JP2004331917A

JP2004331917A - Method of manufacturing fatty acids

Info

Publication number: JP2004331917A
Application number: JP2003133245A
Authority: JP
Inventors: Hideo Tawara; 秀雄田原; Kaoru Omae; 薫大前; Minoru Kase; 実加瀬
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2003-05-12
Filing date: 2003-05-12
Publication date: 2004-11-25
Anticipated expiration: 2023-05-12
Also published as: JP4261978B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of fractionating saturated and unsaturated fatty acids in raw fatty acids easily and efficiently in a natural manner. <P>SOLUTION: The method comprises mixing raw fatty acids with a polyglycerol fatty acid ester and cooling the mixture to crystalize so as to fractionate saturated and unsaturated fatty acids and is characterized by adding the ester in divided parts at two or more points through the entire process. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、脂肪酸混合物から飽和脂肪酸と不飽和脂肪酸とを自然分別法により効率良く分離する方法に関する。
【０００２】
【従来の技術】
脂肪酸類は、モノグリセリド、ジグリセリド等の食品の中間原料や、その他各種の工業製品の添加剤、中間原料として広く利用されている。かかる脂肪酸類は、一般に、菜種油、大豆油等の植物油や牛脂等の動物油を高圧法や酵素分解法により加水分解することにより製造されている。
【０００３】
ところが、上記のように動植物油を単に加水分解して製造された脂肪酸類は、不飽和脂肪酸と飽和脂肪酸の混合物であって、そのままの脂肪酸組成では産業上の素原料として必ずしも好適なものではない。すなわち、利用の目的によって、不飽和脂肪酸と飽和脂肪酸に分別することが必要となる。
【０００４】
一般に、脂肪酸類の分別には、溶剤分別法、湿潤剤分別法が採用されているが、これらの方法は分離効率（収率）は高いものの、設備投資、溶剤や湿潤剤水溶液の回収等のランニングコストがかかるという問題を有している。これに対し、溶剤を使用しない自然分別法（無溶剤分別法）は、安価な分別法であり、従来、同分別法の問題点とされていた濾過速度の低下等についても、ポリグリセリン脂肪酸エステル等の乳化剤を使用することにより解決が図られている（特許文献１参照）。
【０００５】
【特許文献１】
特開平１１−１０６７８２号
【０００６】
【発明が解決しようとする課題】
しかしながら、ポリグリセリン脂肪酸エステルを用いる自然分別法によっても、予め分別対象である原料脂肪酸類に全量溶解させる方法では、原料脂肪酸の種類によっては大きな結晶のほかに微小結晶が生成し濾過効率が低くなることが明らかとなった。
従って、本発明の目的は、ポリグリセリン脂肪酸エステルの添加時期、及び種類をコントロールすることによりサイクルタイムの短縮、濾過効率、品質、収率の向上した、ポリグリセリン脂肪酸エステルを用いた脂肪酸類の自然分別法を提供することにある。
【０００７】
【課題を解決するための手段】
本発明者は、種々検討したところ、ポリグリセリン脂肪酸エステルの添加時期については、冷却工程において最適な時期があり、また添加するポリグリセリン脂肪酸エステルの種類についても、原料脂肪酸の種類や、冷却工程中の温度によって最適なものがあることが判明した。そこで、冷却工程中の飽和脂肪酸濃度に合わせ、最適なポリグリセリン脂肪酸エステルを分割又は連続して添加すると、原料脂肪酸類中の飽和脂肪酸の結晶が大きく成長し、微細結晶の生成を抑制し、濾過効率が顕著に向上することから、飽和脂肪酸と不飽和脂肪酸が効率良く分別できることを見出した。
特に、本発明を用いることにより、デカグリセリンエステルなど重合度の高いポリグリセリン脂肪酸エステルのみならず、これまで、脂肪酸の自然分別用添加剤としてろ過容易な結晶状態を得ることが困難であった低重合度のポリグリセリン脂肪酸エステルを用いても、工業的に自然分別を行うことが可能となった。
【０００８】
すなわち、本発明は、原料脂肪酸類にポリグリセリン脂肪酸エステルを添加混合し、冷却することにより結晶を析出させて、飽和脂肪酸類と不飽和脂肪酸類を分別する方法であって、ポリグリセリン脂肪酸エステルを全工程中において２以上の時点で分割して添加する飽和脂肪酸類と不飽和脂肪酸類の製造法を提供するものである。
また、本発明は、原料脂肪酸類にポリグリセリン脂肪酸エステルを添加混合し、冷却することにより結晶を析出させて、飽和脂肪酸類と不飽和脂肪酸類を分別する方法であって、ポリグリセリン脂肪酸エステルを全工程中において連続して添加する飽和脂肪酸類と不飽和脂肪酸類の製造法を提供するものである。
【０００９】
【発明の実施の形態】
本発明において、「自然分別法」とは、処理対象の原料脂肪酸類を、分相する量の水を含まず、かつ溶剤を使用せず、必要に応じ撹拌しながら冷却し、析出した固体成分を濾過、遠心分離、沈降分離等することにより固−液分離を行う方法をいう。「脂肪酸組成」、「飽和脂肪酸比率」とは、ガスクロマトグラフィーにより測定した値をいい、「透明融点」とは、基準油脂分析法（２．２．４．１−１９９６）により測定した値をいう。
【００１０】
本発明において、飽和脂肪酸と不飽和脂肪酸の分別の対象となる原料脂肪酸類は、菜種油、大豆油等の植物油や牛脂等の動物油を、水蒸気分解法による加水分解や、リパーゼを触媒として加水分解等することにより製造される。本発明の方法は、原料脂肪酸類中の脂肪酸の量が５０質量％以上、特に８５質量％以上であるような場合により有効であり、部分グリセリドが存在していてもよい。また、この原料脂肪酸類としては、脂肪酸組成中のパルミチン酸、ステアリン酸等の飽和脂肪酸（Ｃ１２〜Ｃ２２）の比率が、５〜６０質量％、特に８〜５０質量％のものが好ましい。例えば大豆油、パーム油等の植物油由来の脂肪酸を用いることができる。
【００１１】
本発明で用いられるポリグリセリン脂肪酸エステルの由来は限定されず、天然物由来のポリグリセリンと脂肪酸とのエステル化反応により得られたもの、及びグリシドール、エピクロルヒドリン等を重合して得られる合成系ポリグリセリンと脂肪酸とのエステル化反応により得られたもののいずれでもよい。ポリグリセリン脂肪酸エステルにおけるポリグリセリンの平均重合度は、濾過容易な結晶状態を得る点から大きい方が好ましく、好ましくは３以上、特に４以上が好ましい。また、ポリグリセリンと反応させる脂肪酸は、濾過容易な結晶状態を得る点から、炭素数１０〜２２、特に炭素数１２〜１８の飽和又は不飽和の脂肪酸から構成されることが好ましい。当該脂肪酸は、単一の脂肪酸で構成されていてもよいが、炭素数が異なるもの、又は不飽和脂肪酸と飽和脂肪酸の混合脂肪酸で構成されている場合が特に濾過容易な結晶状態を得る点から好ましい。ポリグリセリンと脂肪酸とのエステル化反応は、これらの混合物に水酸化ナトリウム等のアルカリ触媒を添加し、窒素等の不活性ガス気流下、２００〜２６０℃で直接エステル化させる方法、酵素を使用する方法等のいずれの方法によってもよい。
【００１２】
上記ポリグリセリン脂肪酸エステルは、２種以上を併用してもよく、またその全添加量は、原料脂肪酸類に対して０．００１〜５質量％、特に０．０５〜１質量％程度が好ましい。
【００１３】
本発明では、上記の如く、原料脂肪酸類に添加剤としてポリグリセリン脂肪酸エステルを全工程中において２以上の時点で分割して添加混合して、冷却して結晶を析出させ、液体部と結晶部とを分別することにより、効率よく飽和脂肪酸と不飽和脂肪酸を製造する。なお、ここで液体部は不飽和脂肪酸を多く含む部分であり、結晶部は飽和脂肪酸を多く含む部分である。当該ポリグリセリン脂肪酸エステルの一部を原料脂肪酸類に予め添加混合する場合は、完全に溶解できるように、ポリグリセリン脂肪酸エステルの透明融点より高い温度で混合溶解することが好ましい。
【００１４】
ポリグリセリン脂肪酸エステルを一部分割添加する時期は、分別対象である原料脂肪酸類の種類により、全工程中から適宜選択するが、最初に一部添加する時期は、原料脂肪酸中の飽和脂肪酸の結晶析出開始前とすることが好ましい。例えば、飽和脂肪酸の割合が多く、高い温度から結晶化が始まる原料脂肪酸類であれば、冷却工程のより高い温度の時点において、まず一部添加することが好ましく、冷却開始前に予め原料脂肪酸類に添加混合しておくことが特に好ましい。
【００１５】
一部分割添加するポリグリセリン脂肪酸エステルの種類は、分別対象である原料脂肪酸類中（結晶析出中にあっては、その液体部中）の飽和脂肪酸（Ｃ１２〜Ｃ２２）比率（質量％）をｘ、ポリグリセリン脂肪酸エステルの透明融点（℃）をｙとしたときに、０．３８ｘ＋１３≦ｙ≦０．５４ｘ＋４４で表される透明融点を有するポリグリセリン脂肪酸エステルを用いることが好ましい。またｙは、より好ましくは０．３８ｘ＋１９≦ｙ≦０．５４ｘ＋４０であり、特に０．３８ｘ＋２８≦ｙ≦０．５４ｘ＋３６が好ましい。また、その透明融点が、予め原料脂肪酸類に添加混合したもの、又はそれ以前に一部分割添加したものの透明融点よりも低いものであることが好ましい。これは、濾過容易な状態に結晶を成長させるため、冷却工程中のどの時点においても、結晶化する脂肪酸に合わせて、ポリグリセリン脂肪酸エステルを有効な状態で系内に存在させる必要があるからである。
【００１６】
脂肪酸の結晶化の過程において、ポリグリセリン脂肪酸エステルが系内に存在することにより、濾過容易な結晶状態となるのは、核発生を抑制し、この抑制効果が結晶の形状に影響を及ぼすためと思われる。結晶化がある程度進行し、ある程度の結晶が生成している状態において、新たな核の発生が抑制されると、微細結晶の生成が少なく、結晶が大きく成長するからである。
【００１７】
即ち、融解した原料脂肪酸類を冷却していくと、ある温度で脂肪酸の結晶化が開始するが、この際に、濾過容易な結晶状態とするのに有効なポリグリセリン脂肪酸エステルも同時に結晶化を開始するため、その後にそれよりも低温度で結晶化する脂肪酸に対しては、原料脂肪酸類に対するポリグリセリン脂肪酸エステルの濃度が低下するため有効に作用しない場合がある。すると、結晶化がある程度進行し、ある程度の結晶が生成している状態において、新たな核の発生が抑制されず、微細結晶が多くなり好ましくない。
【００１８】
そこで、脂肪酸の結晶化段階に合わせて、各々の温度で最適なポリグリセリン脂肪酸エステルを、微細結晶が発生する前に段階的に分割して添加していくのが好ましい。このうち、一部分割添加の１回目を結晶析出開始前、好ましくは冷却前とし、２回目以降を冷却工程中とすることが好ましい。各添加は、１回目に全添加量の１０〜９０質量％、２回目以降にその残余である９０〜１０質量％を分割して添加することが好ましい。分割添加の回数が増加するときは、ポリグリセリン脂肪酸エステルを９０〜１０質量％の範囲で適宜配分するのが好ましい。一部分割添加の回数は、２〜６回が好ましく、２〜４回が特に好ましいが、原料脂肪酸類の飽和脂肪酸含有量が多いほど、回数を多くすることが好ましい。また、添加後のポリグリセリン脂肪酸エステルが、分別対象である脂肪酸の液体部に均一混合することが好ましく、よって、ポリグリセリン脂肪酸エステルが結晶状態であれば、予め添加する時点の系内温度において液体である脂肪酸に溶解しておいたものを添加することが好ましい。
【００１９】
更に、冷却工程中、系内の液体部中の飽和脂肪酸の過飽和率が６０％以上となった時点で、ポリグリセリン脂肪酸エステルを一部分割添加することが好ましい。過飽和率が６０％以上となると新たな結晶核が生成し易いため、当該時点で添加することが、濾過容易な結晶状態とするのに好ましいからである。また、過飽和率が６０％以上では冷却速度を４℃／ｈ以下に制御することが好ましい。過飽和率とは、式（１）で算出した値であり、ある温度（ｔと略す）での濃度（Ｃと略す）を、準安定域内で０〜１００％になるように示した値である。
【００２０】
【数１】

【００２１】
溶解度（Ｃｓと略す）、過溶解度（Ｃｕと略す）及び、準安定域の定義は、改訂五版化学工学便覧（丸善株式会社発刊）Ｐ．４３４に示す。濃度とは液体部の飽和脂肪酸比率（Ｃ１２〜Ｃ２２）をいう。ある温度（ｔと略す）で濃度（Ｃと略す）が、過溶解度（Ｃｕと略す）と等しい場合過飽和率が１００％、溶解度（Ｃｓと略す）と等しい場合過飽和率が０％となる。
【００２２】
結晶化を速やかに行わせるためには、速やかに冷却し過飽和率を１００％となるように設定すればよいが、冷却が速すぎると結晶成長が十分でないため結晶が微細となり濾過効率が悪化する。一方、過飽和率が０％では、結晶析出がおこらない。本発明では、速やかに分別操作を行うため、過飽和率がなるべく高い条件下で冷却工程を行うことが好ましいが、濾過効率の良い大きな結晶を生成し微細結晶の生成を抑制させる点、及び品質、収率の両者から、冷却操作を過飽和率が６０％以上では冷却速度を４℃／ｈ以下に制御し、当該時点でポリグリセリン脂肪酸エステルを一部分割添加することが好ましい。また、平均結晶粒径は、１００μｍ以上、特に２００μｍ以上とすることが好ましい。
【００２３】
また、本発明においては、ポリグリセリン脂肪酸エステルを分別の全工程中において、連続して添加することも可能である。この場合は、最初に添加する時期は、分割添加の場合と同様に、原料脂肪酸中の飽和脂肪酸の結晶析出開始前とすることが好ましく、冷却開始前に予め原料脂肪酸類に添加混合しておくことが特に好ましい。そして、冷却工程中において、添加する時点の系内温度において液体である脂肪酸に溶解したものを連続して系内に移送し、また系内の温度に合わせてポリグリセリン脂肪酸エステル、及びこれを溶解する脂肪酸を連続的に切り替えながら添加することが好ましい。なお、製造工程の簡略化の点から、工程中連続して添加するよりは、分割して添加することが好ましい。
【００２４】
また、濾過効率の良い大きな結晶を生成し微細結晶の生成を抑制させる点から冷却の間、撹拌するのが好ましく、撹拌速度は撹拌翼を１０〜２００ｒ／ｍｉｎで回転させるのがより好ましい。
【００２５】
生成した結晶の分離法としては、濾過方式、遠心分離方式、沈降分離方式等が適用でき、回分式処理でも連続式処理でもよい。
【００２６】
【実施例】
以下の実施例において、脂肪酸組成、飽和脂肪酸比率は、ガスクロマトグラフィーにより測定した。脂肪酸の透明融点は、基準油脂分析法（２．２．４．１−１９９６）により測定した。
【００２７】
〔原料脂肪酸の調製〕
表１に示す油脂を常法により加水分解し、原料脂肪酸を調製した。使用した脂肪酸の脂肪酸組成、飽和脂肪酸比率（質量％）、脂肪酸濃度を表１に示す。
【００２８】
【表１】

【００２９】
実施例１
１Ｌビーカーにアンカー翼を取り付けた分別槽を用い、分別原料として表１に示す大豆脂肪酸を５００ｇ、結晶調整剤として表２に示すＰＧＥ１を１．０ｇ加え、７０℃で均一に溶解する。次いで、５５ｒ／ｍｉｎで撹拌しつつ、４℃／ｈで冷却し３０℃から４℃／ｈで冷却した。飽和脂肪酸濃度が４％の液体部脂肪酸５０ｇに表２に示すＰＧＥ２を０．５ｇ溶解して３０℃に調整しておいた。これを、冷却途中の１０℃の時点において加えた。−５℃まで冷却後１時間熟成した。次いで、ナイロン製濾布ＮＹ１２６０ＮＬＫ（三菱化工機（株））（濾過面積６．２ｃｍ^２）を用い０．０３ＭＰａで加圧濾過して液体部（不飽和脂肪酸）と固体部（結晶部；飽和脂肪酸）に分別した。１１０ｍＬの濾液を得るために必要な濾過時間、液体部の収率及び液体部と固体部の脂肪酸組成（Ｃ１２〜Ｃ２２飽和脂肪酸の比率）を測定した結果を表４（分別条件Ｎｏ１）に示す。
【００３０】
実施例２
２Ｌビーカーにアンカー翼を取り付けた分別槽を用い、分別原料として表１に示す大豆脂肪酸を１０００ｇ、結晶調整剤として表３に示すＰＧＥ３を１．５ｇ加え、８０℃で均一に溶解する。次いで、５０ｒ／ｍｉｎで撹拌しつつ、５℃／ｈで冷却し３０℃から２℃／ｈで冷却した。飽和脂肪酸濃度が４％の液体部脂肪酸１００ｇに表３に示すＰＧＥ４を０．５ｇ溶解して１０℃に調整しておいた。これを、冷却途中の１０℃の時点において加えた。この時点の過飽和率は６０％以上である。−６℃まで冷却後３時間熟成した。次いで、ナイロン製濾布ＮＹ１２６０ＮＬＫ（三菱化工機（株））（濾過面積３９ｃｍ^２）を用い０．０３ＭＰａで加圧濾過して液体部（不飽和脂肪酸）と固体部（結晶部；飽和脂肪酸）に分別した。５００ｍＬの濾液を得るために必要な濾過時間、液体部の収率及び液体部と固体部の脂肪酸組成（Ｃ１２〜Ｃ２２飽和脂肪酸の比率）を測定した結果を表４（分別条件Ｎｏ２）に示す。
【００３１】
実施例３
２Ｌビーカーにアンカー翼を取り付けた分別槽を用い、分別原料として表１に示すパーム脂肪酸１０００ｇ、結晶調整剤として表３に示すＰＧＥ５を２ｇ加え、８０℃で均一に溶解する。次いで、５０ｒ／ｍｉｎで撹拌しつつ、５℃／ｈで冷却し５０℃から２℃／ｈで冷却した。飽和脂肪酸濃度が１０％の液体部脂肪酸１００ｇに表３に示すＰＧＥ６を１ｇ溶解して３５℃に調整しておいた。これを、冷却途中の３５℃の時点において加えた。この時点の過飽和率は６０％以上である。飽和脂肪酸濃度が１０％の液体部脂肪酸１００ｇに表３に示すＰＧＥ７を１ｇ溶解して２８℃に調整しておいた。これを、冷却途中の２８℃の時点において加えた。この時点の過飽和率は６０％以上である。２５℃まで冷却後１時間熟成した。次いで、実施例２と同じ条件で加圧濾過し、分別した。結果を表４（分別条件Ｎｏ３）に示す。
【００３２】
比較例１
実施例１で使用した分別槽を用い、大豆脂肪酸５００ｇ、結晶調整剤として表２に示すＰＧＥ１を１．０ｇとＰＧＥ２を０．５ｇ加え、７０℃で均一に溶解する。次いで、５５ｒ／ｍｉｎで撹拌しつつ、３０℃から４℃／ｈで冷却し−５℃まで冷却後１時間熟成した。次いで、実施例１と同じ条件で加圧濾過し、分別した。結果を表５（分別条件Ｎｏ４）に示す。
【００３３】
比較例２
実施例２で使用した分別槽を用い、大豆脂肪酸１０００ｇ、結晶調整剤として表３に示すＰＧＥ３を１．５ｇとＰＧＥ４を０．５ｇ加え、８０℃で均一に溶解する。次いで、５０ｒ／ｍｉｎで撹拌しつつ、５℃／ｈで冷却し３０℃から２℃／ｈで冷却し−６℃まで冷却後３時間熟成した。次いで、実施例２と同じ条件で加圧濾過し、分別した。結果を表５（分別条件Ｎｏ５）に示す。
【００３４】
比較例３
実施例２で使用した分別槽を用い、パーム脂肪酸１０００ｇ、結晶調整剤として表３に示すＰＧＥ５を２ｇ、ＰＧＥ６とＰＧＥ７をそれぞれ１ｇ加え、８０℃で均一に溶解する。次いで、５０ｒ／ｍｉｎで撹拌しつつ、５℃／ｈで冷却し５０℃から２℃／ｈで冷却し２５℃まで冷却後１時間熟成した。次いで、実施例２と同じ条件で加圧濾過し、分別した。結果を表５（分別条件Ｎｏ６）に示す。
【００３５】
【表２】

【００３６】
【表３】

【００３７】
【表４】

【００３８】
【表５】

【００３９】
表４及び表５における分別条件１と４、分別条件２と５、分別条件３と６の対比から明らかなように、ポリグリセリン脂肪酸エステルを分割添加した場合は、飽和脂肪酸の結晶が大きく成長し、微細結晶の生成を抑制するため、より短時間で効率的に飽和脂肪酸と不飽和脂肪酸が自然分別できることがわかる。
【００４０】
【発明の効果】
本発明によれば、原料脂肪酸中の飽和脂肪酸と不飽和脂肪酸とを、効率良く自然分別することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for efficiently separating a saturated fatty acid and an unsaturated fatty acid from a fatty acid mixture by a natural fractionation method.
[0002]
[Prior art]
Fatty acids are widely used as intermediate raw materials for foods such as monoglyceride and diglyceride, additives for various industrial products, and intermediate raw materials. Such fatty acids are generally produced by hydrolyzing vegetable oils such as rapeseed oil and soybean oil and animal oils such as beef tallow by a high pressure method or an enzymatic decomposition method.
[0003]
However, the fatty acids produced by simply hydrolyzing animal and vegetable oils as described above are a mixture of unsaturated fatty acids and saturated fatty acids, and the fatty acid composition as it is is not necessarily suitable as an industrial raw material. . That is, it is necessary to separate unsaturated fatty acids and saturated fatty acids depending on the purpose of use.
[0004]
In general, for the separation of fatty acids, a solvent separation method and a wetting agent separation method are employed. These methods have high separation efficiency (yield), but require equipment investment, recovery of a solvent or an aqueous solution of a wetting agent, and the like. There is a problem that running costs are high. On the other hand, the natural fractionation method using no solvent (solvent-free fractionation method) is an inexpensive fractionation method, and the polyglycerol fatty acid ester is used to reduce the filtration speed, which has been a problem of the conventional fractionation method. A solution has been achieved by using an emulsifier such as that described above (see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-11-106782 [0006]
[Problems to be solved by the invention]
However, even in the natural fractionation method using polyglycerin fatty acid ester, in the method of dissolving the whole amount in advance in the raw material fatty acids to be separated, depending on the type of the raw material fatty acid, fine crystals are generated in addition to large crystals, and the filtration efficiency is reduced. It became clear.
Therefore, an object of the present invention is to reduce the cycle time, improve the filtration efficiency, the quality and the yield by controlling the timing and type of polyglycerin fatty acid ester to be added. To provide a classification method.
[0007]
[Means for Solving the Problems]
The present inventor has made various studies and found that there is an optimum time in the cooling step for the addition time of the polyglycerin fatty acid ester, and also about the kind of the polyglycerin fatty acid ester to be added, the kind of the raw material fatty acid and during the cooling step. It has been found that there is an optimum one depending on the temperature of the glass. Therefore, when the optimal polyglycerin fatty acid ester is divided or continuously added in accordance with the saturated fatty acid concentration during the cooling step, crystals of the saturated fatty acid in the raw material fatty acids grow large, suppressing the generation of fine crystals, and filtering. Since the efficiency is remarkably improved, it has been found that the saturated fatty acid and the unsaturated fatty acid can be efficiently separated.
In particular, by using the present invention, not only polyglycerol fatty acid esters having a high degree of polymerization, such as decaglycerin ester, but also it has been difficult to obtain a crystalline state that is easy to filter as an additive for natural separation of fatty acids. Even if a polyglycerin fatty acid ester having a degree of polymerization is used, natural separation can be performed industrially.
[0008]
That is, the present invention is a method of adding and mixing a polyglycerin fatty acid ester to a raw material fatty acid, precipitating crystals by cooling, and separating a saturated fatty acid and an unsaturated fatty acid. An object of the present invention is to provide a method for producing saturated fatty acids and unsaturated fatty acids which are added at two or more points during the entire process.
Further, the present invention is a method of adding and mixing a polyglycerin fatty acid ester to a raw material fatty acid, precipitating crystals by cooling, and separating a saturated fatty acid and an unsaturated fatty acid. An object of the present invention is to provide a method for producing saturated fatty acids and unsaturated fatty acids which are continuously added during all steps.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
In the present invention, the "natural fractionation method" means that the raw fatty acids to be treated do not contain the amount of water to be subjected to phase separation, and do not use a solvent. Is subjected to solid-liquid separation by filtration, centrifugation, sedimentation and the like. "Fatty acid composition" and "saturated fatty acid ratio" refer to values measured by gas chromatography, and "transparent melting point" refers to a value measured by a standard fat and oil analysis method (2.2.4.1-1996). Say.
[0010]
In the present invention, raw fatty acids to be separated from saturated fatty acids and unsaturated fatty acids include vegetable oils such as rapeseed oil and soybean oil, and animal oils such as beef tallow, which are hydrolyzed by a steam cracking method, or hydrolyzed using a lipase as a catalyst. It is manufactured by doing. The method of the present invention is more effective when the amount of fatty acids in the raw fatty acids is 50% by mass or more, particularly 85% by mass or more, and partial glycerides may be present. The raw fatty acids preferably have a proportion of saturated fatty acids (C12 to C22) such as palmitic acid and stearic acid in the fatty acid composition of 5 to 60% by mass, particularly 8 to 50% by mass. For example, fatty acids derived from vegetable oils such as soybean oil and palm oil can be used.
[0011]
The origin of the polyglycerin fatty acid ester used in the present invention is not limited, and is obtained by esterification reaction between a naturally occurring polyglycerin and a fatty acid, and a synthetic polyglycerin obtained by polymerizing glycidol, epichlorohydrin and the like. Any of those obtained by an esterification reaction of a fatty acid with a fatty acid may be used. The average degree of polymerization of polyglycerin in the polyglycerin fatty acid ester is preferably large from the viewpoint of obtaining a crystalline state that can be easily filtered, and is preferably 3 or more, particularly preferably 4 or more. In addition, the fatty acid to be reacted with polyglycerin is preferably composed of a saturated or unsaturated fatty acid having 10 to 22 carbon atoms, particularly 12 to 18 carbon atoms, from the viewpoint of obtaining a crystalline state that can be easily filtered. The fatty acid may be composed of a single fatty acid, but is preferably composed of a fatty acid having a different number of carbon atoms or a mixed fatty acid of an unsaturated fatty acid and a saturated fatty acid. preferable. For the esterification reaction between polyglycerin and a fatty acid, a method in which an alkali catalyst such as sodium hydroxide is added to the mixture and esterification is performed directly at 200 to 260 ° C. under an inert gas stream such as nitrogen, using an enzyme. Any method such as a method may be used.
[0012]
Two or more polyglycerin fatty acid esters may be used in combination, and the total amount thereof is preferably about 0.001 to 5% by mass, particularly preferably about 0.05 to 1% by mass, based on the raw material fatty acids.
[0013]
In the present invention, as described above, a polyglycerin fatty acid ester as an additive is added to the raw material fatty acids as an additive at two or more points during the entire process, and the mixture is added and mixed, and cooled to precipitate crystals. And thereby efficiently producing saturated fatty acids and unsaturated fatty acids. Here, the liquid part is a part containing a large amount of unsaturated fatty acids, and the crystal part is a part containing a large amount of saturated fatty acids. When a part of the polyglycerin fatty acid ester is previously added to and mixed with the raw material fatty acids, it is preferable that the polyglycerin fatty acid ester be mixed and dissolved at a temperature higher than the transparent melting point of the polyglycerin fatty acid ester so as to be completely dissolved.
[0014]
The timing of partial addition of the polyglycerin fatty acid ester is appropriately selected during the entire process depending on the type of raw material fatty acids to be separated. Preferably before the start. For example, if the raw material fatty acids have a high ratio of saturated fatty acids and the crystallization starts from a high temperature, it is preferable to first add a part of the raw fatty acids at a higher temperature of the cooling step, and before starting the cooling, It is particularly preferable to add and mix them.
[0015]
The kind of the polyglycerin fatty acid ester to be partially added is x, the saturated fatty acid (C12-C22) ratio (% by mass) in the raw material fatty acids to be separated (in the liquid part during the crystal precipitation), When the transparent melting point (° C.) of the polyglycerin fatty acid ester is y, it is preferable to use a polyglycerin fatty acid ester having a transparent melting point represented by 0.38x + 13 ≦ y ≦ 0.54x + 44. Further, y is more preferably 0.38x + 19 ≦ y ≦ 0.54x + 40, and particularly preferably 0.38x + 28 ≦ y ≦ 0.54x + 36. Further, it is preferable that the transparent melting point is lower than the transparent melting point of a material which is previously added to and mixed with the raw material fatty acids, or which is partially added before that. This is because, at any point during the cooling step, the polyglycerin fatty acid ester must be present in the system in an effective state in accordance with the fatty acid to be crystallized in order to grow the crystal in an easily filtered state. is there.
[0016]
In the process of fatty acid crystallization, the presence of polyglycerol fatty acid ester in the system results in a crystalline state that is easily filtered because nucleation is suppressed and this suppressing effect affects the shape of the crystal. Seem. This is because, in a state where crystallization has progressed to some extent and a certain amount of crystals have been generated, if the generation of new nuclei is suppressed, the generation of fine crystals is small and the crystals grow large.
[0017]
That is, as the melted raw fatty acids are cooled, the crystallization of the fatty acids starts at a certain temperature. At this time, the polyglycerin fatty acid ester, which is effective for making the crystalline state easy to filter, also crystallizes. In order to start, fatty acids that crystallize at a lower temperature thereafter may not act effectively because the concentration of polyglycerol fatty acid ester with respect to the raw material fatty acids decreases. Then, in a state where crystallization has progressed to some extent and some crystals have been generated, generation of new nuclei is not suppressed, and the number of fine crystals increases, which is not preferable.
[0018]
Therefore, it is preferable to add the polyglycerin fatty acid ester which is optimal at each temperature stepwise before the generation of fine crystals in accordance with the crystallization stage of the fatty acid. Of these, it is preferable that the first partial addition is before the start of crystal precipitation, preferably before cooling, and the second and subsequent times are during the cooling step. In each addition, it is preferable to add 10 to 90% by mass of the total addition amount in the first time, and to add the remaining 90 to 10% by mass in the second and subsequent times. When the number of divided additions increases, it is preferable to appropriately distribute the polyglycerol fatty acid ester in the range of 90 to 10% by mass. The number of times of the partial addition is preferably 2 to 6 times, particularly preferably 2 to 4 times, but it is preferable to increase the number as the saturated fatty acid content of the raw material fatty acids increases. Further, it is preferable that the polyglycerin fatty acid ester after addition is uniformly mixed with the liquid portion of the fatty acid to be separated, and therefore, if the polyglycerin fatty acid ester is in a crystalline state, the liquid is preliminarily added at the system temperature at the time of addition. It is preferable to add those dissolved in the fatty acid which is as follows.
[0019]
Further, during the cooling step, when the supersaturation rate of the saturated fatty acid in the liquid portion in the system becomes 60% or more, it is preferable to add the polyglycerin fatty acid ester in part. If the supersaturation ratio is 60% or more, new crystal nuclei are likely to be generated, and it is preferable to add them at that time to obtain a crystalline state that can be easily filtered. When the supersaturation rate is 60% or more, it is preferable to control the cooling rate to 4 ° C./h or less. The supersaturation rate is a value calculated by the equation (1), and is a value indicating a concentration (abbreviated as C) at a certain temperature (abbreviated as t) so as to be 0 to 100% within a metastable region. .
[0020]
(Equation 1)

[0021]
The definitions of solubility (abbreviated as Cs), supersolubility (abbreviated as Cu), and metastable region are described in Chemical Engineering Handbook, Revised 5th Edition (published by Maruzen Co., Ltd.). 434. The concentration refers to a saturated fatty acid ratio (C12 to C22) in the liquid part. When the concentration (abbreviated as C) at a certain temperature (abbreviated as t) is equal to the supersolubility (abbreviated as Cu), the supersaturation ratio is 100%, and when the concentration is equal to the solubility (abbreviated as Cs), the supersaturation ratio is 0%.
[0022]
In order to perform crystallization promptly, it is sufficient to rapidly cool and set the supersaturation rate to 100%. However, if the cooling is too fast, the crystal growth is not enough and the crystals become fine and the filtration efficiency deteriorates. . On the other hand, when the supersaturation ratio is 0%, no crystal precipitation occurs. In the present invention, in order to perform the separation operation promptly, it is preferable to perform the cooling step under conditions where the supersaturation rate is as high as possible.However, the generation of large crystals with high filtration efficiency and suppression of the production of fine crystals, and the quality, From both of the yields, it is preferable to control the cooling rate to 4 ° C./h or less when the supersaturation rate is 60% or more and to add the polyglycerin fatty acid ester partially at that time. The average crystal grain size is preferably 100 μm or more, particularly preferably 200 μm or more.
[0023]
In the present invention, it is also possible to continuously add the polyglycerin fatty acid ester during the entire separation process. In this case, the timing of the initial addition is preferably before the start of crystal precipitation of the saturated fatty acid in the raw fatty acid, as in the case of the split addition, and is added to the raw fatty acid in advance before cooling is started. Is particularly preferred. Then, during the cooling step, the substance dissolved in the fatty acid which is liquid at the temperature in the system at the time of addition is continuously transferred into the system, and the polyglycerin fatty acid ester and the polyglycerol fatty acid ester are dissolved in accordance with the temperature in the system. It is preferable that the fatty acids to be added are added while being continuously switched. From the viewpoint of simplification of the manufacturing process, it is preferable to add in portions rather than continuously during the process.
[0024]
In addition, stirring is preferably performed during cooling from the viewpoint of generating large crystals with good filtration efficiency and suppressing generation of fine crystals, and the stirring speed is more preferably set to rotate the stirring blade at 10 to 200 r / min.
[0025]
As a method for separating the generated crystals, a filtration method, a centrifugal separation method, a sedimentation separation method, or the like can be applied, and a batch processing or a continuous processing may be used.
[0026]
【Example】
In the following examples, the fatty acid composition and the saturated fatty acid ratio were measured by gas chromatography. The transparent melting point of the fatty acid was measured by a standard fat analysis method (2.2.4.1-1996).
[0027]
(Preparation of raw material fatty acid)
The fats and oils shown in Table 1 were hydrolyzed by a conventional method to prepare raw material fatty acids. Table 1 shows the fatty acid composition, saturated fatty acid ratio (% by mass), and fatty acid concentration of the fatty acids used.
[0028]
[Table 1]

[0029]
Example 1
Using a separation tank having an anchor blade attached to a 1 L beaker, 500 g of soybean fatty acid shown in Table 1 as a separation raw material and 1.0 g of PGE1 shown in Table 2 as a crystal modifier are added and uniformly dissolved at 70 ° C. Next, the mixture was cooled at 4 ° C./h while being stirred at 55 r / min, and cooled from 30 ° C. at 4 ° C./h. 0.5 g of PGE2 shown in Table 2 was dissolved in 50 g of a liquid fatty acid having a saturated fatty acid concentration of 4%, and the temperature was adjusted to 30 ° C. This was added at 10 ° C. during cooling. After cooling to −5 ° C., it was aged for 1 hour. Subsequently, the liquid part (unsaturated fatty acid) and the solid part (crystal part; saturated fatty acid) were filtered under pressure at 0.03 MPa using a nylon filter cloth NY1260NLK (Mitsubishi Kakoki Co., Ltd.) (filtration area 6.2 cm ² ). ). Table 4 (fractionation condition No. 1) shows the results of measuring the filtration time, the yield of the liquid part, and the fatty acid composition (the ratio of C12 to C22 saturated fatty acids) of the liquid part and the solid part required to obtain a 110 mL filtrate.
[0030]
Example 2
Using a separation tank having an anchor blade attached to a 2L beaker, 1000 g of soybean fatty acid shown in Table 1 as a separation raw material and 1.5 g of PGE3 shown in Table 3 as a crystal modifier are added and uniformly dissolved at 80 ° C. Next, the mixture was cooled at 5 ° C./h while being stirred at 50 r / min, and then cooled from 30 ° C. to 2 ° C./h. 0.5 g of PGE4 shown in Table 3 was dissolved in 100 g of a liquid fatty acid having a saturated fatty acid concentration of 4%, and the temperature was adjusted to 10 ° C. This was added at 10 ° C. during cooling. The supersaturation rate at this point is 60% or more. After cooling to −6 ° C., it was aged for 3 hours. Then, it was subjected to pressure filtration at 0.03 MPa using a nylon filter cloth NY1260NLK (Mitsubishi Kakoki Co., Ltd.) (filtration area: 39 cm ² ) to form a liquid portion (unsaturated fatty acid) and a solid portion (crystal portion; saturated fatty acid). Sorted out. Table 4 (fractionation condition No. 2) shows the results of measuring the filtration time required to obtain a 500 mL filtrate, the yield of the liquid part, and the fatty acid composition of the liquid part and the solid part (the ratio of C12 to C22 saturated fatty acids).
[0031]
Example 3
Using a separation tank having an anchor blade attached to a 2 L beaker, 1000 g of palm fatty acid shown in Table 1 as a separation raw material and 2 g of PGE5 shown in Table 3 as a crystal modifier are added and uniformly dissolved at 80 ° C. Next, the mixture was cooled at 5 ° C./h while being stirred at 50 r / min, and then cooled from 50 ° C. to 2 ° C./h. 1 g of PGE6 shown in Table 3 was dissolved in 100 g of a liquid fatty acid having a saturated fatty acid concentration of 10%, and the temperature was adjusted to 35 ° C. This was added at 35 ° C. during cooling. The supersaturation rate at this point is 60% or more. 1 g of PGE7 shown in Table 3 was dissolved in 100 g of a liquid fatty acid having a saturated fatty acid concentration of 10%, and the temperature was adjusted to 28 ° C. This was added at 28 ° C. during cooling. The supersaturation rate at this point is 60% or more. After cooling to 25 ° C., it was aged for 1 hour. Subsequently, the mixture was filtered under pressure under the same conditions as in Example 2 and separated. The results are shown in Table 4 (fractionation condition No. 3).
[0032]
Comparative Example 1
Using the separation tank used in Example 1, 500 g of soybean fatty acid, 1.0 g of PGE1 shown in Table 2 and 0.5 g of PGE2 shown in Table 2 as a crystal modifier were added and uniformly dissolved at 70 ° C. Next, while stirring at 55 r / min, the mixture was cooled from 30 ° C. at 4 ° C./h, cooled to −5 ° C., and then aged for 1 hour. Subsequently, the mixture was filtered under pressure under the same conditions as in Example 1 and separated. The results are shown in Table 5 (fractionation condition No. 4).
[0033]
Comparative Example 2
Using the separation tank used in Example 2, 1000 g of soybean fatty acid, 1.5 g of PGE3 shown in Table 3 and 0.5 g of PGE4 shown in Table 3 as a crystal modifier were added, and uniformly dissolved at 80 ° C. Next, while stirring at 50 r / min, the mixture was cooled at 5 ° C / h, cooled from 30 ° C to 2 ° C / h, cooled to -6 ° C, and then aged for 3 hours. Subsequently, the mixture was filtered under pressure under the same conditions as in Example 2 and separated. The results are shown in Table 5 (fractionation condition No5).
[0034]
Comparative Example 3
Using the separation tank used in Example 2, 1000 g of palm fatty acid, 2 g of PGE5 shown in Table 3 as a crystallization modifier, and 1 g of PGE6 and PGE7 shown in Table 3 were added, and uniformly dissolved at 80 ° C. Next, the mixture was cooled at 5 ° C./h with stirring at 50 r / min, cooled from 50 ° C. to 2 ° C./h, cooled to 25 ° C., and then aged for 1 hour. Subsequently, the mixture was filtered under pressure under the same conditions as in Example 2 and separated. The results are shown in Table 5 (fractionation condition No. 6).
[0035]
[Table 2]

[0036]
[Table 3]

[0037]
[Table 4]

[0038]
[Table 5]

[0039]
As is clear from the comparison of the separation conditions 1 and 4, the separation conditions 2 and 5, and the separation conditions 3 and 6 in Tables 4 and 5, when the polyglycerol fatty acid ester was added in portions, the crystals of the saturated fatty acid grew greatly. It can be seen that, in order to suppress the generation of fine crystals, the saturated fatty acid and the unsaturated fatty acid can be naturally separated efficiently in a shorter time.
[0040]
【The invention's effect】
According to the present invention, a saturated fatty acid and an unsaturated fatty acid in a raw material fatty acid can be efficiently and naturally fractionated.

Claims

A method in which a polyglycerin fatty acid ester is added to a raw material fatty acid, mixed and cooled to precipitate a crystal, thereby separating a saturated fatty acid and an unsaturated fatty acid from each other. The method for producing saturated fatty acids and unsaturated fatty acids which are added in portions at the time of the step.

2. The method according to claim 1, wherein the time of the first addition of the polyglycerin fatty acid ester is before the start of crystal precipitation.

2. The method according to claim 1, wherein the first addition of the polyglycerin fatty acid ester is a step of preliminarily adding and mixing the raw material fatty acids before cooling.

The method according to any one of claims 1 to 3, wherein the transparent melting point of the polyglycerin fatty acid ester added during the cooling step is lower than the transparent melting point of the polyglycerin fatty acid ester added before that.

The method according to any one of claims 1 to 4, wherein during the cooling step, when the supersaturation rate becomes 60% or more, the cooling rate is performed at 4 ° C / h or less, and a part of the polyglycerin fatty acid ester is added. .

Polyglycerin fatty acid ester is added to the raw material fatty acids, mixed and cooled to precipitate crystals to separate saturated fatty acids and unsaturated fatty acids. For producing saturated and unsaturated fatty acids to be added by heating.