JP2004121138A

JP2004121138A - Method for producing coffee extract or water-soluble coffee

Info

Publication number: JP2004121138A
Application number: JP2002292268A
Authority: JP
Inventors: Hiroshi Hisamori; 久守　博; Osamu Kashiwai; 柏井　治; Yoshiyuki Kitajima; 北島　義之
Original assignee: UCC Ueshima Coffee Co Ltd
Current assignee: UCC Ueshima Coffee Co Ltd
Priority date: 2002-10-04
Filing date: 2002-10-04
Publication date: 2004-04-22
Anticipated expiration: 2022-10-04
Also published as: JP4282971B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing coffee extract or water-soluble coffee intended for efficiently collecting coffee solid from the unused parts of roasted coffee beans. <P>SOLUTION: The method for producing the coffee comprises a process of filling raw coffee beans and water in a sealing container heatable at high temperature and performing wet heating roasting at temperature exceeding 160°C under pressurization, a process of crushing the roasted coffee beans thus obtained and performing enzyme reaction through mixing with the crushed coffee beans one kind or at least two kinds of enzyme(s) of vegetable polysaccharides splitting enzymes selected from the group consisting of galactomannase, mannase, cellulase and pectinase, and a process of obtaining coffee extract from slurry after the enzyme reaction. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、コーヒーエキスまたは可溶性コーヒーの製造方法に関する。詳しくは、高収率を目的とするコーヒーエキスまたは可溶性コーヒーの製造方法に関する。
【０００２】
【従来の技術】
一般に、飲用に供する焙煎コーヒーは、生コーヒー豆を熱風対流又は直火式の焙煎機で２００℃〜３００℃に加熱（乾式加熱焙煎）して製造する。焙煎は、加熱により生コーヒー豆に独特な加熱風味を生みだすと同時にコーヒー豆に含まれる８％前後の水分が水蒸気に変わり細胞を膨張させ組織を破壊し、コーヒー豆の表面積を増大させ、可溶性固形分の抽出量を増加させる。焙煎コーヒー豆は適宜サイズに粉砕し、１００℃以下の温水で抽出することでコーヒーエキスを得る。このようにしてコーヒー豆から抽出される可溶性の固形物の収率は、２５〜３０％程度であり、残りの不溶性成分は未利用部位として廃棄される。未利用部位の大半は、細胞壁や細胞間部質を構成するセルロース、リグニン、マンナン、アラビノガラクタン等の植物性多糖類と非水溶性のタンパク質、油脂成分である事が知られている（例えば、非特許文献１参照）。
【０００３】
当業界では、これらの未利用成分をできるだけ少なくし、焙煎コーヒー豆の収率を上げるため、細胞壁や細胞間部質を構成するセルロース、リグニン、マンナン、アラビノガラクタン等を分解する方法が検討されてきた。中でも焙煎コーヒー豆の植物性多糖類を酵素により加水分解し固形分の収率を増大させる方法は、２００℃以上の高温高圧水による抽出方法等に較べ、低温、大気圧下の穏やかな条件で行えるため有利である。例えば、精製へミセルラーゼを用い、焙煎コーヒー豆を処理することによるインスタントコーヒーの製造方法が開示されている（例えば、特許文献１参照）。しかしながら、生豆は無論、通常の焙煎コーヒー豆では積層した多糖類が酵素の侵入を妨げ、酵素反応の効率を低下させるため、多量の酵素を必要とする。
【０００４】
また、焙煎コーヒー豆や部分抽出した焙煎コーヒー豆の水性混合物を作成し、加圧下、高温で水蒸気と接触させ、次いで、速やかに大気レベルに減圧する「水蒸気爆発処理」を行い、その後のスラリーを酵素処理することで固形物の収率を増加させる方法が知られている（例えば、特許文献２参照）。しかし、この方法は、通常のコーヒーの製造工程には存在しない水蒸気爆発工程とその装置が新たに必要となり、さらにコーヒー豆に水蒸気爆発による過剰な加熱を与える。
【０００５】
【特許文献１】
特公昭４９−２１７１０号公報
【特許文献２】
特開平７−１１５号公報
【非特許文献１】
「コーヒーテクノロジー（Ｃｏｆｆｅｅ　Ｔｅｃｈｎｏｌｏｇｙ　）」，Ｓｉｖｅｔｓ　＆　Ｄｅｓｒｏｓｉｅｒ，ＡＶＩ　Ｐｕｂｌｉｓｈｉｎｇ，　１９７９，　ｐ．２８５。
【０００６】
【発明が解決しようとする課題】
そこで、本発明の目的は、焙煎コーヒー豆の未利用部分から効率よくコーヒー固形分を回収可能な、コーヒーエキスまたはインスタントコーヒーの製造方法を提供することにある。
【０００７】
【課題を解決するための手段】
本発明者らは、上記目的を達成すべく鋭意研究したところ、植物多糖類分解酵素を効率的に作用させる条件を見出し、本発明を完成するに至った。
【０００８】
即ち、本発明のコーヒーエキスの製造方法は、１）高温での加熱が可能な密封容器に、生コーヒー豆と水を充填し、加圧下１６０℃を超える温度で湿式加熱焙煎を行う工程、２）得られた焙煎コーヒー豆を粉砕し、当該粉砕コーヒー豆にガラクトマンナーゼ、マンナーゼ、セルラーゼおよびペクチナーゼからなる群より選ばれた植物多糖類分解酵素の１種または２種以上の酵素を混合して酵素反応を行う工程、ならびに３）酵素反応後のスラリーからコーヒーエキスを得る工程を含むことを特徴とする。
【０００９】
前記コーヒーエキスの製造方法は、濃縮エキスを製造するためには、さらに４）コーヒーエキスを濃縮する工程を含むことが好ましい。
【００１０】
前記コーヒーエキスの製造方法は、工程１）の湿式加熱焙煎を１６０℃〜２４０℃で行うことが好ましい。
【００１１】
前記コーヒーエキスの製造方法は、工程１）の湿式加熱焙煎を１６０℃〜２４０℃のいずれかの温度で、当該温度での飽和蒸気圧に達する圧力で行うことが好ましい。
【００１２】
本発明の可溶性コーヒーの製造方法は、１）高温での加熱が可能な密封容器に、生コーヒー豆と水を充填し、加圧下１６０℃を超える温度で湿式加熱焙煎を行う工程、２）得られた焙煎コーヒー豆を粉砕し、当該粉砕コーヒー豆にガラクトマンナーゼ、マンナーゼ、セルラーゼおよびペクチナーゼからなる群より選ばれた植物多糖類分解酵素の１種または２種以上の酵素を混合して酵素反応を行う工程、３）酵素反応後のスラリーからコーヒーエキスを得る工程、ならびに４’）コーヒーエキスを可溶性の固体に乾燥する工程を含むことを特徴とする。
【００１３】
前記可溶性コーヒーの製造方法は、工程１）の湿式加熱焙煎を１６０℃〜２４０℃で行うことが好ましい。
【００１４】
また、前記可溶性コーヒーの製造方法は、工程１）の湿式加熱焙煎を１６０℃〜２４０℃のいずれかの温度で、当該温度での飽和蒸気圧に達する圧力で行うことが好ましい。
【００１５】
［作用効果］
本発明のコーヒーエキスの製造方法によると、生コーヒー豆を湿式加熱焙煎した後植物多糖類分解酵素を作用させることにより、過剰な加熱工程を経ないでコーヒーエキスを収率よく抽出することができ、高濃度で味覚にも優れたコーヒーエキスを得るという効果を奏する。本発明の可溶性コーヒーの製造方法によると、前記高濃度のコーヒーエキスを原料とするため濃縮、乾燥が短縮され、高品質の可溶性コーヒーを容易に得るという効果を奏する。また、本発明のコーヒーエキスまたは可溶性コーヒーの製造方法によると、湿式加熱焙煎を所定の条件下で行うことによりコーヒー豆の細胞壁や細胞間層を剥離・破砕させ、従来の焙煎方法による焙煎コーヒー豆に較べ酵素の接触面積を増加させ、コスト的に見合う酵素使用量で、高収率のエキスを得るという効果を奏する。
【００１６】
【発明の実施の形態】
本発明のコーヒーエキスの製造方法は、１）高温での加熱が可能な密封容器に、生コーヒー豆と水を充填し、加圧下１６０℃を超える温度で湿式加熱焙煎を行う工程、２）得られた焙煎コーヒー豆を粉砕し、当該粉砕コーヒー豆にガラクトマンナーゼ、マンナーゼ、セルラーゼおよびペクチナーゼからなる群より選ばれた植物多糖類分解酵素の１種または２種以上の酵素を混合して酵素反応を行う工程、ならびに３）酵素反応後のスラリーからコーヒーエキスを得る工程を含むことを特徴とする。
【００１７】
１）高温での加熱が可能な密封容器に、生コーヒー豆と水を充填し、加圧下１６０℃を超える温度で湿式加熱焙煎を行う工程
本発明で使用される「高温での加熱が可能な密封容器」とは、２４０℃、３．４ＭＰａ程度までの高圧加熱できる容器である。本発明においては、前記装置には容器内の高圧力を強制的に下げる圧力開放弁を具備しないか、具備していても使用しないことが好ましい。その理由は、後述する。
【００１８】
前記密封容器に生コーヒー豆と水を充填する。
【００１９】
本発明に使用する生コーヒー豆の種類は、特に制限されるものではなく、アラビカ種、ロブスタ種、リベリカ種等のものが挙げられる。複数の種類をブレンドした豆を用いてもよい。
【００２０】
前記水は、イオン交換水、蒸留水等コーヒーの抽出に通常使用されるものが用いられうる。
【００２１】
充填する水の量は、コーヒー生豆の重量と容器の容積に応じて適宜設定することができるが、コーヒー生豆の重量に対して０．５〜１２倍量が好ましく、０．５〜９倍量がより好ましい。水の量が０．５倍未満であると、容器内での水分量が不足して生豆が均一に焙煎されない傾向があり、一方、水の量が１２倍を超えると、容器内が液体の水で充足されてしまい、蒸気になる空隙がないため、本発明の焙煎条件にそぐわない。
【００２２】
次いで、生コーヒー豆を加圧下１６０℃を超える温度で湿式加熱焙煎を行う。
【００２３】
加熱温度は１６０℃を超えるが、２４０℃以下が好ましく、より好ましくは１８０〜２１０℃である。加熱温度が１６０℃以下であると、焙煎の進行および完了が順調に行われず、所望の焙煎度を達成しにくい。一方、加熱温度が２４０℃を超えると、コーヒー生豆が短時間で炭化する場合があり、良好な焙煎コーヒー豆が得られにくい。
【００２４】
湿式加熱焙煎時の加圧条件は加熱温度により適宜設定することができるが、コーヒー固形分の回収率を上げるためには前記加熱温度（１６０℃〜２４０℃）で、当該温度での飽和蒸気圧に達する圧力で行うことが好ましい。飽和蒸気圧は、加熱温度と前記密封容器の種類により設定されるが、通常０．６〜３．４ＭＰａの範囲である。
【００２５】
加熱温度が所定の値に達した後、その温度で一定時間保持してもよく、直ちに加熱を終了させてもよい。保持時間は保持温度に応じて適宜設定することができるが、通常０〜６０分である。
【００２６】
その後、加熱時の圧力が常圧（大気圧）に下がるまで放置する。放置時間は密封容器や圧力により異なるが、１５０〜３５０分程度である。
【００２７】
前記放置期間中に、コーヒー生豆の焙煎が進行し、完了する。したがって、本発明では、前記したように、容器内の高圧力を強制的に下げないことが好ましい。また、焙煎で生成された香気成分がすべて容器内に保持されうることも好ましい理由である。
【００２８】
加熱終了後、常圧（大気圧）に戻った容器から焙煎コーヒー豆を取り出す。
【００２９】
２）得られた焙煎コーヒー豆を粉砕し、当該粉砕コーヒー豆にガラクトマンナーゼ、マンナーゼ、セルラーゼおよびペクチナーゼからなる群より選ばれた植物多糖類分解酵素の１種または２種以上の酵素を混合して酵素反応を行う工程
工程１）で得られた焙煎コーヒー豆を粉砕する。粉砕方法は、湿式焙煎したコーヒー豆を粉砕可能な装置と方法を用いて行えばよく、特に制限されるものではない。焙煎コーヒー豆の粉砕の程度も特に制限されるものではなく、酵素反応とコーヒーエキスの抽出に適する粒度に設定すればよい。
【００３０】
次に、粉砕コーヒー豆に植物多糖類分解酵素を混合して酵素反応を行う。
【００３１】
本発明に用いられる植物多糖類分解酵素は、公知の酵素の中からコーヒーに含まれる多糖類を分解可能な観点から選択されたものであり、ガラクトマンナーゼ、マンナーゼ、セルラーゼおよびペクチナーゼが挙げられる。前記酵素は１種を用いてもよく、２種以上の酵素を用いてもよく、水等の溶媒に適宜溶解して使用する。添加する酵素量は、コーヒー豆の乾燥重量に対して通常５０〜８００ｕｎｉｔｓ／ｇ程度である。
【００３２】
粉砕コーヒー豆、酵素液および適宜水を追加して混合したスラリーは、前記酵素の至適ｐＨ内であり、そのまま下記条件で酵素反応を行うことができる。
【００３３】
酵素反応は、用いる酵素に応じて反応温度および反応時間を設定することができるが、通常１０〜６０℃で、０．５〜６５時間程度である。
【００３４】
３）酵素反応後のスラリーからコーヒーエキスを得る工程
酵素反応中にコーヒーの抽出も並行して行われ、反応終了後にスラリーをろ過、遠心分離等によりスラリーの固形物とコーヒーエキスを分離することによりコーヒーエキスを得ることができる。あるいは、スラリーの固形物とコーヒーエキスを分離した後、当該スラリー固形物を抽出器に充填し、水又は温水にて抽出を行うことによりさらにコーヒーエキスを得ることができる。あるいは、酵素反応後のスラリーをそのまま抽出器に充填し、水又は温水にて抽出を行うことによりコーヒーエキスを得ることができる。
【００３５】
前記ろ過または遠心分離は、スラリー固形物を除去可能な条件下で行えばよい。
【００３６】
本工程における抽出方法は、酵素処理されたスラリーを用いることから、大気圧下１００℃以下の水又は温水で行えばよい。この抽出操作を追加することにより、コーヒー固形分の収率をさらに上げることができる。
【００３７】
前記コーヒーエキスの用途は、容器入りコーヒー飲料の原料や希釈用飲料の原料等が挙げられる。
【００３８】
希釈用飲料の原料とする場合、さらに４）コーヒーエキスを濃縮する工程を含むことが好ましい。
【００３９】
本工程における濃縮方法は、コーヒーエキスの風味を保持しつつ濃縮する方法が好ましく、減圧加熱濃縮、凍結濃縮、逆浸透膜濃縮等があげられる。
【００４０】
また、本発明の可溶性コーヒーの製造方法は、１）高温での加熱が可能な密封容器に、生コーヒー豆と水を充填し、加圧下１６０℃を超える温度で湿式加熱焙煎を行う工程、２）得られた焙煎コーヒー豆を粉砕し、当該粉砕コーヒー豆にガラクトマンナーゼ、マンナーゼ、セルラーゼおよびペクチナーゼからなる群より選ばれた植物多糖類分解酵素の１種または２種以上の酵素を混合して酵素反応を行う工程、３）酵素反応後のスラリーからコーヒーエキスを得る工程、ならびに４’）コーヒーエキスを可溶性の固体に乾燥する工程を含むことを特徴とする。
【００４１】
本製造方法において、工程１）ないし工程３）は、前記コーヒーエキスの製造方法と同じである。
【００４２】
４’）コーヒーエキスを可溶性の固体に乾燥する工程
得られたコーヒーエキスを、必要に応じて前記４）コーヒーエキスの濃縮工程を行った後、本工程において噴霧乾燥、凍結乾燥等の常法により可溶性の固体に乾燥する。
【００４３】
【実施例】
以下、本発明の構成と効果を具体的に示す実施例等について説明するが、本発明はこれらの実施例等により何ら制限されるものではない。
【００４４】
（比較例１）
［焙煎コーヒー豆］
直火型のテストロースター（プロバット製）焙煎機で乾式加熱焙煎した。
【００４５】
試料Ａ
上記乾式加熱焙煎したコーヒー豆を、コーヒーカッター（ラッキーコーヒーマシン（株）製、ボンマックＮＣ１１０５）で粉砕した。粉砕した焙煎コーヒー豆３０ｇにヘミセルロース分解酵素（阪急バイオインダストリー（株）製、セルロシンＧＭ５、力価：１００００ｕｎｉｔｓ／ｇ、１ｕｎｉｔはローカストビーンガム（ｐＨ５．０）を基質とし、４０℃、１分間に１μｍｏｌのマンノースに相当する還元力の増加をもたらす酵素量）０．６ｇを加え、全量９００ｇになるように４０℃で１５時間静置反応させた。反応後のスラリーを孔径１００ｍｅｓｈのフィルターで濾液を採取し、コーヒーエキス（試料Ａ）とした。
【００４６】
試料Ｂ
上記試料Ａにおいて、ヘミセルロース分解酵素の代わりに、セルロース分解酵素（阪急バイオインダストリー（株）製、セルロシンＡＣ４０、力価：４０００ｕｎｉｔｓ／ｇ、１ｕｎｉｔは、カルボキシメチルセルロースナトリウム（ｐＨ４．２）を基質とし、４０℃、１分間に１μｍｏｌのグルコースに相当する還元力の増加をもたらす酵素量）０．７５ｇを加えること以外は、同様の処理をしてコーヒーエキス（試料Ｂ）を得た。
【００４７】
試料Ｃ
上記試料Ａにおいて、酵素を加えないこと以外は同様の処理をしてコーヒーエキス（試料Ｃ）を得た。
【００４８】
［抽出液の評価］
上記試料Ａ〜Ｃのコーヒーエキスの収率を以下のようにして求め、比較した。コーヒーエキスのＢｘ濃度をデジタル屈折率計にて測定し、下記式により算出した。
収率（％）＝（抽出液量（ｇ）×Ｂｘ濃度）／豆量（ｇ）
【表１】

表１より、通常の乾式熱風焙煎豆では、ヘミセルロース分解酵素またはセルロース分解酵素を用いて酵素処理をしても大幅な収率の向上は認められないことがわかる。
【００４９】
（実施例１）
１）湿式加熱焙煎
高温での加熱が可能な密封容器に生豆コーヒー４００ｇと水５００ｇを加えて密閉し、２０１℃に加熱した。その時の容器内圧力は１．５ＭＰａ（飽和蒸気圧）であった。その後、加熱を中止し装置内の温度が下がり、装置内の圧力が大気圧になった時点で、湿式焙煎されたコーヒー豆を取り出した。
湿式加熱焙煎１：加水量５００ｇ、到達温度２０１℃、到達容器内圧力１．５ＭＰａ
２）焙煎コーヒー豆の水分量
ＡＯＡＣ９７９．１２法に準じ、恒量を測定したアルミカップに粉砕した焙煎コーヒー豆約３ｇを精秤採取し、減圧加熱乾燥器にて５ｋＰａまで減圧し、７０℃にて１６時間乾燥した。乾燥減量を算出し、水分量とした。
【００５０】
３）コーヒーエキスの調製
上記湿式加熱焙煎１の条件で焙煎したコーヒー豆を、カッターミキサー（大阪ケミカル（株）輸入販売、オースターブレンダー）で粉砕した。粉砕した焙煎コーヒー豆の乾燥換算２０ｇにヘミセルロース分解酵素（阪急バイオインダストリー（株）製、セルロシンＧＭ５、力価：１００００ｕｎｉｔｓ／ｇ）０．４ｇを加え、全量６２０ｇになるように４０℃のイオン交換水を加え、撹拌後、４０℃で１６時間静置反応させた。反応後のスラリーを孔径１００ｍｅｓｈのフィルターで濾液を採取し、コーヒーエキス（試料Ｄ）とした。
【００５１】
（比較例２）
上記実施例１において、ヘミセルロース分解酵素を加えないこと以外は同様の処理をし、コーヒーエキスを調製した（試料Ｅ）。
【００５２】
（比較例３）
１）通常の乾式加熱焙煎
直火型のテストロースター（プロバット製）焙煎機で焙煎した。
【００５３】
２）焙煎コーヒー豆の水分量
ＡＯＡＣ９７９．１２法に準じ、恒量を測定したアルミカップに粉砕した焙煎コーヒー豆約３ｇを精秤採取し、減圧加熱乾燥器にて５ＫＰａまで減圧し、７０℃にて１６時間乾燥した。乾燥減量を算出し水分量とした。
【００５４】
３）コーヒーエキスの調製
上記１）で焙煎したコーヒー豆をカッターミキサー（大阪ケミカル（株）輸入販売、オースターブレンダー）で粉砕した。粉砕した焙煎コーヒー豆の乾燥換算２０ｇにヘミセルロース分解酵素（阪急バイオインダストリー（株）製、セルロシンＧＭ５、力価：１００００ｕｎｉｔｓ／ｇ）０．４ｇを加え、全量６２０ｇになるように４０℃のイオン交換水を加え、撹拌後、４０℃で１６時間静置反応させた。反応後のスラリーを孔径１００ｍｅｓｈのフィルターで濾液を採取し、コーヒーエキス（試料Ｆ）とした。
【００５５】
（比較例４）
比較例３において、ヘミセルロース分解酵素を加えないこと以外は同様の処理をして、コーヒーエキス（試料Ｇ）を得た。
【００５６】
【表２】

表２より、湿式加熱焙煎と酵素処理とを組み合わせることにより、コーヒー固形分の収率が上がることが認められた。
【００５７】
（実施例２）
１）湿式加熱焙煎
高温での加熱が可能な密封容器に生豆コーヒー０．４ｋｇと水０．２〜０．５ｋｇを加えて密閉し、２２０〜１８４℃に加熱した。その後、加熱を中止し装置内の温度が下がり、装置内の圧力が大気圧になった時点で、湿式焙煎されたコーヒー豆を取り出した。
湿式加熱焙煎２：加水量２００ｇ、到達温度２１０℃、到達容器内圧力０．６４ＭＰａ
湿式加熱焙煎３：加水量５００ｇ、到達温度１８４℃、到達容器内圧力１．１ＭＰａ（飽和蒸気圧）
湿式加熱焙煎４：加水量５００ｇ、到達温度２２０℃、到達容器内圧力２．３ＭＰａ（飽和蒸気圧）。
【００５８】
２）焙煎コーヒー豆の水分量
ＡＯＡＣ９７９．１２法に準じ、恒量を測定したアルミカップに粉砕した焙煎コーヒー豆約３ｇを精秤採取し、減圧加熱乾燥器にて５ＫＰａまで減圧し、７０℃にて１６時間乾燥した。乾燥減量を算出し水分量とした。
【００５９】
試料Ｈ
上記湿式加熱焙煎２の条件で焙煎したコーヒー豆をカッターミキサー（大阪ケミカル（株）輸入販売、オースターブレンダー）で粉砕した。粉砕した焙煎コーヒー豆を、実施例１と同様に処理して、コーヒーエキスを得た（試料Ｈ）。
【００６０】
（実施例３）
試料Ｉ
上記湿式加熱焙煎３の条件で焙煎したコーヒー豆をカッターミキサー（大阪ケミカル（株）輸入販売、オースターブレンダー）で粉砕した。粉砕した焙煎コーヒー豆を、実施例１と同様に処理して、コーヒーエキスを得た（試料Ｉ）。
【００６１】
（実施例４）
試料Ｊ
上記湿式加熱焙煎４の条件で焙煎したコーヒー豆をカッターミキサー（大阪ケミカル（株）輸入販売、オースターブレンダー）で粉砕した。粉砕した焙煎コーヒー豆を、実施例１と同様に処理して、コーヒーエキスを得た（試料Ｊ）。
【００６２】
［抽出液の評価］
実施例１〜４で得られコーヒーエキスの収率を以下の条件で測定し、その結果を表３に示す。
【００６３】
コーヒーエキスのＢｘ濃度をデジタル屈折率計にて測定し、下記式によって収率を算出した。
収率（％）＝（抽出液量（ｇ）×Ｂｘ濃度）／豆量（ｇ）
【表３】

表３より、焙煎時の温度が高いほどコーヒー固形分の収率が高い。しかし、焙煎時の温度での飽和蒸気圧に到達しない条件で得られた試料Ｈでは、収率の有意な上昇が認められず、焙煎時の温度で圧力を飽和蒸気圧まで上げることが好ましいことがわかる。
【００６４】
（実施例５）
１）湿式加熱焙煎
高温での加熱が可能な密封容器に生豆コーヒー０．４ｋｇと水３．５ｋｇを加えて密閉し、２１０℃に加熱した。その時の到達容器内圧力は１．９ＭＰａ（飽和蒸気圧）であった。その後、加熱を中止し装置内の温度が下がり、装置内の圧力が大気圧になった時点で、湿式焙煎されたコーヒー豆を取り出した。
【００６５】
２）焙煎コーヒー豆の水分量
ＡＯＡＣ９７９．１２法に準じ、恒量を測定したアルミカップに粉砕した焙煎コーヒー豆約３ｇを精秤採取し、減圧加熱乾燥器にて５ＫＰａまで減圧し、７０℃にて１６時間乾燥した。乾燥減量を算出し水分量とした。
【００６６】
試料Ｋ
上記湿式加熱焙煎後の焙煎豆と浸漬水とを分離し、浸漬水を第一抽出液とした。次に、焙煎豆をカッターミキサー（大阪ケミカル（株）輸入販売、オースターブレンダー）で粉砕した。粉砕した焙煎コーヒー豆の乾物換算１３．５ｇにヘミセルロース分解酵素（阪急バイオインダストリー（株）製、セルロシンＧＭ５、力価：１００００ｕｎｉｔｓ／ｇ）０．６ｇを加え、全量６１３．５ｇになるように４０℃のイオン交換水を加え、撹拌後、４０℃で１６時間静置反応させた。反応後のスラリーを孔径１００ｍｅｓｈのフィルターで濾液を採取し、第二抽出液とした。
【００６７】
試料Ｌ
上記試料Ｋにおいて、ヘミセルロース分解酵素をペクチン分解酵素（阪急バイオインダストリー（株）製、セルロシンＭＥ、力価：８０００ｕｎｉｔｓ／ｇ、１ｕｎｉｔは、ジャガイモ切片（ｐＨ５．０、直径１３ｍｍ、厚み２ｍｍ）を基質とし、４０℃、３時間反応で切片の直径を０．５ｍｍ減少させる酵素量）とし、１．２ｇ加えること以外は同様の処理をして、第一抽出液および第二抽出液を得た。
【００６８】
（比較例４）
上記実施例５の試料Ｋにおいて、酵素を加えないこと以外は同様の処理をして試料Ｍ（第一抽出液および第二抽出液）を得た。
【００６９】
［抽出液の評価］
実施例５および比較例４で得られコーヒーエキスの収率を以下の条件で測定し比較した。
【００７０】
コーヒーエキスのＢｘ濃度をデジタル屈折率計にて測定し、下記式によって収率を算出した。
【００７１】
収率（％）＝（抽出液量（ｇ）×Ｂｘ濃度）／豆量（ｇ）
【表４】

表４より、湿式加熱焙煎とヘミセルロース分解酵素処理または湿式加熱焙煎とペクチン分解酵素処理を組み合わせることにより、湿式加熱焙煎単独よりもコーヒー固形分の収率が高くなることが認められた。
【００７２】
（実施例６）
１）湿式加熱焙煎
高温での加熱が可能な密封容器に生豆コーヒー４００ｇと水５００ｇを加えて密閉し、２０１℃に加熱した。その時の容器内圧力は、１．５ＭＰａ（飽和蒸気圧）であった。その後、加熱を中止し装置内の温度が下がり、装置内の圧力が大気圧になった時点で、湿式焙煎されたコーヒー豆を取り出した。
湿式加熱焙煎１：加水量５００ｇ、到達温度２０１℃、到達容器内圧量１．５ＭＰａ
２）焙煎コーヒー豆の水分量
ＡＯＡＣ９７９．１２法に準じ、恒量を測定したアルミカップに粉砕した焙煎コーヒー豆約３ｇを精秤採取し、減圧加熱乾燥器にて５ＫＰａまで減圧し、７０℃にて１６時間乾燥した。乾燥減量を算出し水分量とした。
【００７３】
３）コーヒーエキスの調製
上記湿式加熱焙煎１の条件で焙煎したコーヒー豆を、カッターミキサー（大阪ケミカル（株）輸入販売、オースターブレンダー）で粉砕した。粉砕した焙煎コーヒー豆の乾燥換算２０ｇにヘミセルロース分解酵素（阪急バイオインダストリー（株）製、セルロシンＧＭ５、力価：１００００ｕｎｉｔｓ／ｇ）０．１３４ｇ、セルロース分解酵素（阪急バイオインダストリー（株）製、セルロシンＡＣ４０、力価：４０００ｕｎｉｔｓ／ｇ）０．１３４ｇおよびペクチン分解酵素（阪急バイオインダストリー（株）製、セルロシンＭＥ、力価：８０００ｕｎｉｔｓ／ｇ）０．１３４ｇを加え、全量６００ｇになるように４０℃のイオン交換水を加え、撹拌後、４０℃で１６時間静置反応させた。反応後のスラリーを孔径１００ｍｅｓｈのフィルターで濾液を採取し、コーヒーエキスとした。
【００７４】
（比較例５）
上記実施例６において、酵素を加えないこと以外は実施例６と同様にして、コーヒーエキスを得た。
【００７５】
［抽出液の評価］
実施例６および比較例５で得られコーヒーエキスの収率を以下の条件で測定し比較した。
【００７６】
コーヒーエキスのＢｘ濃度をデジタル屈折率計にて測定し、下記式によって収率を算出した。
【００７７】
収率（％）＝（抽出液量（ｇ）×Ｂｘ濃度）／豆量（ｇ）
【表５】

表５より、酵素を３種類併用した場合、無添加の比較例に比べ、収率が８．９％増加した。多糖類分解酵素の併用により、多糖類分解酵素単独使用と同等またはそれ以上の収率が得られることがわかる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a coffee extract or soluble coffee. More specifically, the present invention relates to a method for producing a coffee extract or soluble coffee for the purpose of high yield.
[0002]
[Prior art]
Generally, roasted coffee to be used for drinking is produced by heating green coffee beans to 200 ° C. to 300 ° C. by a hot air convection or direct fire type roasting machine (dry heating roasting). Roasting produces a unique heated flavor in green coffee beans by heating, and at the same time, about 8% of the water contained in the coffee beans is turned into water vapor to expand the cells and destroy the tissue, increasing the surface area of the coffee beans and increasing the solubility. Increase the solids extraction. The roasted coffee beans are pulverized to an appropriate size and extracted with hot water of 100 ° C. or lower to obtain a coffee extract. The yield of soluble solids extracted from coffee beans in this way is about 25 to 30%, and the remaining insoluble components are discarded as unused parts. It is known that most of the unused sites are plant polysaccharides such as cellulose, lignin, mannan, and arabinogalactan, which constitute cell walls and intercellular stroma, water-insoluble proteins, and oils and fats (for example, , Non-Patent Document 1).
[0003]
In the industry, to reduce these unused components as much as possible and to increase the yield of roasted coffee beans, a method to decompose cellulose, lignin, mannan, arabinogalactan, etc. constituting the cell wall and intercellular matrix is studied. It has been. Above all, the method of hydrolyzing the vegetable polysaccharide of roasted coffee beans with an enzyme to increase the yield of solids is more gentle under low temperature and atmospheric pressure than the extraction method using high-temperature and high-pressure water at 200 ° C or higher. This is advantageous because it can be performed in For example, a method for producing instant coffee by treating roasted coffee beans using purified hemicellulase is disclosed (for example, see Patent Document 1). However, of course, green beans require a large amount of enzymes in ordinary roasted coffee beans because the stacked polysaccharides prevent the invasion of enzymes and reduce the efficiency of the enzyme reaction.
[0004]
In addition, an aqueous mixture of roasted coffee beans and partially extracted roasted coffee beans is prepared, brought into contact with steam at a high temperature under pressure, and then `` steam explosion treatment '' is performed to quickly reduce the pressure to the atmospheric level. There is known a method of increasing the yield of a solid by enzymatic treatment of a slurry (for example, see Patent Document 2). However, this method requires a new steam explosion step and its equipment that are not present in a normal coffee production step, and also gives excessive heat to the coffee beans due to the steam explosion.
[0005]
[Patent Document 1]
Japanese Patent Publication No. 49-21710 [Patent Document 2]
JP-A-7-115 [Non-Patent Document 1]
"Coffee Technology", Sivets & Desrosier, AVI Publishing, 1979, p. 285.
[0006]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a method for producing a coffee extract or instant coffee that can efficiently collect coffee solids from an unused portion of roasted coffee beans.
[0007]
[Means for Solving the Problems]
Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and have found conditions under which a plant polysaccharide-degrading enzyme acts efficiently, thereby completing the present invention.
[0008]
That is, the method for producing a coffee extract of the present invention comprises the following steps: 1) filling green coffee beans and water in a sealed container capable of being heated at a high temperature, and performing wet heat roasting at a temperature exceeding 160 ° C. under pressure; 2) The obtained roasted coffee beans are ground, and one or more enzymes of a plant polysaccharide-degrading enzyme selected from the group consisting of galactomannase, mannase, cellulase and pectinase are mixed with the ground coffee beans. And 3) obtaining a coffee extract from the slurry after the enzyme reaction.
[0009]
Preferably, the method for producing a coffee extract further includes 4) a step of concentrating the coffee extract in order to produce a concentrated extract.
[0010]
In the method for producing the coffee extract, it is preferable that the wet roasting in step 1) is performed at 160 ° C to 240 ° C.
[0011]
In the method for producing a coffee extract, the wet roasting in step 1) is preferably performed at any temperature of 160 ° C. to 240 ° C. at a pressure that reaches a saturated vapor pressure at that temperature.
[0012]
The method for producing soluble coffee according to the present invention comprises the following steps: 1) filling green coffee beans and water in a sealed container capable of being heated at a high temperature, and performing wet roasting at a temperature exceeding 160 ° C. under pressure 2). The obtained roasted coffee beans are crushed, and the crushed coffee beans are mixed with one or more enzymes of a plant polysaccharide-degrading enzyme selected from the group consisting of galactomannase, mannase, cellulase and pectinase. It is characterized by including a step of performing an enzymatic reaction, 3) a step of obtaining a coffee extract from the slurry after the enzymatic reaction, and 4 ′) a step of drying the coffee extract to a soluble solid.
[0013]
In the method for producing soluble coffee, the wet roasting in step 1) is preferably performed at 160 ° C to 240 ° C.
[0014]
In the method for producing soluble coffee, the wet roasting in step 1) is preferably performed at any temperature of 160 ° C. to 240 ° C. at a pressure that reaches a saturated vapor pressure at that temperature.
[0015]
[Effects]
According to the method for producing a coffee extract of the present invention, a green coffee bean is wet-heat roasted and then allowed to act on a plant polysaccharide-decomposing enzyme, whereby the coffee extract can be extracted in a high yield without an excessive heating step. It is possible to obtain a coffee extract having a high concentration and excellent taste. According to the method for producing soluble coffee of the present invention, since the high-concentration coffee extract is used as a raw material, concentration and drying are shortened, and high-quality soluble coffee is easily obtained. Further, according to the method for producing a coffee extract or soluble coffee of the present invention, cell walls and intercellular layers of coffee beans are peeled and crushed by performing wet heating roasting under predetermined conditions, and roasting by a conventional roasting method is performed. The effect of increasing the contact area of the enzyme as compared with the roasted coffee beans, and obtaining a high-yield extract with the use amount of the enzyme corresponding to the cost is exhibited.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
The method for producing a coffee extract of the present invention includes the following steps: 1) a step of filling green coffee beans and water in a sealed container capable of heating at a high temperature and performing wet roasting at a temperature exceeding 160 ° C. under pressure 2). The obtained roasted coffee beans are crushed, and the crushed coffee beans are mixed with one or more enzymes of a plant polysaccharide-degrading enzyme selected from the group consisting of galactomannase, mannase, cellulase and pectinase. A step of performing an enzyme reaction; and 3) a step of obtaining a coffee extract from the slurry after the enzyme reaction.
[0017]
1) A process in which green coffee beans and water are filled in a sealed container capable of being heated at a high temperature, and the wet roasting is performed at a temperature exceeding 160 ° C. under pressure. The “sealed container” is a container that can be heated at 240 ° C. and at a high pressure up to about 3.4 MPa. In the present invention, it is preferable that the device does not include a pressure relief valve for forcibly reducing the high pressure in the container, or does not use it even if it does. The reason will be described later.
[0018]
The sealed container is filled with green coffee beans and water.
[0019]
The type of green coffee beans used in the present invention is not particularly limited, and examples thereof include Arabica, Robusta, and Rebellica. Beans in which a plurality of types are blended may be used.
[0020]
As the water, those usually used for extracting coffee such as ion-exchanged water and distilled water can be used.
[0021]
The amount of water to be filled can be appropriately set according to the weight of the green coffee beans and the volume of the container, and is preferably 0.5 to 12 times the weight of the green coffee beans, and 0.5 to 9 times. Double amounts are more preferred. When the amount of water is less than 0.5 times, the amount of water in the container tends to be insufficient, so that green beans tend not to be roasted uniformly. On the other hand, when the amount of water exceeds 12 times, the container Since there is no space that is filled with liquid water and becomes steam, it does not meet the roasting conditions of the present invention.
[0022]
Next, the green coffee beans are subjected to wet heat roasting at a temperature exceeding 160 ° C. under pressure.
[0023]
The heating temperature exceeds 160 ° C., but is preferably 240 ° C. or less, more preferably 180 to 210 ° C. When the heating temperature is 160 ° C. or lower, the progress and completion of roasting are not performed smoothly, and it is difficult to achieve a desired degree of roasting. On the other hand, if the heating temperature exceeds 240 ° C., the green coffee beans may be carbonized in a short time, and it is difficult to obtain good roasted coffee beans.
[0024]
The pressurizing condition during the wet heating roasting can be appropriately set according to the heating temperature. However, in order to increase the recovery rate of the coffee solids, the saturated steam at the heating temperature (160 ° C. to 240 ° C.) is required. It is preferred to carry out at a pressure that reaches the pressure. The saturated vapor pressure is set depending on the heating temperature and the type of the sealed container, and is usually in the range of 0.6 to 3.4 MPa.
[0025]
After the heating temperature reaches a predetermined value, the temperature may be maintained for a certain period of time, or the heating may be terminated immediately. The holding time can be appropriately set according to the holding temperature, and is usually 0 to 60 minutes.
[0026]
After that, it is left until the pressure at the time of heating decreases to normal pressure (atmospheric pressure). The leaving time varies depending on the sealed container and the pressure, but is about 150 to 350 minutes.
[0027]
During the standing period, roasting of the green coffee beans proceeds and is completed. Therefore, in the present invention, as described above, it is preferable not to forcibly reduce the high pressure in the container. It is also a preferable reason that all flavor components generated by roasting can be held in the container.
[0028]
After the heating, the roasted coffee beans are taken out of the container which has returned to normal pressure (atmospheric pressure).
[0029]
2) The obtained roasted coffee beans are ground, and one or more enzymes of a plant polysaccharide-degrading enzyme selected from the group consisting of galactomannase, mannase, cellulase and pectinase are mixed with the ground coffee beans. The roasted coffee beans obtained in the step 1) are subjected to an enzymatic reaction. The pulverizing method may be performed using a device and a method capable of pulverizing wet roasted coffee beans, and is not particularly limited. The degree of pulverization of the roasted coffee beans is not particularly limited, and may be set to a particle size suitable for enzymatic reaction and extraction of coffee extract.
[0030]
Next, an enzymatic reaction is carried out by mixing the plant polysaccharide-degrading enzyme with the ground coffee beans.
[0031]
The plant polysaccharide-decomposing enzyme used in the present invention is selected from known enzymes from the viewpoint of decomposing the polysaccharide contained in coffee, and includes galactomannase, mannase, cellulase and pectinase. One of the above enzymes may be used, or two or more of them may be used. The enzyme is appropriately dissolved and used in a solvent such as water. The amount of the enzyme to be added is usually about 50 to 800 units / g with respect to the dry weight of the coffee beans.
[0032]
The slurry obtained by adding the ground coffee beans, the enzyme solution, and water as appropriate is within the optimum pH of the enzyme, and the enzyme reaction can be directly performed under the following conditions.
[0033]
In the enzymatic reaction, the reaction temperature and the reaction time can be set according to the enzyme to be used, but it is usually 10 to 60 ° C. and about 0.5 to 65 hours.
[0034]
3) Step of obtaining coffee extract from slurry after enzymatic reaction Coffee is extracted in parallel during the enzymatic reaction, and after the reaction is completed, the slurry is filtered, centrifuged, etc. to separate the solid from the slurry and the coffee extract. You can get coffee extract. Alternatively, the coffee extract can be further obtained by separating the solid matter of the slurry and the coffee extract, filling the extractor with the slurry solid matter, and performing extraction with water or hot water. Alternatively, a coffee extract can be obtained by filling the extractor with the slurry after the enzymatic reaction as it is and performing extraction with water or warm water.
[0035]
The filtration or centrifugation may be performed under conditions capable of removing the solid slurry.
[0036]
Since the extraction method in this step uses a slurry that has been subjected to an enzyme treatment, it may be performed with water or hot water at 100 ° C. or lower under atmospheric pressure. By adding this extraction operation, the yield of coffee solids can be further increased.
[0037]
Examples of the use of the coffee extract include a raw material for a coffee beverage in a container and a raw material for a beverage for dilution.
[0038]
When used as a raw material for a beverage for dilution, it is preferable to further include a step of 4) concentrating the coffee extract.
[0039]
The method of concentration in this step is preferably a method of concentration while maintaining the flavor of the coffee extract, and examples thereof include concentration under reduced pressure heating, freeze concentration, and reverse osmosis membrane concentration.
[0040]
In addition, the method for producing soluble coffee of the present invention comprises the following steps: 1) filling green coffee beans and water in a sealed container capable of heating at a high temperature, and performing wet heat roasting at a temperature exceeding 160 ° C. under pressure; 2) The obtained roasted coffee beans are ground, and one or more enzymes of a plant polysaccharide-degrading enzyme selected from the group consisting of galactomannase, mannase, cellulase and pectinase are mixed with the ground coffee beans. And 3) obtaining a coffee extract from the slurry after the enzyme reaction, and 4 ′) drying the coffee extract to a soluble solid.
[0041]
In this production method, steps 1) to 3) are the same as the above-mentioned method for producing a coffee extract.
[0042]
4 ′) Step of drying the coffee extract to a soluble solid The obtained coffee extract is subjected to the above-mentioned 4) Concentration step of the coffee extract, if necessary, and then, in this step, by a conventional method such as spray drying or freeze drying. Dry to a soluble solid.
[0043]
【Example】
Hereinafter, examples and the like specifically illustrating the configuration and effects of the present invention will be described, but the present invention is not limited by these examples and the like.
[0044]
(Comparative Example 1)
[Roasted coffee beans]
Dry heat roasting was conducted with a direct fire type test roaster (probat) roaster.
[0045]
Sample A
The dry heat roasted coffee beans were pulverized by a coffee cutter (Lucky Coffee Machine Co., Ltd., Bonmac NC1105). A hemicellulose-degrading enzyme (manufactured by Hankyu Bio-Industry Co., Ltd., cellulosin GM5, titer: 10,000 units / g, 1 unit is made of locust bean gum (pH 5.0) as a substrate at 30 ° C. for 1 minute) 0.6 g of an enzyme capable of increasing the reducing power corresponding to 1 μmol of mannose) was added thereto, and the mixture was allowed to stand at 40 ° C. for 15 hours so that the total amount became 900 g. The filtrate after the reaction was collected with a filter having a pore size of 100 mesh to obtain a coffee extract (sample A).
[0046]
Sample B
In the above sample A, instead of the hemicellulose degrading enzyme, a cellulose degrading enzyme (manufactured by Hankyu Bioindustry Co., Ltd., cellulosin AC40, titer: 4000 units / g, 1 unit was obtained by using sodium carboxymethylcellulose (pH 4.2) as a substrate, A coffee extract (sample B) was obtained in the same manner as above except that 0.75 g of an enzyme which increased the reducing power equivalent to 1 μmol of glucose per minute at 0.7 ° C. was added.
[0047]
Sample C
A coffee extract (Sample C) was obtained in the same manner as in Sample A except that the enzyme was not added.
[0048]
[Evaluation of extract]
The yields of the coffee extracts of Samples A to C were determined and compared as follows. The Bx concentration of the coffee extract was measured with a digital refractometer and calculated by the following equation.
Yield (%) = (amount of extract (g) × Bx concentration) / amount of beans (g)
[Table 1]

From Table 1, it can be seen that in the case of ordinary dry hot air roasted beans, no significant improvement in yield is observed even when the enzyme treatment is carried out using hemicellulose-degrading enzyme or cellulose-degrading enzyme.
[0049]
(Example 1)
1) Wet heating roasting 400 g of green coffee and 500 g of water were added to a sealed container capable of heating at a high temperature and sealed, and heated to 201 ° C. The pressure in the vessel at that time was 1.5 MPa (saturated vapor pressure). Thereafter, when the heating was stopped and the temperature in the apparatus was lowered to a pressure in the apparatus at atmospheric pressure, the wet roasted coffee beans were taken out.
Wet heating roasting 1: 500g of water, ultimate temperature 201 ° C, ultimate pressure in container 1.5MPa
2) Moisture content of roasted coffee beans According to AOAC979.12 method, about 3 g of roasted coffee beans pulverized in an aluminum cup whose constant weight was measured was precisely weighed, and the pressure was reduced to 5 kPa with a reduced pressure heating dryer, and the temperature was reduced to 70 ° C. For 16 hours. The loss on drying was calculated and defined as the water content.
[0050]
3) Preparation of coffee extract The coffee beans roasted under the conditions of the above wet heating roasting 1 were pulverized by a cutter mixer (imported and sold by Osaka Chemical Co., Ltd., Ooster Blender). 0.4 g of hemicellulose-degrading enzyme (Cellulosin GM5, manufactured by Hankyu Bio-Industry Co., Ltd., titer: 10,000 units / g) was added to 20 g of the ground roasted coffee beans on a dry basis, and ion exchange at 40 ° C. was performed so that the total amount became 620 g. Water was added, and the mixture was stirred and allowed to stand still at 40 ° C. for 16 hours. The filtrate after the reaction was collected with a filter having a pore size of 100 mesh to obtain a coffee extract (sample D).
[0051]
(Comparative Example 2)
A coffee extract was prepared in the same manner as in Example 1 except that no hemicellulose-degrading enzyme was added (Sample E).
[0052]
(Comparative Example 3)
1) Roasting was carried out using a conventional dry heating roasting direct fire type test roaster (probat) roaster.
[0053]
2) Moisture content of roasted coffee beans According to AOAC979.12 method, about 3 g of roasted coffee beans ground into an aluminum cup whose constant weight was measured was precisely weighed, and the pressure was reduced to 5 KPa with a reduced pressure heating dryer, and the temperature was reduced to 70 ° C. For 16 hours. The loss on drying was calculated and defined as the water content.
[0054]
3) Preparation of coffee extract The coffee beans roasted in the above 1) were pulverized by a cutter mixer (Oster Blender, imported and sold by Osaka Chemical Co., Ltd.). 0.4 g of hemicellulose-degrading enzyme (Cellulosin GM5, manufactured by Hankyu Bio-Industry Co., Ltd., titer: 10,000 units / g) was added to 20 g of the ground roasted coffee beans on a dry basis, and ion exchange at 40 ° C. was performed so that the total amount became 620 g. Water was added, and the mixture was stirred and allowed to stand still at 40 ° C. for 16 hours. The filtrate after the reaction was collected with a filter having a pore size of 100 mesh to obtain a coffee extract (sample F).
[0055]
(Comparative Example 4)
A coffee extract (sample G) was obtained in the same manner as in Comparative Example 3, except that no hemicellulose-degrading enzyme was added.
[0056]
[Table 2]

From Table 2, it was confirmed that the combination of wet heat roasting and enzyme treatment increased the yield of coffee solids.
[0057]
(Example 2)
1) Wet heating roasting 0.4 kg of green coffee and 0.2 to 0.5 kg of water were added to a sealed container capable of heating at a high temperature and sealed, and heated to 220 to 184 ° C. Thereafter, when the heating was stopped and the temperature in the apparatus was lowered to a pressure in the apparatus at atmospheric pressure, the wet roasted coffee beans were taken out.
Wet heat roasting 2: 200g of water, ultimate temperature 210 ° C, internal pressure of container 0.64MPa
Wet heating roasting 3: 500 g of water, ultimate temperature 184 ° C, ultimate pressure in vessel 1.1 MPa (saturated vapor pressure)
Wet heating roasting 4: amount of water 500 g, ultimate temperature 220 ° C., internal pressure of the container 2.3 MPa (saturated vapor pressure).
[0058]
2) Moisture content of roasted coffee beans According to AOAC979.12 method, about 3 g of roasted coffee beans ground into an aluminum cup whose constant weight was measured was precisely weighed, and the pressure was reduced to 5 KPa with a reduced pressure heating dryer, and the temperature was reduced to 70 ° C. For 16 hours. The loss on drying was calculated and defined as the water content.
[0059]
Sample H
The coffee beans roasted under the condition of the wet heating roasting 2 were pulverized by a cutter mixer (Oster Blender, imported and sold by Osaka Chemical Co., Ltd.). The ground roasted coffee beans were treated in the same manner as in Example 1 to obtain a coffee extract (Sample H).
[0060]
(Example 3)
Sample I
The coffee beans roasted under the wet heating roasting conditions 3 were pulverized by a cutter mixer (Oster Blender, imported and sold by Osaka Chemical Co., Ltd.). The ground roasted coffee beans were treated in the same manner as in Example 1 to obtain a coffee extract (Sample I).
[0061]
(Example 4)
Sample J
The coffee beans roasted under the conditions of the wet heating roasting 4 were pulverized with a cutter mixer (Oster Blender, imported and sold by Osaka Chemical Co., Ltd.). The ground roasted coffee beans were treated in the same manner as in Example 1 to obtain a coffee extract (Sample J).
[0062]
[Evaluation of extract]
The yield of the coffee extract obtained in Examples 1 to 4 was measured under the following conditions, and the results are shown in Table 3.
[0063]
The Bx concentration of the coffee extract was measured with a digital refractometer, and the yield was calculated by the following equation.
Yield (%) = (amount of extract (g) × Bx concentration) / amount of beans (g)
[Table 3]

From Table 3, the higher the temperature during roasting, the higher the yield of coffee solids. However, in the sample H obtained under the condition that the saturated vapor pressure at the temperature during roasting was not reached, no significant increase in the yield was observed, and the pressure was increased to the saturated vapor pressure at the temperature during roasting. It turns out to be favorable.
[0064]
(Example 5)
1) Wet heating roasting 0.4 kg of green coffee beans and 3.5 kg of water were added to a sealed container capable of heating at a high temperature, and sealed, and heated to 210 ° C. At that time, the pressure in the attained vessel was 1.9 MPa (saturated vapor pressure). Thereafter, when the heating was stopped and the temperature in the apparatus was lowered to a pressure in the apparatus at atmospheric pressure, the wet roasted coffee beans were taken out.
[0065]
2) Moisture content of roasted coffee beans According to AOAC979.12 method, about 3 g of roasted coffee beans ground into an aluminum cup whose constant weight was measured was precisely weighed, and the pressure was reduced to 5 KPa with a reduced pressure heating dryer, and the temperature was reduced to 70 ° C. For 16 hours. The loss on drying was calculated and defined as the water content.
[0066]
Sample K
The roasted beans after the wet heat roasting and the immersion water were separated, and the immersion water was used as a first extract. Next, the roasted beans were pulverized with a cutter mixer (Osaka Chemical Co., Ltd., imported and sold, Ooster Blender). 0.6 g of hemicellulose-decomposing enzyme (manufactured by Hankyu Bio-Industry Co., Ltd., cellulosin GM5, titer: 10,000 units / g) was added to 13.5 g in terms of dry matter of the ground roasted coffee beans, so that the total amount was 40. C., ion-exchanged water was added, and the mixture was stirred and allowed to stand still at 40.degree. C. for 16 hours. The filtrate after the reaction was collected with a filter having a pore size of 100 mesh to obtain a second extract.
[0067]
Sample L
In sample K, hemicellulose-degrading enzyme was a pectin-degrading enzyme (manufactured by Hankyu Bioindustry Co., Ltd., cellulosin ME, titer: 8000 units / g, 1 unit was a potato slice (pH 5.0, diameter 13 mm, thickness 2 mm) as a substrate). At 40 ° C. for 3 hours to reduce the diameter of the section by 0.5 mm), and the same treatment was carried out except that 1.2 g was added to obtain a first extract and a second extract.
[0068]
(Comparative Example 4)
Sample M (first extract and second extract) was obtained in the same manner as in sample K of Example 5 except that no enzyme was added.
[0069]
[Evaluation of extract]
The yield of the coffee extract obtained in Example 5 and Comparative Example 4 was measured and compared under the following conditions.
[0070]
The Bx concentration of the coffee extract was measured with a digital refractometer, and the yield was calculated by the following equation.
[0071]
Yield (%) = (amount of extract (g) × Bx concentration) / amount of beans (g)
[Table 4]

From Table 4, it was confirmed that the combination of wet heat roasting and hemicellulose degrading enzyme treatment or wet heat roasting and pectin degrading enzyme treatment resulted in higher coffee solids yield than wet heat roasting alone.
[0072]
(Example 6)
1) Wet heating roasting 400 g of green coffee and 500 g of water were added to a sealed container capable of heating at a high temperature and sealed, and heated to 201 ° C. The pressure in the vessel at that time was 1.5 MPa (saturated vapor pressure). Thereafter, when the heating was stopped and the temperature in the apparatus was lowered to a pressure in the apparatus at atmospheric pressure, the wet roasted coffee beans were taken out.
Wet heating roasting 1: 500 g of water, ultimate temperature 201 ° C., internal pressure of container 1.5 MPa
2) Moisture content of roasted coffee beans According to the AOAC979.12 method, about 3 g of roasted coffee beans pulverized into an aluminum cup whose constant weight was measured was precisely weighed, and the pressure was reduced to 5 KPa with a reduced pressure heating dryer, and the temperature was reduced to 70 ° C. For 16 hours. The loss on drying was calculated and defined as the water content.
[0073]
3) Preparation of coffee extract The coffee beans roasted under the conditions of the wet heating roasting 1 were pulverized by a cutter mixer (Oster Blender, imported and sold by Osaka Chemical Co., Ltd.). 0.134 g of hemicellulose-degrading enzyme (manufactured by Hankyu Bio-Industry Co., Ltd., cellulosin GM5, titer: 10,000 units / g) and cellulose degrading enzyme (manufactured by Hankyu Bio-Industry Co., Ltd., 20 g) 0.134 g of AC40, titer: 4000 units / g) and 0.134 g of pectin-degrading enzyme (Cellulosin ME, manufactured by Hankyu Bio Industries Co., Ltd., titer: 8000 units / g) were added at 40 ° C. so that the total amount was 600 g. Ion-exchanged water was added, and the mixture was stirred and allowed to stand still at 40 ° C. for 16 hours. The filtrate after the reaction was collected with a filter having a pore size of 100 mesh to obtain a coffee extract.
[0074]
(Comparative Example 5)
A coffee extract was obtained in the same manner as in Example 6 except that the enzyme was not added.
[0075]
[Evaluation of extract]
The yield of the coffee extract obtained in Example 6 and Comparative Example 5 was measured and compared under the following conditions.
[0076]
The Bx concentration of the coffee extract was measured with a digital refractometer, and the yield was calculated by the following equation.
[0077]
Yield (%) = (amount of extract (g) × Bx concentration) / amount of beans (g)
[Table 5]

As shown in Table 5, when three kinds of enzymes were used in combination, the yield increased by 8.9% as compared with the comparative example without addition. It can be seen that the combined use of the polysaccharide-degrading enzyme can provide a yield equivalent to or higher than that of the polysaccharide-degrading enzyme used alone.

Claims

1) A step of filling green coffee beans and water in a sealed container capable of being heated at a high temperature, and performing wet heat roasting at a temperature exceeding 160 ° C. under pressure, and 2) crushing the obtained roasted coffee beans. Mixing the ground coffee beans with one or more enzymes of a plant polysaccharide-degrading enzyme selected from the group consisting of galactomannase, mannase, cellulase and pectinase to carry out an enzymatic reaction; and 3) enzyme A method for producing a coffee extract, comprising a step of obtaining a coffee extract from the slurry after the reaction.

The method according to claim 1, further comprising the step of: 4) concentrating the coffee extract.

The method according to claim 1, wherein the wet roasting in step 1) is performed at 160 ° C. to 240 ° C. 4.

The method according to claim 3, wherein the wet roasting in step 1) is carried out at any temperature of 160C to 240C at a pressure that reaches the saturated vapor pressure at that temperature.

1) A step of filling green coffee beans and water in a sealed container capable of being heated at a high temperature, and performing wet heat roasting at a temperature exceeding 160 ° C. under pressure, and 2) crushing the obtained roasted coffee beans. Performing an enzymatic reaction by mixing one or more enzymes of a plant polysaccharide degrading enzyme selected from the group consisting of galactomannase, mannase, cellulase and pectinase with the ground coffee beans; 3) enzymatic reaction A method for producing a soluble coffee, comprising a step of obtaining a coffee extract from the subsequent slurry and a step of 4 ′) drying the coffee extract to a soluble solid.

The method according to claim 5, wherein the wet roasting in step 1) is performed at 160C to 240C.

The method according to claim 6, wherein the wet roasting in step 1) is carried out at any temperature between 160C and 240C at a pressure that reaches the saturated vapor pressure at that temperature.