JP3654628B2

JP3654628B2 - Method for processing food ingredients containing okara

Info

Publication number: JP3654628B2
Application number: JP2000349594A
Authority: JP
Inventors: 邦夫新井; 雅文阿尻; 東一郎高井; 透粟津; 健二笠間; 正人西; 原成天野
Original assignee: Takai Tofu and Soymilk Equipment Co
Current assignee: Takai Tofu and Soymilk Equipment Co
Priority date: 1999-11-16
Filing date: 2000-11-16
Publication date: 2005-06-02
Anticipated expiration: 2020-11-16
Also published as: JP2001204415A

Description

【０００１】
【発明の属する技術分野】
この発明は、超臨界条件や亜臨界条件の下でオカラを含む食品を生産する、オカラを含む食品原料の加工方法に関する。
【０００２】
【従来の技術】
近年、超臨界水や亜臨界水中での加水分解や酸化反応を利用して、産業廃棄物や家庭の廃棄物を無害化したり、有効利用し得る生成物を得る試みがなされている。例えば、特開平５−３１０００号公報には、種々の高分子化合物を超臨界水や亜臨界水を用いて加水分解する方法が開示されている。また、オカラを出さない豆腐の製造方法として、高圧ホモジナイザーを用いた方法も開示されている（特公昭６２−１７５０９号公報：特許第１４２３２８５号）。
【０００３】
超臨界状態や亜臨界状態では、水の性質が大きく変化し、水の極性が下がり、水に油が溶けるようになり、水のイオン積（常温常圧下１０^-14）が１０^-11〜１０^-12と１００〜１０００倍に高まり、高密度の水蒸気状態になる（図３参照）。そのような状態では、高分子の低分子化（加水分解）や、酸素存在下では「水の中で燃える」ような酸化（燃焼、熱分解）反応が起こる。そこで、上記従来公報のような技術が開示され、ダイオキシンや有害廃棄物の安全な処理で注目されている。なお、ゴミ発電や廃棄物処理のような全てを分解・燃焼する方法も注目されている。
【０００４】
しかし、これら従来のものは、産業廃棄物や家庭の廃棄物の処理を主目的とするもので、食品原料一般に超臨界水や亜臨界水中での高分子の変性や一部の分解を利用する加工方法は、未だ開示されていない。なお、焼酎搾り粕、魚のあら・内臓、籾殻で加水分解による工業原料分離回収等の研究が試みられている。特に、豆腐の製造過程で多量に生じるオカラのように、食品を製造する過程で生じる可食性の未利用副生成物を食品原料として再利用するために、超臨界水や亜臨界水中での高分子の変性や一部の分解を利用する加工方法は、未だ開示されていない。すなわち、食品材料の加工としては、種々のものがあるが、例えば、ロングライフ牛乳のように、滅菌を目的としても、食品成分へのダメージを考慮し、１ＭＰａ、１３０°Ｃを超える条件は取られない。大豆等を１．１〜３ＭＰａ、１２０〜２００°Ｃで処理する、２軸エキストルーダーを使う方法（特開平０４−５８８５３号公報）もあるが、低圧処理であり、短時間反応を正確に行うには問題がある。超高圧処理の研究では６０°Ｃ以下１０００ＭＰａ以下の条件で、大豆タンパク質の変性や耐熱性胞子の殺菌に関する事例があるが、１３０°Ｃを越える条件での知見はなく、トリプシンインヒビターはほとんど失活しないという問題がある（さんえい出版「加圧食品」参照）。また、従来の豆腐の製造では、常圧〜０．２ＭＰａ、１００〜１１０°Ｃという条件で加熱加工されている。なお、特開平９−２６８１６６号公報には、タンパク質を加水分解してアミノ酸を製造する方法において、加水分解を超臨界状態又は亜臨界状態の水で行うものが開示されている。しかし、タンパク質、繊維質、糖質、脂質などを含む多成分系である、可食性の天然有機原料一般に適用可能な汎用性のあるものではない。単一成分系では、生成物の予想は付きやすいが、多成分系では各成分から由来する生成物間の影響（例えば有機酸生成によるｐＨ変化など）で、予期せぬ成分の生成も起こり得る。多成分系では一成分に加工条件を合わせても、他の成分の加工が、うまく行かないという問題がある。一方、高圧ホモジナイザーを使用した方法では、５６ＭＰａで３回通す必要があり、処理液を豆乳に混合し、凝固剤で凝固させても、豆腐の食感はザラザラし、保水性に乏しく、商品価値が低いのが現状である。
【０００５】
【発明が解決しようとする課題】
このように、従来において、超臨界水や亜臨界水中での高分子の変性や一部の分解を利用して、新しい食品原料の加工方法は未だ開発されていない。特に、オカラのような多成分系では、複雑な反応が起こり、分析が難しいことや日持ちが悪いこと等から、食品素材として栄養価も安全性も高いにもかかわらず、多量のオカラの再利用を図る加工方法は開発されていない。
【０００６】
なお、今までの超臨界水利用の話題は、酸化反応が先行し、難分解性物やゴミ処理など、環境分野の技術として研究開発が進んできており、一部で実用化されている。
【０００７】
しかし、化学原料回収方法については、タンパク質からアミノ酸への加水分解やペプチド（アミノ酸からの再合成）、グルコース等の低分子成分への加水分解に係わる特許出願が行われている（特開平９−２６８１６６号公報や特開平５−３１０００号公報等）。また、タンパク質やセルロースなど単独成分の変化は、基礎的な知見として重要であり、実験や生成液の分析が比較的容易であり研究開発が先行している。しかし、実際の応用面では、多成分系の原料が対象であり、生成液の分析が難しく、研究開発や用途開発が遅れている。なお、食品粕の再利用を高温高圧水で試みている研究機関もないではないが（例えば、籾殻、魚、焼酎粕について）、いずれも分解による低分子の有用成分の成分分離に関して研究し、食品加工に関する技術開発ではない。
【０００８】
そこで、この発明の目的は、オカラを含む食品を水の超臨界状態と亜臨界状態で加工するとオカラを含む食品の安全性が確保される等様々な利点があることを見出し、食品素材として栄養価も安全性も高いオカラの有効な再利用を図るため、オカラを含む食品の加工方法を提供することにある。
【０００９】
【課題を解決するための手段】
本発明者等は、オカラの高温高圧条件での加工処理の研究を長年行い、多量に生じるオカラの安全で有効かつ経済的な加工方法を見い出し、本発明を完成した。すなわち、本発明の請求項１記載のオカラを含む食品原料の加工方法は、オカラ、液状のオカラ、オカラに水を加えたスラリー、又はこれらオカラを含む多成分系の食品原料を、３７４°Ｃ以上かつ２２．１ＭＰａ以上の水の超臨界条件と、１００°Ｃ以上３７４°Ｃ未満でその温度における水の飽和蒸気圧以上の亜臨界条件とのいずれかの高温高圧条件又はこれらを組み合わせた条件の下において、０．０１秒以上６０分以下で、高分子の高次構造の変化を起こす加工処理をすることを特徴とする。加工時間は温度・圧力条件によって異なるが、極短時間（例えば０．０１秒）から数十分の範囲が好ましい。ここで、水の超臨界状態と亜臨界条件の高温高圧条件を単独或いは、２以上の条件を組み合わせて処理する工程とを備える。水の超臨界状態と亜臨界条件の高温高圧条件を２以上組み合わせるとは、少なくとも水の超臨界状態と亜臨界条件の下であれば、いずれか一方条件で行った後に他方の条件で行う場合、超臨界条件から亜臨界条件に亘る範囲で行う場合、更に、同じ条件で複数行う場合を含む。なお、本発明は、酸化剤（過酸化水素、酸素など）や薬剤（酸・アルカリなどの薬剤）の添加による酸化又は加水分解や熱分解を主とする加工法ではない。
【００１０】
この請求項１の発明によれば、水の超臨界や亜臨界各条件という高温高圧処理によって、オカラは例えば「高圧圧力釜で高温極短時間、調理」された状態になる。オカラの形態はほとんど損なわないか、又は物理的に軟化、微細化された状態になる。オカラ中の各組織・各成分は有為に選択的かつ部分的に、変性・粗分解し、食品原料として再利用しやすくなる。ここで、上記高温高圧処理は栄養成分（タンパク質、アミノ酸、脂質、糖質、食物繊維等）の分解、風味（味、香り、色など）の低下を防ぐため、できるだけ低温短時間処理が好ましい。また、ここでの水には、氷、氷水、温水、高温高圧水、亜臨界水、超臨界水、水蒸気、過熱水蒸気などを含む。なお、本発明では、主として変性・軟化・微細化（コロイド粒子化）などが中心であり、成分の分解はあくまで副反応で起こりうる。一般的に調理加熱は、喫食・消化しやすく物性改良することが主たる目的だが、副次的に甘み旨味や香りの生成（例えば炊飯や石焼いも等）が知られている。本発明でも同様にタンパク質や繊維質を僅かに部分的に分解することによってブドウ糖、グルタミン酸などの甘み等、甘み・旨味成分を官能的に感じるだけ極少量生成させ、風味向上も図る。ただし、このような低分子を大量に生成することを目的とはしていない。タンパク質や食物繊維のように栄養的価値をできるだけ保持した加工方法を目指している。そして、本発明によれば、オカラの一般細菌や耐熱性細菌胞子を死滅させ、日持ちを良くすることのみならず、不溶性繊維成分は軟化・微細化し、滑らかな風味の良い「オカラ乳」になる。このオカラ乳中のタンパク質は適度な変性状態になり、豆腐の副原料として使っても、保水性や凝固反応には悪影響しない。少なくとも豆腐製造用の食品原料や飲料用のものとしては、何ら問題なく、むしろ栄養価も安全性も高い。豆腐製造用に使用すると、豆腐中の可溶性食物繊維量が増え、保水性も高まり、栄養特性が向上する。オカラを廃棄物として排出せず、食品としての加工特性を有する有機食品原料としてほとんど全てを再利用することができる。このような高温高圧水加工において、オカラ等における各成分・各組織や加工後の性状や用途に応じて、２以上の条件を組み合わせることによって、目的に応じて本加工オカラの品質を調整することができる。例えばオカラを低温の２００°Ｃ前後数十秒で組織の軟化・微細化、タンパク質抽出や食物繊維の可溶化等を行った後、風味向上のため、高温の３５０〜４００°Ｃで、極短時間（数秒以下）の加工を行うことによって、食品原料としての付加価値を向上させることが可能になる。
【００１１】
本発明の請求項２記載のオカラを含む食品原料の加工方法は、請求項１の加工方法の前工程又は後工程で、オカラ又はオカラに水を加えたスラリー状のオカラを、高圧ホモジナイザー処理する。すなわち、水の超臨界状態と亜臨界条件やこれらの組み合わせ条件の高温高圧条件での加工の前か後にオカラを高圧ホモジナイザーで処理する。具体的には、次のような態様が考えられる。（１）最初に、高圧ホモジナイザーで処理し、次いで、高温高圧水加工を行う。（２）最初に、高圧ホモジナイザーで処理し、次いで、高温高圧水加工を行い、再度高圧ホモジナイザーで処理する。（３）最初に、高温高圧水加工を行い、次いで、高圧ホモジナイザーで処理する。（４）これらを、交互に数回繰り返す。その回数は問わない。
【００１２】
まず、オカラを含む原料を高圧ホモジナイザーによって前処理すると、原料粒子の微細化やタンパク質や繊維質など高分子の高次構造の変性が起きる。そのため、分子各部位で様々な反応に敏感になり、その後の工程の高温高圧水による部分分解や熱・圧力による変性を、より穏やかな温度・圧力条件、より短時間かつ正確に行うことが可能になる。また、高圧ホモジナイザーによる前処理では、圧力が瞬間に変化するため、動植物や微生物の細胞壁を破壊できる。細胞内成分の抽出が容易になり、直後の工程で固液分離を行えば、豆乳として歩留り向上を図ることが可能である。ただし、固液分離せずに豆乳に混合し、豆腐の製造に再利用するには、保水性やザラツキのある食感から全て利用するには限界があるが、その後の請求項１記載の高温高圧水加工により、ほとんど全て食品原料として再利用が可能となる。
【００１３】
他方、高圧ホモジナイザーを高温高圧条件の加工処理の後処理に使うと、軟化した原料スラリーを滑らかな沈殿物のないコロイド分散液に加工することができる。この高温高圧加工と高圧ホモジナイザーの後処理の際には、オカラを含む食品原料の加工度を抑えて、すなわち細胞壁や細胞膜、高分子成分などの軟化に止め、なおかつ、有用低分子成分（遊離糖、遊離アミノ酸など）への分解をできるだけ抑えた条件を設定するのが実用的であるが、その場合、高温高圧加工済みの原料は、加工前に比べて、高圧ホモジナイザーによって容易に舌触りの滑らかな分散液体状（コロイド状）にすることが可能になる。あまり強い高温高圧条件では着色、焦げ臭が発生し、食品原料として好ましくない性状になる。これを回避するため、できるだけ短時間で、できるだけ低温での高温高圧加工に止めて、その後、高圧ホモジナイザーによる加工を行うことが望ましい。後処理に高圧ホモジナイザーを使用する場合、この前工程での高温高圧加工の条件を「一ゆで」程度の加減で、必要最小限の条件にできる。
【００１４】
本発明の請求項３記載のオカラを含む食品原料の加工方法は、請求項１又は請求項２記載の発明を前提として、前記水の超臨界条件と亜臨界条件のいずれか又はこれらを組み合わせた加工の際に、前記オカラを含む食品原料に、高温高圧水を注入するか、又は、高圧水蒸気や過熱水蒸気を吹込むことにより、前記水の超臨界条件または亜臨界条件を段階的又は勾配的に温度条件を調節することを特徴とする。
【００１５】
この請求項３記載の発明によれば、一気に所定温度まで昇温し、或いは多段階的又は勾配的に昇温を行ない、高圧（系内の最高温度における飽和蒸気圧以上）下、１つ或いは多段階的又は勾配的な温度（高温高圧）条件を設定する。その目的は、不溶性食物繊維やタンパク質、ＤＮＡ（組み替え遺伝子を含む）、大豆オリゴ糖、イソフラボンなど各成分や大豆の部位（種皮、へそ、子葉、胚軸など）や、目的の風味に応じた加工条件を設定することにある。
【００１６】
また、高圧熱水（又は水蒸気、過熱水蒸気）との混合により、原料液温度を急激に上昇させることが可能で、高温高圧加工を短時間の反応で正確に行なえる。この点は請求項２のうち、前処理として高圧ホモジナイザーを使うことによって、相乗的に正確な反応を実現できる。なお、高温高圧水（亜臨界水、超臨界水）を注入する方法、つまり熱水注入法は、スラリーの流動性を増すとともに、伝熱面の焦げ付きもなく、熱伝達が良くなり、均一かつ急速な昇温と正確な温度制御を実現することができる、原料を傷めず、焦げ付きなども少ない、最も有効な方法である。ただし、原料液の数倍の熱水を使う必要があるため、原料液が薄まる欠点がある。しかし、この場合は、本発明の請求項４のように、フラッシングによって濃縮が可能になる。また、高圧水蒸気や高圧過熱水蒸気を用いることによって、蒸気潜熱を利用でき、加水量を抑えることができ、後の濃縮工程を省くことも可能になる。
【００１７】
本発明の請求項４記載のオカラを含む食品原料の加工方法は、前記請求項３記載の発明を前提として、前記水の超臨界条件と亜臨界条件のいずれか又はこれらを組み合わせた加工の後、冷却段階に際してはその減圧前の温度における飽和蒸気圧以下まで減圧することによって加工液をフラッシングすることを特徴とする。
【００１８】
この請求項４記載の発明によれば、冷却段階に際して水蒸気をフラッシング（急激な圧力降下）することによって、蒸発潜熱による急冷と、水分蒸発による濃縮（原液濃度に近くなる）と、瞬間的な膨張力による高分子組織の破壊が起きる。したがって、高温高圧加工時にいて、過度の加熱ダメージを最小限に行うとともに、物理的に弱いＤＮＡやタンパク質等高分子を破壊することが可能であり、一連の加工工程の一端を担う。熱交換器による冷却手段が一般的であるが、やや緩慢な冷却になり、濃縮ができないなどの問題もある。ただし熱交換器との併用も可能である。
【００１９】
本発明の請求項５記載のオカラを含む食品原料の加工方法は、請求項１乃至請求項４の各工程のオカラを含む食品原料をアルカリ成分又は酸成分により３から９の範囲にｐＨ調整することを特徴とする。
【００２０】
請求項１乃至請求項４の各工程とは、原料（液）をあらかじめｐＨ調整しておくこと、熱水のｐＨを調製しておくこと、冷却段階の注入冷却水のｐＨを調整しておくこと、系外に出た生成液の中和を含めてｐＨを調製しておくこと等を含む。従来塩酸などの強酸を大量に用いる加水分解（ｐＨ３未満）によってタンパク質原料から調味料液などを製造している。しかし、請求項５記載の発明によれば、主としてクエン酸ナトリウム、炭酸水素ナトリウム、酢酸ナトリウム、リン酸三ナトリウムアンモニアなどの弱アルカリ成分や、少量の炭酸ナトリウム、水酸化ナトリウム等の強アルカリ成分を用いることによって原料液ｐＨをアルカリ方向にｐＨ１０までの範囲に調整し、又は、主としてクエン酸や酢酸などの弱酸成分やそれらを含む食品素材や少量の塩酸などの強酸成分を利用して、原料液ｐＨを酸性方向にｐＨ３までの範囲に調製することによって、食感や風味・色調等の物性改良や部分分解を有利に行うことができ、高温高圧加工の効果をより高め得る。
【００２１】
【発明の実施の形態】
以下、本発明の一実施の形態について図面を参照しながら説明する。以下、オカラの加工を例に説明するが、本願発明は、オカラ（生オカラ、乾燥オカラ、発酵オカラ、再生オカラ）は勿論、オカラと同じ成分が含まれる大豆・大豆粉・分離大豆タンパク質・大豆の各部位（脱皮粕等の種皮、へそ、子葉、胚軸など、オカラを分別した場合も含む）など大豆成分を含む有機食品原料の加工にも応用したので、これらについても説明を加える。なお、水の超臨界状態と亜臨界条件については、図４に示す。
【００２２】
（本実施の形態の加工システムの基本的構成）本実施の形態のオカラを含む食品原料の加工システムは、図１に示すような各装置を適宜組み合わせたシステムであり、その工程で各加工工程Ａ１，Ｂ，Ａ２，Ｃ，Ｄ，Ｅが行われる。
【００２３】
本実施の形態のオカラを含む食品原料の加工システムは、図１乃至図３に示すように、オカラが貯蔵される貯蔵室２ａと、（蒸留）水が貯蔵される貯蔵室２ｂと、供給ポンプ３を介して接続される高圧ホモジナイザー５Ａと、この高圧ホモジナイザー５Ａと供給ポンプ６、高圧ポンプ７ｂを介して接続される高温高圧装置１と、この高温高圧装置１と供給ポンプ３を介して接続される高圧ホモジナイザー５Ｂとを備える。高圧ホモジナイザー５Ａ，５Ｂは、０〜２００ＭＰａに加圧した原液試料をホモバルブを通過させることによりせん断、破砕、均質化するものである。高温高圧装置１は、超臨界又は亜臨界流体用の加熱装置であり、また飽和水蒸気や過熱水蒸気の発生装置としても利用できる。その種類としては、溶融塩浴装置１１、流動砂浴装置１５、電気炉装置１４等があるが、これらに限定されず、これらを組み合わせて使用することも可能である。原料への加水工程の有無１ａ，１ｂは適宜選択する。ただし、酸化剤（酸素、過酸化水素など）や薬剤（酸・アルカリなどの薬剤）の添加による酸化又は加水分解で加工するものではない。
【００２４】
また、本実施の形態の加工システムは、高温高圧装置１と連結される高圧ポンプ７ｂや、加熱装置として高温高圧水を注入する高温高圧注入装置８ｂ、又は、高圧水蒸気を吹き込む高圧水蒸気吹き込み装置８ａが備えられると共に、熱交換器１２、冷却装置１３、減圧装置１８（オリフィス、背圧弁、蒸発缶などで構成される工程Ｄ）、取出装置１７（背圧弁、ポンプ、ロータリーバルブなど）が配設されている（図２中の符号Ｃ，Ｄ）。熱交換器１２としては、多管式、プレート式、掻き取り式等いずれのものでも良くその種類は問われない。また、冷却装置１３は、公知の装置が使用されている。また、冷水注入装置２０によるものでもよい。
【００２５】
このような構成により、前記オカラの流体（固体分散液、コロイド状ペースト状流体）又は固体を、飽和蒸気圧以上の高温高圧条件で１段〜多段階又は連続的に、温度を変化（上昇・下降）させる。減圧装置１８（工程Ｄ）を介して、減圧前の流体温度における飽和水蒸気圧未満に１段〜多段階に減圧し、水蒸気を放出させ、急速或いは多段階的濃縮工程と冷却工程を同時に行う。多段階的又は連続的温度降下の場合、上記加熱工程と同様な加工（反応）が行なわれる。最終的には、取出装置１７を介して取り出すときには、大気圧および大気圧時の水沸点以下の温度になる。これらの段階的加熱工程Ｂや段階的冷却工程Ｃ、Ｄは各々複数の条件を組み合わせてもよい。高温高圧水の注入８ｂや高圧水蒸気の吹き付け８ａは数回行っても良い。また、減圧装置１８（工程Ｄ）から得た高圧高温水蒸気や熱交換器１２で得た高熱の熱媒は、再び原料の加熱に使うことができるため、エネルギー循環による経済的なシステムを構築しやすい。特に水蒸気は気体であり移送しやすく、直接加熱や間接加熱でその潜熱を利用できるので、効率の良い経済的な加工システムを実現できる。
【００２６】
以上の加工システムは、次のような基本的な使用の態様が考えられる。（１）最初に、高圧ホモジナイザー５Ａで処理し、次いで、高温高圧水加工Ｂを行う。（２）最初に、高圧ホモジナイザー５Ａで処理し、次いで、高温高圧水加工Ｂを行い、再度高圧ホモジナイザー５Ｂで処理する。（３）最初に、高温高圧水加工Ｂを行い、次いで、高圧ホモジナイザー５Ｂで処理する。（４）これらを、交互に数回繰り返す。その回数は問わない。なお、Ｃ，Ｄ，Ｅの工程は適宜組み合わせる。
【００２７】
本実施の形態では、先ず、蒸留水をプランジャー２連式高圧ポンプ（ＮＰ−ＡＸ−１５日本精密科学製）で送液し、出口の背圧弁にて所定の高圧力に調整し、途中、高温高圧装置１を通過させ所定の高温度まで加熱し、高温高圧水、すなわち超臨界水か亜臨界水、または高温高圧水蒸気、すなわち飽和水蒸気、過熱水蒸気を得る。一方、別経路で、原料液を同じく高圧で送液し、前記高温高圧水または高温高圧水と合流させ、原料液を室温から一気に２００〜３００°Ｃまで加熱装置で予備加熱し、さらに所定の温度（３００°Ｃ又は４００°Ｃ）に調整した流動砂浴式加熱装置１５（反応槽）を通過させて温度を安定させ、所定の時間（３秒、５秒、１０秒）加熱加工する。この加熱加工は、加熱装置から冷却装置までの配管長やポンプ流速（７ａ，７ｂ等）を調整しながら行う。その後、冷却装置１３を通過させて一気に水温まで冷却し、背圧弁を介して加工液を得る。
【００２８】
上記加工システムは、豆腐の製造工程に組み込まれるように構成されている。すなわち、通常の豆腐の加工に使う場合、漬け大豆を磨砕するとき本加工液を水の代わりに使用する。本加工液は、不溶性の繊維質や沈殿物をほとんど含まない滑らかな液体であり、豆乳中に２割以上混在しても豆腐の品質に影響しない。本加工液に含まれるタンパク質が豆乳に加わるため、通常と同じ濃度を得る場合、加水量は多くでき、その分（約１０〜６０％）が歩留まり増加になる。結果的に、ほとんど大豆全てを使って高品質の豆腐を製造でき、おからの有効利用が図られる。
【００２９】
（本実施の形態による加工方法）まず、オカラ又はオカラに水を加えたスラリー状又は液状のオカラを高圧ホモジナイザー５Ａにより数〜数百ＭＰａで前処理し（図中の符号Ａ１）、微細化、細胞組織破壊、微乳化等する。次いで、オカラに新たな水を加えて膨潤・浸漬・乳化したペースト状のものや分散したスラリー状のものを高圧ポンプ３で圧送し、高温高圧装置１に送る。ここで、高温高圧系内（すなわち、高圧ポンプ７ａ、７ｂ〜取出装置１７までの間）の最高温度における飽和蒸気圧以上、（例えば２００°Ｃのとき１．５５３８ＭＰａ以上、３００°Ｃのとき８．５８１ＭＰａ以上等）で圧送する（図４参照）。また、例えば、４００°Ｃ３０ＭＰａの高温高圧水注入装置８ｂによる注入や、高圧水蒸気（例えば飽和水蒸気３００°Ｃ８．５ＭＰａか、或いは、その高圧系の圧力と同等以上、又は過熱水蒸気３６０°Ｃ８．５ＭＰａ）の吹込み装置８ａによる吹込み等によって直接加熱する。すなわち、水の亜臨界状態が１００°Ｃ以上かつその温度における飽和蒸気圧以上の圧力（例えば１５０°Ｃのとき０．４７６ＭＰａ以上）、又は、水の超臨界条件（３７４°Ｃ以上かつ２２．１ＭＰａ以上）を、１または２以上の条件を組み合わせて、各条件で所定時間（例えば０．０１秒〜６０分）形成する。
【００３０】
この工程で、大豆タンパク質を豆乳や豆腐などへの食品加工特性、栄養特性を損なわない、適正な変性状態（高次構造の変化）にし、かつミジン（大豆の細かい欠片、不溶性繊維成分）の柔軟化や薄質化によってざらつく食感を改良し、または、食物繊維としての栄養特性を残しながら、可溶性食物繊維に改良することができる。また、負の栄養成分である大豆オリゴ糖（ラフィノース、スタキオースなど鼓腸成分）の一部を分解し、また、トリプシンインヒビターの一部を変性失活させ消化性を向上させ得る。ただし、大豆オリゴ糖の含有量は、不溶性繊維質に比べて極めて少なく、「加水分解」が本発明において起き得たとしても、主ではなく、副たる反応であり、あくまで付随効果である。また、遺伝子組換大豆を原料としたオカラについては、導入遺伝子由来のＤＮＡやタンパク質を変性させ得る。
【００３１】
高圧ホモジナイザー５Ａの前処理工程（符号Ａ１）では、オカラの粒子が微細化されて、滑らかなペースト状になる。それは、そのまま食品原料としても利用できる。例えば、豆乳に混合し、通常の凝固剤、すなわち塩化マグネシウム（ニガリ）、硫酸カルシウム（すまし粉）、グルコノ−δ−ラクトン（ＧＤＬ）、塩化カルシウム、塩化マグネシウム、トランスグルタミナーゼ、有機酸などを用いて、豆腐に加工することは可能である。しかし、微細化された不溶性繊維質にもかかわらず、豆腐中の異物として保水性を低下させ、ザラツキのある食感を与えるため、豆乳への混入割合は多くはできず、１割程度までであり、オカラを全て利用するには限界がある。また、前処理に高圧ホモジナイザー５Ａを使って、０．５〜２ｍｍ程度の粒子の大きいオカラのスラリーを、０．１〜０．０１ｍｍ以下の滑らかなスラリーにすることによって、流動性が高くなり、熱伝達、伝熱の効率が良くなる。さらに、オカラのように大きな粒子があると、高圧ポンプの逆止弁や取り出し装置等に引っ掛かかり、送液ができなくなるおそれがある。また、物理的にもできるだけ細かくした方が、できる限り低い温度圧力条件で、できるだけ短時間の条件によって、原料全体を均一に正確にスムーズに加工することができ、風味や色合い違和感のない食品原料としての特性を維持することができる。さらに、細粒化により流動性が高まるので、原料への加水を最小限にできる効果もある。
【００３２】
また、上記加熱加工済みの「大豆や、大豆成分や大豆部位を含む高温高圧流体（又は固体分散液、コロイド状ペースト状流体）又は固体」を、直接又は冷却工程途中又は冷却工程を終えた後、背圧弁又はロータリーバルブ等の取出装置１７又は高圧ポンプ６等を介して、高温高圧系から加工済み原料を取出す工程Ｅが設けられている。
【００３３】
また、上記加熱加工済みの「大豆や大豆成分を含む高温高圧流体（又は固体分散液、コロイド状ペースト状流体）又は固体」を、直接又は冷却工程途中又は冷却工程を終えた後、高圧ホモジナイザー５Ｂを用い、数〜数百ＭＰa（例えば５〜２００ＭＰａ）で後処理（微細化、細胞組織破壊、微乳化等）する工程Ａ２が設けられている。
【００３４】
ここで、大豆や大豆成分や大豆各部位を含むものである有機食品原料の場合は、前処理の高圧ホモジナイザー５Ａによって、原料粒子の微細化やタンパク質や繊維質など高分子の高次構造の変性が起きる。そのため、分子各部位で様々な反応に敏感になり、その後の工程Ｂａ〜ｃの高温高圧水による粗分解や熱・圧力による変性を、より穏やかな温度・圧力条件により、更に短時間かつ正確に行うことが可能になる。また、大豆や大豆成分を含むものである有機食品原料の場合は、大豆組織、即ち「へそ」や種皮等の柔軟化、細胞膜や細胞壁組織等の柔軟化・粗分解、大豆中の構成高分子（セルロース、ペクチン、タンパク質、ＤＮＡ、例えば遺伝子組換大豆中の微生物由来ＤＮＡやタンパク質等）に対する熱・圧力・時間による変性、タンパク質であればＳＳ結合（他イオン結合、静電結合、疎水結合、水素結合）やサブユニット結合の解離や再結合による高分子の高次構造（２次構造〜４次構造）の変化や、大豆中の構成成分、即ち前記高分子や消化酵素阻害成分トリプシンインヒビター（タンパク質）の失活や、スタキオースやラフィノースといった鼓腸性オリゴ糖（嫌われる成分）や、ダイジン、ゲニスチンというイソフラボン配糖体（糖鎖を切ったイソフラボンはより高い女性ホルモン活性がある）等の低分子成分が副反応として部分的に分解し、付随的に栄養価を高め得る。またタンパク質や不溶性繊維質の一部分もわずかに副反応として粗分解し、甘みや旨味成分（低〜中分子）を生成し得る。
【００３５】
このような加工システムにより、超臨界条件と亜臨界条件の温度条件を段階的又は勾配的に選択すると、次のような各成分に応じた加工が可能である。
【００３６】
（１）例えば１００〜３００°Ｃで１０ＭＰａ以下では、繊維質やタンパク質など大豆の構成高分子が変性し、細胞壁など繊維質が軟化し、タンパク質で生理活性物質（悪影響成分）であるトリプシンインヒビターを失活させ消化性を向上させる。一般にタンパク質であれば、サブユニット集合体（四次構造）から個々のサブユニット（三次構造）への解離、個々のサブユニット（三次構造）の緩みや疎水性領域の露出などの変化、アルファーら旋構造やベータ構造（折りたたみ構造）のランダム構造への変化（二次構造）が起こる。本願発明では、原料はほとんど分解せず、このような変性した状態に加工することができる。
【００３７】
（２）例えば３００〜３５０°Ｃで３０ＭＰａでは、高分子は部分的に分解を受け、中程度の分子（例えば、繊維質はポリデキストリンへ、タンパク質はポリペプチドへ）に分解できる。本願発明では、原料はほとんど分解せず、変性した状態からβ−Ｄ−グルコースが数個から数百個連なったいわゆる「可溶性食物繊維」、また、グルタミン酸のようなアミノ酸が２個以上つながったペプチドや１０個以上つながったポリペプチドのような「甘み旨味、生理活性成分」、さらに、遺伝子組換作物（大豆等）の場合、バクテリア由来のＤＮＡ（遺伝子）を含めて、ＤＮＡやＲＮＡ（遺伝子）を変性させ、一部をオリゴヌクレオシドに分解可能である。完全に分解しなくとも中程度に分解した分子がより多く含まれるよう加工された状態になる。これら説明は、比較的大きな分子が、高圧ホモジナイザー５Ｂの後処理やフラッシング（急激な圧力降下）によって微細化し、コロイド粒子状になる場合も含む。
【００３８】
（３）例えば３５０〜４００°Ｃで３０ＭＰａでは、高分子は大半が分解を受け、低分子にすることができる。例えば、繊維質やポリデキストリンから、例えば単糖であるβ−Ｄ−グルコースのような「甘み成分」を生成し、タンパク質やポリペプチドからは、例えばアミノ酸の１種であるグルタミン酸（大豆中最も多いアミノ酸）のような、いわゆる「旨味成分」を生成し、これらを多く含む味を向上させた加工品を得ることができる。バクテリア由来の組み替え遺伝子をヌクレオシドやヌクレオチドやアグリコン（グアニン、シトシン、アデニン、チミン、ウラシルなどの塩基）まで分解し、より安心できる加工品を得ることもできる。また、大豆オリゴ糖（ラフィノース、スタキオースなど鼓腸成分）を単糖に部分分解し、鼓腸作用を低減できる。また、大豆イソフラボンの配糖体（ゲニスチンやダイジン等）の糖質残基を除去し、アグリコン（ゲニステインやダイゼイン等）に分解し、女性ホルモンとしての生理活性効果を高め得る（糖質部分は分解を受けやすく、イソフラボン骨格は比較的安定と見られる）。
【００３９】
そして、本実施の形態の加工システムによれば、高圧送液ポンプ３は高価なスラリー対応ポンプである必要がなくなり、コスト軽減が図られる。また、背圧弁など閉塞する心配が少なくなり、安定な稼動とコスト軽減が図られる。この工程においては、高温高圧系において（原料送液ポンプ、加熱工程Ｂ、冷却工程Ｃ、取出装置工程Ｅを含む）中で、高温高圧条件から高温高圧系内の最低温度における飽和水蒸気圧以上の範囲で、オリフィス、背圧弁等を介して、１段〜多段階に減圧変更し、各圧力条件を所定時間に設ける。
【００４０】
また、前記加熱加工済みのオカラの高温高圧流体（水の亜臨界、超臨界条件で、滑らかな液体の他、固体分散液、コロイド状ペースト状流体、やバッチ式の場合、固体を含む）を、熱交換器１２を通して急速或いは多段階的又は連続的な冷却を行う冷却工程Ｃおよび多段階的又は連続的温度降下の場合、上記加熱工程と同様な加工（反応）を行う。なお、各工程Ｂ，Ｃ，Ｄにおいて熱を冷ました状態で各工程Ｂ，Ｃ，Ｄをそのまま続けても良い。
【００４１】
さらに、本実施の形態の加工システムにおいては、図２に示すように、冷却工程Ｃ（減圧工程Ｄを含む）等は、循環的なシステムとして構成することが好ましい。生オカラのみならず乾燥オカラ等を効率的に加工処理するためである。すなわち、本実施の形態の加工システムに更に、冷却工程で得た飽和水蒸気、又はその飽和水蒸気を加圧し再凝縮させた高圧高温水、又は熱交換器１２を経て得た高温高圧水又は飽和水蒸気を、再び、原料流入側に戻し、上記のように熱交換器１２による間接加熱、又は、直接加熱によって原料を加熱するための熱回収工程を配することが好ましく（図２中符号Ｆ）、省エネルギーであり経済的である。
【００４２】
上記Ａ１，Ｂ（Ｂａ〜ｃ），Ａ２〜Ｄ，Ｅまでの工程を、その条件を選択的に多段階に、又は連続的に設定すると、繊維質やタンパク質など大豆の構成高分子が変性し、軟化・微細化するだけでなく、副反応として、それらの一部を分解し、低分子成分を適当量含有させることができる。例えばβ−Ｄ−グルコース（セルロースの構成成分）のような、いわゆる「甘み成分」、グルタミン酸（大豆中最も多いアミノ酸）のような、いわゆる「旨味成分」、きな粉や煎り豆のような「香ばしい香り成分」など付加価値のある成分を加工生成物中に含ませることができる。その生成量は味覚に感じる程度の少量で良い。例えばグルタミン酸であれば、最終食品中０．０３〜０．１％程度あれば十分旨みを感じることができる。すなわち、本実施の形態は、食品添加物を使用しない「風味付け加工」といえるものである。
【００４３】
したがって、先行技術のように、付加価値のある成分を高収率で単離・精製する目的とは異なる。また、本願ではβ−Ｄ−グルコースが数個から数百個連なったいわゆる「可溶性食物繊維」、また、グルタミン酸のようなアミノ酸が２個以上つながったペプチド・ポリペプチドのような「甘み旨味、生理活性成分」など、完全に分解しなくとも中程度に分解した分子も選択的に適量含有させ得る。
【００４４】
次いで、本実施の形態の加工システムの製造規模に応じた使用の仕方を図３を用いて概説する。製造規模が中規模から大規模に使用できる場合は、図３の上段に示すように、高温高圧水連続加工装置として構成し、上記工程Ｂａ〜Ｄを連続的に行えるようにする。ここでは、各ポンプＰ１〜Ｐ４や高圧ポンプ７ａ，７ｂ等を使用して連続的な加工システムを構築する。次に、製造規模が小規模に使用できる場合は、図３の下段に示すように、高温高圧水セミバッチ加工装置として構成し、上記工程Ｂｃ〜Ｄを連続的に行えるようにする。次に、製造規模が極小規模に使用できる場合は、図３の中段に示すように、高温高圧水バッチ加工装置として構成し、上記工程Ｂｂ〜Ｄを回分式に行えるようにする。これらの場合（図３中の中段、下段）は、オカラ（生オカラ）と水を所定の容器に充填する充填工程を経て高温高圧加工が行われる。なお、何れの工程（図３中の全て）でも加水工程の有無１ａ，１ｂは適宜選択する。このような構築をすると、本実施の形態を製造規模や企業規模に応じた加工システムが実現できる。
【００４５】
以上から、本発明の加工システムと加工方法によれば、オカラは勿論、オカラを含む食品原料の加工のみならず、オカラと同じ成分が含まれる大豆・大豆粉・分離大豆タンパクなど大豆成分や大豆各部位を含む有機食品原料の他、その他有機食品原料の加工にも応用し得るものである。したがって、大豆と同じように、無機成分が少なく、炭水化物（繊維質、糖質）やタンパク質、脂肪等栄養成分からなり、加工後に食品原料に成り得る有機性原料（パルプ、木材粉、木綿、とうもろこし芯、蕎麦殻、小麦麩、酒粕、ビール粕、ブドウ酒搾り粕、醤油粕、餡粕、サトウキビ搾り粕、ミカンやリンゴ、ブドウなど果汁搾り粕、茶殻、畜肉残渣・血液廃液等）等にも適用することが可能である。
【００４６】
【実施例】
（実施例１）上記実施の形態において、オカラ０．５ｇを１０ｍｌ高温耐圧容器（ＳＵＳ３１６Ｌ製肉厚圧管）１９にとり、所定の温度で所定の圧力になるよう貯蔵室２ｂの水（蒸留水）を所定量加え密栓した。耐圧管１９を所定温度（２５０°Ｃ，３００°Ｃ，３５０°Ｃ、４００°Ｃ）に調整した溶融塩浴装置（溶融した硝酸塩を熱媒に使用）１１に漬け込み、所定時間（１分、５分、６０分）経過後、直ちに取り出し、水槽に漬け込み急冷した。高温高圧装置１により加工は（図中符号Ｂ）、３０ＭＰａと４０ＭＰａで、時間は６０秒〜３，６００秒（６０分）の範囲内で行った。すなわち、表１の左欄に示す1〜11の各条件の下で実験し、高温高圧水加工後、耐圧管１９を開き、加工液を取り出し、性状評価を行った。その結果を表１に示す。性状評価は、オカラ残渣、残渣沈降、着色程度、風味等について行った（実施例１の水の飽和蒸気線図は、図４の星印を参照）。
【００４７】
【表１】

【００４８】
表１から明らかなように、高温高圧装置１により、３０ＭＰａ、３５０°Ｃ、５分の条件（Ｎｏ６）や、３０ＭＰａ、４００°Ｃ、５分の条件（Ｎｏ８）では、オカラの残渣がなく、褐色の液体となった。また、３０ＭＰａ、４００°Ｃで、６０分の条件（Ｎｏ９、Ｎｏ１０）になると、強い焦げ臭い臭いがした。ただし、着色は逆に淡くなってきた。これらの条件はかなりの成分変化が起き、官能的には食品原材料としては利用しがたい点もあるが、３０ＭＰａ、３００°Ｃ以下の条件（Ｎｏ１，２，３，４）では、オカラ残渣は認められるが、チキンスープやコーヒー風味が生じ、食品原料としての利用価値が認められた。なお、若干の着色は起こしている。これらからオカラを含む原料成分の過度のダメージを防ぐためには、高温高圧水加工は短時間処理が好ましいことが分かる。そして、水の超臨界や亜臨界各条件という高温高圧水による短時間処理によって、オカラ中の各成分は有為に選択的かつ部分的に、変性・分解し、食品原料として再利用の途が開かれる。例えば、豆腐の副原料として使うと、オカラを廃棄物として排出せず、安全に再利用することができ、豆腐中の可溶性食物繊維量が増え、保水性も高まり、栄養特性を向上させることができる。
【００４９】
（実施例２）オカラ１ｋｇに２．５倍量の水を加えスラリー状とし、高圧ホモジナイザー（ＮＳ２０６ＬＰＯＮＹ、Niro Soavi社製）５Ａを３５ＭＰａで３回処理し、滑らかなオカラスラリーを調製した。このオカラスラリーを５倍に希釈し、１５０メッシュ以上の粗い粒子を除き、高圧ポンプ（ＮＰ−ＡＸ−１５日本精密科学製）７ａで１．５ｍｌ／ｍｉｎの割合で送液した。別に純水を高圧ポンプ６で３ｍｌ／ｍｉｎの割合で送液し、予め４００°Ｃまで加熱した。オカラスラリーに加熱装置で高熱水を連続的に注入・混合し、約２００°Ｃまで急速に昇温し予備加熱を行なった。次に所定の温度（３００°Ｃ、４００°Ｃ）に調整した流動砂浴装置１５（反応槽）を通過させ、約１０秒間反応を行ない、直ちに冷却装置１３にて冷却し、背圧弁を介して、生成液を得た（超臨界処理、Ｎｏ１）。背圧弁の調整で、３０ＭＰａ、１０ＭＰａの条件を採った（亜臨界処理、Ｎｏ２）。このようにして得た生成液の条件及び分析結果を表２に示した（実施例２の水の飽和蒸気線図は、図４の三角印を参照）。
【００５０】
【表２】

【００５１】
表２のＡ欄において、Ｎｏ３（（３））が超臨界水の処理であり、Ｎｏ２（（２））が亜臨界水の処理であり、Ｎｏ１（（１））がコントロール（未処理）である。未処理とは、超臨界処理も亜臨界処理も行われず、これらＮｏ１，２とオカラと水の調製等の条件を同じにしたことを示す（ただし、前２条件で熱水が混合されており、同じ割合で蒸留水を添加した。）。これらの各試料について、ガラス電極法によるｐＨ測定、１０５°Ｃ乾燥法による固形分、ケルダール法とアミノ酸自動分析計によるタンパク質、溶剤抽出による脂質、５５０°Ｃ灰化による灰分、差し引き計算により炭水化物を測定した（Ａ欄参照）。炭水化物には可溶性の糖質（全糖）と不溶性食物繊維（食物繊維）を含む。タンパク質（アミノ酸態）は、酸分解後、アミノ酸自動分析計による２８種のアミノ酸の定量分析より求めた。アミノ酸自動分析計は、タンパク質の分解物や遊離アミノ酸をイオン交換クロマトグラフィーで分離定量する方法である。なお、ケルダール法は、有機試料中の窒素をアンモニアとして測定し、換算乗数５．７１を乗じて、タンパク質を求める方法で、アミノ酸以外のアミノ態窒素も測り得る。
【００５２】
未処理（Ｎｏ１）、亜臨界処理（Ｎｏ２）、超臨界処理（Ｎｏ３）の順に、炭水化物、固形分、タンパク質（アミノ酸態）が減った。明らかに、オカラ中の各成分が分解し、消失していることが分かる。食物繊維を含む炭水化物は劇的に減少している。脂質も超臨界処理（Ｎｏ３）で減少しているが分かる。
【００５３】
タンパク質はケルダール法によってアミノ体窒素等を測定しているため、見かけのタンパク質全量の変化は認められなかった。しかし、アミノ酸分析の結果から、明らかにタンパク構成アミノ酸として存在する量は減少しており、タンパク質の変性および粗分解を示している。なお、タンパク質の変性、すなわち、高次構造の変化が本条件ではかなり進んでしまっているが、アミノ酸への分解の手前で起きうる。
【００５４】
超臨界処理（Ｎｏ３）では食物繊維など炭水化物はほとんど消失しているにもかかわらず、アミノ酸が存在し、タンパク質としての存在も示唆しており、ケルタール法とアミノ酸自動分析計によるタンパク質食品加工特性（例えば、塩凝固性等）を残している可能性を暗示している。
【００５５】
また、外観を目視により観察した結果を表２のＢ欄に示した。
【００５６】
亜臨界水の加工処理（Ｎｏ２）、超臨界水の加工処理（Ｎｏ３）にはオカラのように直ぐに分離する沈殿は見られず、ほとんど微細化、可溶化した。未処理（Ｎｏ１）、亜臨界水の加工処理（Ｎｏ２）、超臨界水の加工処理（Ｎｏ３）の順に、褐色の着色や臭いが強くなったが、反応時間１０秒間というやや過酷な条件であり、分解が進み過ぎ、重合物が生成していた。以上の結果から、水の超臨界や亜臨界各条件を適当に設定することによって、オカラの組織が有為に変化し、各成分は有為に選択的かつ部分的に、分解し、食品の原料として再利用しやすく、付加価値が高め得ることが分かった。
【００５７】
（実施例３）オカラ１ｋｇに２．５倍量の水を加えスラリー状とし、高圧ホモジナイザー（ＮＳ２００６ＬＰＯＮＹ、ＮｉｒｏＳｏａｖｉ社製）５Ａにより１４０ＭＰａで１回処理し、滑らかなオカラスラリーを調製した。このオカラスラリーを５倍に希釈し、高圧ポンプ（ＮＰ−ＡＸ−１５日本精密科学製）７ａで３．０乃至４．５ｍｌ／ｍｉｎの割合で送液した。別に純水を高圧ポンプ（同上）で６．０乃至９．０ｍｌ／ｍｉｎの割合で送液し、予め４５０°Ｃまで加熱した。オカラスラリーに高熱水を連続的に注入・混合し、約２００°Ｃまで急速に昇温し予備加熱を行なった。次に所定の温度（２００°Ｃ、２５０°Ｃ、３００°Ｃ）に調整した流動砂浴装置１５（反応槽）を通過させ、１あるいは３秒間反応を行ない、直ちに冷却装置１３にて冷却し、背圧弁を介して、生成液を得た。背圧弁の調整で、３０ＭＰａに固定した。そして、高温高圧水加工後に、高圧ホモジナイザー５Ｂで後処理を行った。このようにして得た加工液の性状評価を表３に示した。性状評価は、オカラ残渣、残渣沈降、着色程度、風味等について行った（実施例３の水の飽和蒸気線図は、図４の菱形印を参照）。
【００５８】
【表３】

【００５９】
まず、高温高圧装置１による高温高圧水加工の前後における高圧ホモジナイザー５Ａ，５Ｂの加工の効果について検討した。表４の（１）のコントロール（未処理）に比べて、（２）のオカラを高圧ホモジナイザー５Ａで１４０ＭＰａで処理するだけでも、０．５〜２ｍｍ程度の粒子の大きいオカラのスラリーが０．１〜０．０１ｍｍ以下の滑らかなスラリーになった。しかし、食感はわずかにざらついていた（性状評価参照）。また、（３）の高温高圧加工のみに比べて、（４）の高温高圧加工のみならず高圧ホモジナイザー５Ａの前処理によってオカラ残渣粒子が小さく、滑らかになった。さらに、（４）の高温高圧装置１による加工時間を１秒と短くすると、同様な滑らかさで、着色も食品材料としてほとんど影響のない程度の状態になった。ここで、高温高圧装置１による加工時間は、温度にもよるが、例えば０．０１秒から６０秒というような短時間処理が好ましい。
【００６０】
次に、（５）が高温高圧装置１による１秒間の加工後、高圧ホモジナイザー５Ｂにかけた場合であるが、１００°Ｃ以上の高温高圧加工による加工液は無菌であるために、貯蔵は可能である。ただし、希に、貯蔵中に成分の分離、凝集・沈殿を起こす。これを防止するため、高温高圧加工の後、高圧ホモジナイザー５Ｂを用いて均質化処理（５〜２００ＭＰａ）を行うと、安定化な加工液を得ることができる。また、比較的温和な高温高圧加工（例えば２５０°Ｃ３０ＭＰａで１秒）では、着色や異臭もなく食品原料として好ましい。しかし、完全に不溶性繊維質は可溶化せず、最初から沈殿を生成する。そこで高温高圧加工後、高圧ホモジナイザー５Ａを用いて均質化処理（５〜２００ＭＰａ）を行うと、細かな分散液を得ることができる。また、（６）は、（５）の条件の工程で高圧ホモジナイザー５Ａで処理を行ったものであるが、均質・分散効果によってオカラ残渣がほとんど沈降しない加工液を得た。
【００６１】
このように、高温高圧水加工の前後における高圧ホモジナイザー５Ａ・５Ｂによる加工によって沈降性残渣もなく、食感や臭いなどの点においても違和感なく、食品原材料として利用することが可能であることが分かる。ここでは、沈殿物の消失は食品原料として必要条件ではなく、もっと緩い条件でも不溶性繊維質が軟化、微細化による、ザラツキ感の改善には十分可能である。
【００６２】
（実施例４）オカラ１ｋｇに２．５Ｌの水を加えスラリー状とし、高圧ホモジナイザー（ＮＳ２００６ＬＰＯＮＹ、ＮｉｒｏＳｏａｖｉ社製）５Ａを１４０ＭＰａで１回処理し、滑らかなオカラスラリーを調製した。このオカラスラリーを５倍に希釈し、攪拌しながら、高圧ポンプ（ＮＰ−ＡＸ−１５日本精密科学製）７ｂで３．０ｍｌ／ｍｉｎの割合で送液した。別に純水を高圧ポンプ（７ａ）で６．０ｍｌ／ｍｉｎの割合で送液し、予め４００°Ｃまで加熱した。オカラスラリーに高熱水を連続的に注入・混合し、約２００°Ｃまで急速に昇温し予備加熱を行なった。次に所定の温度（２００°Ｃ、２５０°Ｃ、３００°Ｃ）に調整した流動砂浴装置１５（高温高圧装置１内）を通過させ、（２）の２００°Ｃの一定温度３．０秒の加工、又、（３）３００°Ｃの一定温度３．０秒の加工を行ない、更に、（４）の２００°Ｃ〜３００°Ｃで、６．０秒間昇温加工を行い、直ちに熱交換器１２で冷却した。また、熱交換器１２で冷却する前に、１ＭＰａまで減圧し、フラッシング（急激な圧力降下）による急冷を行った。これを（５）として示す。それぞれ背圧弁を介して生成液を得た。その高温高圧条件と性状評価の結果を表５に示した。性状評価は、オカラ残渣、残渣沈降、着色程度、風味等について行った。なお、この表４は、亜臨界条件の高温高圧水処理によるものである（実施例３の水の飽和蒸気線図は、図４の楕円印を参照）。
【００６３】
【表４】

【００６４】
いずれの条件でもオカラ残渣は認められたが、その残渣の沈降性に差があった。すなわち、（２）の２００°Ｃで３秒に比べて、（３）３００°Ｃで３秒の方がオカラ残渣の沈降性は小さいが、着色や焦げ臭が認められた。（４）の２００°Ｃから３００°Ｃへ昇温させると、オカラ残渣の沈降性も小さく、着色や香りも遜色のない状態になった。２００°Ｃではオカラスラリーの状態はあまり変化が見られなかった。２５０°Ｃ以上では、温度、時間に比例して褐色を帯びていた。沈殿物の状態は、２５０°Ｃで５．０秒以上の条件でかなり、少なくなる傾向が見られた。着色以外、粘質物など重合物の生成は認められなかった。このように水の亜臨界条件を短時間に行うことによっても、オカラ中の繊維成分を有為に変化させることが分かる。フラッシング（急激な圧力降下）により、蒸発潜熱による急冷と、水分蒸発による濃縮（原液濃度に近くなる）と、過度の加熱ダメージを最小限に行うことが分かる。
【００６５】
（実施例５）次に、高温高圧条件下、弱酸、弱アルカリ等の添加によるｐＨ調整を行った。その結果を表５に示す。
【００６６】
【表５】

【００６７】
ここで、ｐＨ調整に用いられる原材料としては次のものが挙げられる。（１）食品添加物（化学合成以外の食品添加物：いわゆる天然添加物も含む）では、主としてクエン酸ナトリウム、炭酸水素ナトリウム、酢酸ナトリウム、リン酸三ナトリウムアンモニアなどの弱アルカリや少量の炭酸ナトリウム、水酸化ナトリウムやかんすい等の強アルカリ成分や主としてクエン酸や酢酸などの弱酸成分や少量の塩酸などの強酸成分、（２）食品素材では例えばヨーグルトなどの乳酸発酵食品、柑橘系の酸性果汁、（３）、水では酸性・アルカリイオン水、温泉水、地下水、海水やこれらの氷や氷水等の食品水適合水等である。
【００６８】
表５から明らかなように、クエン酸の添加（１％添加）によってグルコースの生成量が２６０°Ｃという低温の条件においても認められた。ｐＨ無調整（中性）では、４００°Ｃでセルロースの分解が認められた。ｐＨの変化も少なく、高温条件でも酸の生成が抑制された。したがって、事後、中和する場合、アルカリ量も少量でよい。一方、弱アルカリ（重曹）の１％添加では、亜臨界から超臨界条件において焦げ臭等が少なく、逆にコントロールや弱酸に比べて好ましい風味であった。また、凝固性タンパク質量も亜臨界条件下（２６０°Ｃ、３４０°Ｃ）では２８０ｎｍの吸収がコントロールに比べて高くなっており、タンパク質の変性度合いが進んでいることが分る。超臨界状態での処理によってもｐＨをほぼ中性に維持できた。逆に酸添加では亜臨界条件（特に２６０°Ｃ）において、白さを表すＬ値がより高く、着色が抑制されていたことが分る。グルコースの生成などの目的によっては圧力や温度条件を低く設定することも可能であり、装置コストや運転コストを大幅に軽減することが可能になる。なお、グルコースの生成を指標にしたが、本願ではグルコースの成分は主たる目的ではなく、分析手法上、グルコースの生成を実際にはセルロース高分子の部分的な崩壊が本来の目的である。
【００６９】
過去、超臨界条件において酸やアルカリ添加によって、加水分解反応が促進される知見は得られている（特公平０３−３６７１号：化学工学会徳島大会講演要旨集Ｐ１６１、１９９９年）。従来塩酸などの強酸を大量に用いる加水分解（ｐＨ３未満）によってタンパク質原料から調味料液などを製造している。また、塩酸等は食品加工助剤として使用許可を受けた食品添加物であるが、劇薬であり、作業環境、後工程の精製工程、装置の腐食、中和に逆液性の強アルカリや弱酸などを使用すると、コストアップと危険を伴う。
【００７０】
しかし、本発明によれば、食品原材料を高温高圧加工においてｐＨ調整すると、食感や風味・色調や物性を有効に制御する手段であることがわかる。温度、圧力、時間の要素とともに調節の幅が増え、生成物（液）の品質調整、差別化を多彩に行うことが可能となる。このように、生成物（液）の性質・性状が大きく左右され、目的によって有利な方向に品質をコントロールすることができる。高温高圧条件下、弱酸、弱アルカリ等の添加によるｐＨ調整によって、無調製時に比べて高温高圧加工の効果をより高め得る。
【００７１】
以上、上記各実施例は、オカラを含む食品原料によるものであるが、上記各実施の形態からも明らかなように、大豆や大豆成分を含む多成分系にも汎用的に適用可能であり、食品原料にも広く適用可能である。
【００７２】
（実施例６）オカラ３ｋｇに３Ｌの水を加えスラリー状とし、高圧ホモジナイザー（ＮＳ２００６ＬＰＯＮＹ、ＮｉｒｏＳｏａｖｉ社製）５Ａを１４０ＭＰａで１回処理し、滑らかなオカラスラリーを調製した。このオカラスラリーを補助ポンプ（自作）を用いて、高圧ポンプ（ＮＰ−ＡＸ−１５日本精密科学製）７ｂで１４．０ｍｌ／ｍｉｎの割合で送液した。別に純水を高圧ポンプ（７ａ）で３．０ｍｌ／ｍｉｎの割合で送液し、予め２．０ＭＰａ下、２２２°Ｃまで加熱し、高温高圧水蒸気を得た。また同様に予め２．１ＭＰａ下、３７０°Ｃまで加熱し、高温高圧過熱水蒸気を得た。オカラスラリーにその水蒸気を連続的に注入・混合し、約２００°Ｃまで急速に昇温し加熱を行なった。約２．５秒後、熱交換器１２で冷却し、背圧弁を介して生成液（オカラ乳、固形分約１０％ｗｔ）を得た。オカラ乳と常法によって得た豆乳（固形分約１１％ｗｔ）を１：２で混合し、計算上ほぼ大豆全粒を利用した全粒豆乳を得た。冷却した全粒豆乳に、ＧＤＬ（グルコノ−δ−ラクトン）０．１５％、塩化マグネシウム（ＭｇＣｌ₂・６Ｈ₂Ｏ）０．１５％、トランスグルタミナーゼ製剤（味の素社製「アクティバ」スーパーカード、有効成分０．２％）０．２％を水に溶いて添加・混合した。次に豆腐用包装容器（ポリプロピレン製）に充填包装し、６０°Ｃ３０分に続いて８０°Ｃ３０分加熱凝固した。豆乳、豆腐は一夜冷蔵後、品質測定を行った。その結果を表６に示した。
【００７３】
【表６】

【００７４】
高温高圧水蒸気を用いても、オカラ乳との混合後には高温高圧水と同様な高温高圧状態（亜臨界条件）が得られた。オカラのざらつき感のあるコントロールに比べても、十分滑らかな食感に改善することができた。更に本結果では、飽和水蒸気よりも過熱水蒸気を用いた方が僅かながら、滑らかな食感になった。その他の品質は、コントロール１と比較しても大差はなかった。
【００７５】
【発明の効果】
本発明では、水の超臨界状態と亜臨界条件の高温高圧水処理によって、オカラ中の各成分は有為に選択的かつ部分的に、変性・粗分解し、食品原料として再利用しやすく、安全で、しかも、付加価値を高め得る。また、高圧ホモジナイザーでの加工を前処理として行うと、その後の工程の高温高圧水による部分分解や熱・圧力による変性を、より穏やかな温度・圧力条件により、更に短時間かつ正確に行うことが可能になる。他方、高圧ホモジナイザーでの加工を後処理で行うと、この前工程となる高温高圧加工の条件を「一ゆで」程度の加減で、必要最小限の条件にすることが可能である。
【００７６】
さらに、高温高圧水を注入したり、高温高圧水蒸気を吹込むこと等すると、不溶性食物繊維やタンパク質、ＤＮＡ、大豆オリゴ糖、イソフラボンなど各成分に応じた加工条件を設定することが可能である。したがって、本発明によれば、オカラを再利用するための加工に最適であり、汎用性に優れ、他の食品原料にも適用することが期待される。
【００７７】
【図面の簡単な説明】
【図１】本発明の一実施の形態のオカラの加工処理システムを示す図である。
【図２】上記一実施の形態のシステムの循環システムを示す図である。
【図３】上記一実施の形態のオカラの加工処理システムの応用例を示す図である。
【図４】水の超臨界条件と水の亜臨界条件を説明する図である。
【符号の説明】
１高温高圧装置、
５Ａ前処理としての高圧ホモジナイザー、
５Ｂ後処理としての高圧ホモジナイザー、
７ａ，７ｂ高圧ポンプ、
８ａ高温高圧水注入装置、
８ｂ高圧水蒸気吹き付け装置、
１１溶融塩浴装置、
１２熱交換器、
１３冷却装置、
１４電気炉装置、
１５流動砂浴装置、
Ｐ１〜Ｐ４ポンプ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for processing a food material containing okara that produces a food containing okara under supercritical conditions or subcritical conditions.
[0002]
[Prior art]
In recent years, attempts have been made to detoxify industrial waste and household waste or to obtain products that can be used effectively by utilizing hydrolysis or oxidation reaction in supercritical water or subcritical water. For example, JP-A-5-31000 discloses a method of hydrolyzing various polymer compounds using supercritical water or subcritical water. In addition, a method using a high-pressure homogenizer is also disclosed as a method for producing tofu that does not produce okara (Japanese Patent Publication No. 62-17509: Japanese Patent No. 1423285).
[0003]
In the supercritical state and subcritical state, the properties of water change greatly, the polarity of water decreases, and the oil becomes soluble in water. ^-14 ) Is 10 ^-11 -10 ^-12 It increases to 100 to 1000 times and becomes a high-density water vapor state (see FIG. 3). In such a state, lowering of the polymer (hydrolysis) and oxidation (combustion, thermal decomposition) reaction such as “burning in water” occur in the presence of oxygen. Therefore, a technique such as the above-described conventional publication has been disclosed, and has attracted attention in the safe treatment of dioxins and hazardous waste. In addition, a method of decomposing and burning everything such as garbage power generation and waste disposal is also attracting attention.
[0004]
However, these conventional products are mainly intended for the treatment of industrial waste and household waste, and food raw materials generally use modification of polymers or partial decomposition in supercritical water or subcritical water. The processing method has not yet been disclosed. In addition, researches such as shochu squeezed sardines, fish meals / internal organs, and rice husks have been attempted to separate and recover industrial raw materials by hydrolysis. In particular, in order to reuse edible unused by-products generated in the process of food production, such as okara, which is produced in large quantities in the process of tofu, A processing method using molecular modification or partial decomposition has not yet been disclosed. In other words, there are various types of processing of food materials. For example, as in the case of long-life milk, even for the purpose of sterilization, taking into consideration damage to food components, conditions exceeding 1 MPa and 130 ° C. are taken. I can't. There is also a method using a biaxial extruder that treats soybeans etc. at 1.1 to 3 MPa, 120 to 200 ° C. (Japanese Patent Laid-Open No. 04-58853). Has a problem. In the research on ultra-high pressure treatment, there are examples of soy protein denaturation and heat-resistant spore sterilization under conditions of 60 ° C or lower and 1000MPa or lower, but there is no knowledge under conditions exceeding 130 ° C, and trypsin inhibitor is almost inactivated. There is a problem of not (see Sanei publication "Pressurized food"). Moreover, in the manufacture of the conventional tofu, it is heat-processed on the conditions of normal pressure -0.2MPa and 100-110 degreeC. JP-A-9-268166 discloses a method for producing an amino acid by hydrolyzing a protein, in which hydrolysis is carried out with water in a supercritical state or a subcritical state. However, it is not a versatile one that is generally applicable to edible natural organic raw materials that are multi-component systems including proteins, fibers, carbohydrates, lipids, and the like. In a single-component system, the product is likely to be predicted, but in a multi-component system, unexpected product formation may occur due to the influence between products derived from each component (for example, pH change due to organic acid production). . In a multi-component system, there is a problem that processing of other components does not work well even if processing conditions are adjusted to one component. On the other hand, in the method using a high-pressure homogenizer, it is necessary to pass 3 times at 56 MPa, and even if the treatment liquid is mixed with soy milk and coagulated with a coagulant, the texture of tofu is rough, poor water retention, and commercial value Is low.
[0005]
[Problems to be solved by the invention]
Thus, conventionally, a new food raw material processing method has not yet been developed by utilizing the modification or partial decomposition of a polymer in supercritical water or subcritical water. In particular, in multi-component systems such as Okara, complicated reactions occur, analysis is difficult, and shelf life is poor. No processing method has been developed.
[0006]
The topic of the use of supercritical water so far has been preceded by oxidation reaction, and research and development is progressing as a technology in the environmental field such as difficult-to-decompose materials and waste disposal, and it has been put into practical use in part.
[0007]
However, regarding chemical raw material recovery methods, patent applications relating to hydrolysis from proteins to amino acids, hydrolysis to peptides (resynthesis from amino acids), and low molecular components such as glucose have been filed (Japanese Patent Laid-Open No. Hei 9-). No. 268166 and JP-A-5-31000). In addition, changes in single components such as protein and cellulose are important as basic knowledge, and it is relatively easy to conduct experiments and analysis of the generated solution, and research and development are ahead. However, in actual application, it is intended for multi-component raw materials, and it is difficult to analyze the produced liquid, and research and development and application development are delayed. In addition, there is no research institution that is trying to reuse food straw with high-temperature and high-pressure water (for example, rice husk, fish, shochu), but all research on component separation of low-molecular useful components by decomposition, It is not technical development related to food processing.
[0008]
Accordingly, the object of the present invention is to find that there are various advantages such as ensuring the safety of food containing okara when food containing okara is processed in a supercritical state and a subcritical state of water. The object is to provide a method for processing food containing okara in order to effectively reuse okara which is high in value and safety.
[0009]
[Means for Solving the Problems]
The inventors of the present invention have studied the processing of Okara under high temperature and high pressure conditions for many years, and found a safe, effective and economical processing method for Okara that occurs in large quantities, and completed the present invention. That is, the processing method of the food raw material containing okara according to claim 1 of the present invention includes okara, liquid okara, slurry obtained by adding water to okara, or these okara. Multicomponent High temperature and high pressure of the food material, either supercritical conditions of water of 374 ° C. or higher and 22.1 MPa or higher and subcritical conditions of 100 ° C. or higher and lower than 374 ° C. and higher than the saturated vapor pressure of water at that temperature Under conditions or a combination of these, Changes in the higher order structure of the polymer in 0.01 seconds or more and 60 minutes or less It is characterized by processing. The processing time varies depending on the temperature and pressure conditions, but is preferably in the range from an extremely short time (for example, 0.01 seconds) to several tens of minutes. Here, it includes a process of treating the supercritical state of water and the high-temperature and high-pressure conditions of subcritical conditions alone or in combination of two or more conditions. The combination of two or more high-temperature and high-pressure conditions of water supercritical state and subcritical condition means that it is performed under either condition after at least one of the supercritical state and subcritical condition of water In addition, the case where the process is performed in a range from the supercritical condition to the subcritical condition includes the case where a plurality of processes are performed under the same condition. The present invention is not a processing method mainly based on oxidation, hydrolysis or thermal decomposition by addition of an oxidizing agent (hydrogen peroxide, oxygen, etc.) or a chemical (chemical such as acid or alkali).
[0010]
According to the first aspect of the present invention, the high-temperature and high-pressure treatment of each of the supercritical and subcritical conditions of water makes the okara, for example, “cooked in a high-pressure pressure kettle for a short time at a high temperature”. The form of okara is hardly impaired or is physically softened and refined. Each tissue and each component in Okara is selectively and partially modified and roughly decomposed, making it easy to reuse as a food material. Here, the high-temperature and high-pressure treatment is preferably a low-temperature and short-time treatment as much as possible in order to prevent degradation of nutritional components (proteins, amino acids, lipids, carbohydrates, dietary fibers, etc.) and deterioration of flavor (taste, aroma, color, etc.). The water here includes ice, ice water, hot water, high-temperature and high-pressure water, subcritical water, supercritical water, water vapor, superheated water vapor, and the like. In the present invention, mainly modification, softening, miniaturization (colloid particle formation) and the like are the main, and decomposition of components can occur only as a side reaction. In general, cooking and heating is mainly intended to improve physical properties so that it is easy to eat and digest, but secondary generation of sweet umami and aroma (such as cooked rice and grilled rice) is known. In the present invention, the protein and fiber are similarly partially decomposed to produce a very small amount of sweetness and umami components such as the sweetness of glucose, glutamic acid, etc. so that they can be sensed, thereby improving the flavor. However, it is not intended to produce such small molecules in large quantities. It aims at processing methods that retain nutritional value as much as possible, such as protein and dietary fiber. According to the present invention, not only Okara general bacteria and heat-resistant bacterial spores are killed and the shelf life is improved, but also the insoluble fiber component is softened and refined to become a smooth and savory “Okara milk”. . The protein in this okara milk is in a moderately denatured state, and even when used as a secondary material for tofu, it does not adversely affect water retention and coagulation reactions. There is no problem at least as a food ingredient for tofu production and for beverages, but it is rather nutritious and safe. When used for tofu production, the amount of soluble dietary fiber in tofu increases, water retention increases, and nutritional characteristics improve. Okara is not discharged as waste, and almost all can be reused as an organic food raw material having processing characteristics as food. In such high-temperature and high-pressure water processing, the quality of this processed Okara is adjusted according to the purpose by combining two or more conditions according to each component and structure in Okara etc., and the properties and applications after processing. Can do. For example, after softening and refining the tissue in a few tens of seconds around 200 ° C at a low temperature, protein extraction and solubilization of dietary fiber, etc., it is extremely short at 350 to 400 ° C at a high temperature to improve the flavor. By performing processing for a time (several seconds or less), it becomes possible to improve the added value as a food raw material.
[0011]
The processing method of the food raw material containing the okara according to claim 2 of the present invention is a high-pressure homogenizer treatment of the okara or the slurry-like okara in which water is added to the okara in a pre-process or a post-process of the processing method of claim 1. . That is, Okara is treated with a high-pressure homogenizer before or after processing under high-temperature and high-pressure conditions such as the supercritical state and subcritical conditions of water or a combination thereof. Specifically, the following modes can be considered. (1) First, it is treated with a high-pressure homogenizer, and then subjected to high-temperature and high-pressure water processing. (2) First, it is treated with a high-pressure homogenizer, then subjected to high-temperature and high-pressure water processing, and again treated with a high-pressure homogenizer. (3) First, high-temperature and high-pressure water processing is performed, and then it is processed with a high-pressure homogenizer. (4) These are repeated several times alternately. The number of times does not matter.
[0012]
First, when a raw material containing okara is pretreated with a high-pressure homogenizer, finer raw material particles and modification of higher-order structures of proteins such as proteins and fibers occur. Therefore, it becomes sensitive to various reactions at each molecular site, and it is possible to perform partial decomposition with high-temperature and high-pressure water in the subsequent process and denaturation by heat and pressure in a milder temperature and pressure condition in a shorter time and more accurately. become. In addition, in the pretreatment with the high-pressure homogenizer, the pressure changes instantaneously, so that the cell walls of animals, plants and microorganisms can be destroyed. Extraction of intracellular components becomes easy, and if solid-liquid separation is performed in the immediately following process, it is possible to improve the yield as soy milk. However, in order to mix with soymilk without solid-liquid separation and reuse it for the production of tofu, there is a limit to using it from the water-retaining and rough texture, but the high temperature according to claim 1 thereafter Almost all can be reused as food ingredients by high-pressure water processing.
[0013]
On the other hand, when the high-pressure homogenizer is used for the post-processing of the processing under the high-temperature and high-pressure conditions, the softened raw material slurry can be processed into a colloidal dispersion without a smooth precipitate. During this high-temperature and high-pressure processing and post-processing of the high-pressure homogenizer, the degree of processing of food ingredients including okara is suppressed, that is, the softening of cell walls, cell membranes, polymer components, etc. is stopped, and useful low-molecular components (free sugars) It is practical to set conditions that minimize degradation to free amino acids, etc., but in that case, raw materials that have been processed at high temperature and high pressure are easier to touch with a high-pressure homogenizer than before processing. It becomes possible to make the liquid dispersion (colloidal). Under very strong high temperature and high pressure conditions, coloring and a burning odor are generated, which is undesirable as a food material. In order to avoid this, it is desirable to stop the high-temperature and high-pressure processing at the lowest possible temperature in the shortest possible time, and then perform the processing with the high-pressure homogenizer. When a high-pressure homogenizer is used for the post-treatment, the conditions for the high-temperature and high-pressure processing in the previous process can be reduced to the minimum necessary level by adjusting the level of “boiled”.
[0014]
The processing method of the food raw material containing the okara according to claim 3 of the present invention is based on the invention according to claim 1 or claim 2, and the supercritical condition and subcritical condition of the water or a combination thereof is combined. In the processing, the supercritical condition or subcritical condition of the water is stepped or graded by injecting high-temperature high-pressure water into the food material containing the okara or blowing high-pressure steam or superheated steam. It is characterized by adjusting the temperature condition.
[0015]
According to the third aspect of the present invention, the temperature is raised to a predetermined temperature at once, or the temperature is raised in a multistage or gradient manner, and one or more under high pressure (above the saturated vapor pressure at the maximum temperature in the system) Set multi-stage or gradient temperature (high temperature and high pressure) conditions. The purpose is processing according to each ingredient such as insoluble dietary fiber, protein, DNA (including recombinant genes), soy oligosaccharide, isoflavone and soy parts (seed coat, navel, cotyledon, hypocotyl) and the desired flavor The condition is to set.
[0016]
In addition, by mixing with high-pressure hot water (or steam or superheated steam), the temperature of the raw material liquid can be rapidly increased, and high-temperature and high-pressure processing can be accurately performed in a short reaction. This point can be realized synergistically and accurately by using a high-pressure homogenizer as a pretreatment. In addition, the method of injecting high-temperature high-pressure water (subcritical water, supercritical water), that is, the hot water injection method, increases the fluidity of the slurry, does not burn the heat transfer surface, improves heat transfer, and is uniform. It is the most effective method that can realize rapid temperature rise and accurate temperature control, does not damage the raw material, and has little scorching. However, since it is necessary to use hot water several times as much as the raw material liquid, there is a drawback that the raw material liquid is diluted. However, in this case, as in claim 4 of the present invention, concentration is possible by flushing. Further, by using high-pressure steam or high-pressure superheated steam, the latent heat of steam can be used, the amount of water added can be suppressed, and the subsequent concentration step can be omitted.
[0017]
The processing method of the food raw material containing the okara according to claim 4 of the present invention is based on the invention according to claim 3, and after the processing that combines either the supercritical condition or the subcritical condition of water or a combination thereof. In the cooling stage, the working fluid is flushed by reducing the pressure to a value equal to or lower than the saturated vapor pressure at the temperature before the pressure reduction.
[0018]
According to the fourth aspect of the present invention, the water vapor is flushed (rapid pressure drop) in the cooling stage, thereby rapidly cooling due to latent heat of vaporization, concentration due to water evaporation (close to the concentration of the stock solution), and instantaneous expansion. The polymer structure is destroyed by force. Therefore, at the time of high-temperature and high-pressure processing, it is possible to minimize excessive heat damage and to destroy physically weak polymers such as DNA and proteins, and play a part in a series of processing steps. Cooling means using a heat exchanger is common, but there are also problems such as slow cooling and inability to concentrate. However, it can be used in combination with a heat exchanger.
[0019]
In the method for processing a food material containing okara according to claim 5 of the present invention, the pH of the food material containing okara in each step of claims 1 to 4 is adjusted to a range of 3 to 9 with an alkali component or an acid component. It is characterized by that.
[0020]
The steps of claims 1 to 4 are that the pH of the raw material (liquid) is adjusted in advance, the pH of hot water is adjusted, and the pH of the injection cooling water in the cooling stage is adjusted. And adjusting the pH including neutralization of the product solution that has come out of the system. Conventionally, a seasoning liquid or the like is produced from a protein raw material by hydrolysis (less than pH 3) using a large amount of a strong acid such as hydrochloric acid. However, according to the invention described in claim 5, weak alkali components such as sodium citrate, sodium hydrogen carbonate, sodium acetate, trisodium phosphate ammonia, and strong alkali components such as a small amount of sodium carbonate and sodium hydroxide are mainly used. By adjusting the pH of the raw material liquid to the range of up to pH 10 by using it, or using mainly weak acid components such as citric acid and acetic acid, food materials containing them, and strong acid components such as a small amount of hydrochloric acid, By adjusting the pH in the range of up to pH 3 in the acidic direction, physical properties such as texture, flavor and color tone can be advantageously improved and partial decomposition can be advantageously performed, and the effect of high-temperature and high-pressure processing can be further enhanced.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Hereinafter, processing of okara will be described as an example, but the present invention is not limited to okara (raw okara, dried okara, fermented okara, regenerated okara), but also soybeans, soybean powder, separated soybean protein, soybeans containing the same ingredients as okara. These are also applied to the processing of organic food ingredients containing soy components such as seed coats such as molting pods, navel, cotyledons, hypocotyls, etc., and so on. The supercritical state and subcritical conditions of water are shown in FIG.
[0022]
(Basic configuration of the processing system of the present embodiment) The food raw material processing system including the okara of the present embodiment is a system in which devices as shown in FIG. A1, B, A2, C, D, E are performed.
[0023]
As shown in FIGS. 1 to 3, the processing system for a food material containing okara according to the present embodiment includes a storage chamber 2a for storing okara, a storage chamber 2b for storing (distilled) water, and a supply pump. The high-pressure homogenizer 5A connected via the high-pressure homogenizer 5A, the high-pressure high-pressure device 1 connected via the high-pressure homogenizer 5A and the supply pump 6 and the high-pressure pump 7b, and the high-temperature high-pressure device 1 connected via the supply pump 3 High-pressure homogenizer 5B. The high-pressure homogenizers 5A and 5B are for shearing, crushing, and homogenizing an undiluted solution sample pressurized to 0 to 200 MPa through a homo valve. The high-temperature and high-pressure device 1 is a heating device for supercritical or subcritical fluid, and can also be used as a device for generating saturated steam or superheated steam. The types include a molten salt bath device 11, a fluidized sand bath device 15, an electric furnace device 14, and the like, but are not limited thereto, and these can be used in combination. Presence or absence 1a, 1b of the hydration process to a raw material is selected suitably. However, it is not processed by oxidation or hydrolysis by addition of an oxidizing agent (oxygen, hydrogen peroxide, etc.) or a chemical (chemicals such as acid and alkali).
[0024]
In addition, the processing system of the present embodiment includes a high-pressure pump 7b connected to the high-temperature and high-pressure apparatus 1, a high-temperature and high-pressure injection apparatus 8b that injects high-temperature and high-pressure water as a heating apparatus, or a high-pressure steam blowing apparatus 8a that blows high-pressure steam. And a heat exchanger 12, a cooling device 13, a pressure reducing device 18 (process D composed of an orifice, a back pressure valve, an evaporator, etc.) and an extraction device 17 (a back pressure valve, a pump, a rotary valve, etc.) are arranged. (References C and D in FIG. 2). The heat exchanger 12 may be any type such as a multi-tube type, a plate type, or a scraping type, and the type thereof is not limited. A known device is used as the cooling device 13. Alternatively, the cold water injection device 20 may be used.
[0025]
With such a configuration, the temperature of the Okara fluid (solid dispersion, colloidal paste-like fluid) or solid is changed (increased / Down). Via the decompression device 18 (process D), the pressure is reduced in one to multiple stages below the saturated water vapor pressure at the fluid temperature before decompression to release water vapor, and the rapid or multistage concentration process and the cooling process are performed simultaneously. In the case of multistage or continuous temperature drop, the same processing (reaction) as in the heating step is performed. Eventually, when taking out via the take-out device 17, the temperature is equal to or lower than the atmospheric pressure and the boiling point of water at atmospheric pressure. These stepwise heating step B and stepwise cooling steps C and D may each be combined with a plurality of conditions. The injection of high-temperature and high-pressure water 8b and the spraying of high-pressure steam 8a may be performed several times. Moreover, since the high-pressure high-temperature steam obtained from the decompression device 18 (process D) and the high-temperature heat medium obtained by the heat exchanger 12 can be used again for heating the raw material, an economical system by energy circulation is constructed. Cheap. In particular, water vapor is a gas and can be easily transported, and its latent heat can be used by direct heating or indirect heating, so that an efficient and economical processing system can be realized.
[0026]
The above-described processing system can be considered for the following basic usage modes. (1) First, it is treated with a high-pressure homogenizer 5A, and then high-temperature high-pressure water processing B is performed. (2) First, it is treated with the high-pressure homogenizer 5A, then the high-temperature and high-pressure water processing B is performed, and the treatment is performed again with the high-pressure homogenizer 5B. (3) First, high-temperature high-pressure water processing B is performed, and then the high-pressure homogenizer 5B is used. (4) These are repeated several times alternately. The number of times does not matter. Note that the processes of C, D, and E are appropriately combined.
[0027]
In the present embodiment, first, distilled water is fed with a plunger double-type high pressure pump (NP-AX-15 manufactured by Nippon Seimitsu Kagaku), adjusted to a predetermined high pressure with a back pressure valve at the outlet, High temperature and high pressure water, that is, supercritical water or subcritical water, or high temperature and high pressure steam, that is, saturated water vapor and superheated water vapor, is obtained by passing through the high temperature and high pressure device 1 and heating to a predetermined high temperature. On the other hand, in another path, the raw material liquid is similarly fed at a high pressure, merged with the high-temperature high-pressure water or the high-temperature high-pressure water, the raw material liquid is preheated from room temperature to 200 to 300 ° C. at a stretch by a heating device, The temperature is stabilized by passing through a fluidized sand bath type heating device 15 (reaction tank) adjusted to a temperature (300 ° C. or 400 ° C.), and is heated for a predetermined time (3 seconds, 5 seconds, 10 seconds). This heating process is performed while adjusting the pipe length from the heating device to the cooling device and the pump flow rate (7a, 7b, etc.). Then, the cooling device 13 is passed through and cooled to the water temperature at once, and a working fluid is obtained through the back pressure valve.
[0028]
The said processing system is comprised so that it may be integrated in the manufacturing process of tofu. That is, when using it for the processing of normal tofu, this processing liquid is used instead of water when grinding pickled soybeans. This processing liquid is a smooth liquid containing almost no insoluble fibers or precipitates, and even if 20% or more is mixed in soy milk, the quality of tofu is not affected. Since the protein contained in this processing liquid is added to soy milk, when obtaining the same concentration as usual, the amount of water can be increased, and that amount (about 10 to 60%) increases the yield. As a result, high-quality tofu can be produced using almost all soybeans, and effective utilization from okara is achieved.
[0029]
(Processing method according to the present embodiment) First, slurry or liquid okara in which water is added to okara or okara is pre-treated at a high pressure homogenizer 5A at several to several hundreds of MPa (symbol A1 in the figure), refined, Cell tissue destruction, microemulsification, etc. Next, a paste-like product that is swollen, immersed, or emulsified by adding fresh water to okara or a dispersed slurry-like product is pumped by the high-pressure pump 3 and sent to the high-temperature and high-pressure device 1. Here, not less than the saturated vapor pressure at the maximum temperature in the high-temperature and high-pressure system (that is, between the high-pressure pumps 7a and 7b to the take-out device 17), for example, 1.5538 MPa or more at 200 ° C., 8 at 300 ° C. (Refer to FIG. 4). Further, for example, injection by a high-temperature high-pressure water injection device 8b at 400 ° C. and 30 MPa, high-pressure steam (for example, saturated steam 300 ° C. 8.5 MPa, or a pressure equal to or higher than the pressure of the high-pressure system, or superheated steam 360 ° C. 8.5 MPa ) Is directly heated by blowing by the blowing device 8a. That is, the subcritical state of water is 100 ° C. or higher and a pressure equal to or higher than the saturated vapor pressure at that temperature (for example, 0.476 MPa or higher at 150 ° C.), or the supercritical condition of water (374 ° C. or higher and 22.2. 1 MPa or more) is formed for a predetermined time (for example, 0.01 second to 60 minutes) under each condition by combining one or more conditions.
[0030]
In this process, soy protein is made into an appropriate modified state (change in higher-order structure) that does not impair food processing characteristics and nutritional characteristics such as soy milk and tofu, etc., and softening of midine (fine pieces of soybean, insoluble fiber components) It is possible to improve the texture that is rough by thinning or thinning, or to improve the soluble dietary fiber while leaving the nutritional characteristics as dietary fiber. In addition, a part of soybean oligosaccharide (flatulence component such as raffinose and stachyose) which is a negative nutrient component can be decomposed, and a part of trypsin inhibitor can be denatured and deactivated to improve digestibility. However, the content of soybean oligosaccharide is extremely small compared to insoluble fiber, and even if “hydrolysis” can occur in the present invention, it is not a main reaction but a secondary reaction, and it is an accompanying effect. In addition, for Okara using genetically modified soybean as a raw material, DNA and protein derived from the transgene can be denatured.
[0031]
In the pre-processing step (symbol A1) of the high-pressure homogenizer 5A, the particles of okara are refined to form a smooth paste. It can be used as a raw material for food as it is. For example, mixed with soy milk and using normal coagulants such as magnesium chloride (nigari), calcium sulfate (smooth flour), glucono-δ-lactone (GDL), calcium chloride, magnesium chloride, transglutaminase, organic acids, etc. It can be processed into tofu. However, in spite of the refined insoluble fiber, it reduces the water retention as a foreign substance in tofu and gives a rough texture. Yes, there are limits to using all of Okara. In addition, by using a high pressure homogenizer 5A for pretreatment and making a slurry of large particles of about 0.5 to 2 mm into a smooth slurry of 0.1 to 0.01 mm or less, the fluidity becomes high, Heat transfer and heat transfer efficiency are improved. Further, if there are large particles such as okara, the particles may be caught by a check valve or a take-out device of the high-pressure pump and liquid feeding may not be possible. In addition, food materials that are as fine as possible can be processed uniformly, accurately and smoothly under conditions of the lowest possible temperature and pressure and for as short a time as possible, with no flavor or color discomfort. The characteristics as can be maintained. Furthermore, since the fluidity is increased by making the particles finer, there is an effect that the addition to the raw material can be minimized.
[0032]
In addition, the above-described heat-processed “soybean, high-temperature and high-pressure fluid (or solid dispersion, colloidal paste-like fluid) or solid containing soybean components and soybean parts”, or directly after the cooling process or after the cooling process is finished. In addition, a process E for taking out the processed raw material from the high-temperature and high-pressure system is provided via the take-out device 17 such as a back pressure valve or a rotary valve or the high-pressure pump 6.
[0033]
In addition, the above-described heat-processed “high-temperature and high-pressure fluid (or solid dispersion, colloidal paste-like fluid) or solid containing soybean components” or the solid is directly or during the cooling process or after the cooling process, and then the high-pressure homogenizer 5B. Step A2 for post-processing (miniaturization, cell tissue destruction, fine emulsification, etc.) at several to several hundred MPa (for example, 5 to 200 MPa) is provided.
[0034]
Here, in the case of organic food raw materials containing soybeans, soybean components and soybean parts, pretreatment high-pressure homogenizer 5A causes refinement of raw material particles and modification of higher-order structures of proteins such as proteins and fibers. . Therefore, it becomes sensitive to various reactions at each molecular site, and the subsequent decomposition of the process Ba to c with high-temperature and high-pressure water and denaturation due to heat and pressure can be performed more quickly and accurately under milder temperature and pressure conditions. It becomes possible to do. In addition, in the case of organic food ingredients containing soybeans and soybean components, soy tissue, ie, “navel” and seed coat, etc. are softened, cell membranes and cell wall tissues etc. are softened and roughly decomposed, and constituent polymers in soybean (cellulose) , Pectin, protein, DNA, such as microorganism-derived DNA and protein in genetically modified soybeans, denaturation by heat, pressure, and time, and if protein, SS bond (other ion bond, electrostatic bond, hydrophobic bond, hydrogen bond) ) And changes in the higher order structure (secondary structure to quaternary structure) of the polymer due to dissociation and recombination of subunit bonds, and components in soybean, that is, the polymer and digestive enzyme inhibitory trypsin inhibitor (protein) Deactivation, flatulence oligosaccharides such as stachyose and raffinose (disliked components), and isoflavone glycosides such as daidzin and genistin Isoflavones Higher is female hormone activity) low molecular components or the like is partially degraded as a side reaction, may enhance incidental nutritious. Moreover, a part of protein and insoluble fiber is also slightly decomposed as a side reaction, and sweetness and umami components (low to medium molecules) can be generated.
[0035]
When the temperature conditions of the supercritical condition and the subcritical condition are selected stepwise or gradient by such a processing system, processing according to the following components is possible.
[0036]
(1) For example, at 100 to 300 ° C. and 10 MPa or less, the constituent polymer of soybean such as fiber and protein is denatured, the fiber such as cell wall is softened, and a trypsin inhibitor that is a physiologically active substance (adverse component) is protein. Inactivates and improves digestibility. In general, for proteins, dissociation of subunit assemblies (quaternary structures) into individual subunits (tertiary structures), changes in looseness of individual subunits (tertiary structures), exposure of hydrophobic regions, and alpha Changes to the random structure (secondary structure) of the swirl structure and beta structure (folding structure) occur. In the present invention, the raw material is hardly decomposed and can be processed into such a modified state.
[0037]
(2) For example, at 300 to 350 ° C. and 30 MPa, the polymer is partially decomposed and can be decomposed into moderate molecules (for example, fiber is converted into polydextrin and protein is converted into polypeptide). In the present invention, the raw material hardly decomposes, so-called “soluble dietary fiber” in which several to several hundreds of β-D-glucose are connected from a denatured state, and a peptide in which two or more amino acids such as glutamic acid are connected. In addition, in the case of genetically modified crops (such as soybeans), DNA and RNA (genes) including bacteria-derived DNA (genes) Can be modified and a part can be decomposed into oligonucleosides. Even if it is not completely decomposed, it is processed so as to contain more moderately decomposed molecules. These explanations also include cases where relatively large molecules are refined into colloidal particles by post-processing or flushing (rapid pressure drop) of the high-pressure homogenizer 5B.
[0038]
(3) For example, at 350 MPa to 400 ° C. and 30 MPa, most of the polymer is decomposed and can be reduced to a low molecule. For example, a “sweet ingredient” such as β-D-glucose, which is a monosaccharide, is produced from fiber or polydextrin, and glutamic acid, which is one of amino acids, is the most common among soybeans. A so-called “umami ingredient” such as an amino acid) is produced, and a processed product with an improved taste containing a large amount of these can be obtained. The recombinant gene derived from bacteria can be decomposed into nucleosides, nucleotides, and aglycones (bases such as guanine, cytosine, adenine, thymine, and uracil) to obtain a processed product with greater peace of mind. In addition, soy oligosaccharides (flatulence components such as raffinose and stachyose) can be partially decomposed into monosaccharides to reduce flatulence. In addition, carbohydrate residues of soy isoflavone glycosides (genistin, daidzin, etc.) can be removed and decomposed into aglycones (genistein, daidzein, etc.), which can enhance bioactive effects as female hormones (the carbohydrate part is degraded) The isoflavone skeleton appears to be relatively stable).
[0039]
And according to the processing system of this Embodiment, the high pressure liquid feed pump 3 does not need to be an expensive slurry corresponding | compatible pump, and cost reduction is achieved. In addition, there is less concern about the back pressure valve being blocked, and stable operation and cost reduction are achieved. In this process, in the high-temperature and high-pressure system (including the raw material feed pump, the heating process B, the cooling process C, and the take-out apparatus process E), the saturated water vapor pressure at the lowest temperature in the high-temperature and high-pressure system is exceeded. Within a range, the pressure is changed from one stage to multiple stages through an orifice, a back pressure valve, etc., and each pressure condition is set at a predetermined time.
[0040]
In addition, the heat-processed Okara's high-temperature and high-pressure fluid (including sublimation and supercritical conditions of water, including smooth liquids, solid dispersions, colloidal pasty fluids, and solids in the case of batch systems) In the case of the cooling process C in which rapid or multistage or continuous cooling is performed through the heat exchanger 12 and the multistage or continuous temperature drop, the same processing (reaction) as in the heating process is performed. In addition, you may continue each process B, C, D as it is in the state which cooled the heat in each process B, C, D.
[0041]
Furthermore, in the processing system of the present embodiment, as shown in FIG. 2, the cooling process C (including the decompression process D) and the like are preferably configured as a cyclic system. This is to efficiently process not only raw okara but also dried okara. That is, saturated water vapor obtained in the cooling process, high-pressure high-temperature water obtained by pressurizing and re-condensing the saturated water-vapor, or high-temperature high-pressure water or saturated water vapor obtained through the heat exchanger 12 is further added to the processing system of the present embodiment. Is preferably returned to the raw material inflow side, and a heat recovery step for heating the raw material by indirect heating by the heat exchanger 12 or direct heating as described above is arranged (reference F in FIG. 2). It is energy saving and economical.
[0042]
When the above steps A1, B (Ba to c), A2 to D, and E are selectively set in multiple stages or continuously, the constituent polymer of soybean such as fiber and protein is denatured. In addition to softening and miniaturization, as a side reaction, a part of them can be decomposed to contain an appropriate amount of a low molecular component. For example, so-called “sweet ingredients” such as β-D-glucose (a constituent of cellulose), so-called “umami ingredients” such as glutamic acid (the most abundant amino acid in soybeans), “fragrant aromas such as kinako and roasted beans” Value-added components such as “components” can be included in the processed product. The amount produced may be as small as the taste. For example, if it is glutamic acid, if it is about 0.03-0.1% in the final food, sufficient umami can be felt. That is, this embodiment can be said to be “flavoring processing” in which no food additive is used.
[0043]
Therefore, it is different from the purpose of isolating and purifying a component with added value in a high yield as in the prior art. In the present application, a so-called “soluble dietary fiber” in which several to several hundreds of β-D-glucose are connected, and a “sweet taste, physiological” such as a peptide / polypeptide in which two or more amino acids such as glutamic acid are connected. An appropriate amount of a molecule that has not been completely decomposed, such as an “active ingredient”, but is moderately decomposed can be selectively contained.
[0044]
Next, how to use the processing system of the present embodiment according to the manufacturing scale will be outlined with reference to FIG. When the production scale can be used from a medium scale to a large scale, as shown in the upper part of FIG. 3, it is configured as a high-temperature and high-pressure water continuous processing apparatus so that the above steps Ba to D can be performed continuously. Here, a continuous machining system is constructed using the pumps P1 to P4, the high-pressure pumps 7a and 7b, and the like. Next, when the production scale can be used on a small scale, as shown in the lower part of FIG. 3, it is configured as a high-temperature high-pressure water semi-batch processing apparatus so that the above-described steps Bc to D can be performed continuously. Next, when the production scale can be used on a very small scale, as shown in the middle part of FIG. 3, it is configured as a high-temperature and high-pressure water batch processing apparatus so that the above-described steps Bb to D can be performed batchwise. In these cases (middle stage and lower stage in FIG. 3), high-temperature and high-pressure processing is performed through a filling step of filling predetermined containers with okara (raw okara) and water. In any step (all in FIG. 3), the presence / absence 1a and 1b of the hydration step is appropriately selected. With this construction, the processing system according to the manufacturing scale and the enterprise scale can be realized with the present embodiment.
[0045]
From the above, according to the processing system and processing method of the present invention, not only okara, but also the processing of food ingredients containing okara, soy components such as soy, soy flour, and soy protein containing the same components as okara and soy In addition to organic food raw materials containing each part, it can also be applied to processing of other organic food raw materials. Therefore, like soybeans, organic ingredients (pulp, wood flour, cotton, corn) that have few inorganic components, are composed of nutrients such as carbohydrates (fibers and sugars), proteins, and fats, and can become food ingredients after processing. Core, buckwheat husk, wheat straw, sake lees, beer lees, beer lees, soy sauce lees, lees, sugar cane lees, mandarin oranges, apples, grape juices, tea husks, meat residues, blood waste, etc.) It is possible to apply.
[0046]
【Example】
(Example 1) In the above embodiment, 0.5 g of okara is placed in a 10 ml high-temperature pressure-resistant container (SUS316L wall thickness pressure tube) 19 and water (distilled water) in the storage chamber 2b is brought to a predetermined pressure at a predetermined temperature. A predetermined amount was added and sealed. The pressure tube 19 is immersed in a molten salt bath apparatus (using molten nitrate as a heating medium) 11 adjusted to a predetermined temperature (250 ° C., 300 ° C., 350 ° C., 400 ° C.), for a predetermined time (1 minute, After 5 minutes and 60 minutes), it was immediately taken out, immersed in a water tank and rapidly cooled. Processing by the high-temperature and high-pressure apparatus 1 (reference numeral B in the figure) was performed at 30 MPa and 40 MPa, and the time was within a range of 60 seconds to 3,600 seconds (60 minutes). That is, an experiment was performed under conditions 1 to 11 shown in the left column of Table 1, and after the high-temperature and high-pressure water processing, the pressure tube 19 was opened, the processing liquid was taken out, and the properties were evaluated. The results are shown in Table 1. The properties were evaluated for okara residue, residue sedimentation, coloring degree, flavor, and the like (for the saturated vapor diagram of water in Example 1 see the star in FIG. 4).
[0047]
[Table 1]

[0048]
As is apparent from Table 1, the high-temperature and high-pressure apparatus 1 did not leave any okara residue under the conditions of 30 MPa, 350 ° C., 5 minutes (No 6) and 30 MPa, 400 ° C., 5 minutes (No 8). It became a brown liquid. Moreover, when it became the conditions (No9, No10) for 60 minutes at 30 MPa and 400 degreeC, there was a strong burning smell. However, the coloring has become lighter. Under these conditions, considerable component changes occur, and there are some points that are functionally difficult to use as food ingredients, but under conditions of 30 MPa and 300 ° C or lower (

No

1, 2, 3, 4), Although it was recognized, chicken soup and coffee flavor were produced, and the utility value as a food ingredient was recognized. Note that some coloration occurs. From these, in order to prevent excessive damage to raw material components including okara, it is understood that high-temperature and high-pressure water processing is preferably performed for a short time. And by the short-time treatment with high-temperature and high-pressure water under the supercritical and subcritical conditions of water, each component in Okara is significantly selectively and partially denatured and decomposed, and can be reused as a food ingredient. be opened. For example, when used as an auxiliary material for tofu, it does not discharge okara as waste and can be reused safely, increasing the amount of soluble dietary fiber in tofu, increasing water retention, and improving nutritional characteristics. it can.
[0049]
(Example 2) 2.5 kg of water was added to 1 kg of okara to form a slurry, and a high-pressure homogenizer (NS206L PONY, manufactured by Niro Soavi) 5A was treated 3 times at 35 MPa to prepare a smooth okara slurry. This okara slurry was diluted 5 times, coarse particles of 150 mesh or more were removed, and the mixture was fed at a rate of 1.5 ml / min with a high-pressure pump (NP-AX-15 manufactured by Nippon Seimitsu Kagaku) 7a. Separately, pure water was fed at a rate of 3 ml / min with the high-pressure pump 6 and heated to 400 ° C. in advance. Hot water was continuously poured and mixed into the okara slurry with a heating device, and the temperature was rapidly raised to about 200 ° C. to perform preheating. Next, it is passed through a fluidized sand bath device 15 (reaction tank) adjusted to a predetermined temperature (300 ° C., 400 ° C.), reacted for about 10 seconds, immediately cooled by the cooling device 13, and passed through a back pressure valve. Thus, a product liquid was obtained (supercritical treatment, No1). By adjusting the back pressure valve, conditions of 30 MPa and 10 MPa were adopted (subcritical processing, No. 2). The conditions and analysis results of the product solution thus obtained are shown in Table 2 (see the triangle mark in FIG. 4 for the saturated vapor diagram of water in Example 2).
[0050]
[Table 2]

[0051]
In column A of Table 2, No3 ( (3) ) Is the treatment of supercritical water, No2 ( (2) ) Is the treatment of subcritical water, No1 ( (1) ) Is the control (untreated). “Untreated” means that neither supercritical treatment nor subcritical treatment was performed, and the conditions such as No. 1 and No. 2, Okara and water were made the same (however, hot water was mixed under the previous two conditions) , Distilled water was added at the same rate). About each of these samples, pH measurement by glass electrode method, solid content by 105 ° C drying method, protein by Kjeldahl method and amino acid automatic analyzer, lipid by solvent extraction, ash content by ashing at 550 ° C, carbohydrate by subtraction calculation Measured (see column A). Carbohydrates include soluble carbohydrates (total sugar) and insoluble dietary fiber (dietary fiber). The protein (amino acid state) was determined by quantitative analysis of 28 amino acids using an amino acid automatic analyzer after acid decomposition. The automatic amino acid analyzer is a method for separating and quantifying protein degradation products and free amino acids by ion exchange chromatography. The Kjeldahl method is a method in which nitrogen in an organic sample is measured as ammonia and multiplied by a conversion multiplier of 5.71 to obtain a protein, and amino nitrogen other than amino acids can also be measured.
[0052]
In the order of untreated (No1), subcritical treatment (No2), and supercritical treatment (No3), carbohydrate, solid content, and protein (amino acid state) decreased. Obviously, it can be seen that each component in okara has decomposed and disappeared. Carbohydrates containing dietary fiber are dramatically reduced. It can be seen that the lipid is also decreased by the supercritical treatment (No 3).
[0053]
Since the protein was measured for amino nitrogen and the like by the Kjeldahl method, no apparent change in the total amount of protein was observed. However, from the results of amino acid analysis, the amount present as protein-constituting amino acids is clearly reduced, indicating protein denaturation and crude degradation. Note that protein denaturation, that is, a change in higher-order structure has progressed considerably under these conditions, but it can occur before degradation into amino acids.
[0054]
In supercritical processing (No.3), carbohydrates such as dietary fiber have almost disappeared, but amino acids are present, suggesting the existence of proteins. Protein food processing characteristics by Keltar method and amino acid automatic analyzer ( For example, the possibility of leaving salt coagulation property or the like is implied.
[0055]
Moreover, the result of having observed the external appearance visually was shown in the B column of Table 2.
[0056]
In the subcritical water processing (No. 2) and supercritical water processing (No. 3), precipitates that were separated immediately like Okara were not observed, and almost refined and solubilized. In the order of untreated (No1), subcritical water processing (No2), supercritical water processing (No3), the brown coloration and odor became stronger, but the reaction time was 10 seconds, which was rather severe. The decomposition progressed too much and a polymer was formed. From the above results, by appropriately setting each of the supercritical and subcritical conditions of water, the structure of Okara changes significantly, each component is decomposed selectively and partially, It was found that it can be easily reused as a raw material, and can add value.
[0057]
(Example 3) A 2.5-fold amount of water was added to 1 kg of okara to form a slurry, which was treated once at 140 MPa with a high-pressure homogenizer (NS2006L PONY, manufactured by Niro Soavi) 5A to prepare a smooth okara slurry. This okara slurry was diluted 5-fold and fed at a rate of 3.0 to 4.5 ml / min with a high-pressure pump (NP-AX-15 manufactured by Nippon Seimitsu Kagaku) 7a. Separately, pure water was fed at a rate of 6.0 to 9.0 ml / min with a high-pressure pump (same as above), and heated to 450 ° C. in advance. Hot water was continuously poured and mixed into the okara slurry, and the temperature was rapidly raised to about 200 ° C. to perform preheating. Next, it is passed through a fluidized sand bath device 15 (reaction tank) adjusted to a predetermined temperature (200 ° C, 250 ° C, 300 ° C), reacted for 1 or 3 seconds, and immediately cooled by the cooling device 13. A product solution was obtained through a back pressure valve. The back pressure valve was adjusted to 30 MPa. And after high temperature high pressure water processing, the post-process was performed with the high pressure homogenizer 5B. Table 3 shows the evaluation of properties of the machining fluid thus obtained. The property evaluation was performed for okara residue, residue sedimentation, coloring degree, flavor, and the like (for the saturated vapor diagram of water in Example 3 see the diamonds in FIG. 4).
[0058]
[Table 3]

[0059]
First, the effect of processing of the high-pressure homogenizers 5A and 5B before and after the high-temperature and high-pressure water processing by the high-temperature and high-pressure apparatus 1 was examined. Of Table 4 (1) Compared to the control (untreated) (2) Even when the Okara was processed at 140 MPa with the high-pressure homogenizer 5A, a large Okara slurry having a particle size of about 0.5 to 2 mm became a smooth slurry of 0.1 to 0.01 mm or less. However, the texture was slightly rough (see property evaluation). Also, (3) Compared to only high-temperature and high-pressure processing of (4) Okara residue particles were made small and smooth not only by the high-temperature and high-pressure processing, but also by pretreatment with the high-pressure homogenizer 5A. further, (4) When the processing time of the high-temperature and high-pressure apparatus 1 was shortened to 1 second, the color became smooth and had almost no influence on the food material. Here, although the processing time by the high-temperature high-pressure apparatus 1 depends on the temperature, a short-time treatment such as 0.01 to 60 seconds is preferable.
[0060]
next, (5) However, after processing for 1 second by the high-temperature and high-pressure apparatus 1, it is applied to the high-pressure homogenizer 5B. However, since the processing liquid by high-temperature and high-pressure processing at 100 ° C. or higher is aseptic, it can be stored. However, it rarely causes separation, aggregation and precipitation during storage. In order to prevent this, if a homogenization treatment (5-200 MPa) is performed using the high-pressure homogenizer 5B after the high-temperature and high-pressure processing, a stable processing liquid can be obtained. In addition, relatively mild high-temperature and high-pressure processing (for example, 250 ° C. and 30 MPa for 1 second) is preferable as a food material without coloring or off-flavor. However, completely insoluble fiber does not solubilize and forms a precipitate from the beginning. Therefore, a fine dispersion can be obtained by performing homogenization (5-200 MPa) using the high-pressure homogenizer 5A after the high-temperature and high-pressure processing. Also, (6) Is (5) The processing liquid was processed with the high-pressure homogenizer 5A in the process of the above condition, and a working liquid in which the okara residue hardly settled due to the homogenous / dispersing effect was obtained.
[0061]
Thus, it can be seen that the high-pressure homogenizers 5A and 5B before and after the high-temperature and high-pressure water processing can be used as a food raw material without any sedimentation residue and without feeling uncomfortable in terms of texture and smell. . Here, the disappearance of the precipitate is not a necessary condition as a raw material for food, and even in a looser condition, the insoluble fiber can be sufficiently softened and refined to improve the roughness.
[0062]
(Example 4) 2.5 L of water was added to 1 kg of okara to form a slurry, and a high-pressure homogenizer (NS2006L PONY, manufactured by Niro Soavi) 5A was treated once at 140 MPa to prepare a smooth okara slurry. This okara slurry was diluted 5 times and fed at a rate of 3.0 ml / min with a high-pressure pump (NP-AX-15 manufactured by Nippon Seimitsu Kagaku) 7b while stirring. Separately, pure water was fed at a rate of 6.0 ml / min with a high-pressure pump (7a) and heated to 400 ° C. in advance. Hot water was continuously poured and mixed into the okara slurry, and the temperature was rapidly raised to about 200 ° C. to perform preheating. Next, the fluidized sand bath apparatus 15 (inside the high temperature and high pressure apparatus 1) adjusted to a predetermined temperature (200 ° C, 250 ° C, 300 ° C) is passed, (2) Processing at a constant temperature of 200 ° C. for 3.0 seconds, (3) Processing at a constant temperature of 300 ° C for 3.0 seconds, (4) The heating process was performed at 200 ° C. to 300 ° C. for 6.0 seconds and immediately cooled by the heat exchanger 12. Further, before cooling with the heat exchanger 12, the pressure was reduced to 1 MPa and rapid cooling was performed by flushing (rapid pressure drop). this (5) As shown. Each product liquid was obtained through a back pressure valve. The high-temperature and high-pressure conditions and the results of property evaluation are shown in Table 5. The properties were evaluated for okara residue, residue sedimentation, coloring degree, flavor, and the like. In addition, this Table 4 is based on the high-temperature / high-pressure water treatment under subcritical conditions (for the saturated vapor diagram of the water in Example 3, see the ellipses in FIG. 4).
[0063]
[Table 4]

[0064]
Ocara residue was observed under any condition, but there was a difference in the sedimentation property of the residue. That is, (2) Compared to 3 seconds at 200 ° C, (3) At 300 ° C. for 3 seconds, the sedimentation of the okara residue was smaller, but coloring and a burning odor were observed. (4) When the temperature was raised from 200 ° C. to 300 ° C., the settleability of the okara residue was small, and the coloring and aroma were inferior. At 200 ° C, the state of the okara slurry did not change much. Above 250 ° C, it was brownish in proportion to temperature and time. There was a tendency that the state of the precipitate considerably decreased at 250 ° C. under the condition of 5.0 seconds or more. Except for coloring, the formation of a polymer such as a sticky product was not observed. Thus, it can be seen that the fiber component in the okara is changed significantly by performing the subcritical condition of water in a short time. It can be seen that flushing (rapid pressure drop) minimizes excessive cooling damage due to rapid cooling due to latent heat of evaporation, concentration due to water evaporation (close to the concentration of the stock solution), and so on.
[0065]
(Example 5) Next, pH was adjusted by adding weak acid, weak alkali, etc. under high temperature and high pressure conditions. The results are shown in Table 5.
[0066]
[Table 5]

[0067]
Here, the following are mentioned as a raw material used for pH adjustment. (1) For food additives (food additives other than chemical synthesis, including so-called natural additives), weak alkalis such as sodium citrate, sodium bicarbonate, sodium acetate, trisodium ammonia, and small amounts of sodium carbonate, hydroxide Strong alkali components such as sodium and citrus, mainly weak acid components such as citric acid and acetic acid, and strong acid components such as a small amount of hydrochloric acid, (2) Examples of food materials include lactic acid fermented foods such as yogurt, citrus acid juice, (3) Water is acidic / alkaline ion water, hot spring water, ground water, seawater, and food water compatible water such as ice and ice water.
[0068]
As is apparent from Table 5, the amount of glucose produced by addition of citric acid (1% addition) was also observed under a low temperature condition of 260 ° C. With no pH adjustment (neutral), decomposition of cellulose was observed at 400 ° C. There was little change in pH, and acid generation was suppressed even under high temperature conditions. Therefore, when neutralizing after the fact, the amount of alkali may be small. On the other hand, the addition of 1% of weak alkali (bicarbonate) had less burnt odor and the like under subcritical to supercritical conditions. In addition, the amount of coagulable protein also shows that the absorption at 280 nm is higher than that in the control under subcritical conditions (260 ° C. and 340 ° C.), indicating that the degree of protein denaturation is progressing. The pH could be maintained almost neutral even by treatment in the supercritical state. On the other hand, it can be seen that in the addition of acid, under subcritical conditions (especially 260 ° C.), the L value representing whiteness was higher and coloring was suppressed. Depending on the purpose such as the production of glucose, the pressure and temperature conditions can be set low, and the apparatus cost and operation cost can be greatly reduced. In addition, although the production | generation of glucose was made into the parameter | index, the component of glucose is not the main objective in this application, and the partial decay | disintegration of the cellulose polymer | macromolecule is the original purpose for the production | generation of glucose actually from an analytical method.
[0069]
In the past, the knowledge that hydrolysis reaction is promoted by addition of acid or alkali under supercritical conditions has been obtained (Japanese Patent Publication No. 03-3671: Abstracts of Tokushima Conference P161, 1999). Conventionally, a seasoning liquid or the like is produced from a protein raw material by hydrolysis (less than pH 3) using a large amount of a strong acid such as hydrochloric acid. Hydrochloric acid is a food additive that has been approved for use as a food processing aid, but it is a powerful drug, and it is a strong alkaline or weak acid that is a reverse liquid for working environment, subsequent purification process, equipment corrosion, and neutralization. Using such as involves a cost increase and danger.
[0070]
However, according to the present invention, it is understood that when the pH of food raw materials is adjusted in high-temperature and high-pressure processing, it is a means for effectively controlling the texture, flavor, color tone and physical properties. The range of adjustment increases with factors of temperature, pressure, and time, and it becomes possible to perform a variety of product (liquid) quality adjustment and differentiation. Thus, the properties and properties of the product (liquid) are greatly affected, and the quality can be controlled in an advantageous direction depending on the purpose. By adjusting the pH by adding a weak acid, weak alkali or the like under high temperature and high pressure conditions, the effect of high temperature and high pressure processing can be further enhanced as compared with the case of no preparation.
[0071]
As described above, each of the above examples is based on a food material containing okara, but as is apparent from each of the above embodiments, it can be applied universally to multi-component systems containing soybeans and soybean components, Widely applicable to food ingredients.
[0072]
(Example 6) 3 L of water was added to 3 kg of okara to form a slurry, and a high-pressure homogenizer (NS2006L PONY, manufactured by Niro Soavi) 5A was treated once at 140 MPa to prepare a smooth okara slurry. This okara slurry was fed at a rate of 14.0 ml / min with a high-pressure pump (NP-AX-15 manufactured by Nippon Seimitsu Kagaku) 7b using an auxiliary pump (self-made). Separately, pure water was fed at a rate of 3.0 ml / min with a high-pressure pump (7a) and heated to 222 ° C. under 2.0 MPa in advance to obtain high-temperature and high-pressure steam. Similarly, it was preliminarily heated to 370 ° C. under 2.1 MPa to obtain high-temperature and high-pressure superheated steam. The steam was continuously poured and mixed into the okara slurry, and the temperature was rapidly raised to about 200 ° C. and heated. About 2.5 seconds later, the product was cooled by the heat exchanger 12, and a product liquid (okara milk, solid content of about 10% wt) was obtained through a back pressure valve. Okara milk and soy milk obtained by a conventional method (solid content: about 11% wt) were mixed at a ratio of 1: 2 to obtain whole soy milk using almost whole soybeans in calculation. To whole cooled soymilk, 0.15% GDL (glucono-δ-lactone), magnesium chloride (MgCl ₂ ・ 6H ₂ O) 0.15%, transglutaminase preparation (Ajinomoto "Activa" super card, active ingredient 0.2%) 0.2% dissolved in water was added and mixed. Next, it was filled and packaged in a tofu packaging container (made of polypropylene), and solidified by heating at 60 ° C. for 30 minutes and then at 80 ° C. for 30 minutes. The quality of soy milk and tofu was measured after refrigeration overnight. The results are shown in Table 6.
[0073]
[Table 6]

[0074]
Even when high-temperature and high-pressure steam was used, a high-temperature and high-pressure state (subcritical condition) similar to that of high-temperature and high-pressure water was obtained after mixing with okara milk. Compared to Okara's rough texture control, the texture was sufficiently smooth. Further, in this result, the texture was slightly smoother when using superheated steam than saturated steam. Other qualities were not significantly different from those of Control 1.
[0075]
【The invention's effect】
In the present invention, by high-temperature and high-pressure water treatment in the supercritical state and subcritical conditions of water, each component in okara is significantly and selectively modified, roughly decomposed, and easily reused as a food material. It is safe and can add value. In addition, if processing with a high-pressure homogenizer is performed as a pretreatment, partial decomposition with high-temperature and high-pressure water in the subsequent process and denaturation by heat and pressure can be performed more accurately in a shorter time and under milder temperature and pressure conditions. It becomes possible. On the other hand, when the processing with the high-pressure homogenizer is performed as a post-treatment, the conditions for the high-temperature and high-pressure processing, which is the previous step, can be reduced to the minimum necessary level by adjusting the level of “boiled”.
[0076]
Furthermore, when high-temperature high-pressure water is injected or high-temperature high-pressure steam is blown in, it is possible to set processing conditions according to each component such as insoluble dietary fiber, protein, DNA, soybean oligosaccharide, and isoflavone. Therefore, according to the present invention, it is optimal for processing for reusing okara, is excellent in versatility, and is expected to be applied to other food ingredients.
[0077]
[Brief description of the drawings]
FIG. 1 is a diagram showing an okara processing system according to an embodiment of the present invention.
FIG. 2 is a diagram showing a circulation system of the system according to the embodiment.
FIG. 3 is a diagram showing an application example of the okara processing system according to the embodiment.
FIG. 4 is a diagram for explaining supercritical conditions of water and subcritical conditions of water.
[Explanation of symbols]
1 High temperature and high pressure equipment,
5A High-pressure homogenizer as pretreatment,
5B High-pressure homogenizer as post-treatment,
7a, 7b high pressure pump,
8a High-temperature high-pressure water injection device,
8b High-pressure steam spraying device,
11 Molten salt bath device,
12 heat exchanger,
13 Cooling device,
14 Electric furnace equipment,
15 Fluid sand bath equipment,
P1-P4 pump

Claims

Okara, liquid okara, slurry of water added to okara, or multi-component food raw materials containing these okaras, either high temperature high pressure conditions of water supercritical conditions or water subcritical conditions, or these A method for processing a food ingredient containing okara, which is characterized by performing a processing that causes a change in the higher-order structure of the polymer in 0.01 seconds to 60 minutes under combined conditions.

The processing method of the food raw material containing the okara characterized by processing the food raw material containing the said okara with a high-pressure homogenizer in the pre-process or post process of the processing method of Claim 1.

When processing one of the supercritical condition and subcritical condition of water or a combination thereof, high-temperature high-pressure water is injected into the food material containing the okara, or high-pressure steam or superheated steam is blown into the raw material. The method for processing a food material containing okara according to claim 1 or 2, wherein the temperature condition is adjusted stepwise or gradiently by the supercritical condition or subcritical condition of the water.

After the processing of either the supercritical condition or the subcritical condition of water or a combination thereof, the working fluid is flushed by reducing the pressure to a value equal to or lower than the saturated vapor pressure at the temperature before the pressure reduction in the cooling step. The processing method of the foodstuff raw material containing the okara of Claim 3.

A method for processing a food material containing okara, wherein the pH of the food material containing okara in each step of claims 1 to 4 is adjusted to a range of 3 to 10 with an alkali component or an acid component.