を接種後、３０℃で静置培養した。
培養１日以降、経時的にｐＨを測定してｐＨが３．５〜５．５の間になる様に酸を添加して調整した。
乳酸菌発酵途中で培養液を濾過してアミノ酸分析計によりγ―アミノ酪酸の生成量を測定した結果を次表１に示した。
【００２３】
【表２】

培養９日後のγ―アミノ酪酸生成量５．０％の値から計算するとはグルタミン酸からγ―アミノ酪酸への生成モル収率は９１％であった。培養途中、及び９日培養後に於いても乳酸菌以外に雑菌の汚染は見られず香味良いものであった。
実施例３
市販の豆乳４５０ｍｌにグルタミン酸ソーダを１０ｇ、２０ｇ、３０ｇ、４０ｇ、又は５０ｇを添加してｐＨを５．２に調整した後に全量を５００ｍｌにして１リットル容三角フラスコに入れた。これを、加熱殺菌操作を行わずに乳酸菌発酵に使用した。あらかじめ培養しておいた乳酸菌種培養液５ｍｌを添加した。使用した豆乳の成分値は１００ｇ当たり蛋白質３．７ｇ、脂質３．７ｇ、炭水化物２．６ｇ、ナトリウム８５．５ｇ、ビタミンＥ１ｍｇ、カルシウム５５ｍｇ、マグネシウム２２ｍｇ、レシチン１３０ｍｇ、コレステロール検出せず、イソフラボン２９ｍｇである。種培養培地としては、酵母エキス、グルコースを各１ｗ／ｖ％、ポリペプトンを０．５ｗ／ｖ％、酢酸ソーダを０．０２ｗ／ｖ％、硫酸マグネシウム、硫酸鉄、食塩を０．００１ｗ／ｖ％含有してｐＨを６．８に調整したＧＹＰ培地を用いた。ＧＹＰ培地を１２０℃、１５分高温高圧滅菌した後、乳酸菌としてラクトバチルスブレビスＩＦＯ−１２００５を１白金耳接種して３０℃で２日間培養した。種培養液を接種後、３０℃で静置培養した。乳酸菌発酵後に得られた培養液上清をｐＨ２．２のクエン酸緩衝液で希釈した後にアミノ酸分析計によりγ―アミノ酪酸の生成量を測定した結果を次表３に示した。
【００２４】
【表３】

表３に示した様に５００ｍｌ当たりグルタミン酸ソーダを１０ｇ添加した場合は培養２日目の発酵液上清中のγ―アミノ酪酸の量は１．１ｇであった。同様にグルタミン酸ソーダをそれぞれ２０ｇ、３０ｇ、４０ｇ及び５０ｇ添加した場合は、それぞれ培養３日、５日、７日及び７日後の発酵液上清１００ｍｌ中のγ―アミノ酪酸生成量はそれぞれ２．１ｇ、２．９ｇ、４．１ｇ、及び５．１ｇであった。いずれの実験に於いても培養途中、及び培養終了後も雑菌の汚染は見られず香味良いものであった。
実施例４
麦焼酎醪を減圧蒸留して乙類焼酎を生産した後の蒸留残渣（麦焼酎粕）５８０リットルにグルタミン酸ソーダ（１水塩）を３６ｋｇ添加した後４０％苛性ソーダでｐＨを５．２に調整した。これを加熱殺菌操作を行わずに乳酸菌発酵の為の培地（６００リットル）とした。使用した焼酎粕の成分値はｐＨ３．６、全窒素０．６９ｗ／ｖ％、フォルモール窒素０．１５ｗ／ｖ％、全糖３．５ｗ／ｖ％、水分９１．３ｖ／ｖ％である。あらかじめ培養しておいた乳酸菌種培養液７リットルを接種した。種培養培地としては、酵母エキス、グルコースを各１ｗ／ｖ％、ポリペプトンを０．５ｗ／ｖ％、酢酸ソーダを０．０２ｗ／ｖ％、硫酸マグネシウム、硫酸鉄、食塩を０．００１ｗ／ｖ％含有してｐＨを６．８に調整したＧＹＰ培地を用いた。ＧＹＰ培地を１２０℃、１５分高温高圧滅菌した後、乳酸菌としてはラクトバチルスブレビスＩＦＯ−１２００５を使用した。ＧＹＰ培地１０ｍｌを試験管に入れて１２０℃、１５分高温高圧滅菌した試験管培地に保存菌株寒天培地培養物から１白金耳を接種して３０℃、２日間１次静置種培養した。１次種培養液０．７ｍｌを、同じくＧＹＰ培地７０ｍｌを２００ｍｌ三角フラスコに入れて１２０℃、１５分高温高圧滅菌した２次種培養培地に接種し、３０℃、２日、２次静置培養した。次いで、２次種培養液７０ｍｌを、ＧＹＰ培地７リットルを１５リットル容ステンレス容器に入れて１２０℃、１５分高温高圧滅菌した培地に添加した。次いで、３０℃、２日間静置培養（３次種培養）した。これを焼酎粕本培養培地６００リットルに添加して３０℃で本培養を開始した。本培養１日目に１回、２日目に２回、３日目に１回濃塩酸を添加して培養液ｐＨを３．５〜５．５に調整した。発酵３日目にγ―アミノ酪酸の生成濃度は３．２ｗ／ｖ％となり、添加したグルタミン酸は大部分がγ―アミノ酪酸に変換された。発酵は通常の非密閉型容器で行ったが、培養途中の雑菌汚染は無く、培養液からは固液分離、活性炭処理を行うことで、薄い着色（黄色）の透明な香味良い液が得られた。
【００２５】
尚、上記した麦焼酎粕を使用した例と同様に、芋焼酎粕、米焼酎粕を使用した場合には、それぞれ３．０ｗ／ｖ％、及び３．１ｗ／ｖ％のγ―アミノ酪酸を含む乳酸菌発酵液が得られた。
実施例５
実施例４で得られた透明な発酵液２リットルをロータリーエバポレーターで濃縮（外液温度６０℃）し４００ｍｌとした。この液はγ―アミノ酪酸を１５ｗ／ｖ％含有していた。非常に香味良い液であり、０．２ｍｌ中に人の高血圧抑制効果に対する１日当たり摂取必要量とされているγ―アミノ酪酸３０ｍｇを含んでいる。この濃縮液は常温条件で長時間保存可能であり、製品として流通に便利である。
実施例６
定法に従い生産した生揚げ醤油１リットルに実施例５で得られた１５ｗ／ｖ％γ―アミノ酪酸含有濃縮発酵液を１０ｍｌ添加して機能性醤油を試作した。得られた醤油は香味良い上に、γ−アミノ酪酸を０．１５ｗ／ｖ％含有していた。この操作で機能性を有する調味料を生産することが出来た。一般分析値は全窒素１．８６ｗ／ｖ％、フォルモール窒素０．８７ｗ／ｖ％、ブリックス３８．６、食塩１７．４ｗ／ｖ％、直接還元等３．１ｗ／ｖ％、ｐＨ４．４、アルコール２．５ｖ／ｖ％であった。
実施例７
白ワイン５００ｍｌに実施例５で得られた１５ｗ／ｖ％γ―アミノ酪酸含有濃縮発酵液を５ｍｌ添加してγ―アミノ酪酸を含有するワインタイプの酒を試作した。この酒類の分析値は、γ―アミノ酪酸０．１５ｗ／ｖ％、エキス３．５９ｗ／ｖ％、アルコール１２．０ｖ／ｖ％、ｐＨ３．４、及び総酸０．５６ｗ／ｖ％であった。香味は乳酸菌発酵液無添加のものと違いは見られなかった。
実施例８
市販の調整豆乳２リットルに実施例１で得られた５．２ｗ／ｖ％γ―アミノ酪酸を含有する豆乳乳酸菌発酵液６ｍｌを添加してγ―アミノ酪酸を強化した豆乳を得た。この豆乳の分析値は２００ｍｌ当たり、γ―アミノ酪酸３１ｍｇ、蛋白質７．５ｇ、脂質７．４ｇ、炭水化物５．６ｇ、ナトリウム１８１．９ｇ、ビタミンＥ２ｍｇ、カルシウム１１５ｍｇ、マグネシウム４６ｍｇ、レシチン２５０ｍｇ、コレステロール検出せず、イソフラボン６１ｍｇであった。香味は豆乳乳酸菌発酵液無添加のものと差が無く、嗜好性に優れたものであった。人がこの豆乳を毎日２００ｍｌ摂取することにより高血圧抑制作用、学習機能向上、老化防止等の健康効果が期待される。
【００２６】
【発明の効果】
本発明によれば、２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料に、グルタミン酸脱炭酸酵素生産能を有する乳酸菌を作用させることにより抗高血圧作用等を有する機能性物質であるγ―アミノ酪酸を高濃度に製造することが出来る。この様な操作で得られた発酵生成物は各種機能性を有する食品、栄養補助剤等として利用出来るだけで無く、飼料、餌料、肥料、又は農薬等の原料として使用することも期待出来る。本発明は２０ｗ／ｖ％以下のグルタミン酸及び／又はその塩を含む／又は添加された各種食品素材、各種未利用食品素材、又はそれらの後処理物より選択した原料に乳酸菌を作用させるに際して、当該原料に含まれる栄養物質、機能性物質の変質を防止する為にそれらの栄養物質、機能性物質の安定性に応じて乳酸菌発酵操作の前後の当該食品素材原料の加熱処理過程での加熱温度を適当に調整するか又は非加熱で行っても良く、更に、本発明方法に使用する容器には密閉容器を用いても良いが、非密閉容器（解放型容器）でも実用上充分な保存効果が達成出来、実用的、経済的、かつ効率的な各種食品素材の保存方法を提供するものである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing γ-aminobutyric acid, a method for producing food, feed, feed, fertilizer, or pesticide containing γ-aminobutyric acid, and a food, feed, feed, fertilizer, or pesticide obtained by the method. Etc. The present invention is also characterized in that lactic acid bacteria decarboxylase reaction makes the storage object anaerobic and suppresses contamination by various bacteria, and the lactic acid bacteria fermentation process allows various food materials, various unused food materials, or the like. An object of the present invention is to provide an economical and efficient method for preserving raw materials selected from post-treatment products.
[0002]
[Prior art]
Due to the bias of nutritional balance, such as the overdose of animal fats and the overdose of sweeteners from fast foods, snacks and soft drinks due to the westernization of the diet in Japan in recent years, cancer and mental health Lifestyle diseases such as diseases, obesity, allergic diseases, and arteriosclerosis are rapidly increasing. Serious problems have also occurred with respect to food preservation, such as food poisoning due to pathogenic Escherichia coli O-157 and Staphylococcus aureus, the addition of unregulated food preservatives, and the problem of residual pesticides in imported agricultural products. With the average life expectancy of both men and women being the highest in the world, the aging of the population is rapidly progressing, and there is a need for measures such as rising national medical expenses, maintaining the health of the elderly, and preventing aging. In addition, there is a demand for the development of foods that have a stressful work environment in an advanced information society, a relaxing function for spending in a living environment, and an anti-stress effect.
[0003]
Recently, as a measure to alleviate the above-mentioned anxiety about eating habits facing the present people, agricultural and marine products, their functional components (phytochemicals), and disease prevention and health maintenance / enhancement using various fermentation production processes have recently been developed. New research and development of new processed foods, pharmaceutical materials, functional food materials, and the like having functions such as functions have been attracting attention.
[0004]
Soy is a raw material of traditional fermented foods such as natto, miso, and soy sauce, and recent studies have scientifically demonstrated that these foods are involved in longevity of Japanese people. It has been proven that soybean saponin has an anticancer effect, antiatherosclerotic effect, and cholesterol-lowering effect, soybean protein and unsaturated fatty acid have a cholesterol-lowering effect, and isoflavonoids have an effect on menopause and osteoporosis. However, the green odor of n-hexanal contained in soybean, the bitterness of soybean protein, and the astringency due to isoflavonoids have become problems with the expansion of consumption of soybeans.
When producing tofu and the like, about 40% of the dry weight of soybeans is equivalent to lees, so that the amount of soybean soybean husk by-produced throughout the country is enormous. The husk contains 4.8% protein and 3.6% fat, and is relatively rich in nutrients, but has a high water content of about 80%. ing.
Some of the husks are used in the food field, such as "Unohana", but most are for animal feed and incineration.
Sweet potatoes are rich in β-carotene, dietary fiber, vitamins and anthocyanins, and have functions such as a liver function improving effect, an active oxygen removing ability, a hypertension suppressing effect, and an improvement in bowel movement.
In addition, the use of highly pigmented sweet potatoes containing a large amount of orange and purple pigments in paste flakes, natural pigments, beverages, chips, powderers, and the like has been studied. In Kagoshima Prefecture, about 210,000 tons of sweet potatoes are used annually for starch production, and about 60,000 tons (80% water equivalent) of sweet potato starch lees are discharged each year. Starch lees contain most of the functional components of sweet potatoes other than starch and are very useful, but are very susceptible to spoilage and are only partially used in livestock feed.
[0005]
In addition, potato shochu lees produced as a by-product in the production of sweet potato shochu using sweet potatoes as a raw material are produced by a large amount (about 200,000 tons / year) every year. Most of the sweet potato starch is converted to ethanol by the action of alcoholic yeast, and most of the other functional components originally contained in sweet potatoes are contained in shochu lees, the residue of alcohol distillation. It remains. Although shochu lees is a useful food material that is very nutrient-rich and has high functionality, it is very susceptible to spoilage and its unique taste and odor hinders its use as a food. At present, only a part is used as livestock feed.
[0006]
Until now, the by-products and waste liquid produced during food production were often dumped into the ocean or incinerated. However, in May 2001, the Food Recycling Law was enacted and based on the rapid economic growth of mass consumption and mass disposal. It has become essential to establish a zero-emission (recycling) society based on the effective use, reduction, and reuse of food waste and by-products. As a numerical target, around 2007, each company will be required to recycle at least 20% of its waste.
[0007]
From the above situation, in order to achieve effective utilization of various agricultural and marine products, unused food materials and factory by-products, it is necessary to improve the peculiar taste and odor of raw materials, and to improve the various agricultural and marine products and unused food materials. It can be considered that improving the storage stability of factory by-products is the most important. Furthermore, it would be very beneficial if the functional substance could be recovered and / or produced through the above storage process.
[0008]
Γ-aminobutyric acid is a functional substance that exhibits an antihypertensive effect, an alcohol metabolism promoting effect, an antiobesity effect, an antistress effect, an antiaging effect, a learning ability improving effect, and the like, which is derived from glutamic acid by the action of glutamate decarboxylase. Generated. Glutamate decarboxylase is widely distributed in microorganisms, plant and animal tissues, and methods for producing various γ-aminobutyric acid-rich foods using these glutamate decarboxylase have been reported.
[0009]
A method for producing γ-aminobutyric acid using glutamate decarboxylase derived from plants such as tomato, pumpkin, and carrot has been proposed (see Patent Documents 1 and 2). Methods for producing γ-aminobutyric acid using lactic acid bacteria have been proposed in Patent Documents 3 and 4. A method of producing a fermented product containing a high concentration of γ-aminobutyric acid by growing black whiskers (Rhizopus) on steamed soybeans has also been reported (see Non-Patent Document 1). There is also a report that lactic acid bacteria were cultured in a GYP (containing glucose, yeast extract, peptone, etc.) medium supplemented with sodium glutamate to produce 3 w / v% or more of γ-aminobutyric acid (Non-Patent Document 2). reference).
[0010]
However, from various food materials, various unused food materials, or post-processed products thereof, the raw materials thereof are not subjected to a sterilization treatment such as a heating step or the like, and / or a non-sealed container (open type container) or the like is used. No method for producing γ-aminobutyric acid using the same and no prior art for economically and efficiently storing these raw materials have been found so far. Further, there has been a demand for the development of a method of manufacturing economical, efficient, and safe food, feed, feed, fertilizer, pesticides, and the like that does not require a large capital investment and can be handled by conventional equipment. In addition, the peculiar taste and odor peculiar to various food materials, various unused food materials, or their post-processed products are obstacles to their use in foods, feeds, etc., and are economically and effectively improved. The establishment of a method was required.
[Patent Document 1]
JP-A-03-224467
[Patent Document 2]
JP-A-03-244366
[Patent Document 3]
JP 2000-14346 A
[Patent Document 4]
JP-A-2000-210075
[Non-patent document 1]
Journal of the Japanese Society of Agricultural Chemistry, vol. 75, extra edition, p. 269 (2001)
[Non-patent document 2]
Journal of the Japanese Society of Agricultural Chemistry, volume 75, extra edition, page 271 (2001)
[0011]
[Problems to be solved by the invention]
An object of the present invention is to provide glutamic acid decarboxylation to a raw material selected from various food materials containing and / or added with 20 w / v% or less of glutamic acid and / or a salt thereof, various unused food materials, or post-treated products thereof. A method for producing γ-aminobutyric acid, which is a functional substance having an antihypertensive action, characterized by allowing a lactic acid bacterium having an enzyme-producing ability to act, a lactic acid bacterium containing a high concentration of γ-aminobutyric acid obtained by the method An object of the present invention is to provide a method for producing a food, feed, feed, or pesticide using a fermented liquid in the production process thereof, and a food, feed, feed, fertilizer, fertilizer, or pesticide containing γ-aminobutyric acid.
[0012]
Also, the object of the present invention is to act on lactic acid bacteria, when the nutrient substances contained in the raw materials, functional substances are altered by heat treatment or the like, to prevent the alteration of the nutritional substances, the stability of the functional substances. Depending on the lactic acid bacteria fermentation process or the like, the heat treatment temperature of the food material concerned before or after may be appropriately adjusted or may be performed without heating, and further used in the method of the present invention, a container for performing lactic acid bacteria fermentation. Although a closed container may be used, an unsealed container (open type container) can achieve a practically sufficient storage effect, and provides a practical, economical, and efficient method for storing various food materials. is there.
[0013]
[Means for solving the problem]
To summarize the present invention, the first invention is a raw material selected from various food materials containing glutamic acid and / or a salt thereof of 20 w / v% or less, various unused food materials, or post-treated products thereof. A method for producing γ-aminobutyric acid, wherein a lactic acid bacterium capable of producing glutamate decarboxylase is caused to act on the lactic acid bacterium. The second invention is a practical, economical, and efficient method for preserving food materials selected from various food materials, various unused food materials, or post-processed materials thereof, which can be achieved as a result of the first invention. . A third invention is a method for producing a food, feed, feed, fertilizer, pesticide, or the like, which includes the first invention in a production process. A fourth invention relates to a food, feed, feed, fertilizer, or pesticide obtained by the third invention. In the fifth invention, when carrying out the first to third inventions, the raw material can be subjected to either heat treatment or non-heat treatment, and the first to third inventions can be carried out in a sealed container or a non-heated container. It is an object of the present invention to provide an economical and efficient manufacturing method which can be performed in any sealed container.
[0014]
The present inventor makes various microorganisms act on raw materials selected from various food materials, various unused food materials, or post-processed products thereof containing and / or added with 20 w / v% or less of glutamic acid and / or a salt thereof. And carried out research to produce useful functional materials. As a result, it has a glutamate decarboxylase-producing ability in various food materials containing 20 w / v% or less of glutamic acid and / or a salt thereof, and / or a raw material selected from various unused food materials or post-treated products thereof. To be able to produce a large amount of the functional substance γ-aminobutyric acid by the action of lactic acid bacteria, and to suppress the deterioration of nutrient substances and functional substances contained in the raw materials if they are altered by heat treatment etc. Nutrient substances, depending on the stability of the functional substance, the heating temperature in the heat treatment process of the food material raw material before and after the lactic acid bacteria fermentation operation may be appropriately adjusted or may be performed without heating, furthermore, the present invention The container used for the lactic acid bacteria fermentation used in the method may be a closed container, but a non-closed container (open type container) can achieve a practically sufficient storage effect, and is economical and efficient. It was found to be able to sufficiently save the various food materials.
The present invention has been made based on these novel facts.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be specifically described. In the present invention, a raw material selected from various food materials, various unused food materials containing and / or added glutamic acid and / or a salt thereof of 20 w / v% or less, or post-treated products thereof is used.
Specifically, food materials such as soy milk, milk, skim milk powder, kelp extract, fruit juice, fruit juice, or vegetable juice, and cheese whey, soybean soup, tofu wastewater, husk, bonito soup, canned (pineapple, Orange, peach, etc.) Juices, alcohol distillation waste (potato shochu lees, rice shochu lees, barley shochu lees, etc.), unused food materials such as sweet potato starch lees, potato starch lees, etc., or raw materials selected from their post-processed products And so on. Soy milk used in the present invention is not limited to soybeans, mung bean, red beans, peas, peanuts, sword beans, hidden beans, etc., generally humans, as long as they are obtained from beans that are consumed by livestock, there is no particular limitation. For example, it may be in a state containing a solid content as it is ground, or an upper solution obtained by solid-liquid separation may be used. As livestock milk, milk is suitable for use in terms of supply amount, cost and the like, but other livestock milk, for example, milk of goats, sheep, etc., can also be favorably used as the raw material of the present invention. Alternatively, skimmed milk of various animals, for example, skim milk powder, can be used. As the seaweed extract, kelp extract is suitable for the present invention because it contains glutamic acid exceeding 3 w / w% (glutamic acid content in dried seaweed) depending on the supply amount, cost, and cultivar. However, other seaweeds such as wakame extract and hijiki extract can also be used. Common fruits such as tangerine, pineapple, lemon, peach, pear and apple can be used as fruit juice, and common vegetables such as tomato, cabbage, Chinese cabbage, radish can be used as vegetable juice.
These may be used after being crushed, but may be used after solid-liquid separation, for example. It is also possible to use fish meat extracts such as bonito and saba-node. Proteins such as soybean, corn, wheat, and rice are solubilized by enzymatic decomposition using enzyme agents such as soy sauce koji, rice koji or protease, and a decomposed solution containing a large amount of glutamic acid after being amino acidized is also used as a raw material of the present invention. You can do it.
In the present invention, in addition to the above-described food materials, food materials that are considered unused or waste can be used. Cheese whey, which is a by-product of cheese production, is a very nutritious food material, but is becoming more difficult to treat as dairy consumption increases. Various types of soybean broth such as soybean broth and red bean broth produced during the production of bean products are also discharged in large quantities, and companies are in need of disposal. In addition, the processing of husk and tofu wastewater, which are produced in large quantities in tofu production, has become a major problem. The method of treating bonito broth discharged during the production of bonito flakes and fish broth by-produced during the production of various types of canned fish also poses a problem. Food processing companies have a problem in treating canned juice when using various canned raw materials. In the production of various types of starch, there is a need to consider a method of treating corn starch cake, sweet potato starch cake, potato starch cake, kuzukuri starch cake, katakari starch cake, tapioca starch cake, etc., which are produced in large quantities in the production of various starches. In addition, wastewater produced as a by-product in various alcohol production processes, for example, alcohol-distilled wastewater produced as a result of distilling mash, is currently difficult to treat. For example, large amounts of alcohol by-produced in alcohol production from raw materials such as residue produced by the production of distilled liquor such as second class shochu, awamori, first class shochu, rum, vodka, gin, tequila, brandy, etc., molasses, corn, etc. There is a need for a proposal for a method for treating distillation residues and the like. In the present invention, these unused food materials can be used.
At the time of use, these unused food materials can be used as they are without performing solid-liquid separation. It is also possible to use the supernatant from which solids have been removed by solid-liquid separation or the solids obtained by performing solid-liquid separation, again suspended in water or the like. Furthermore, these can be used after being concentrated by a vacuum concentrator or the like. Sake lees, mirin lees, and the like may be difficult to use as they are because of their high alcohol content. In that case, for example, it is preferable to produce shochu-extracted shochu using sake lees as a raw material, and to use shochu distillation waste liquid (shochu lees) by-produced at that time. Stirring, suspension, concentration, solid-liquid separation and the like are performed by a conventional method, and this operation is an example of the post-treatment in the present invention.
Among the above-mentioned food materials, a raw material containing 3 to 10 w / v% glutamic acid, such as kelp extract or a protein enzyme-decomposed solution, can be fermented with lactic acid bacteria without adding glutamic acid or a salt thereof, for example. However, in the case of other raw materials, lactic acid bacteria fermentation is carried out by adding glutamic acid and / or a salt thereof in a range of generally 20 v / w% or less. Further, in the present invention, the above-mentioned food material may be used alone as a medium for fermenting lactic acid bacteria, or a plurality of raw materials may be appropriately mixed and used. For example, by adding sodium glutamate to a mixture of milk and soy milk in equal amounts and performing lactic acid bacteria fermentation, a highly functional yogurt-type food containing a high concentration of γ-amino acid can be obtained. The same is true for shochu lees and husk, vegetable juice and orange juice, cheese whey and skim milk powder, shochu lees and tofu drainage and cheese whey, rice shochu lees, wheat shochu lees, potato shochu lees and soy milk. Can be combined.
The lactic acid bacterium used in the present invention is not particularly limited as long as it has glutamic acid decarboxylase-producing ability. Examples of lactic acid bacteria that can be used include those belonging to the genus Lactobacillus (Lactococcus), Lactococcus, Streptococcus, Leuconostoc, Pediococcus, and the like. Can be mentioned. Among these, lactic acid bacteria of the genus Lactobacillus are most suitable. Examples are Lb. brevis, Lb. plantarum, Lactobacillus delbrueckii, Lactobacillus bulgaricus, Lactobacillus herpeticus et al. Can be mentioned. Among these, preferred bacteria include Lactobacillus brevis IFO-12005, Lactobacillus brevis IFO-3345, Lactobacillus brevis IFO-12520, Lactobacillus brevis IFO-3960, Lactobacillus plantarum IFO-12519, Lactobacillus plantarum IFO- 3070, Lactobacillus plantarum IAM-1041 and the like can be used.
As the lactic acid bacteria, it is preferable to use a culture solution that has been seed-cultured in advance. The medium used for the seed culture is not particularly limited as long as the lactic acid bacteria can grow well, but in order to measure the degree of growth of the bacteria, it is preferable to perform the seed culture in a light-colored transparent medium. . For example, 1 w / v% of yeast extract and glucose, 0.5 w / v% of polypeptone, 0.02 w / v% of sodium acetate, 0.001 w / v% of magnesium sulfate, iron sulfate, and sodium chloride are contained in GYP medium adjusted to 6.8 can be used.
The seed-cultured lactic acid bacteria culture solution may be used as it is, or may be subjected to a pretreatment such as cell collection, washing, concentration, or suspension before use.
Usually, glutamic acid and / or a salt thereof are added to various food materials, unused food materials, and the like, and lactic acid bacteria fermentation is performed. A high concentration of γ-aminobutyric acid can be produced by increasing the substrate concentration of glutamate decarboxylase. Glutamic acid may be added at the initial stage of lactic acid bacteria fermentation, or may be added in two, three, or four stages during lactic acid bacteria fermentation. There is no strict limitation on the concentration of the additive, but it is preferably 20 w / v% or less, and most preferably 0 to 10 w / v%. Further, vitamins, inorganic salts, nitrogen sources and the like may be added to the above raw materials as nutrients of lactic acid bacteria.
After adding glutamic acid and / or its salt, the pH of the food material is adjusted to 3.0 to 7.0, preferably 4.5 to 5.5 before inoculation with the lactic acid bacteria seed culture. When the pH is lower than 3.0, the growth of lactic acid bacteria is suppressed, and when the pH is higher than 7.0, the growth is similarly inhibited, and contamination of various bacteria is likely to occur, so that the desired γ-aminobutyric acid production cannot be achieved.
[0016]
The raw food material before lactic acid bacteria fermentation may be sterilized, but this operation is not essential, and the lactic acid bacteria fermentation may be directly performed without performing the sterilization operation according to the situation. If the nutrient raw materials and functional raw materials contained in the raw materials are altered by heat treatment or the like, the food material raw materials before and after the lactic acid bacterium fermentation operation according to the stability of the nutrient substances and functional substances to prevent the deterioration The heating temperature in the heat treatment step may be adjusted appropriately or may be performed without heating. Although a closed container may be used as a container for lactic acid bacteria fermentation used in the method of the present invention, a practically sufficient storage effect can be achieved even with a non-closed container (open type container). If the opening at the top of the container is as narrow as possible, the lactic acid bacteria fermentation liquid by the carbon dioxide gas generated by the decarboxylase reaction, and the deoxygenation of the liquid surface of the container are sufficiently performed, and by the formation of a sufficient anaerobic state, Bacterial contamination is more effectively prevented. However, even in the case of an open container, the intended purpose can be sufficiently achieved by covering the upper part with a lid or the like. As a result, various food materials can be sufficiently preserved economically and efficiently. The number of cells to be inoculated for lactic acid bacteria fermentation is not particularly limited. However, when the inoculated amount is small, bacterial contamination is likely to occur, and when the inoculated amount is large, the cost of producing a seed culture solution increases. Therefore, the number of initial bacteria is 1 × 10 ⁵ From 1x10 ⁹ It is preferable to inoculate the cells individually. As culturing conditions for lactic acid bacteria fermentation, the temperature is preferably 20 to 45 ° C, and more preferably 30 to 37 ° C. Any culture method of aeration, stirring, and standing may be used, but standing culture is most suitable from the viewpoint of economy. The fermentation time may be appropriately set between several hours and 10 days while considering the amount of γ-aminobutyric acid produced.
When sodium glutamate is present in the raw material, the pH of the fermented lactic acid bacterium rises due to the release of sodium ions accompanying the elimination of the carboxyl group of the glutamic acid molecule by the glutamate decarboxylase reaction. Lactic acid bacteria generally die at a later stage of fermentation due to a decrease in pH due to lactic acid, acetic acid or the like produced by the lactic acid bacterium. However, in fermentation in the presence of sodium glutamate, which is an embodiment of the present invention, an exceptional phenomenon is pH. Rise to neutral or higher. This is suitable for the survival of the lactic acid bacteria themselves, but also increases the possibility of bacterial contamination. Therefore, in the present invention, the pH is set to pH 3.0 to 6.0, preferably pH 3.5, which is a stable region of glutamate decarboxylase produced in the cells after one day of culture in which lactic acid bacteria grow in a sufficient amount. It is characterized in that the pH of the lactic acid fermentation liquor is adjusted with an acid or alkali in the range of 5.5 to 5.5. Glutamate decarboxylase molecules are localized in the outer layer of the cell membrane of lactic acid bacteria, and the cells themselves catalyze like enzyme protein molecules (immobilized enzymes) without any special treatment. .
Most of the putrefactive bacteria that frequently occur during storage of food are butyric acid bacteria, and the production value of butyric acid causes a drastic decrease in food value in terms of palatability. In order to suppress the growth of butyric acid bacteria, it is important to reduce the dissolved oxygen to lower the pH. In the present invention, it can be considered that the growth of butyric acid bacteria is suppressed by driving dissolved oxygen out of the system by generating carbon dioxide gas in the glutamate decarboxylase reaction and maintaining the pH in an acidic state. Also, aerobic bacteria such as Bacillus sp. Cannot grow under the acidic anaerobic conditions of the present invention. Furthermore, molds that frequently contaminate food under acidic conditions are also difficult to grow under the anaerobic conditions of the present invention. The fact that the liquid surface of the container was sufficiently anaerobic under the conditions of the present invention was also confirmed by the fact that the fire was immediately extinguished when the ignited match was placed in the container.
The quantification of glutamic acid and γ-aminobutyric acid in the fermented lactic acid bacterium solution was performed using a Hitachi amino acid automatic analyzer L-8500A (manufactured by Hitachi, Ltd.) after diluting the measurement sample with a citrate buffer having a pH of 2.2.
After the production of γ-aminobutyric acid by lactic acid bacteria fermentation, the fermented liquor may be used as it is as a food, feed, feed, or the like, or may be subjected to isolation and purification operations and post-treatment operations. The isolation operation is performed by a combination of operations such as solid-liquid separation, chromatography, decolorization, salting out, electrodialysis, microfiltration, and reverse osmosis. The post-treatment operation is performed by combining centrifugation, concentration, membrane separation, activated carbon treatment, and the like. The purified γ-aminobutyric acid may be used as a product in the form of a concentrated solution, or may be dried together with dextrin, maltose, or the like by a spray dryer to obtain a powdery product. These production methods can be performed by a usual method.
By such an operation, a fermented lactic acid bacterium containing a high concentration of γ-aminobutyric acid can be produced from a natural food material. For example, the odor of soymilk, astringency, the odor of vegetable juice, the peculiar odor of potato shochu lees, and the like, which were problems with the expansion of consumption, were reduced by lactic acid bacteria fermentation.
[0017]
Lactic acid bacteria are the safest microorganisms in terms of food hygiene, and are widely used for the purpose of improving the flavor, preservability, and removing off-flavors of many processed foods including dairy products.
Humans have domesticated sheep, goats, cows, etc. before BC, and have actively used the milk using lactic acid bacteria. Meanwhile, lactic acid bacteria have been ingested by humans through fermented foods into the body from the history to the present, and can be said to be very safe bacteria, so-called GRAS (Generally Recognized AsSafe). Lactic acid bacteria, and fermented foods using lactic acid bacteria, have immunity enhancement, antibacterial, blood cholesterol suppression, intestinal regulation, lactose degrading, vaginitis prevention, alveolar pyorrhea prevention, antitumor effect, etc. Both have been confirmed by many studies and tests. In recent years, the importance of preventive medicine has been emphasized, and the concept of probiotics, which aims to prevent or improve the disease of a host person by utilizing intestinal microorganisms, especially lactic acid microbiota, has been attracting attention.
[0018]
γ-Aminobutyric acid is a functional substance that exhibits antihypertensive action, alcohol metabolism promoting action, antiobesity action, antistress action, antiaging action, learning ability improving effect, etc. on humans. As a substance exhibiting an anti-stress-like effect on plants, there are gibberellins, cytokinins, and 5-aminolevulinic acid (ALA) which is a precursor of chlorophyll as a compound for imparting salt tolerance to plants. It is expected that γ-aminobutyric acid, which exhibits anti-stress activity for humans and animals, may also exhibit some anti-stress effect on plants, and studies on the effect of γ-aminobutyric acid on imparting salt tolerance to plants have been conducted. Is being done. These facts indicate that the fermented lactic acid bacterium obtained in the present invention may be used as a certain pesticide (plant nutrient).
The food to be used in the present invention is not particularly limited, and examples thereof include health food, health liquor, seasonings, beverages, pickles, and the like.
When used as a health food, the fermented lactic acid bacterium obtained in the present invention can be consumed as it is. Further, if necessary, operations such as solid-liquid separation, concentration, purification, and powdering are performed, and further, various types of granulating devices can be used to produce granular solids, and in some cases, sugar-coated tablets. Further, depending on the purpose, it is also possible to prepare a product in the form of jelly, syrup, granule, powder, or drink. These can be implemented using techniques and equipment commonly practiced in this field.
Health liquor is mixed with crude drugs such as mirin, fragrance, and caffeine, scented cabbage, dirt, peonies, ginkgo, carrots, boufu, turmeric, yakumoso, etc. to the lactic acid bacteria fermented liquor or post-treated product obtained in the present invention. And heat treatment, dregs, membrane filtration, filling and the like.
Seasoning, soybean, wheat, barley, to the lactic acid bacteria fermented solution or post-treated product obtained in the present invention and seasoning raw materials such as rice, soy sauce koji, rice koji, or enzyme preparation, and salt, alcohol, etc. , Decomposition and aging, followed by solid-liquid separation, sedimentation, activated carbon treatment, microfiltration, heating and filling, if necessary.
The beverage is prepared by adding a flavor, an acidulant, and a sugar to the lactic acid bacteria fermented solution or the post-treated product obtained in the present invention, and, if necessary, adding a concentrated solution of juice of apple, grape, mandarin, lemon, etc., and then adding carbon dioxide. It can be produced by blowing and filling.
[0019]
In the production of pickles, the fermented lactic acid bacterium solution or the post-treated product obtained in the present invention may be added at the same time as adding the seasoning liquid, additives and the like used in the production.
The food obtained by performing the above-mentioned operation is γ-aminobutyric acid, a functional substance having an anti-hypertensive effect, an alcohol metabolism promoting effect, an anti-obesity effect, an anti-stress effect, an anti-aging effect, a learning ability improving effect, etc. In addition to containing a large amount, it also has the functionality inherent in various agricultural and marine product raw materials. Furthermore, when the lactic acid bacteria fermented liquor is used without solid-liquid separation, the lactic acid bacterium itself has functions such as immunostimulatory ability, activation of digestive enzyme secretion, and prevention of opportunistic infection.
The fermented lactic acid bacterium obtained in the present invention may be sprayed on fields as fertilizer, and can be sufficiently used as feed for cultured fish.
[0020]
The feed referred to in the present invention is not particularly limited, but may be provided by appropriately mixing the fermented lactic acid bacterium solution or the post-treated product obtained in the present invention with barley, crow barley, straw or the like. In the dairy industry, lactic acid bacteria have been added to feeds to prevent larval diseases, especially diarrhea. In addition, the growth of lactic acid bacteria is very important for preserving pasture and obtaining good quality silage with long-term preservation rich in livestock taste. The purpose of silage is to prevent butyric acid fermentation. Butyric acid bacteria grow most actively at pH 7.0. Lactic acid bacteria produce lactic acid using grass sugar as a raw material, and the acid suppresses the growth of various bacteria such as butyric acid bacteria, thereby preventing silage from deteriorating. The lactic acid produced by the lactic acid bacteria turns the pasture into a pickled state and suppresses poor fermentation. It is important to keep the pH below 4.2 to make a good feed. The present invention is, for example, as if various foods and food materials were subjected to silage treatment, and when various unused food materials were used as feed, the peculiar smell and peculiar taste which were said to be inconveniently synthesized components And the like are reduced by lactic acid bacteria fermentation, and become feeds with a very high preference for livestock such as cows, horses, and chickens. Furthermore, the proliferation of lactic acid bacteria suppresses the propagation of various bacteria, and can greatly enhance the preservability.
Liquors having γ-aminobutyric acid can be produced using the lactic acid bacteria fermented liquor or the post-treated product obtained in the present invention. Although there is no particular limitation on the target liquor, liquors such as sake, wine, beer, brandy, whiskey, mirin, honey, miscellaneous liquor and the like can be exemplified. In order to produce these alcoholic beverages, an appropriate amount of the lactic acid bacteria fermented liquor or post-treated product obtained in the present invention may be added at least once during the production process. The liquor thus obtained is a product containing a high concentration of γ-aminobutyric acid and having high functionality and flavor.
Thus, according to the present invention, γ-aminobutyric acid, which is a functional substance having an antihypertensive action and the like by lactic acid bacteria fermentation, is produced from a raw material selected from various food materials, various unused food materials, or post-treated products thereof. Method, production method of food, feed, feed, fertilizer, or pesticide including the lactic acid bacterium fermentation in the production process to obtain high concentration of γ-aminobutyric acid, and food, feed, feed, fertilizer containing γ-aminobutyric acid Or pesticides can be obtained. Further, according to the present invention, the dehydration of the lactic acid bacteria fermentation with a raw material selected from various food materials, various unused food materials, or post-processed products thereof containing and / or added at 20 w / v% or less of glutamic acid and / or a salt thereof. It is possible to provide an economical and efficient method for preserving various food materials utilizing the formation of an anaerobic state due to the generation of carbon dioxide in a carbonic enzyme reaction.
[0021]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Example 1
After adjusting the pH to 5.2 by adding 50 g of sodium glutamate to 450 ml of commercially available soymilk, the total amount was adjusted to 500 ml, and the mixture was placed in a 1-liter Erlenmeyer flask. This was used for the following lactic acid bacteria fermentation without performing a heat sterilization operation. The component values of the used soy milk were 3.7 g of protein, 3.7 g of lipid, 2.6 g of carbohydrate, 85.5 g of sodium, 1 mg of vitamin E, 55 mg of calcium, 22 mg of magnesium, 22 mg of lecithin, and 130 mg of cholesterol per 100 g of isoflavone per 100 g without detection. is there. As a seed culture medium, yeast extract and glucose were each 1 w / v%, polypeptone was 0.5 w / v%, sodium acetate was 0.02 w / v%, magnesium sulfate, iron sulfate, and salt were 0.001 w / v%. A GYP medium containing and adjusting the pH to 6.8 was used. After the GYP medium was sterilized at 120 ° C. for 15 minutes under high pressure and high temperature, one loopful of Lactobacillus brevis IFO-12005 was inoculated as a lactic acid bacterium and cultured at 30 ° C. for 2 days. In the main culturing operation, the seed culture was inoculated and then statically cultured at 30 ° C. After one day of the culture, the pH was measured over time and adjusted by adding an acid so that the pH was between 3.5 and 5.5. The culture solution was filtered during the fermentation of the lactic acid bacteria, and the amount of γ-aminobutyric acid produced was measured using an amino acid analyzer. The results are shown in Table 1 below.
[0022]
[Table 1]

By the glutamate decarboxylase reaction, one molecule of glutamic acid is decarboxylated to produce one molecule of γ-aminobutyric acid. The molecular weight of sodium glutamate (monohydrate) used was 187.1, and the molecular weight of γ-aminobutyric acid was 103. From these calculations, when the amount of γ-aminobutyric acid produced after 7 days of culture was 5.2%, the molar yield of glutamic acid to γ-aminobutyric acid produced was 95%. During the cultivation and after 7 days of cultivation, no contamination of bacteria other than lactic acid bacteria was observed, and the flavor was good.
Example 2
After adjusting the pH to 5.2 by adding 500 g of sodium glutamate to 4.5 liters of commercially available soymilk, the total amount was adjusted to 5 liters, and the mixture was placed in a 10-liter glass filter bottle (Buchner funnel filter bottle). This was used for lactic acid bacteria fermentation without heating.
50 ml of a previously cultured lactic acid bacteria seed culture was added. The component values of the soymilk used were: 3.8 g of protein, 2.5 g of fat, 4.7 g of carbohydrate, 60 mg of sodium, 60 mg of vitamin E, 0.4 mg of calcium, 40 mg of magnesium, 20 mg of magnesium, 100 mg of lecithin, 100 mg of cholesterol, and 25 mg of isoflavone per 100 g. is there. As a seed culture medium, yeast extract and glucose were each 1 w / v%, polypeptone was 0.5 w / v%, sodium acetate was 0.02 w / v%, magnesium sulfate, iron sulfate, and salt were 0.001 w / v%. A GYP medium containing and adjusting the pH to 6.8 was used. After the GYP medium was sterilized at 120 ° C. for 15 minutes under high pressure and high temperature, one loopful of Lactobacillus brevis IFO-12005 was inoculated as a lactic acid bacterium and cultured at 30 ° C. for 2 days. After inoculation of the seed culture, the culture was allowed to stand still at 30 ° C.
After one day of the culture, the pH was measured over time and adjusted by adding an acid so that the pH was between 3.5 and 5.5.
The culture solution was filtered during the fermentation of the lactic acid bacteria, and the amount of γ-aminobutyric acid produced was measured using an amino acid analyzer. The results are shown in Table 1 below.
[0023]
[Table 2]

Calculating from the value of the amount of γ-aminobutyric acid produced after 9 days of cultivation of 5.0%, the molar yield of glutamic acid to γ-aminobutyric acid produced was 91%. During the cultivation and after 9 days of cultivation, no contamination by germs other than lactic acid bacteria was observed and the flavor was good.
Example 3
To 450 ml of commercially available soy milk, 10 g, 20 g, 30 g, 40 g, or 50 g of sodium glutamate was added to adjust the pH to 5.2, and the total amount was adjusted to 500 ml, followed by placing in a 1-liter Erlenmeyer flask. This was used for lactic acid bacteria fermentation without performing a heat sterilization operation. 5 ml of a previously cultured lactic acid bacteria seed culture was added. The component values of soymilk used were 3.7 g protein, 3.7 g lipid, 2.6 g carbohydrate, 85.5 g sodium, 1 mg vitamin E, 55 mg calcium, 22 mg magnesium, 22 mg lecithin, 130 mg cholesterol, and 29 mg isoflavone per 100 g. is there. As a seed culture medium, yeast extract and glucose were each 1 w / v%, polypeptone was 0.5 w / v%, sodium acetate was 0.02 w / v%, magnesium sulfate, iron sulfate, and salt were 0.001 w / v%. A GYP medium containing and adjusting the pH to 6.8 was used. After the GYP medium was sterilized at 120 ° C. for 15 minutes under high pressure and high temperature, one loopful of Lactobacillus brevis IFO-12005 was inoculated as a lactic acid bacterium and cultured at 30 ° C. for 2 days. After inoculation of the seed culture, the culture was allowed to stand still at 30 ° C. The culture supernatant obtained after fermentation of the lactic acid bacteria was diluted with a citrate buffer at pH 2.2, and the amount of γ-aminobutyric acid produced was measured using an amino acid analyzer. The results are shown in Table 3 below.
[0024]
[Table 3]

As shown in Table 3, when 10 g of sodium glutamate was added per 500 ml, the amount of γ-aminobutyric acid in the supernatant of the fermentation broth on the second day of culture was 1.1 g. Similarly, when 20 g, 30 g, 40 g and 50 g of sodium glutamate were added, respectively, the production amount of γ-aminobutyric acid in 100 ml of the fermented liquor supernatant after 3, 5, 7, and 7 days of culture was 2.1 g, respectively. 2.9 g, 4.1 g, and 5.1 g. In any of the experiments, no contamination of various bacteria was observed during and after the culture, and the flavor was good.
Example 4
36 kg of sodium glutamate (monohydrate) was added to 580 liters of the distillation residue (wheat shochu lees) after the barley shochu mash was distilled under reduced pressure to produce type B shochu, and the pH was adjusted to 5.2 with 40% sodium hydroxide. . This was used as a medium (600 liters) for lactic acid bacteria fermentation without performing a heat sterilization operation. The component values of the used shochu lees were pH 3.6, total nitrogen 0.69 w / v%, formol nitrogen 0.15 w / v%, total sugar 3.5 w / v%, and water 91.3 v / v%. . 7 liters of a previously cultured lactic acid bacteria seed culture was inoculated. As a seed culture medium, yeast extract and glucose were each 1 w / v%, polypeptone was 0.5 w / v%, sodium acetate was 0.02 w / v%, magnesium sulfate, iron sulfate, and salt were 0.001 w / v%. A GYP medium containing and adjusting the pH to 6.8 was used. After sterilizing the GYP medium at a high temperature and a high pressure for 15 minutes at 120 ° C., Lactobacillus brevis IFO-12005 was used as a lactic acid bacterium. 10 ml of GYP medium was put into a test tube, and a platinum loop was inoculated from a culture of the stock agar medium into a test tube medium which had been subjected to high-temperature and high-pressure sterilization at 120 ° C. for 15 minutes, followed by primary stationary seed culture at 30 ° C. for 2 days. 0.7 ml of the primary seed culture was similarly inoculated into a 200 ml Erlenmeyer flask containing 70 ml of GYP medium and sterilized at 120 ° C. for 15 minutes at a high temperature and high pressure. did. Next, 70 ml of the secondary seed culture was added to a medium which had been sterilized by high-temperature and high-pressure sterilization at 120 ° C. for 15 minutes in a 15-liter stainless steel container containing 7 liters of GYP medium. Subsequently, the cells were cultured at 30 ° C. for 2 days by static culture (tertiary seed culture). This was added to 600 liters of shochu lees main culture medium, and main culture was started at 30 ° C. Concentrated hydrochloric acid was added once on the first day of the main culture, twice on the second day, and once on the third day to adjust the pH of the culture solution to 3.5 to 5.5. On the third day of fermentation, the production concentration of γ-aminobutyric acid was 3.2 w / v%, and the added glutamic acid was mostly converted to γ-aminobutyric acid. Fermentation was carried out in a normal non-closed container, but there was no germ contamination during the cultivation, and solid-liquid separation and activated carbon treatment were performed from the culture solution to obtain a light-colored (yellow) transparent and flavorful liquid. Was.
[0025]
In addition, similarly to the above-mentioned example using barley shochu lees, when potato shochu lees and rice shochu lees are used, 3.0 w / v% and 3.1 w / v% of γ-aminobutyric acid are respectively used. A lactic acid bacteria fermented broth containing lactic acid bacteria was obtained.
Example 5
2 liters of the clear fermentation broth obtained in Example 4 was concentrated (outside solution temperature 60 ° C.) with a rotary evaporator to 400 ml. This solution contained 15 w / v% of γ-aminobutyric acid. It is a very savory liquid and contains 30 mg of γ-aminobutyric acid in 0.2 ml, which is required to be taken per day for suppressing hypertension in humans. This concentrated solution can be stored for a long time under normal temperature conditions, and is convenient for distribution as a product.
Example 6
10 ml of the concentrated fermented solution containing 15 w / v% γ-aminobutyric acid obtained in Example 5 was added to 1 liter of freshly fried soy sauce produced according to a standard method to produce a functional soy sauce as a trial. The obtained soy sauce had good flavor and 0.15 w / v% of γ-aminobutyric acid. By this operation, a seasoning having functionality could be produced. General analysis values were 1.86 w / v% of total nitrogen, 0.87 w / v% of formal nitrogen, 38.6 of brix, 17.4 w / v% of sodium chloride, 3.1% w / v% of direct reduction, pH 4.4, The alcohol was 2.5 v / v%.
Example 7
5 ml of the 15 w / v% γ-aminobutyric acid-containing concentrated fermentation solution obtained in Example 5 was added to 500 ml of white wine to produce a wine type liquor containing γ-aminobutyric acid. Analytical values of this liquor were 0.15 w / v% of γ-aminobutyric acid, 3.59 w / v% of extract, 12.0 v / v% of alcohol, pH 3.4, and 0.56 w / v% of total acid. Was. The flavor was not different from that without the lactic acid bacteria fermentation broth.
Example 8
To 2 liters of a commercially available soymilk, 6 ml of a fermented solution of soymilk lactic acid bacteria containing 5.2 w / v% γ-aminobutyric acid obtained in Example 1 was added to obtain soymilk enriched with γ-aminobutyric acid. The analysis value of this soymilk was as follows: γ-aminobutyric acid 31 mg, protein 7.5 g, lipid 7.4 g, carbohydrate 5.6 g, sodium 181.9 g, vitamin E 2 mg, calcium 115 mg, magnesium 46 mg, lecithin 250 mg, cholesterol detection per 200 ml Without this, it was 61 mg of isoflavone. The flavor was not different from that without the addition of the fermented liquid of soymilk lactic acid bacteria and was excellent in palatability. When a person ingests 200 ml of this soy milk every day, health effects such as an antihypertensive effect, an improved learning function, and prevention of aging are expected.
[0026]
【The invention's effect】
According to the present invention, glutamic acid decarboxylation is applied to raw materials selected from various food materials containing 20 w / v% or less of glutamic acid and / or a salt thereof and / or various unused food materials, or post-treated products thereof. Γ-aminobutyric acid, a functional substance having an antihypertensive effect and the like, can be produced at a high concentration by allowing lactic acid bacteria having enzyme-producing ability to act. The fermentation product obtained by such an operation can be used not only as a food having various functionalities, as a nutritional supplement and the like, but also as a raw material for feeds, feeds, fertilizers, agricultural chemicals and the like. The present invention relates to a method for allowing lactic acid bacteria to act on a raw material selected from various food materials, various unused food materials, and / or post-processed products thereof containing and / or containing 20 w / v% or less of glutamic acid and / or a salt thereof. In order to prevent the deterioration of nutrient substances and functional substances contained in the raw materials, the heating temperature in the heat treatment process of the food material raw materials before and after the lactic acid bacteria fermentation operation according to the stability of those nutrient substances and functional substances is controlled. It may be carried out appropriately or without heating, and the container used in the method of the present invention may be a closed container. However, a non-closed container (open type container) has a sufficient storage effect for practical use. The present invention provides a practical, economical, and efficient method for preserving various food materials.

Claims

A lactic acid bacterium having a glutamic acid decarboxylase-producing ability is used as a raw material selected from various food materials containing 20 w / v% or less of glutamic acid and / or a salt thereof and / or various unused food materials, or post-treated products thereof. A method for producing γ-aminobutyric acid, wherein the method is carried out.

The food material is soy milk, milk, skim milk powder, kelp extract, fruit juice, fruit juice, fish meat extract, enzyme decomposed products of various proteins or vegetable juice, etc., cheese whey, soy broth, tofu wastewater, husk Unused food materials such as bonito, bonito juice, canned (pineapple, orange, peach, etc.) juice or alcohol distilled waste (potato shochu lees, rice shochu lees, barley shochu lees, etc.), sweet potato starch lees, potato starch lees, or The method for producing γ-aminobutyric acid according to claim 1, wherein the raw material is selected from the post-treated products.

3. The γ-aminobutyric acid according to claim 1 or 2, wherein the lactic acid bacterium having the ability to produce glutamic acid decarboxylase is a lactic acid bacterium belonging to Lactobacillus brevis or Lactobacillus plantarum. Manufacturing method.

The γ-aminobutyric acid according to any one of claims 1 to 3, wherein during the fermentation of the lactic acid bacterium, the pH of the fermentation liquor after one day from the start of the culture is adjusted to pH 3.5 to 5.5 in a timely manner. Manufacturing method.

The method according to any one of claims 1 to 4, wherein various food materials which are not sterilized by heating or the like are used, and / or a non-closed container (open type container) is used. Production method of γ-aminobutyric acid and storage method of various food materials.

A method for producing a food, feed, feed, fertilizer, pesticide, or the like, characterized in that the production or storage method according to any one of claims 1 to 5 is included in a part of the production process.

A food, feed, feed, fertilizer, pesticide, or the like obtained by the production method according to claim 6.