JP3769095B2

JP3769095B2 - Aji detection method

Info

Publication number: JP3769095B2
Application number: JP09483397A
Authority: JP
Inventors: 秀和池崎; 悦伸内藤; 紀寛前田
Original assignee: 株式会社インテリジェントセンサーテクノロジー
Priority date: 1997-03-27
Filing date: 1997-03-27
Publication date: 2006-04-19
Anticipated expiration: 2017-03-27
Also published as: JPH10267894A

Description

【０００１】
【発明の属する技術分野】
この発明は、人間の五感の一つである味覚を代行できるようにしたセンサを利用して、例えば飲食物の味の違いを検出する方法に係り、特に、従来の方法では検出、識別が困難であった飲食物等で水に難溶な物質が含まれるものの味の違いまで、検出、識別できるようにしたアジ検出法に関する。また、アジを検出することで測定対象に含まれる呈味物質の割合や割合の変化を検出できるようにした技術に関する。
【０００２】
【用語の意味】
味の基本要素として、塩味、甘味、苦味、酸味、うま味があるといわれていてそれぞれに程度の大小があるものとされている。人間の感覚で評価できるこれらの味の違いは、あるいは、塩味なら塩味についての（同種の）味の違いは、物理的に計測可能な量として把握できるものとし、計測可能な味または味の違い（比較または対比的な味）をここでは「アジ」と称することとする。
【０００３】
【従来の技術】
まず、アジを測定する技術について説明する。
本願出願人は他と共同して、「味覚センサ及びその製造方法」について特許出願（特開平3- 54446号）をし、その明細書及び図面で、疎水性の部分と親水性の部分とをもつ分子で成る脂質性物質を高分子のマトリックス内に定着させ、その表面に脂質性分子の親水性部分が整列するような構造をもつ脂質性分子膜が、アジのセンサ、すなわち、人間の味覚に代わりうる味覚センサとなることを示した。
【０００４】
前記脂質性分子膜の膜式図を、化学物の設計法で使われている表現方法で表わしたものが図４である。脂質性分子のうち円で示した球状部は親水基ａすなわち親水性部位ａであり、それから原子配列が長く延びる炭化水素の鎖構造ｂ（例えばアルキル基）がある。図ではいずれの場合も２本の鎖が延びて一つの分子を表わしており、全体で分子群を構成している。この炭化水素の鎖の部分は、疎水性部位ｂである。このような脂質性分子群31が、膜部材32の表面のマトリックス33（表面の構造、平面的なひろがりをもったミクロな構造）の中に、一部はマトリックス内部に溶け込ませた形（例えば図４の31′）で収容されている。その収容のされ方は、親水性部位が表面に配列するようなものとなっている。
【０００５】
この脂質性分子膜を用いて、マルチチャンネルの味覚センサとしたものが図５（ａ），（ｂ）である。本図ではマルチチャンネルのアレイ電極のうち三つの感応部が示されている。
図示の例では、基材１に 0.5mmφの孔を貫通して、それに銀の丸棒を差し込み電極２とした。脂質性分子膜３（以後、脂質膜とも分子膜ともいう）は緩衝層４を介して電極２に接触するように基材１に張りつけている。
【０００６】
前記マルチチャンネルの味覚センサを用いたアジの測定系を図６に示す。
呈味物質の水溶液を作り、それを被測定溶液11とし、ビーカーのような容器12に入れる。被測定溶液中に、前に述べたような、アクリル板（基材）上に脂質膜と電極とを配置して作った味覚センサアレイ13を入れた。使用前に、塩化カリウム 1m mole／ｌ水溶液で電極電位を安定化した。図中、14−１，……14−８は各々の脂質膜を黒点で示したものである。
測定の基準となる電位を発生する電極として参照電極15を用意し、それを被測定溶液に入れる。味覚センサアレイ13と参照電極15とは所定の距離を隔てて設置する。参照電極15の表面には、緩衝層16として、塩化カリウム 100m mole／ｌを寒天で固化したもので覆ってあるから、結局、電極系は銀２｜塩化銀４｜脂質膜３(14)｜被測定溶液12｜緩衝層（塩化カリウム 100m mole／ｌ）16｜塩化銀４｜銀２という構成となっている。
【０００７】
脂質膜からの電気信号は、図では８チャンネルの信号となり、リード線17−１，……，17−８によってそれぞれバッファ増幅器19−１，……，19−８に導かれる。バッファ増幅器19の各出力は、アナログスイッチ（８チャンネル）20で選択されてＡ／Ｄ変換器21に加えられる。参照電極15からの電気信号もリード線18を介してＡ／Ｄ変換器21に加えられ、膜からの電位との差をディジタル信号に変換する。このディジタル信号はマイクロコンピュータ22で適当に処理され、またＸ−Ｙレコーダ23で表示される。
この例では、８チャンネルの味覚センサが用いられ、各チャンネルは、人間の味覚を再現できるような多くの味覚情報を得るために、それぞれ味に対して異なる応答特性を持つ表１に示す脂質性分子膜で構成されている。
【０００８】
【表１】

【０００９】
前記明細書にいう味覚センサは正に味覚センサであって、人の味覚器官である舌に近い物理化学的性質を持ち、呈味物質が異なっても同様な味であれば同様な出力が得られるし、異なる味に対してもなんらかの出力がえられる。
【００１０】
この味覚センサを用いてアジを測定する方法として、本願出願人は他と共同して、「アジ検出方法」（特開平4-064053号）を特許出願した。この発明によりビール等の食品の銘柄差やロット差等の微細なアジの差まで識別可能となった。概略を以下に述べる。
脂質性分子を用いた味覚センサによるアジの検出、測定を再現性よく行うために、基準液として被測定サンプル液と近いものを用いることとし、味覚センサを基準液に十分に浸漬することとし、味覚センサに測定ごとに同様な刺激を加えることとし、測定時刻を表面電位の安定後であって内部電位が緩慢に変化する時に選ぶこことし、基準液と被測定サンプル液の測定値の差を計算することとした。
測定対象がビールならビールまたは、ビールに近い物を基準液とし、味覚センサを予め前記基準液に漬けて、味覚センサを前記基準液になじませておく。これにより、ビール中に含有する脂質膜に吸着性のある物質を予め吸着させておいて、各種のビールを測定した時、吸着性物質の影響を少なくするものである。脂質膜に吸着性のある物質に対する感度は低くなるものの、再現性が非常に向上する効果がある。
【００１１】
上記「アジ検出方法」をより進めた検出方法として本願出願人の一部が出願人となった「アジの検出方法」（特開平6-174688号）を特許出願した。
この中の第１の発明のアジの検出方法によれば、両親媒性物質または苦味物質の分子膜（以後、分子膜という）を用いた味覚センサによるアジの検出、測定を再現性よく行うために、第一の基準液及び第二の基準液としてサンプル液と近いものを用いることとし、第一の基準液（Ｖ0 ）→第二の基準液（Ｖk ）→第一の基準液（Ｖ0 ´）→サンプル液（Ｖs ）の順に測定しサンプル液測定値の基準値からの相対値｛（Ｖs −Ｖ0 ´）−（Ｖk −Ｖ0 ）｝を計算することにより味覚センサの継続的なドリフトにおける相対値のばらつきを無くし、第一の基準液を用いることによって第一の基準液の味が変化しても測定値への影響を無くした。
【００１２】
【発明が解決しようとする課題】
前述のように、分子膜を用いた味覚センサを使用するアジの測定法は、再現性の向上、情報量の増大（これは、アジの識別力の増大ともいえるし、アジの分解能の向上ともいえる。）、等のために種々の工夫がなされてきた。しかし、測定対象によっては、なお、アジの差が有りながら、その識別が困難なものも有る。
その一つに、水に難溶な物質を含むものがある。分子膜を用いた味覚センサは水に溶けないものには応答しないので、苦味物質、油脂類、繊維質、固体化されたもの等を含む医薬品、ドレッシング、肉類等々のアジはその検出、識別が困難である。
【００１３】
この発明の目的は、上述のような従来技術ではアジの検出、識別が困難であった水に難溶な物質を含む測定対象のアジも検出、識別ができるようにしたアジ検出法を提供することである。
【００１４】
【課題を解決するための手段】
前述の課題を解決するため、本発明の請求項１〜３の発明のアジ検出法は、両親媒性物質または苦味物質を含む膜を用いた味覚センサを使用する、水に難溶な物質が含まれる被測定物のアジ検出法であって、前記被測定物に添加剤を加えて被測定溶液とする前処理の段階と、該前処理によって得られた被測定溶液に前記味覚センサを浸漬してその電気特性を測定する段階とを含んでおり、その添加剤として、水に溶ける有機溶剤、界面活性剤、酸およびアルカリの少なくとも一方を用いたことを特徴としている。
【００１５】
請求項７の発明のアジ検出法は、両親媒性物質または苦味物質を含む膜を用いた味覚センサを使用する、油脂類が含まれる被測定物のアジ検出法であって、前記被測定物に添加剤を加えて前記油脂類が分散した被測定溶液とする前処理の段階と、該前処理によってエマルジョン（emulsion :乳濁液、乳状液、液体の小粒がその液体を溶解しない他の液体中に分散してできた系）となった被測定溶液に前記味覚センサを浸漬してその電気特性を測定する段階とを含んでいる。
【００１６】
請求項４〜６の発明のアジ検出法は、両親媒性物質または苦味物質を含む膜を用いた味覚センサを使用する、苦味物質が含まれる被測定物のアジ検出法であって、前記被測定物に添加剤を加えて被測定溶液とする前処理の段階と、該前処理によって得られた被測定溶液に前記味覚センサを浸漬してその電気特性を測定する段階とを含んでおり、その添加剤として、水に溶ける有機溶剤、界面活性剤、酸およびアルカリの少なくとも一方を用いたことを特徴としている。
【００１７】
請求項８〜１０の発明のアジ検出法は、請求項７のアジ検出法において、前記添加剤が水に溶ける有機溶剤、界面活性剤、酸およびアルカリの少なくとも一方であることを特徴としている。
【００２２】
請求項１１の発明のアジ検出法は、両親媒性物質または苦味物質を含む膜を用いた味覚センサを使用する、水に難溶な物質が含まれる被測定物のアジ検出法であって、前記被測定物の基準サンプルおよび前記被測定物が含む物質のうちの所定の物質の含有量が前記基準サンプルとは異なる標準サンプルを準備する段階と、該基準サンプルに添加剤を加えて基準サンプル溶液を準備する段階と、該標準サンプルに添加剤を加えて標準サンプル溶液を準備する段階と、前記基準サンプル溶液および標準サンプル溶液に前記味覚センサを浸漬してその電気特性を測定し基準サンプル測定値および標準サンプル測定値を得る段階と、該基準サンプル測定値および標準サンプル測定値と予め求められている前記基準サンプルおよび標準サンプルの官能評価値を用いて、前記測定値から前記官能評価値を推定するモデル式を求める段階と、前記被測定物のサンプルに添加剤を加えて被測定溶液とする前処理の段階と、該前処理によって得られた被測定溶液に前記味覚センサを浸漬してその電気特性を測定しサンプル測定値を得る段階と、該サンプル測定値を前記モデル式に代入して前記サンプルの官能評価値を推定する段階とを含んでいる。
【００２３】
請求項１２の発明のアジ検出法は、両親媒性物質または苦味物質を含む膜を用いた味覚センサを使用する、水に難溶な物質が含まれる被測定物のアジ検出法であって、前記被測定物の基準サンプルおよび前記被測定物が含む物質のうちの所定の物質の含有量が前記基準サンプルとは異なる標準サンプルを準備する段階と、該基準サンプルに物理的処理を施して基準サンプル溶液を準備する段階と、該標準サンプルに物理的処理を施して標準サンプル溶液を準備する段階と、前記基準サンプル溶液および標準サンプル溶液に前記味覚センサを浸漬してその電気特性を測定し基準サンプル測定値および標準サンプル測定値を得る段階と、該基準サンプル測定値および標準サンプル測定値と予め求められている前記基準サンプルおよび標準サンプルの官能評価値を用いて、前記測定値から前記官能評価値を推定するモデル式を求める段階と、前記被測定物のサンプルに物理的処理を施して被測定溶液とする前処理の段階と、該前処理によって得られた被測定溶液に前記味覚センサを浸漬してその電気特性を測定しサンプル測定値を得る段階と、該サンプル測定値を前記モデル式に代入して前記サンプルの官能評価値を推定する段階とを含んでいる。
【００２４】
【作用】
被測定物に添加剤を添加して、または物理的処理を施して、被測定溶液としたことで、前記被測定物に含まれる水に難溶な物質が該被測定溶液中に溶け出し（あるいは分散し）、被測定溶液に対する味覚センサの応答が変化し、前処理（添加剤の添加または物理的処理）をしない場合には得ることができない、水に難溶な物質のアジの情報を含んだアジの情報が得られる。
【００２５】
被測定物を似たアジのもの、例えば同一種や同一銘柄に限れば、同一の前処理を行うことで、アジは変化するが、被測定溶液間の相対的なアジの関係は変わらない傾向にある。図３はこのことを説明する図である。図中、Ａ1 ，Ｂ1 ，Ｃ1 ，Ｄ1 ，Ｅ1 は被測定物Ａ，Ｂ，Ｃ，Ｄ，Ｅの官能評価による位置関係であり、Ａ2 ，Ｂ2 ，Ｃ2 ，Ｄ2 ，Ｅ2 は被測定物Ａ，Ｂ，Ｃ，Ｄ，Ｅを前処理して味覚センサで測定して得た位置関係である。横軸、縦軸のアジの要素とは、例えば、酸味、塩味の様な基本味や基本味を複合した味で、被測定物の位置関係をアジ平面とでも呼べるようなもので表すためにスケールとして選んだものである。アジは前処理によって変化してしまうが、お互いの位置関係はあまり変化しない。そこで、例えば被測定物を同種のドレッシングならドレッシング、あるいはドレッシングの中でも同一銘柄のドレッシングに限り、その中から基準サンプル、標準サンプルであるイ，ロ，ハを選び、それらについて官能評価値と味覚センサの測定値との相関からモデル式求めておく。そうすれば、他の被測定物（例えば、同一銘柄のドレッシング）ニ，ホ，ヘ，ト，チについては、味覚センサで測定し、前記モデル式を用いて、官能評価値を推定することができる。
【００２６】
味覚センサは、従来技術の欄で述べたようにアジに関する出力が得られるので、前処理後の被測定溶液のアジの評価はできが、一般的に前処理によってアジが変化するため、前処理前の被測定物のアジの評価には使えないと考えられていた。しかし、前述のようにモデル式を求めて、前処理によるアジの変化分を除けば、被測定物のアジの評価が行える。また、測定対象の元の（前処理前の）アジが推定できることで測定対象に含まれる呈味物質の割合や割合の変化を推定できる。
【００２７】
【発明の実施の形態】
図１は本発明の第一の実施の形態のフローチャートである。図１に基づいて第一の実施の形態を説明する。測定対象は水に難溶な物質として油脂類を含むものとする。また、味覚センサ（センサ）の膜は、両親媒性物質の一種である脂質を含んだ脂質膜であるとして説明する。
（１）準備段階
基準液（基準溶液）の準備
測定対象に加える界面活性剤と同種の界面活性剤を、純水に被測定溶液と同濃度となるように加えた水溶液（基準溶液）を用意する。ここで、基準溶液は純水に、味覚センサの出力を安定させるため、例えば１０ｍｍｏｌ／ｌのＫＣｌを加えただけのものでもよい。この場合は、被測定溶液にも同じく１０ｍｍｏｌ／ｌのＫＣｌを加える。
【００２８】
（２）測定
２−１．前処理
測定対象に界面活性剤を加える。
界面活性剤には、陰イオン界面活性剤（高級アルコール硫酸エステル類、脂肪酸硫酸エステル類及びスルホン酸形陰イオン界面活性剤など）、非イオン界面活性剤、セッケン、等がある。加える量は、例えば、溶液に界面活性剤を入れ撹拌後静置しても油脂類が分離しなくなる量である。測定によっては、予め決めた所定の量を加える場合もある。
２−２．味覚センサによる測定
▲１▼ 基準液（洗浄用）へ味覚センサの出し入れを１０回行う。基準液（洗浄用）で洗浄するといってもよいし、基準液に断続的に浸漬するといってもよいし、味覚センサの脂質膜の表面に刺激を与えるということもできる。
▲２▼ 基準液で測定用として用意したものに浸漬し、約２０秒後に味覚センサの電位を測定し、測定値をＶ0 とする。味覚センサの電気特性は電位、インピーダンス、等があるがこの実施の形態では電位を測定することとする。
▲３▼ 手順▲１▼、▲２▼を２回以上繰り返し、測定ごとに今回の測定値Ｖ0 と前回の測定値Ｖ0 の差が所定の値以下かどうかを判断し、所定の値以下（つまりＶ0 が安定したら）であれば手順▲４▼へ進む。
▲４▼ 味覚センサを基準液（測定用）から出して、サンプル液（洗浄用）で洗浄する。（前記▲１▼と同様に１０回出し入れをする。）
▲５▼ サンプル液（測定用）に味覚センサを浸漬し、約２０秒後に味覚センサの電位Ｖs を測定する。
▲６▼ サンプル液のデータΔＶs ＝Ｖs −Ｖ0 を求める。
▲７▼ 測定の手順▲１▼に戻り手順▲１▼〜▲６▼を繰り返す。所定の回数繰り返したら手順を終わる。
【００２９】
得られたデータ（測定値）等は次のようにして利用する。
（１）エマルジョン化されたサンプル液の味覚センサの電位Ｖs またはデータΔＶs から設定範囲を越えたかどうかを判定して、異常検知を行う。マルチチャネルのセンサの方が情報も多く判定の精度が向上する。食品工場での油脂の混合割合のチェック等に利用できる。
（２）エマルジョン化されたサンプル液のマルチチャネルの味覚センサの電位Ｖs またはデータΔＶs から多変量解析やパターン認識をもちいてサンプルのアジの変化を調べたり、位置づけしたりする。
【００３０】
（３）エマルジョン化されたサンプル液のマルチチャネルの味覚センサの電位Ｖs またはデータΔＶs から被測定物の元の（前処理前の）アジを推定する。
この場合、前記被測定物の基準サンプルおよび前記被測定物が含む物質のうちの所定の物質の含有量が前記基準サンプルとは異なる標準サンプルを決め、それらについて、官能評価をして官能評価値を求めておく。前記基準サンプルに添加剤を加えて基準サンプル溶液、前記標準サンプルに添加剤を加えて標準サンプル溶液をそれぞれ作製し、前記基準サンプル溶液および標準サンプル溶液に前記味覚センサを浸漬してその電気特性を測定し基準サンプル測定値および標準サンプル測定値を得る。それらの測定値と予め求められている官能評価値とを用いて、前記測定値から前記官能評価値を推定するモデル式を求める。
このようにして、基準サンプルおよび標準サンプルでモデル式を求めておいて、被測定サンプルを測定し得られた前記味覚センサの電位Ｖs またはデータΔＶs を前記モデル式に代入して前記被測定サンプルの官能評価値を推定する。
元の被測定サンプルの官能評価値を推定することで、例えば食品工場における製造品質の管理等が官能評価値のレベルで行える。
【００３１】
図２は本発明の第二の実施の形態のフローチャートである。第二の実施の形態では、前処理で超音波による攪拌を行う。第一の実施の形態とは前処理の方法が異なり、他は同じであるので、前処理の段階についてだけ説明する。
印加する超音波の強さ、印加する時間、等は測定対象により異なり、一概にはいえない。油脂類等が分離していないかどうかは目視で確認するほかなく、また、この方法の場合は、超音波の印加を止めてから時間がたつにつれて徐々に油脂類等の水との分離が進む。
【００３２】
以上の実施の形態では、添加剤として界面活性剤を用いたもの、物理的処理として超音波を印加したもの、したものを挙げた。
ここで、添加剤について説明を加えると、添加剤としては、▲１▼水に溶ける有機溶剤〔例えば、低級アルコール（メタノール，エタノール），アセトン，等〕、▲２▼界面活性剤〔例えば、洗剤，乳化剤（レシチン），等〕、▲３▼酸，アルカリ〔ＨＣｌ，ＫＯＨ，ＮａＯＨ，等〕がある。▲３▼酸，アルカリは、水に難溶な物質としての油脂類には不向きであるが、▲１▼〜▲３▼いずれの添加剤も、水に難溶な物質としての、苦味物質（キニーネ等）、繊維類（肉類等）、固体化されたもの（タンパク質等）、等々に有効である。
【００３３】
物理的処理についていえば、物理的処理には▲１▼攪拌、▲２▼超音波の印加、▲３▼加熱がある。▲３▼加熱を用いるときは、味覚センサによる測定も高温状態（６０℃程度。あまり高いと味覚センサに用いられている膜の特性が変化してしまう。）での測定となる。▲１▼攪拌および▲２▼超音波の印加は苦味物質には効果が小さく、▲３▼加熱は油脂類には効果が小さいが、それ以外の水に難溶な物質には有効である。
第一の実施の形態もそうであるが、添加剤の添加と物理的処理を併せて行った方が効果がある。例えば、界面活性剤を使用すると、溶液に溶解する油脂類等の量が、単に攪拌するだけより多くなること、また、エマルジョン状態が安定するので測定に有利である。このことは、別な見方をすれば、攪拌に要する時間が少なくて済むということである。
【００３４】
【発明の効果】
本発明のアジ検出法によれば、被測定物に前処理を施して被測定溶液を作製し、両親媒性物質または苦味物質を含む膜を用いた味覚センサで測定を行うようにしたから、従来技術ではアジの検出、識別が困難であった水に難溶な物質を含む測定対象のアジも検出、識別ができるようにしたアジ検出法が提供できる。
【図面の簡単な説明】
【図１】本発明の第一の実施の形態のフローチャート。
【図２】本発明の第二の実施の形態のフローチャート。
【図３】被測定物の官能評価値と本発明のアジ検出方法による測定値との関係を説明す
るための図。
【図４】単分子膜を化学物の設計法で使われている表現方法で表わした模式図。
【図５】味覚センサの模式図であり、図５(a) は、正面図、図５(b) は断面図。
【図６】アジの測定系を示す図。
【符号の説明】
１基材
２電極
３脂質膜
４緩衝層
５リード線
１０膜電位の測定系の基本構成
１１被測定溶液
１２容器
１３味覚センサアレイ
１４−１〜１４−８各々の脂質膜（黒点で示す）
１５参照電極
１６緩衝層
１７−１〜１７−８リード線
１８リード線
１９−１〜１９−８バッファ増幅器
２０アナログスイッチ
２１Ａ／Ｄ変換器
２２マイクロコンピュータ
２３Ｘ−Ｙレコーダ
２４接地電位
３１，３１′ 脂質性分子群
３２膜部材
３３マトリックス[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for detecting, for example, a difference in taste of food and drink using a sensor that can substitute for the sense of taste that is one of the human senses, and in particular, it is difficult to detect and identify with a conventional method. The present invention relates to a method for detecting horse mackerel that can detect and identify even the difference in taste of foods and drinks that contain water-insoluble substances. In addition, the present invention relates to a technique that can detect a ratio of a taste substance contained in a measurement object and a change in the ratio by detecting horse mackerel.
[0002]
[Meaning of terms]
It is said that there are saltiness, sweetness, bitterness, sourness, and umami as basic elements of taste. The difference in taste that can be evaluated by human senses, or in the case of saltiness, the difference in taste (same type) with respect to saltiness can be grasped as a physically measurable amount, and the difference in measurable taste or taste (Comparative or contrasting taste) will be referred to herein as “Aji”.
[0003]
[Prior art]
First, a technique for measuring horse mackerel will be described.
The applicant of the present application jointly filed a patent application (Japanese Patent Laid-Open No. 3-54446) for “taste sensor and manufacturing method thereof” in cooperation with others. In the description and drawings, the hydrophobic portion and the hydrophilic portion Lipid molecular membranes that have a structure in which a lipid substance composed of molecules possessed in a matrix of macromolecules and the hydrophilic part of the lipid molecules are aligned on the surface of the lipid molecules are the sensor of the horse mackerel, that is, the human taste It was shown that it could be a taste sensor that could replace
[0004]
FIG. 4 shows the membrane diagram of the lipid molecular membrane expressed in the expression method used in the chemical design method. A spherical portion indicated by a circle in the lipid molecule is a hydrophilic group a, that is, a hydrophilic site a, and has a hydrocarbon chain structure b (for example, an alkyl group) from which the atomic arrangement extends. In each of the figures, two chains extend to represent one molecule, and constitute a molecular group as a whole. This hydrocarbon chain part is a hydrophobic part b. Such a lipid molecule group 31 is partly dissolved in the matrix 33 (surface structure, micro structure having a planar expansion) on the surface of the membrane member 32 (for example, It is accommodated at 31 ') in FIG. The accommodation method is such that hydrophilic portions are arranged on the surface.
[0005]
FIGS. 5A and 5B show a multichannel taste sensor using this lipidic molecular film. In this figure, three sensitive portions of the multi-channel array electrode are shown.
In the example shown in the figure, a hole of 0.5 mmφ is passed through the base material 1, and a silver round bar is used as the insertion electrode 2. A lipid molecular film 3 (hereinafter also referred to as a lipid film or a molecular film) is attached to the substrate 1 so as to be in contact with the electrode 2 through a buffer layer 4.
[0006]
FIG. 6 shows a system for measuring horse mackerel using the multi-channel taste sensor.
An aqueous solution of a taste substance is prepared, which is used as a solution to be measured 11 and put in a beaker 12. In the solution to be measured, a taste sensor array 13 made by arranging a lipid film and an electrode on an acrylic plate (base material) as described above was placed. Prior to use, the electrode potential was stabilized with an aqueous 1 mMole / l potassium chloride solution. In the figure, 14-1,..., 14-8 indicate the respective lipid membranes with black dots.
A reference electrode 15 is prepared as an electrode for generating a potential serving as a measurement reference, and is put in a solution to be measured. The taste sensor array 13 and the reference electrode 15 are installed with a predetermined distance therebetween. Since the surface of the reference electrode 15 is covered with a buffer layer 16 of potassium chloride 100 mMole / l solidified with agar, the electrode system is eventually silver 2 | silver chloride 4 | lipid membrane 3 (14) | Solution to be measured 12 | buffer layer (potassium chloride 100m mole / l) 16 | silver chloride 4 | silver 2
[0007]
The electrical signal from the lipid membrane is an 8-channel signal in the figure and is led to the buffer amplifiers 19-1,..., 19-8 by the lead wires 17-1,. Each output of the buffer amplifier 19 is selected by an analog switch (8 channels) 20 and applied to an A / D converter 21. An electric signal from the reference electrode 15 is also applied to the A / D converter 21 via the lead wire 18, and the difference from the potential from the film is converted into a digital signal. This digital signal is appropriately processed by the microcomputer 22 and displayed on the XY recorder 23.
In this example, an 8-channel taste sensor is used, and each channel has lipid characteristics shown in Table 1 having different response characteristics with respect to taste in order to obtain a lot of taste information that can reproduce human taste. It is composed of molecular films.
[0008]
[Table 1]

[0009]
The taste sensor referred to in the above description is exactly a taste sensor, has physicochemical properties close to the tongue, which is a human taste organ, and can produce a similar output even if the taste substances are different. And some output for different tastes.
[0010]
As a method for measuring horse mackerel using this taste sensor, the applicant of the present application jointly filed a patent application for “Aji detection method” (Japanese Patent Laid-Open No. 4-064053) in cooperation with others. According to the present invention, it is possible to discriminate even a fine difference of a horse mackerel such as a brand difference or a lot difference of food such as beer. An outline is described below.
In order to detect and measure horse mackerel with a taste sensor using lipid molecules with good reproducibility, the reference solution should be close to the sample solution to be measured, and the taste sensor should be sufficiently immersed in the reference solution. The same stimulus is applied to the taste sensor for each measurement, and the measurement time is selected when the internal potential changes slowly after the surface potential is stabilized, and the difference between the measured values of the reference liquid and the sample liquid to be measured is determined. It was decided to calculate.
If the measurement target is beer, beer or an object close to beer is used as a reference solution, a taste sensor is soaked in the reference solution in advance, and the taste sensor is adjusted to the reference solution. As a result, an adsorbing substance is adsorbed in advance on the lipid membrane contained in the beer, and when various beers are measured, the influence of the adsorbing substance is reduced. Although the sensitivity to a substance having an adsorptivity to a lipid membrane is lowered, the reproducibility is greatly improved.
[0011]
As a detection method that further advanced the above-mentioned “Aji detection method”, a patent application was filed for “Aji detection method” (Japanese Patent Laid-Open No. 6-146888), which was partly filed by the present applicant.
According to the method for detecting horse mackerel according to the first aspect of the invention, the detection and measurement of horse mackerel with a taste sensor using a molecular film of an amphiphilic substance or a bitter substance (hereinafter referred to as a molecular film) is performed with good reproducibility. The first reference liquid and the second reference liquid are similar to the sample liquid, and the first reference liquid (V0) → second reference liquid (Vk) → first reference liquid (V0 ′). ) → sample liquid (Vs) in order, and relative value in the continuous drift of the taste sensor is calculated by calculating a relative value {(Vs−V0 ′) − (Vk−V0)} from the reference value of the sample liquid measurement value. Even if the taste of the first reference solution was changed by eliminating the variation of the values and using the first reference solution, the influence on the measured value was eliminated.
[0012]
[Problems to be solved by the invention]
As described above, the method of measuring horse mackerel using a taste sensor using a molecular film improves the reproducibility and increases the amount of information (this can be said to increase the discrimination power of horse mackerel and improve the resolution of horse mackerel). Various ideas have been made for such reasons. However, depending on the object to be measured, there are still some differences in horse mackerel, which are difficult to identify.
One of them includes substances that are sparingly soluble in water. Taste sensors using molecular membranes do not respond to water-insoluble substances, so it is not possible to detect and identify drugs such as bitter substances, fats and oils, fibers, solidified foods, dressings, meats, etc. Have difficulty.
[0013]
An object of the present invention is to provide a method for detecting a horse mackerel that can also detect and identify a horse mackerel containing a substance that is hardly soluble in water, which has been difficult to detect and identify a horse mackerel by the conventional technology as described above. That is.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the method of detecting abscises according to claims 1 to 3 of the present invention uses a taste sensor using a film containing an amphiphilic substance or a bitter substance, and a substance hardly soluble in water. A method for detecting an object to be measured, comprising: a pretreatment stage in which an additive is added to the measurement object to obtain a measurement solution; and the taste sensor is immersed in the measurement solution obtained by the pretreatment And measuring its electrical characteristics, and using as its additive at least one of an organic solvent soluble in water, a surfactant, an acid and an alkali .
[0015]
The method for detecting absills according to the invention of claim 7 is a method for azide detection of an object to be measured containing fats and oils using a taste sensor using a film containing an amphiphilic substance or a bitter substance. A pretreatment stage in which an additive is added to obtain a solution to be measured in which the fats and oils are dispersed, and emulsion (emulsion: emulsion, milky liquid, other liquid in which small particles of liquid do not dissolve the liquid) And immersing the taste sensor in a solution to be measured, which is a system formed by dispersing the taste sensor, and measuring its electrical characteristics.
[0016]
The azide detection method of the inventions of claims 4 to 6 is a method for detecting a sample containing a bitter substance using a taste sensor using a film containing an amphipathic substance or a bitter substance. A pretreatment step of adding an additive to the measurement object to obtain a solution to be measured, and a step of immersing the taste sensor in the solution to be measured obtained by the pretreatment and measuring its electrical characteristics , As the additive, an organic solvent soluble in water, a surfactant, an acid, or an alkali is used .
[0017]
According to the eighth to tenth aspects of the present invention, in the seventh aspect of the present invention, the additive is characterized in that the additive is at least one of an organic solvent, a surfactant, an acid and an alkali soluble in water .
[0022]
Mackerel detection method of the invention of claim 1 1, using the taste sensor using a film containing amphiphile or bitter substance, a mackerel detection method of the object that contains the sparingly soluble substance in water A step of preparing a standard sample in which the content of a predetermined substance out of the reference sample of the object to be measured and the substance included in the object to be measured is different from the reference sample, and adding an additive to the reference sample Preparing a sample solution; adding an additive to the standard sample to prepare a standard sample solution; and immersing the taste sensor in the reference sample solution and the standard sample solution to measure the electrical characteristics of the standard sample solution. Obtaining a measurement value and a standard sample measurement value, and a reference sensor measurement value of the reference sample and the standard sample obtained in advance By using a value, obtaining a model formula for estimating the sensory evaluation value from the measured value, adding a additive to the sample of the object to be measured to obtain a solution to be measured, and performing the pretreatment Immersing the taste sensor in the obtained solution to be measured and measuring its electrical characteristics to obtain a sample measurement value; and substituting the sample measurement value into the model formula to estimate a sensory evaluation value of the sample Including.
[0023]
Mackerel detection method of the invention of claim 1 2, using a taste sensor using a film containing amphiphile or bitter substance, a mackerel detection method of the object that contains the sparingly soluble substance in water Preparing a standard sample in which the content of a predetermined substance of the reference sample of the object to be measured and the substance included in the object to be measured is different from the reference sample, and subjecting the reference sample to physical processing Preparing a reference sample solution; applying a physical treatment to the standard sample to prepare a standard sample solution; and immersing the taste sensor in the reference sample solution and the standard sample solution to measure electrical characteristics thereof. Obtaining a reference sample measurement value and a standard sample measurement value, and the reference sample measurement value and the standard sample measurement value obtained in advance and the reference sample and the standard sample obtained in advance Using the sensory evaluation value, obtaining a model formula for estimating the sensory evaluation value from the measurement value, and performing a pretreatment stage by subjecting the sample of the object to be measured to a physical treatment to obtain a solution to be measured; A step of immersing the taste sensor in a solution to be measured obtained by the pretreatment to measure its electrical characteristics to obtain a sample measurement value; and substituting the sample measurement value into the model formula to obtain a sensory evaluation value of the sample Estimating.
[0024]
[Action]
By adding an additive to the object to be measured or applying a physical treatment to obtain a solution to be measured, a substance hardly soluble in water contained in the object to be measured dissolves into the solution to be measured ( Or disperse), the response of the taste sensor to the solution to be measured changes, and it is not possible to obtain it without pretreatment (addition of additives or physical treatment). Information about the horse mackerel included is obtained.
[0025]
If the object to be measured is similar to the same horse mackerel, for example, the same species or the same brand, the same pretreatment will change the horse mackerel, but the relative horse mackerel relationship between the solutions to be measured will not change. It is in. FIG. 3 is a diagram for explaining this. In the figure, A1, B1, C1, D1, and E1 are positional relationships based on sensory evaluation of the objects A, B, C, D, and E, and A2, B2, C2, D2, and E2 are objects A and B to be measured. , C, D, E are pre-processed and measured by a taste sensor. Axis elements on the horizontal and vertical axes are, for example, a taste that combines basic tastes and basic tastes such as acidity and saltiness, and is used to express the positional relationship of the object to be measured in what can be called the Aji plane. It is chosen as a scale. The horse mackerel changes due to the pretreatment, but the positional relationship with each other does not change much. Therefore, for example, if the object to be measured is the same type of dressing, or only dressings of the same brand in the dressing, select the reference sample and the standard samples A, B, and C, and sensory evaluation value and taste sensor for them The model equation is obtained from the correlation with the measured value. Then, for other objects to be measured (for example, dressings of the same brand) d, e, h, h, t, h, the sensory evaluation value can be estimated using the above-described model formula by measuring with a taste sensor. it can.
[0026]
As described in the section of the prior art, the taste sensor can obtain the output of the horse mackerel, so it is possible to evaluate the horse mackerel of the solution to be measured after the pre-treatment. It was thought that it could not be used for the evaluation of the horse mackerel of the previous object. However, if the model formula is obtained as described above and the change in the horse mackerel due to the preprocessing is removed, the horse mackerel of the object to be measured can be evaluated. Moreover, the ratio of the taste substance contained in a measuring object and the change of a ratio can be estimated because the original (before pre-processing) horse mackerel of a measuring object can be estimated.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a flowchart of the first embodiment of the present invention. The first embodiment will be described with reference to FIG. The object to be measured shall contain fats and oils as a substance hardly soluble in water. The film of the taste sensor (sensor) will be described as a lipid film containing lipid, which is a kind of amphiphile.
(1) Preparation of the preparation stage reference solution (reference solution) Prepare an aqueous solution (reference solution) in which the same type of surfactant as the target to be measured is added to pure water to the same concentration as the solution to be measured To do. Here, the reference solution may be simply pure water added with, for example, 10 mmol / l KCl in order to stabilize the output of the taste sensor. In this case, 10 mmol / l KCl is also added to the solution to be measured.
[0028]
(2) Measurement 2-1. A surfactant is added to the pretreatment measurement target.
Surfactants include anionic surfactants (such as higher alcohol sulfates, fatty acid sulfates and sulfonic acid type anionic surfactants), nonionic surfactants, soaps, and the like. The amount to be added is, for example, such an amount that oils and fats are not separated even if a surfactant is added to the solution and left standing after stirring. Depending on the measurement, a predetermined amount determined in advance may be added.
2-2. Measurement by taste sensor (1) Put the taste sensor in and out of the reference solution (for washing) 10 times. It may be said that it is cleaned with a reference solution (for cleaning), may be intermittently immersed in the reference solution, or may be stimulated on the surface of the lipid membrane of the taste sensor.
(2) Immerse in a reference solution prepared for measurement, measure the potential of the taste sensor after about 20 seconds, and set the measured value to V0. The electrical characteristics of the taste sensor include potential, impedance, etc. In this embodiment, the potential is measured.
(3) Repeat steps (1) and (2) two or more times, and for each measurement, determine whether the difference between the current measured value V0 and the previous measured value V0 is less than a predetermined value. If V0 is stable), go to step (4).
(4) Remove the taste sensor from the reference solution (for measurement) and wash it with the sample solution (for washing). (Removes and inserts 10 times in the same manner as (1) above.)
(5) Immerse the taste sensor in the sample solution (for measurement), and measure the potential Vs of the taste sensor after about 20 seconds.
(6) Obtain the sample liquid data ΔVs = Vs−V0.
(7) Return to the measurement procedure (1) and repeat the procedures (1) to (6). The procedure ends when it is repeated a predetermined number of times.
[0029]
The obtained data (measured value) is used as follows.
(1) An abnormality is detected by determining whether or not the set range has been exceeded from the potential Vs or data ΔVs of the taste sensor of the emulsified sample liquid. The multi-channel sensor has more information and the determination accuracy is improved. It can be used for checking the mixing ratio of fats and oils in food factories.
(2) Using a multivariate analysis or pattern recognition from the potential Vs of the multichannel taste sensor or the data ΔVs of the emulsified sample solution, the change in the azimuth of the sample is examined or positioned.
[0030]
(3) The original (before pretreatment) of the object to be measured is estimated from the potential Vs or data ΔVs of the multichannel taste sensor of the emulsified sample liquid.
In this case, a standard sample in which the content of a predetermined substance out of the reference sample of the object to be measured and the substance included in the object to be measured is different from the reference sample is determined, and sensory evaluation is performed on these standard samples. Ask for. An additive is added to the reference sample to prepare a reference sample solution, and an additive is added to the standard sample to prepare a standard sample solution, and the taste sensor is immersed in the reference sample solution and the standard sample solution to determine its electrical characteristics. Measure to obtain a reference sample measurement and a standard sample measurement. A model formula for estimating the sensory evaluation value from the measurement value is obtained using those measurement values and the sensory evaluation value obtained in advance.
In this way, the model formula is obtained from the reference sample and the standard sample, and the potential Vs or the data ΔVs of the taste sensor obtained by measuring the sample to be measured is substituted into the model formula to obtain the model sample. Estimate sensory evaluation value.
By estimating the sensory evaluation value of the original sample to be measured, for example, management of manufacturing quality in a food factory can be performed at the level of the sensory evaluation value.
[0031]
FIG. 2 is a flowchart of the second embodiment of the present invention. In the second embodiment, ultrasonic stirring is performed in the pretreatment. Since the pre-processing method is different from the first embodiment, and the others are the same, only the pre-processing stage will be described.
The intensity of ultrasonic waves to be applied, the time to be applied, etc. vary depending on the object to be measured, and cannot be generally described. In addition to visually confirming that oils and fats are not separated, in this method, separation of oils and fats and other water gradually progresses over time after the application of ultrasonic waves is stopped. .
[0032]
In the above embodiment, those using a surfactant as an additive and those applying an ultrasonic wave as a physical treatment are listed.
Here, the additive will be explained. As the additive, (1) an organic solvent soluble in water (for example, lower alcohol (methanol, ethanol), acetone, etc.), (2) a surfactant (for example, detergent) , Emulsifier (lecithin), etc.], (3) acid, alkali [HCl, KOH, NaOH, etc.]. (3) Acids and alkalis are not suitable for fats and oils as substances that are hardly soluble in water, but any of the additives (1) to (3) is a bitter substance (as a substance that is hardly soluble in water). Quinine etc.), fibers (meat etc.), solidified (protein etc.), etc. are effective.
[0033]
Regarding physical treatment, physical treatment includes (1) stirring, (2) application of ultrasonic waves, and (3) heating. (3) When heating is used, the measurement by the taste sensor is also performed in a high temperature state (about 60 ° C. If the temperature is too high, the characteristics of the film used in the taste sensor change). (1) Stirring and (2) application of ultrasonic waves are less effective for bitter substances, and (3) heating is less effective for fats and oils, but is effective for other water-insoluble substances.
As in the first embodiment, it is more effective to perform the addition of additives and physical treatment in combination. For example, the use of a surfactant is advantageous for measurement because the amount of fats and oils dissolved in the solution is larger than simply stirring, and the emulsion state is stabilized. From another viewpoint, this means that less time is required for stirring.
[0034]
【The invention's effect】
According to the aji detection method of the present invention, a solution to be measured is prepared by pre-processing the object to be measured, and the measurement is performed with a taste sensor using a film containing an amphiphilic substance or a bitter substance. It is possible to provide a method for detecting a horse mackerel that can detect and identify a fish to be measured that contains a substance that is hardly soluble in water, which has been difficult to detect and identify in the conventional technique.
[Brief description of the drawings]
FIG. 1 is a flowchart of a first embodiment of the present invention.
FIG. 2 is a flowchart of a second embodiment of the present invention.
FIG. 3 is a view for explaining the relationship between the sensory evaluation value of the object to be measured and the measured value obtained by the method for detecting absills according to the present invention.
FIG. 4 is a schematic diagram showing a monomolecular film in an expression method used in a chemical design method.
FIG. 5 is a schematic diagram of a taste sensor, FIG. 5 (a) is a front view, and FIG. 5 (b) is a cross-sectional view.
FIG. 6 is a diagram showing a measurement system for horse mackerel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base material 2 Electrode 3 Lipid membrane 4 Buffer layer 5 Lead wire 10 Basic structure of membrane potential measurement system 11 Solution to be measured 12 Container 13 Taste sensor array 14-1 to 14-8 Each lipid membrane (indicated by black dots)
15 Reference electrode 16 Buffer layer 17-1 to 17-8 Lead wire 18 Lead wire 19-1 to 19-8 Buffer amplifier 20 Analog switch 21 A / D converter 22 Microcomputer 23 XY recorder 24

Ground potential

31, 31 ′ Lipid molecule group 32 Membrane member 33 Matrix

Claims

A method for detecting an object to be measured using a taste sensor using a film containing an amphipathic substance or a bitter substance and containing a substance hardly soluble in water,
A pretreatment stage in which an additive composed of an organic solvent soluble in water is added to the object to be measured to obtain a solution to be measured;
Dipping the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics.

A method for detecting an object to be measured using a taste sensor using a film containing an amphipathic substance or a bitter substance and containing a substance hardly soluble in water ,
A pretreatment stage in which an additive comprising a surfactant is added to the object to be measured to form a solution to be measured;
Dipping the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics.

A method for detecting an object to be measured using a taste sensor using a film containing an amphipathic substance or a bitter substance and containing a substance hardly soluble in water ,
A pretreatment stage in which an additive comprising at least one of an acid and an alkali is added to the object to be measured to obtain a solution to be measured;
Dipping the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics.

A method for detecting an object to be measured containing a bitter substance using a taste sensor using a film containing an amphiphilic substance or a bitter substance,
A pretreatment stage in which an additive composed of an organic solvent soluble in water is added to the object to be measured to obtain a solution to be measured;
Dipping the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics .

A method for detecting an object to be measured containing a bitter substance using a taste sensor using a film containing an amphiphilic substance or a bitter substance,
A pretreatment stage in which an additive comprising a surfactant is added to the object to be measured to form a solution to be measured;
Dipping the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics .

A method for detecting an object to be measured containing a bitter substance using a taste sensor using a film containing an amphiphilic substance or a bitter substance,
A pretreatment stage in which an additive comprising at least one of an acid and an alkali is added to the object to be measured to obtain a solution to be measured;
Dipping the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics .

A method for detecting an object to be measured containing fats and oils using a taste sensor using a film containing an amphiphilic substance or a bitter substance,
A pretreatment stage in which an additive is added to the object to be measured to obtain a solution to be measured in which the fats and oils are dispersed ;
Dipping the taste sensor in a solution to be measured that has become an emulsion by the pretreatment and measuring its electrical characteristics.

The method for detecting horse mackerel according to claim 7, wherein the additive is an organic solvent that is soluble in water .

The azide detection method according to claim 7, wherein the additive is a surfactant .

The method for detecting absills according to claim 7, wherein the additive is at least one of an acid and an alkali .

A method for detecting an object to be measured using a taste sensor using a film containing an amphipathic substance or a bitter substance and containing a substance hardly soluble in water,
Preparing a standard sample in which the content of a predetermined substance of the reference sample of the object to be measured and the substance included in the object to be measured is different from the reference sample;
Adding an additive to the reference sample to prepare a reference sample solution;
Adding an additive to the standard sample to prepare a standard sample solution;
Immersing the taste sensor in the reference sample solution and the standard sample solution to measure electrical characteristics thereof to obtain a reference sample measurement value and a standard sample measurement value;
Obtaining a model formula for estimating the sensory evaluation value from the measurement value using the reference sample measurement value and the standard sample measurement value and the sensory evaluation value of the reference sample and the standard sample obtained in advance;
A pretreatment stage in which an additive is added to the sample of the object to be measured to form a solution to be measured;
Immersing the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics to obtain a sample measurement value;
Substituting the sample measurement value into the model formula to estimate a sensory evaluation value of the sample .

A method for detecting an object to be measured using a taste sensor using a film containing an amphipathic substance or a bitter substance and containing a substance hardly soluble in water,
Preparing a standard sample in which the content of a predetermined substance of the reference sample of the object to be measured and the substance included in the object to be measured is different from the reference sample;
Applying a physical treatment to the reference sample to prepare a reference sample solution;
Subjecting the standard sample to physical treatment to prepare a standard sample solution;
Immersing the taste sensor in the reference sample solution and the standard sample solution to measure electrical characteristics thereof to obtain a reference sample measurement value and a standard sample measurement value;
Obtaining a model formula for estimating the sensory evaluation value from the measurement value using the reference sample measurement value and the standard sample measurement value and the sensory evaluation value of the reference sample and the standard sample obtained in advance;
A pre-treatment stage in which a sample of the object to be measured is physically treated to form a solution to be measured;
Immersing the taste sensor in a solution to be measured obtained by the pretreatment and measuring its electrical characteristics to obtain a sample measurement value;
Substituting the sample measurement value into the model formula to estimate a sensory evaluation value of the sample .