JP2004099686A

JP2004099686A - Method for producing fatty acid

Info

Publication number: JP2004099686A
Application number: JP2002261255A
Authority: JP
Inventors: Minoru Kase; 加瀬　実; Keiji Shibata; 柴田　啓二
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2002-09-06
Filing date: 2002-09-06
Publication date: 2004-04-02
Anticipated expiration: 2022-09-06
Also published as: JP3927104B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a fatty acid, by which saturated fatty acids and unsaturated fatty acids can efficiently be produced from raw material fatty acids having a high saturated fatty acid rate by a natural fractionation method. <P>SOLUTION: This method for producing saturated fatty acids or unsaturated fatty acids, comprising fractionating raw material fatty acids having a saturated fatty acid rate of ≥20 wt. % in the fatty acid composition by a natural fractionation method using a crystal-adjusting agent, is characterized by adjusting a cooling temperature to control the amount of deposited crystals, thereby dividing the fractionation treatment into two steps or three steps. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、飽和脂肪酸含有量の高い原料脂肪酸類から飽和脂肪酸と不飽和脂肪酸を自然分別法により効率良く製造する方法に関する。
【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、ヒマワリ油、パーム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、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】
そこで、所望の脂肪酸を得るために、脂肪酸組成の調整が必要となる。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（無溶剤法）は、安価な分別法であり、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号公報
【０００６】
【発明が解決しようとする課題】
しかしながら、自然分別法を、綿実油、牛脂、パーム油、パーム核油等由来の、飽和脂肪酸の比率が高い脂肪酸類の分別に適用しようとした場合、結晶析出量が多いことから、濾過の負担が非常に大きくなり、また固体部に付着している液体部の絞り切りがしにくくなり固体部に付着したまま残存してしまう液体部の量が多くなるため、液体部の歩留まりが低くなってしまうという問題がある。このため、このような飽和脂肪酸量の多い脂肪酸類の分別には、コスト高となる溶剤分別法や湿潤剤分別法を適用せざるを得ないのが現状である。
【０００７】
従って、本発明は、自然分別法により、飽和脂肪酸比率の高い脂肪酸類から飽和脂肪酸と不飽和脂肪酸を効率良く製造する方法を提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明者は、自然分別法での冷却温度を調整することで結晶量を制御し、分別処理を２段階又は３段階に分けて行うことにより、飽和脂肪酸比率の高い脂肪酸類を効率よく分別できることを見出した。
【０００９】
すなわち、本発明は、脂肪酸組成中の飽和脂肪酸の比率が２０重量％以上である原料脂肪酸類を、結晶調整剤を用いる自然分別法により飽和脂肪酸と不飽和脂肪酸に分別する方法であって、冷却温度を調整して結晶析出量を制御することにより、分別処理を２段階又は３段階に分割して行う飽和脂肪酸又は不飽和脂肪酸の製造法を提供するものである。
【００１０】
【発明の実施の形態】
〔定義〕
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。また、脂肪酸組成中の飽和脂肪酸比率は、ガスクロマトグラフィーにより測定した値であり、透明融点は、基準油脂分析法（２．２．４．１−１９９６）により測定した値である。
【００１１】
〔原料脂肪酸類〕
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、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の比率が２０重量％以上のものであり、当該比率が２５重量％以上、特に３０重量％以上のものが好ましい。このような飽和脂肪酸の比率が高い原料脂肪酸類は、綿実油、パーム油、パーム核油、牛脂等を、水蒸気分解法又は酵素（リパーゼ）を利用する加水分解等により製造される。このような原料脂肪酸類の分別は、結晶の析出量が過多となることから、従来、自然分別法による分別は不可能であった。また、本発明の方法は、原料脂肪酸類中の脂肪酸の量が５０重量％以上、特に８５重量％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。
【００１２】
〔結晶調整剤〕
本発明における自然分別法では、原料脂肪酸類に適当な結晶調整剤を添加混合して、冷却して結晶を析出させ、濾過することにより、結晶部（飽和脂肪酸）と液体部（不飽和脂肪酸）とを分別する。本発明で用いられる結晶調整剤としては、特に限定されないが、多価アルコール脂肪酸エステルが好ましく、食品添加物であるショ糖脂肪酸エステル、ソルビタン脂肪酸エステル、プロピレングリコール脂肪酸エステル、有機酸モノグリセリド、グリセリン脂肪酸エステル、ポリグリセリン脂肪酸エステル等が挙げられ、なかでもポリグリセリン脂肪酸エステルが好ましい。本発明において特に好ましいポリグリセリン脂肪酸エステルとして、透明融点が次式（１）で示される範囲にあるものが挙げられる。
【００１３】
０．３８ｘ＋１３≦ｙ≦０．５４ｘ＋４４　　　　　（１）
【００１４】
〔ｘ：原料脂肪酸類の脂肪酸組成中の飽和脂肪酸（Ｃ_１２〜Ｃ_２２）比率（重量％）
ｙ：ポリグリセリン脂肪酸エステルの透明融点（℃）〕
【００１５】
より好ましい透明融点（ｙ）の範囲は、０．３８ｘ＋１９≦ｙ≦０．５４ｘ＋４０であり、特に好ましい範囲は、０．３８ｘ＋２８≦ｙ≦０．５４ｘ＋３６である。また、ポリグリセリン脂肪酸エステルの透明融点（ｙ）は、原料脂肪酸類の透明融点より高いことが好ましい。本発明では、各段階における分別対象の脂肪酸類の飽和脂肪酸比率が変化する。すなわち、１段目より２段目、更に３段目と、段階を追うごとに飽和脂肪酸比率が低くなる。従って、各段階で分別対象となる脂肪酸類の飽和脂肪酸比率から、上記式（１）に基づき、適切なポリグリセリン脂肪酸エステルを割り出し、これを結晶調整剤として使用することが好ましい。
【００１６】
また、ポリグリセリン脂肪酸エステルにおける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５以上、特に８〜３０が好ましい。また、ポリグリセリンと反応させる脂肪酸は、ポリグリセリン脂肪酸エステルの透明融点調整の点から、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、単一脂肪酸で構成されてもよいが、混合脂肪酸で構成されているものが、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。
【００１７】
結晶調整剤は２種以上を併用してもよく、またその添加量は、原料脂肪酸類に対して０．００１〜５重量％、特に０．０５〜１重量％程度が好ましい。
【００１８】
〔温度調整〕
結晶調整剤は、原料脂肪酸類に完全に溶解できるように、結晶調整剤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。本発明においては、この混合溶解の後の冷却温度を調整して、結晶の析出を、効率良い分離（濾過等）が可能な量に抑制することにより、分別を２〜３段階に分けて行うものである。冷却温度の調整は、−２０〜５０℃、特に−１０〜４０℃の範囲内で行うことが好ましい。
【００１９】
２段階で分別を行う場合は、１段階目において、結晶の析出量が、理論量の３０〜７０重量％となるように、特に、理論量の４０〜６０重量％となるように、冷却温度を調整して分別した後、２段階目の分別を行うことが好ましい。
【００２０】
３段階で分別を行う場合は、結晶の累積析出量が、１段階目において理論量の２０〜６０重量％となり、２段階目において理論量の４０〜８０重量％となるように、特に、１段階目において理論量の３０〜５０重量％となり、２段階目において理論量の５０〜８０重量％となるように、それぞれ冷却温度を調整して分別した後、３段階目の分別を行うことが好ましい。
【００２１】
なお、最終段階における累積析出量をどの程度とするかは、製造しようとする脂肪酸の凝固温度等、目的に応じて適宜決定すればよい。
【００２２】
ここで、結晶析出の理論量とは、原料脂肪酸類中に含まれる飽和脂肪酸の総量をいう。また、各段階における冷却温度を決定するための指標として、結晶の析出を、効率良い分離が可能な析出量に抑制することのほか、得られる結晶の平均粒径が、１００μｍ以上、特に２００μｍ以上となるようにすることが好ましい。
【００２３】
冷却時間は、原料脂肪酸類の組成により適宜選択すればよいが、０．５〜３０時間、特に１〜３０時間が好ましい。冷却は、回分式処理でも連続式処理でもよい。また、結晶分離法としては、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。
【００２４】
なお、分別を２段階で行うか、それとも３段階で行うかは、分別対象である原料脂肪酸類の当初の飽和脂肪酸量により判断される。本発明の目的は、原料脂肪酸類から飽和脂肪酸と不飽和脂肪酸を自然分別法により効率良く分別することにあるが、そのためには最終段階の分別の直前で、液体部中の飽和脂肪酸量がある程度まで低減されていることが必要である。しかも、各分別工程で低減される飽和脂肪酸の量には限度があるため、当初の分別対象に飽和脂肪酸が多く含まれる場合は多段階で、それほどでもない場合は少ない段階で行うことが、製造コスト及び分別効率の点から好ましい。原料脂肪酸類中の当初の飽和脂肪酸比率が２０〜４０重量％、特に２０〜３５重量％である場合は２段階で行うのが好ましく、３０重量％以上、特に３５重量％以上の場合は３段階で行うのが好ましい。
【００２５】
【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。なお、原料脂肪酸中には、炭素数１４以下及び２０以上の飽和脂肪酸は、結晶化に影響するほどの量は含まれていないため、近似的にパルミチン酸とステアリン酸の合計を飽和脂肪酸比率とした。ポリグリセリン脂肪酸エステルの透明融点は、基準油脂分析法（２．２．４．１−１９９６）により測定した。
【００２６】
実施例１
原料脂肪酸としてパーム核蒸留ボトム脂肪酸（飽和脂肪酸比率：４１．８重量％）を使用した。
【００２７】
（１）１段目分別
１Ｌビーカーにアンカー翼を取り付けた分別槽を用い、原料脂肪酸としてパーム核蒸留ボトム脂肪酸（飽和脂肪酸比率４１．８重量％）５００ｇ、結晶調整剤としてデカグリセリン脂肪酸エステル（透明融点５５．５℃）を１ｇ（０．２重量％）添加し、６０℃で均一に溶解した。次いで、５０ｒｐｍで撹拌しつつ、５℃／ｈで３５℃まで冷却し、１時間熟成した。析出した結晶は約１０００μｍの凝集結晶であり、濾過が可能であった。これをナイロン製濾布ＮＹ１２６０ＮＬＫ（濾過面積３９ｃｍ^２，三菱化工機社）を用い、０．０３ＭＰａの窒素ガスで加圧濾過して、液体部（不飽和脂肪酸類）と固体部（結晶部；飽和脂肪酸類）に分別した。液体部／固体部の品質・歩留まり、濾過性能を評価した。
この結果を表１に示した。液体部の飽和脂肪酸比率は２９．２重量％、歩留まりは６５．９重量％となった。１段目における結晶析出量は、（４１．８−２９．２）／４１．８より、理論量の３０．１重量％である。
【００２８】
【表１】

【００２９】
（２）２段目分別
（１）で得られた液体部を２段目分別した。（１）と同じ装置を用い、結晶調整剤としては、デカグリセリン脂肪酸エステル（透明融点４０℃）を０．２重量％添加し、一度５０℃として結晶調整剤を溶解した後に冷却して分別を行った。３５℃までは１０℃／ｈで冷却し、３５℃から２０℃までは５℃／ｈで冷却し、１時間熟成した。冷却途中のスラリー状態を観察すると、冷却中の液体部は２３℃では透明、２０℃では濁っていたが、析出した結晶は約１０００μｍの凝集結晶であり、濾過は可能であった。これを（１）と同様に加圧濾過して、固−液分離した。液体部／固体部の品質・歩留まり、濾過性能を評価した。
分別結果を表２に示した。液体部の飽和脂肪酸比率は１２．１重量％、歩留まりは５４．６重量％となった。２段目までの累積結晶析出量は、（４１．８−１２．１）／４１．８より、理論量の７１．１重量％である。
【００３０】
【表２】

【００３１】
（３）３段目分別
（２）で得られた液体部を３段目分別した。この液体部の飽和脂肪酸比率１２．１重量％は、大豆脂肪酸（１５重量％）とひまわり脂肪酸（１０重量％）の中間である。そこで、（１）と同じ装置を用い、結晶調整剤としてこれらの脂肪酸が分別可能なデカグリセリン脂肪酸エステル（透明融点３６．５℃）を０．１５重量％添加し、一度４０℃として結晶調整剤を溶解した後に冷却して分別を行った。３０℃までは１０℃／ｈで冷却し、３０℃から７℃までは５℃／ｈで冷却し、１時間熟成した。析出した結晶は１００〜５００μｍの凝集結晶であり、濾過が可能であった。これを（１）と同様に加圧濾過して、固−液分離した。液体部／固体部の品質・歩留まり、濾過性能を評価した。
分別結果を表３に示した。液体部の飽和脂肪酸比率は６．１重量％、歩留まりは８７．０重量％となった。３段目までの累積結晶析出量は、（４１．８−６．１）／４１．８より、理論量の８５．４重量％である。
【００３２】
【表３】

【００３３】
実施例２
原料脂肪酸として綿実脂肪酸（飽和脂肪酸比率：２２．５重量％）を使用した。
【００３４】
（１）１段目分別
１Ｌビーカーにアンカー翼を取り付けた分別槽を用い、原料脂肪酸として綿実脂肪酸（飽和脂肪酸比率２２．５重量％）５００ｇ、結晶調整剤としてデカグリセリン脂肪酸エステル（透明融点４２℃）を１ｇ（０．２重量％）添加し、６０℃で均一に溶解した。次いで、５０ｒｐｍで撹拌しつつ、２℃／ｈで１５℃まで冷却し、１時間熟成した。析出した結晶は約１０００μｍの凝集結晶であり、濾過が可能であった。これをナイロン製濾布ＮＹ１２６０ＮＬＫ（濾過面積３９ｃｍ^２，三菱化工機社）を用い、０．０３ＭＰａの窒素ガスで加圧濾過して、液体部（不飽和脂肪酸類）と固体部（結晶部；飽和脂肪酸類）に分別した。液体部／固体部の品質・歩留まり、濾過性能を評価した。この結果を表４に示した。液体部の飽和脂肪酸比率は１１．３重量％、歩留まりは７６．０重量％となった。１段目における結晶析出量は、（２２．５−１１．３）／２２．５より、理論量の４９．８重量％である。
【００３５】
【表４】

【００３６】
（２）２段目分別
（１）で得られた液体部を２段目分別した。（１）と同じ装置を用い、結晶調整剤としては、デカグリセリン脂肪酸エステル（透明融点３６．５℃）を０．２重量％添加し、一度４０℃以上として結晶調整剤を溶解した後に冷却して分別を行った。３５℃からは２℃／ｈで０℃まで冷却し、１時間熟成した。冷却途中のスラリー状態を観察すると、析出した結晶は約５００〜１０００μｍの凝集結晶であり、濾過は可能であった。これを（１）と同様に加圧濾過して、固−液分離した。液体部／固体部の品質・歩留まり、濾過性能を評価した。
分別結果を表５に示した。液体部の飽和脂肪酸比率は４．０重量％、歩留まりは８４．２重量％となった。２段目までの累積結晶析出量は、（２２．５−４．０）／２２．５より、理論量の８２．２重量％である。
【００３７】
【表５】

【００３８】
比較例１
実施例１と同様の装置を用い、パーム核蒸留ボトム脂肪酸の１段階での自然分別を試みた。
パーム核蒸留ボトム脂肪酸に、結晶調整剤としてデカグリセリン脂肪酸エステル（透明融点５５．５℃）を０．２重量％、デカグリセリン脂肪酸エステル（透明融点４０℃）を０．２重量％、デカグリセリン脂肪酸エステル（透明融点３６．５℃）を０．１５重量％添加し、６０℃で均一に溶解した。次いで、５０ｒｐｍで撹拌しつつ、５℃／ｈで７℃まで冷却した。実施例１より、この温度では結晶析出量は８５重量％になると推定される。１時間熟成後、実施例１と同様に加圧濾過を試みたが、クリーム状の微細結晶が生成しており、濾過不能であった。
【００３９】
比較例２
実施例２と同様の装置を用い、綿実脂肪酸の１段階での自然分別を試みた。
綿実脂肪酸に、結晶調整剤としてデカグリセリン脂肪酸エステル（透明融点４２℃）を０．２重量％、デカグリセリン脂肪酸エステル（透明融点３６．５℃）を０．２重量％添加し、６０℃で均一に溶解した。次いで、５０ｒｐｍで撹拌しつつ、２℃／ｈで０℃まで冷却した。実施例２より、この温度では結晶析出量は８２重量％になると推定される。１時間熟成後、実施例２と同様に加圧濾過を試みたが、クリーム状の微細結晶が生成しており、濾過不能であった。
【００４０】
【発明の効果】
本発明によれば、飽和脂肪酸比率の高い原料脂肪酸類から、自然分別法により、飽和脂肪酸と不飽和脂肪酸を、効率良く製造することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for efficiently producing a saturated fatty acid and an unsaturated fatty acid from natural fatty acids having a high saturated fatty acid content 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, soybean oil, sunflower oil and palm 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 not necessarily suitable as industrial raw materials with the fatty acid composition as it is. That is, it is necessary to separate unsaturated fatty acids and saturated fatty acids depending on the purpose of use.
[0004]
Therefore, in order to obtain a desired fatty acid, it is necessary to adjust the fatty acid composition. 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 separation method using no solvent (solvent-free method) is an inexpensive separation method, and the use of an emulsifier such as a polyglycerin fatty acid ester can be used to reduce the filtration speed, which has been regarded as a problem. (See Patent Document 1).
[0005]
[Patent Document 1]
JP-A-11-106782
[Problems to be solved by the invention]
However, if the natural fractionation method is applied to fractionate fatty acids having a high ratio of saturated fatty acids derived from cottonseed oil, beef tallow, palm oil, palm kernel oil, etc., the burden of filtration is high due to the large amount of crystal precipitation. It becomes very large, and it is difficult to squeeze the liquid portion adhering to the solid portion, and the amount of the liquid portion remaining adhering to the solid portion increases, thereby lowering the yield of the liquid portion. There is a problem. For this reason, at present, it is inevitable to apply a solvent separation method or a wetting agent separation method, which increases costs, to separate such fatty acids having a large amount of saturated fatty acids.
[0007]
Accordingly, an object of the present invention is to provide a method for efficiently producing saturated fatty acids and unsaturated fatty acids from fatty acids having a high ratio of saturated fatty acids by a natural fractionation method.
[0008]
[Means for Solving the Problems]
The present inventor can control the amount of crystals by adjusting the cooling temperature in the natural separation method, and perform the separation process in two or three stages, thereby efficiently separating fatty acids having a high saturated fatty acid ratio. Was found.
[0009]
That is, the present invention is a method of separating raw fatty acids having a ratio of saturated fatty acids in the fatty acid composition of 20% by weight or more into saturated fatty acids and unsaturated fatty acids by a natural separation method using a crystal modifier, It is an object of the present invention to provide a method for producing a saturated fatty acid or unsaturated fatty acid, in which the fractionation treatment is divided into two or three steps by adjusting the temperature to control the amount of crystal precipitation.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
[Definition]
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. The saturated fatty acid ratio in the fatty acid composition is a value measured by gas chromatography, and the transparent melting point is a value measured by a standard fat and oil analysis method (2.2.4.1-1996).
[0011]
(Raw fatty acids)
In the present invention, the raw fatty acids to be separated from the saturated fatty acids and the unsaturated fatty acids are those in which the ratio of the saturated fatty acids such as palmitic acid and stearic acid in the fatty acid composition is 20% by weight or more, and the ratio is 25%. % Or more, particularly preferably 30% by weight or more. Such raw material fatty acids having a high ratio of saturated fatty acids are produced by hydrolyzing cottonseed oil, palm oil, palm kernel oil, tallow, or the like using a steam decomposition method or an enzyme (lipase). Conventionally, it has been impossible to separate such raw material fatty acids by a natural separation method because the amount of precipitated crystals is excessive. Further, the method of the present invention is more effective when the amount of the fatty acid in the raw fatty acids is 50% by weight or more, particularly 85% by weight or more, and a partial glyceride may be present.
[0012]
(Crystal regulator)
In the natural fractionation method of the present invention, a crystal part (saturated fatty acid) and a liquid part (unsaturated fatty acid) are obtained by adding and mixing an appropriate crystal modifier to raw fatty acids, cooling and precipitating crystals, and filtering. And separate. The crystal modifier used in the present invention is not particularly limited, but is preferably a polyhydric alcohol fatty acid ester, and is a food additive such as sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, organic acid monoglyceride, and glycerin fatty acid ester. And polyglycerin fatty acid esters, among which polyglycerin fatty acid esters are preferable. Particularly preferred polyglycerol fatty acid esters in the present invention include those having a transparent melting point in the range represented by the following formula (1).
[0013]
0.38x + 13 ≦ y ≦ 0.54x + 44 (1)
[0014]
[X: Saturated fatty acid (C ₁₂ -C ₂₂ ) ratio (% by weight) in fatty acid composition of raw material fatty acids
y: transparent melting point of polyglycerin fatty acid ester (° C.)]
[0015]
A more preferable range of the transparent melting point (y) is 0.38x + 19 ≦ y ≦ 0.54x + 40, and a particularly preferable range is 0.38x + 28 ≦ y ≦ 0.54x + 36. Further, the transparent melting point (y) of the polyglycerin fatty acid ester is preferably higher than the transparent melting point of the raw material fatty acids. In the present invention, the ratio of saturated fatty acids of the fatty acids to be separated in each stage changes. In other words, the ratio of the saturated fatty acid becomes lower in each of the second, third, and third stages from the first stage. Therefore, it is preferable to determine an appropriate polyglycerol fatty acid ester based on the above formula (1) from the saturated fatty acid ratio of the fatty acids to be separated in each step, and to use this as a crystal modifier.
[0016]
Further, the average degree of polymerization of glycerin in the polyglycerin fatty acid ester is preferably 5 or more, particularly preferably 8 to 30, from the viewpoint of obtaining a crystalline state that can be easily filtered. Further, 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 adjusting the transparent melting point of the polyglycerin fatty acid ester. The fatty acid may be composed of a single fatty acid, but a fatty acid composed of a mixed fatty acid is preferable because a crystalline state that can be easily filtered is obtained. 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.
[0017]
Two or more crystal modifiers may be used in combination, and the amount thereof is preferably 0.001 to 5% by weight, particularly preferably about 0.05 to 1% by weight, based on the raw fatty acids.
[0018]
(Temperature adjustment)
The crystal modifier is preferably mixed and dissolved at a temperature higher than the transparent melting point of the crystal modifier so that it can be completely dissolved in the raw material fatty acids. In the present invention, fractionation is performed in two to three stages by adjusting the cooling temperature after the mixing and dissolving to suppress the precipitation of crystals to an amount that allows efficient separation (such as filtration). Things. Adjustment of the cooling temperature is preferably performed in the range of -20 to 50C, particularly -10 to 40C.
[0019]
When the fractionation is performed in two stages, the cooling temperature in the first stage is set so that the amount of precipitated crystals is 30 to 70% by weight of the theoretical amount, particularly 40 to 60% by weight of the theoretical amount. It is preferable to perform the second-stage separation after the separation by adjusting the temperature.
[0020]
When the fractionation is carried out in three stages, it is particularly preferable that the accumulated amount of crystals be 20 to 60% by weight of the theoretical amount in the first stage and 40 to 80% by weight of the theoretical amount in the second stage. After the cooling temperature is adjusted and separated so that 30 to 50% by weight of the theoretical amount at the stage and 50 to 80% by weight of the theoretical amount at the second stage, the third stage of separation is performed. preferable.
[0021]
The amount of the accumulated precipitate in the final stage may be appropriately determined according to the purpose such as the solidification temperature of the fatty acid to be produced.
[0022]
Here, the theoretical amount of crystallization means the total amount of saturated fatty acids contained in the raw fatty acids. In addition, as an index for determining the cooling temperature in each stage, in addition to suppressing the precipitation of crystals to a precipitation amount capable of efficient separation, the average particle size of the obtained crystals is 100 μm or more, particularly 200 μm or more It is preferable that
[0023]
The cooling time may be appropriately selected according to the composition of the raw material fatty acids, but is preferably 0.5 to 30 hours, particularly preferably 1 to 30 hours. The cooling may be a batch process or a continuous process. In addition, as a crystal separation method, 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.
[0024]
Whether the separation is performed in two steps or in three steps is determined based on the initial saturated fatty acid amount of the raw material fatty acids to be separated. An object of the present invention is to efficiently separate saturated fatty acids and unsaturated fatty acids from raw fatty acids by natural fractionation. For this purpose, just before the final stage of separation, the saturated fatty acid amount in the liquid part is reduced to some extent. Needs to be reduced to In addition, since the amount of saturated fatty acids to be reduced in each separation step is limited, it can be carried out in multiple steps when the initial separation target contains a large amount of saturated fatty acids, and in a small number of steps when the amount is not so large. It is preferable in terms of cost and sorting efficiency. When the initial saturated fatty acid ratio in the raw fatty acids is 20 to 40% by weight, particularly 20 to 35% by weight, it is preferably carried out in two steps, and when it is 30% by weight or more, especially 35% by weight or more, three steps It is preferred to carry out.
[0025]
【Example】
In the following examples, the fatty acid composition and the saturated fatty acid ratio were measured by gas chromatography. Since the raw fatty acids do not contain saturated fatty acids having 14 or less carbon atoms or 20 or more carbon atoms so as to affect crystallization, approximately the total of palmitic acid and stearic acid is defined as the saturated fatty acid ratio. did. The transparent melting point of the polyglycerin fatty acid ester was measured by a standard fat and oil analysis method (2.2.4.1-1996).
[0026]
Example 1
Palm kernel distilled bottom fatty acid (saturated fatty acid ratio: 41.8% by weight) was used as a raw material fatty acid.
[0027]
(1) Using a separation tank having an anchor blade attached to a first-stage separation 1 L beaker, 500 g of palm kernel distilled bottom fatty acid (saturated fatty acid ratio: 41.8% by weight) as raw material fatty acid, and decaglycerin fatty acid ester (transparent) as a crystal modifier 1 g (0.2% by weight) was added and uniformly dissolved at 60 ° C. Next, the mixture was cooled to 35 ° C. at 5 ° C./h while stirring at 50 rpm, and aged for 1 hour. The precipitated crystals were aggregated crystals of about 1000 μm and could be filtered. This was filtered under pressure with nitrogen gas of 0.03 MPa using a nylon filter cloth NY1260NLK (filtration area 39 cm ² , Mitsubishi Kakohki Co., Ltd.) to obtain a liquid part (unsaturated fatty acids) and a solid part (crystal part; saturated). Fatty acids). The quality / yield and filtration performance of the liquid part / solid part were evaluated.
The results are shown in Table 1. The saturated fatty acid ratio in the liquid part was 29.2% by weight, and the yield was 65.9% by weight. The amount of crystal precipitation in the first stage is (41.8-29.2) /41.8, which is 30.1% by weight of the theoretical amount.
[0028]
[Table 1]

[0029]
(2) Second-stage separation The liquid part obtained in (1) was subjected to the second-stage separation. Using the same apparatus as in (1), 0.2% by weight of a decaglycerin fatty acid ester (clear melting point: 40 ° C.) was added as a crystal modifier, and the crystal modifier was once dissolved at 50 ° C., and then cooled to separate. went. The mixture was cooled at 10 ° C./h to 35 ° C., and cooled at 5 ° C./h from 35 ° C. to 20 ° C., and aged for 1 hour. When the state of the slurry during cooling was observed, the liquid portion during cooling was transparent at 23 ° C. and turbid at 20 ° C., but the precipitated crystals were aggregated crystals of about 1000 μm and could be filtered. This was subjected to pressure filtration in the same manner as in (1) to perform solid-liquid separation. The quality / yield and filtration performance of the liquid part / solid part were evaluated.
The results of the fractionation are shown in Table 2. The saturated fatty acid ratio in the liquid part was 12.1% by weight, and the yield was 54.6% by weight. The accumulated crystal deposition amount up to the second stage is (41.8-12.1) /41.8, which is 71.1% by weight of the theoretical amount.
[0030]
[Table 2]

[0031]
(3) Third-stage separation The liquid part obtained in (2) was subjected to the third-stage separation. The saturated fatty acid ratio of 12.1% by weight in this liquid part is intermediate between soybean fatty acids (15% by weight) and sunflower fatty acids (10% by weight). Therefore, using the same apparatus as in (1), 0.15% by weight of a decaglycerin fatty acid ester (transparent melting point: 36.5 ° C.) from which these fatty acids can be separated is added as a crystal modifier, and the temperature is raised to 40 ° C. once. Was dissolved and then cooled for fractionation. It cooled at 10 ° C / h to 30 ° C, cooled at 5 ° C / h from 30 ° C to 7 ° C, and aged for 1 hour. The precipitated crystals were aggregated crystals of 100 to 500 μm and could be filtered. This was subjected to pressure filtration in the same manner as in (1) to perform solid-liquid separation. The quality / yield and filtration performance of the liquid part / solid part were evaluated.
The results are shown in Table 3. The saturated fatty acid ratio in the liquid part was 6.1% by weight, and the yield was 87.0% by weight. The accumulated crystal deposition amount up to the third stage is (41.8-6.1) /41.8, which is 85.4% by weight of the theoretical amount.
[0032]
[Table 3]

[0033]
Example 2
Cottonseed fatty acid (saturated fatty acid ratio: 22.5% by weight) was used as a raw material fatty acid.
[0034]
(1) Using a separation tank having an anchor blade attached to a first-stage separation 1 L beaker, 500 g of cottonseed fatty acid (saturated fatty acid ratio: 22.5% by weight) as a raw material fatty acid, and decaglycerin fatty acid ester (a transparent melting point of 42 C) was added and 1 g (0.2% by weight) was added, and the mixture was uniformly dissolved at 60 ° C. Next, the mixture was cooled to 15 ° C. at 2 ° C./h while stirring at 50 rpm, and aged for 1 hour. The precipitated crystals were aggregated crystals of about 1000 μm and could be filtered. This was filtered under pressure with nitrogen gas of 0.03 MPa using a nylon filter cloth NY1260NLK (filtration area 39 cm ² , Mitsubishi Kakohki Co., Ltd.) to obtain a liquid part (unsaturated fatty acids) and a solid part (crystal part; saturated). Fatty acids). The quality / yield and filtration performance of the liquid part / solid part were evaluated. The results are shown in Table 4. The saturated fatty acid ratio in the liquid part was 11.3% by weight, and the yield was 76.0% by weight. The amount of crystal precipitation in the first stage is (22.5-11.3) /22.5, which is 49.8% by weight of the theoretical amount.
[0035]
[Table 4]

[0036]
(2) Second-stage separation The liquid part obtained in (1) was subjected to the second-stage separation. Using the same apparatus as in (1), 0.2% by weight of decaglycerin fatty acid ester (transparent melting point: 36.5 ° C.) was added as a crystal modifier, and the temperature was once increased to 40 ° C. or higher, followed by cooling, followed by cooling. Was separated. From 35 ° C, the mixture was cooled to 0 ° C at a rate of 2 ° C / h and aged for 1 hour. Observation of the slurry state during the cooling revealed that the precipitated crystals were aggregated crystals of about 500 to 1000 μm, and could be filtered. This was subjected to pressure filtration in the same manner as in (1) to perform solid-liquid separation. The quality / yield and filtration performance of the liquid part / solid part were evaluated.
Table 5 shows the results of the classification. The saturated fatty acid ratio in the liquid part was 4.0% by weight, and the yield was 84.2% by weight. The accumulated crystal deposition amount up to the second stage is (22.5-4.0) /22.5, which is 82.2% by weight of the theoretical amount.
[0037]
[Table 5]

[0038]
Comparative Example 1
Using the same apparatus as in Example 1, natural fractionation of palm kernel distilled bottom fatty acids in one stage was attempted.
0.2% by weight of decaglycerin fatty acid ester (transparent melting point: 55.5 ° C.), 0.2% by weight of decaglycerin fatty acid ester (transparent melting point: 40 ° C.) as a crystal modifier to palm kernel distilled bottom fatty acid, decaglycerin fatty acid 0.15% by weight of an ester (clear melting point: 36.5 ° C.) was added and uniformly dissolved at 60 ° C. Next, the mixture was cooled to 7 ° C. at 5 ° C./h while stirring at 50 rpm. From Example 1, it is estimated that the crystal precipitation amount becomes 85% by weight at this temperature. After aging for 1 hour, filtration under pressure was attempted in the same manner as in Example 1, but fine crystals in the form of cream were formed, and filtration was impossible.
[0039]
Comparative Example 2
Using the same apparatus as in Example 2, one-step natural separation of cottonseed fatty acids was attempted.
0.2% by weight of decaglycerin fatty acid ester (clear melting point: 42 ° C.) and 0.2% by weight of decaglycerin fatty acid ester (transparent melting point: 36.5 ° C.) are added to cottonseed fatty acid as a crystal modifier. Dissolved uniformly. Next, it was cooled to 0 ° C. at 2 ° C./h while stirring at 50 rpm. From Example 2, it is estimated that the crystal precipitation amount is 82% by weight at this temperature. After aging for 1 hour, filtration under pressure was attempted in the same manner as in Example 2, but fine crystals in the form of cream were formed, and filtration was impossible.
[0040]
【The invention's effect】
According to the present invention, saturated fatty acids and unsaturated fatty acids can be efficiently produced from raw fatty acids having a high ratio of saturated fatty acids by a natural fractionation method.

Claims

This is a method of separating raw fatty acids having a saturated fatty acid ratio of 20% by weight or more in a fatty acid composition into saturated fatty acids and unsaturated fatty acids by a natural separation method using a crystal modifier, wherein the cooling temperature is adjusted to adjust the crystallinity. A method for producing a saturated fatty acid or unsaturated fatty acid in which the fractionation treatment is divided into two or three steps by controlling the amount of precipitation.

The separation process is performed in two stages. In the first stage, the cooling temperature is adjusted so that the amount of precipitated crystals is 30 to 70% by weight of the theoretical amount. The method according to claim 1, wherein

The fractionation treatment is performed in three stages. In the first stage, the amount of precipitated crystals becomes 20 to 60% by weight of the theoretical amount, and in the second stage, the accumulated amount of crystals becomes 40 to 80% of the theoretical amount. The method according to claim 1, wherein the cooling temperature is adjusted so as to obtain the percentage, and then the fractionation is performed, and then the third-stage fractionation is performed.