JP3717382B2 - Fermented dairy products - Google Patents

Description

【０００９】
本発明の請求項２に係る発酵乳製品は、上記手段において、光透過性の容器素材が合成樹脂又はガラスであることを特徴とする。
【００１１】
本発明の請求項３に係る発酵乳製品は、上記請求項１又は２の手段において、光透過性の容器素材への遮光手段が、容器素材への着色もしくは着色フィルムの外装によりなされており、着色が橙色、赤色または黄色であることを特徴とする。本発明の請求項４に係る発酵乳製品は、上記請求項３の手段において、上記着色フィルムにより、個別または集合包装されていることを特徴とする。
【００１２】
【発明の実施の形態】
本発明の発酵乳とは、牛乳、山羊乳等の生乳、脱脂粉乳、全脂粉乳、生クリーム等の乳製品、あるいは豆乳をそのままあるいは必要に応じて希釈した溶液中で乳酸菌を培養した発酵物のことであり、乳等省令により定められている発酵乳、乳製品乳酸菌飲料、乳酸菌飲料等の生菌含有タイプの飲料や固形のヨーグルト、発酵豆乳等を含むものである。
また、本発明の発酵乳製品とは、上記発酵乳をそのままあるいはそれらに希釈またはシロップ添加等の加工処理を施した後、容器に充填・包装したもののことである。
【００１３】
発酵乳を調製するために乳製品等に接種する乳酸菌は特に限定されず、ラクトバチルス・カゼイ、ラクトバチルス・アシドフィルス、ラクトバチルス・ガッセリ、ラクトバチルス・ゼアエ、ラクトバチルス・ジョンソニー、ラクトバチルス・デルブルッキー サブスピーシーズ．デルブルッキイ、ラクトバチルス・デルブルッキィ サブスピーシーズ．ブルガリカス等のラクトバチルス属細菌、ストレプトコッカス・サーモフィルス等のストレプトコッカス属細菌、ラクトコッカス・ラクチス、ラクトバチルス・プランタラム、ラクトコッカス・ラフィノラクチス等のラクトコッカス属細菌、ロイコノストック・メセンテロイデス、ロイコノストック・ラクチス等のロイコノストック属細菌、エンテロコッカス・フェーカリス、エンテロコッカス・フェシウム等のエンテロコッカス属細菌等を例示することができる。これらは１種または２種以上を組み合わせて使用することができ、中でもラクトバチルス・カゼイを用いた場合には、菌の耐光性、すなわち過酷な光照射を受けた場合の菌の生残性が特に向上するため好ましい。
【００１４】
また、発酵乳の調製には、ビフィドバクテリウム・ブレーベ、ビフィドバクテリウム・ビフィダム、ビフィドバクテリウム・ロンガム等のビフィドバクテリウム属細菌を乳酸菌とともに使用してもよい。これらも１種または２種以上を組み合わせて使用することができる。
【００１５】
本発明においては、上記の発酵乳を遮光手段を施した光透過性容器に充填する。この光透過性容器とは、４００〜５５０ｎｍの光を透過する容器のことであり、特に、光透過率の平均がおよそ２０％を上回る程度の容器のことである。例えば、この光透過性容器としては、ガラスや合成樹脂素材で成型された容器を例示することができる。合成樹脂素材の具体例としては、ポリスチレン、ポリエチレン、ポリ塩化ビニル、ポリエチレンテレフタレート等を挙げることができ、このうち安価で成形性、安全性に優れているのはポリスチレン、ポリエチレンであり、特に成形性が良好であるのはポリスチレンである。
【００１６】
なお、上記の光透過性容器の光透過率の測定は、積分球式光線透過率測定装置を用い、光源から出た光を試験片（容器）を通し、透過後の光を受光機で測定することにより行う。この測定方法の原理は、「ＪＩＳハンドブック１１プラスチック」（財団法人日本規格協会、１９８７年４月２０日発行）の第２５３頁から第２５５頁に記載されており、また、積分球式光線透過率測定装置の市販品としては、分光測色計（ミノルタ社製）、ヘーズメーター（東洋精機社製）等があり、これらを利用することができる。
【００１７】
本発明では、光透過性容器に充填・包装された発酵乳製品に、波長４００〜５５０ｎｍの光を遮光する遮光手段を施し、内容物中の生菌数の減少を抑制する。遮光の手段は特に限定されないが、遮光に要するコスト、作業性、製品化後の消費者の扱いやすさ等の観点から、例えば、波長４００〜５５０ｎｍを遮断する素材、色彩を用いて、容器に直接着色する方法や、波長４００〜５５０ｎｍを遮断する色彩を施されたフィルムを容器に装着する方法等が好ましい遮光手段として挙げられる。
【００１８】
容器に直接着色を施す場合には、加熱により液状となった合成樹脂素材に各種の顔料や染料を加え着色する方法や、容器成型後に顔料や染料を塗布する方法等を用いることができる。また、着色されたフィルムを容器に装着する場合にも、同様に顔料、染料等を用いて着色すればよく、フィルムは１層でも２層以上重ねて用いてもよい。着色フィルムにより、容器入り発酵乳製品を包装する場合、包装は、個々の製品容器を個別包装しても、複数個の製品容器を集合包装しても良い。
【００１９】
また、着色は、単色・単層で行ってもよいが、２色以上を組み合わせ２層以上の着色層とすれば、光の透過度を低下させるとともに、容器外装のデザインを容易に向上させることができ、また、商品名表示等、表示機能を高めることもできるため好ましい。
【００２０】
ここで、本発明のフィルムとは、プラスチックフィルムのことを指し、フィルムの材質としては、ポリプロピレン、ポリエチレン、ポリスチレン、ポリ塩化ビニル、ポリエチレンテレフタレート等を挙げることができる。
【００２１】
これらの材質は包装目的や包装形態に応じて適宜選択して用いればよく、集合包装にはポリプロピレン、ポリエチレンが適しており、個別包装にはポリスチレン、ポリエチレンテレフタレート等が適している。
【００２２】
また、フィルムの種類については、熱によって収縮するシュリンクフィルムや、フィルムが持つゴム弾性によって物体を締め付けて包装できるストレッチフィルム、自己粘着性を利用したラップフィルム等が挙げられるが、これらの種類も前述した材質と同様に、包装目的や包装形態に応じて適した種類を適宜選択して使用すればよい。
【００２３】
上記遮光手段は、光源の照度２，０００ルクスで１０℃にて１６８時間照射した場合に、下記数式１で算出される波長４００〜５５０ｎｍの可視光の透過エネルギー比の総和を０．１９６８以下に遮断する素材、色彩にて容器全体に渡り行うことが好ましく、特に、０．０３３以下に遮断するものが好ましい。波長４００〜５５０ｎｍの可視光の透過エネルギー比の総和が０．１９６８以下であれば、容器に充填・包装された発酵乳中の菌の耐光性や製品の変色・風味劣化の抑制効果が向上し、０．０３３以下で特に顕著なためである。この透過エネルギー比の総和が容器の部分毎に異なる場合、例えば、複数の色彩にて色づけされた容器などでは、全体の透過エネルギー比の総和の平均値として上記の透過エネルギー比の総和を達成すればよい。
【００２４】
【数１】

【００２５】
透過エネルギー比の総和は、４００〜５５０ｎｍの波長で受けるエネルギー比の総和であり、各波長が持つエネルギーの大きさが異なるため、光源が発する波長の強度比と４００〜５５０ｎｍ間の透過率を用いて各波長でのエネルギー比を算出した後、それを総和し求めることができる。透過エネルギー比の総和が小さいほど容器に充填、包装された発酵乳中の菌が受けるエネルギーが少なく、菌の生残性や発酵乳の変色・風味劣化の抑制効果が高いといえる。
また、光源が発する波長の強度比は、４００〜５５０ｎｍ内の最大強度を１００としたときの各波長での強度割合を示したものである。
【００２６】
本発明においては、透過エネルギー比の総和を算出する手段として、４００〜５５０ｎｍ間を５ｎｍづつに区切り、各々の透過エネルギー比を総和することで算出したが、算出方法はこれに限定されるものではなく、例えば４００〜５５０ｎｍ間を１ｎｍづつに区切り、各々の透過エネルギー比を総和して算出してもよい。
【００２７】
ただし、区切りの範囲を変更すれば、透過エネルギー比の総和の値も変わることとなるため、上記数式１における計算値と直接比較するためには、値を補正する必要がある。例えば１ｎｍづつに区切った場合は、５ｎｍづつに区切った場合と比べ測定箇所の数が５倍となり透過エネルギー比の総和も５倍となるため、１ｎｍで区切った場合の値を５分の１倍して、両者の値を比較すればよい。
【００２８】
４００〜５５０ｎｍでの透過エネルギー比の総和を０．１９６８以下に遮断できる素材、色彩としては、その波長域を遮断できるものであれば特に限定されないが、例えば、可視波長間を全て遮断できる黒色や４００〜５５０ｎｍ間を効果的に遮断できる橙色、赤色、黄色、または茶色などの暖色系色素が挙げられる。中でも、黒色及び暖色系色素は、４００〜５５０ｎｍを０．１９６８以下に遮光できるため好ましい。更に、食品の包装という観点から、また表示上の観点からは、橙色が好適である。
【００２９】
また、本発明において、容器もしくは集合包装体への遮光がなされていない部分（いわゆる露出部分）及びほとんどなされていない部分の割合は、低く抑える必要があり、上記と同様、全体の平均として透過エネルギー比を０．１９６８以下、特に０．０３３以下とすることが好ましい。具体的には、露出部分の面積が５％未満（遮光部分９５％以上）であれば十分な耐光性の向上効果を得ることができる。
【００３０】
なお、製品を個別、あるいは集合包装する場合に、例えばキャップのように製品容器の一部にアルミキャップ等の可視光を遮断する資材が用いられている場合には、必ずしも製品全体を包装する必要はない。また、製品の流通において光の照射がほとんどない製品容器底部については、必ずしも包装する必要はなく、上記遮光部分の面積の割合は、これらの部分の面積を差し引いて算出すればよい。しかし、底部も包装する方がより確実に光の照射を回避することができるため好ましい。
【００３１】
本発明の遮光手段を施された容器入り発酵乳製品としては、２０００ルクスの照度で、１０℃にて１６８時間の光照射を行った場合における発酵乳中の乳酸菌の生残率が、完全遮光した発酵乳（対照品）の乳酸菌の生残率（生残性）の１０％以上、特に８０％以上であることが好ましい。１０％以上であれば、耐光性が充分に向上し、物流段階、店頭での陳列時等において起こり得る光暴露等にも耐え、生菌数、色調、風味等を保証でき、８０％以上でより顕著なためである。このような耐光性を付与した発酵乳製品であれば、例えば、コンビニエンスストアの陳列棚等に品質保持期限である２週間程度陳列された場合、あるいは物流段階での光暴露等を十分に許容し得るのである。
【００３２】
この生残率は、容器入り発酵乳製品の光照射前の生菌数、及び光安定性試験器（ＬＳＴ−３００型、東京理化器械製）を用いて、光を２０００ルクスの照度で１０℃にて１６８時間照射した後生菌数を測定し、この照射前、照射後の生菌数から後述する数式２に従い算出すればよい。この値を完全遮光し、その他の処方、操作は同様に行った対照品と対比することにより、上記生残率の向上度合いを調べることができる。
【００３３】
本発明の発酵乳製品の製造は４００〜５５０ｎｍの光を遮断する手段を施す以外には、常法に従い実施することができる。例えば、まず脱脂粉乳溶液を殺菌処理した後、乳酸菌を接種培養し、これを均質化処理して発酵乳を得る。発酵の方法、条件も通常の条件で良く、特に限定されない。例えば、ラクトバチルス・カゼイを用いるのであれば、乳製品を含む培地に該菌を接種し、３７℃程度でｐＨ３．５〜４．５程度まで培養すればよい。培養方法は、静置培養、攪拌培養、振盪培養、通気培養等から用いる微生物の培養に適した方法を適宜選択して用いればよい。
【００３４】
また、本発明においては、発酵乳にその他の食品素材、すなわち各種糖質や乳化剤、増粘剤、増粘剤、甘味料、酸味料、果汁等を適宜配合してもよい。具体的には、蔗糖、異性化糖、グルコース、フラクトース、パラチノース、トレハロース、ラクトース、キシロース等の糖類、ソルビトール、キシリトール、エリスリトール、ラクチトール、パラチニット、還元水飴、還元麦芽糖水飴等の糖アルコール類、蔗糖脂肪酸エステル、グリセリン脂肪酸エステル、レシチン等の乳化剤、カラギーナン、キサンタンガム、グァーガム、ペクチン、ローカストビーンガム等の増粘（安定）剤、クエン酸、乳酸、リンゴ酸等の酸味料、レモン果汁、オレンジ果汁、ベリー系果汁等の果汁類等が挙げられる。この他にも、ビタミンＡ、ビタミンＢ類、ビタミンＣ、ビタミンＤ、ビタミンＥ等のビタミン類やカルシウム、鉄、マンガン、亜鉛等のミネラル類等を配合することも可能である。
【００３５】
更に、本発明者らが発酵乳の耐光性を向上させ得る成分として見出しているビタミンＣやビタミンＥ、ヤマモモ抽出物、クロロゲン酸、ルチン、β−カロチン、システイン等のチオール類を添加すれば、より高い耐光性が得られるため好ましい。
【００３６】
このようにして得られる本発明の発酵乳製品は、プレーンタイプ、フレーバードタイプ、フルーツタイプ、甘味タイプ等、いずれの種類の製品とすることも可能であり、また、プレーンタイプ、ソフトタイプ、ドリンクタイプ、固形（ハード）タイプ、フローズンタイプ等、いずれの種類の製品とすることも可能である。
【００３７】
【実施例】
以下、実施例を挙げて本発明を更に詳細に説明するが、本発明はこれらに限定されるものではない。なお、表１中の実施品の５、６及び７は、特許請求の範囲外の参考例である。
（試験例１）
（サンプルの調製）
脱脂粉乳（固形分１５．２％、脂肪０．２％、蛋白５．７％）を１２１℃で３秒間殺菌した。ラクトバチルス・カゼイＹＩＴ９０２９の種菌を０．５％接種し、ｐＨ３．６となるまで培養した。得られた発酵乳を１５０ｋｇ／ｃｍ²で均質化後、蔗糖を含むシロップ液を添加、混合した（蔗糖終濃度４．０％、ＳＮＦ３．１）。
【００３８】
（光照射試験）
セル（光路長１ｃｍ）に前記の発酵乳を一定量とり、恒温循環式のセルホルダを装着した分光照射器にセルを置いて種々の可視波長（４００ｎｍ，４５０ｎｍ，５００ｎｍ，５５０ｎｍ）を所定量照射した。恒温循環式セルホルダには、１０℃で水を循環させた。
光照射前、光照射後の乳酸菌の生菌数を測定し、数式２に従い乳酸菌の生残率を算出した。
結果を図１に示す。
【００３９】
【数２】

【００４０】
結果より、５５０ｎｍ未満の可視光を照射することにより、乳酸菌の生存率が低下することが分かった。
【００４１】
（試験例２）
ポリスチレン容器の各波長に対する光の透過率を測定した。
【００４２】
（透過率の測定法）
ポリスチレン容器から一定量のポリスチレン片を取り、積分球式光線透過率測定装置を用い、光源から出た光を試験片（容器）に通し、透過後の光を受光機で測定した。
結果を図２に示す。図２から、ポリスチレン容器は４００〜７００ｎｍの光を５５〜８０％程度透過し、４００〜５５０ｎｍの光も５５〜７５％程度透過することがわかった。
【００４３】
（試験例３）
次に各着色フィルムの各波長に対する光の透過率を測定した。
【００４４】
（透過率の測定法）
一定量の着色フィルムを取り、積分球式光線透過率測定装置を用い、光源から出た光を試験片（着色フィルム）に通し、透過後の光を受光機で測定した。
結果を図３に示す。図３から、各着色フィルムは４００〜５５０ｎｍの光の透過量を４０％程度以下に低減していることがわかった。また、暖色系の色彩を有するものが特に遮光度高かった。
【００４５】
（実施例１）
（色の異なる着色フィルムで全面包装した発酵乳製品の耐光性試験）
脱脂粉乳（固形分１５．２％、脂肪０．２％、蛋白５．７％）を１２１℃で３秒間殺菌した。ラクトバチルス・カゼイＹＩＴ９０２９の種菌を０．５％接種し、ｐＨ３．６となるまで培養した。得られた発酵乳を１５０ｋｇ／ｃｍ²で均質化後、蔗糖を含むシロップ液を添加、混合した（蔗糖終濃度４．０％、ＳＮＦ３．１）。
ポリスチレン製容器に、前記の発酵乳を充填し、表１の各着色フィルムで全面包装し、光源（蛍光灯FL40SW）により、２０００ルクスの照度で１６８時間照射しながら１０℃にて保存した。
なお、紫外線遮断フィルムは３８０ｎｍ以下の波長の透過量を１０％程度以下に低減するフィルムである。
【００４６】
一方、対照品としては、完全に遮光できるようにアルミ箔で全面を覆ったポリスチレン製容器に充填した発酵乳製品と着色フィルムを包装しないポリスチレン製容器に充填した発酵乳製品を用いた。
保存後の完全遮光品と比較した保存後の色差、乳酸菌の生残率と風味評価、ならびに下記数式１により算出した各着色フィルムの４００〜５５０ｎｍにおける透過エネルギー比の総和を表１に示す。
【００４７】
（透過エネルギー比の総和の算出）
透過エネルギー比の総和は、４００〜５５０ｎｍの波長で受けるエネルギー比の総和であり、各波長が持つエネルギーの大きさが異なるため、光源が発する波長の強度比と４００〜５５０ｎｍ間の透過率を用いて各波長でのエネルギー比を算出した後、それを総和し求めることができる。
また、光源が発する波長の強度比は、４００〜５５０ｎｍ内の最大強度を１００としたときの各波長での強度割合を示したものである。
【００４８】
【数１】

【００４９】
光源に用いた蛍光灯FL40SWの光スペクトルを図４に示す。
【００５０】
【表１】

【００５１】
結果より、４００〜５５０ｎｍの可視光を遮断できる橙色の着色層を有する着色フィルムにより包装されたもの（実施品１）は、完全遮光品（実施品７）に劣らず、乳酸菌の生残率を有するものであり、退色や風味の劣化について抑制されたものであった。
さらに、橙色に白色層を重ねたフィルム（実施品２）は橙色だけのフィルムに比べ、より高い耐光性効果が確認された。
また、橙色には若干劣るものの、赤色（実施品３）や黄色（実施品４）についても、乳酸菌の生残率改善や退色の抑制、さらに風味の劣化について効果が認められた。
【００５２】
緑色（実施品５）、青色（実施品６）についても、橙色、赤色、黄色などの暖色系には劣るもののフィルム無し（比較品１）や紫外線遮断フィルム（比較品２）に比べ、乳酸菌の生残率改善や退色の抑制効果が認められた。
以上の結果から、透過エネルギー比の総和を０．２７以下とすれば、完全遮光品の乳酸菌の生残率の１０％以上の生菌数を保証でき、透過エネルギー比の総和を０．０３３以下とすれば８０％以上の生菌数を保証できることが判った。
【００５３】
（実施例２）
（全面および一部着色フィルムで包装された発酵乳製品の耐光性試験）
ある特定の色で着色したフィルムについて効果があることがわかったので、次に効果のある着色フィルムの包装面積を変えた場合について確認した。
【００５４】
実施例１と同様、脱脂粉乳（固形分１５．２％、脂肪０．２％、蛋白５．７％）を１２１℃で３秒間殺菌した。ラクトバチルス・カゼイＹＩＴ９０２９の種菌を０．５％接種し、ｐＨ３．６となるまで培養した。得られた発酵乳を１５０ｋｇ／ｃｍ²で均質化後、蔗糖を含むシロップ液を添加、混合した（蔗糖終濃度４．０％、ＳＮＦ３．１）。
ポリスチレン製容器に、前記の発酵乳を充填し、橙色に白色層を重ねた着色フィルムで全面あるいは一部未包装（容器側面の約５、２０％を未包装）し、光源（蛍光灯FL40SW）により、２０００ルクスの照度で１６８時間照射しながら１０℃にて保存した。
保存前と比較した保存後の色差、乳酸菌の生残率、及び風味評価（実施例１と同様）を表２に示す。
【００５５】
【表２】

【００５６】
【発明の効果】
本発明によれは、波長４００〜５５０ｎｍの可視光を遮光素材、例えば着色フィルムにより遮断することで、流通時等の光照射による製品中の菌数の減少を効果的に防止することができる。
また、本発明によれば、遮光素材、例えば着色フィルムの着色層を異なる色で２層以上重ねれば、より確実に４００〜５５０ｎｍの可視光を遮断できる。なお、着色層の上に重ねる着色層に白色層を用いることで、商品の包装におけるデザイン上も何ら制約のない包装を行うことができる。
更に、本発明によれば、遮光性容器入り乳発酵製品を個別あるいは集合包装のいずれの遮光形態によっても光照射による製品中の菌数の減少を効果的に防止することができる。
【図面の簡単な説明】
【図１】光照射エネルギー量と乳酸菌の生残率の相関図。
【図２】ポリスチレン容器に対する投射光の波長変化と透過率の相関図。
【図３】着色フィルムの波長別透過率の変化図。
【図４】蛍光灯の波長に対する強度比特性図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fermented dairy product in a light-transmitting container provided with a light shielding means for blocking visible light having a wavelength of 400 to 550 nm, and more specifically, to some extent viable lactic acid bacteria even when stored under severe light irradiation The present invention relates to a fermented dairy product in a container provided with means for blocking visible light having a wavelength of 400 to 550 nm, which can guarantee the number and suppress deterioration and fading of flavor.
[0002]
[Prior art]
Conventionally, fermented milk containing lactic acid bacteria and Bifidobacterium has been widely eaten and consumed as health foods having physiological activities such as intestinal regulation and immunostimulatory action. Since the physiological activity of fungi often depends on the number of viable bacteria contained in the product, various survivability improvers, etc., are added to the commercially available products for the purpose of growing and maintaining the number of fungi. Sometimes it is.
[0003]
Glass bottles have long been used as a material for containers filled with fermented milk and used as fermented dairy products (food). However, the weight and fragility of glass bottles are unsuitable for transportation and are also safe for use. There's a problem. For this reason, in recent years, synthetic resins such as polystyrene and polyethylene and paper have been used as container materials. However, paper containers have poor moldability and shape retention. For this reason, from the viewpoint of good moldability and cost, recently, synthetic resin materials are widely used as materials that are easy to use.
[0004]
Moreover, resin films such as polypropylene, polyethylene, polystyrene, polyethylene terephthalate, and vinyl chloride are mainly used as materials for films for individually or collectively packaging fermented milk products.
The containers and films described above are often designed so that fermented milk or fermented milk products can be seen in consideration of product appeal and display effects at the store, etc. Can be said to be expensive.
[0005]
[Problems to be solved by the invention]
By the way, in viable bacteria-containing foods such as fermented milk, if the storage state of the product is inferior to the growth of the fungus, the decrease in the viable cell count may not be suppressed. For example, if a fermented dairy product filled and packaged in a light-transmitting container such as a glass container or a synthetic resin container as described above continues to be exposed to intense light irradiation for a short time or a long time, It has been clarified by the inventor's research that the number of bacteria decreases. Moreover, discoloration, flavor deterioration, etc. of fermented milk may also occur.
[0006]
Depending on the product distribution process and the state of display at each store, the irradiation conditions for the product may differ, and there may be severe light irradiation. To supply a homogeneous product to consumers, In such cases, maintaining the number of bacteria is also important.
However, at present, no countermeasures have been taken against the decrease in the number of bacteria due to such severe light irradiation.
[0007]
Accordingly, an object of the present invention is to provide fermented milk and fermented dairy products in which the survival of lactic acid bacteria is maintained and the flavor and physical properties are not deteriorated even when stored under severe light irradiation conditions. It is.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that even when harsh light irradiation is applied to a fermented dairy product packaged in a light transmissive container, the light transmissive container On the other hand, the present inventors have found that the reduction of the number of bacteria and the deterioration of flavor can be suppressed by applying a light shielding means for blocking a specific wavelength. That is, the fermented milk product according to claim 1 of the present invention is a fermented milk product in which fermented milk is packaged in a light-transmitting container, and blocks visible light having a wavelength of 400 to 550 nm from the light-transmitting container. der which shading means is applied to is, light-shielding function of shielding material constituting the light shielding means, when irradiated for 168 hours at 10 ° C. at an intensity of 2,000 lux light source, it is calculated by the following equation 1 The total transmission energy ratio of visible light having a wavelength of 400 to 550 nm is blocked to 0.1968 or less (excluding a completely light-shielded product) .
[Expression 1]

[0009]
The fermented milk product according to claim 2 of the present invention is characterized in that, in the above means, the light-transmitting container material is a synthetic resin or glass.
[0011]
The fermented dairy product according to claim 3 of the present invention is the means of claim 1 or 2 , wherein the light-shielding means to the light-transmitting container material is made by coloring the container material or by covering the colored film , coloring characterized orange, red or yellow der Rukoto. The fermented dairy product according to claim 4 of the present invention is characterized in that, in the means of claim 3 , it is individually or collectively packaged by the colored film.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The fermented milk of the present invention is a fermented product in which lactic acid bacteria are cultured in a raw milk such as cow's milk, goat milk, dairy products such as skim milk powder, whole milk powder milk, fresh cream, or soy milk as it is or diluted as necessary This includes fermented milk, dairy lactic acid bacteria beverages, lactic acid bacteria beverages and other types of beverages that contain live bacteria, solid yogurt, fermented soy milk, etc.
The fermented dairy product of the present invention is a product obtained by filling and packaging the fermented milk as it is or after subjecting them to a treatment such as dilution or addition of syrup.
[0013]
Lactic acid bacteria to inoculate dairy products etc. to prepare fermented milk are not particularly limited, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus gasseri, Lactobacillus zeae, Lactobacillus johnsonii, Lactobacillus del Brooke Subspecies. Del Brucchii, Lactobacillus del Brucchi Subspecies. Lactobacillus genus bacteria such as Bulgaricus, Streptococcus bacterium such as Streptococcus thermophilus, Lactococcus lactis, Lactobacillus plantarum, Lactococcus raffinolactis etc. Examples include bacteria of the genus Leuconostoc such as stock lactis and bacteria of the genus Enterococcus such as enterococcus faecalis and enterococcus faecium. These can be used alone or in combination of two or more. In particular, when Lactobacillus casei is used, the light resistance of the fungus, that is, the survival of the fungus when subjected to severe light irradiation. Since it improves especially, it is preferable.
[0014]
For the preparation of fermented milk, Bifidobacterium bacteria such as Bifidobacterium breve, Bifidobacterium bifidum and Bifidobacterium longum may be used together with lactic acid bacteria. These can also be used 1 type or in combination of 2 or more types.
[0015]
In the present invention, the fermented milk is filled in a light transmissive container provided with a light shielding means. This light-transmitting container is a container that transmits light of 400 to 550 nm, and in particular, is a container having an average light transmittance exceeding about 20%. For example, examples of the light transmissive container include a container formed of glass or a synthetic resin material. Specific examples of synthetic resin materials include polystyrene, polyethylene, polyvinyl chloride, polyethylene terephthalate, etc. Of these, polystyrene and polyethylene are particularly inexpensive and have excellent moldability and safety. Is good for polystyrene.
[0016]
The light transmittance of the above light transmissive container is measured using an integrating sphere light transmittance measuring device, the light emitted from the light source is passed through a test piece (container), and the light after transmission is measured with a light receiver. To do. The principle of this measurement method is described in pages 253 to 255 of “JIS Handbook 11 Plastic” (Japan Standards Association, issued on April 20, 1987). Examples of commercially available measuring devices include a spectrocolorimeter (manufactured by Minolta), a haze meter (manufactured by Toyo Seiki), and the like.
[0017]
In the present invention, the fermented dairy product filled and packaged in a light transmissive container is provided with a light shielding means for shielding light having a wavelength of 400 to 550 nm to suppress a decrease in the number of viable bacteria in the contents. The light shielding means is not particularly limited, but from the viewpoints of cost required for light shielding, workability, ease of handling by consumers after commercialization, etc., for example, using a material or color that blocks a wavelength of 400 to 550 nm, Examples of preferable light-shielding means include a direct coloring method and a method in which a film having a color that blocks a wavelength of 400 to 550 nm is attached to a container.
[0018]
When the container is directly colored, a method of coloring by adding various pigments or dyes to the synthetic resin material that has become liquid by heating, a method of applying the pigment or dye after molding the container, or the like can be used. In addition, when a colored film is attached to a container, it may be similarly colored using a pigment, a dye or the like, and the film may be used in a single layer or two or more layers. When packaging a fermented milk product in a container with a colored film, the packaging may be individual packaging of individual product containers or multiple product containers.
[0019]
Coloring may be performed in a single color / single layer, but if two or more colors are combined to form a colored layer of two or more layers, the light transmittance is reduced and the design of the container exterior is easily improved. It is also preferable because display functions such as product name display can be enhanced.
[0020]
Here, the film of the present invention refers to a plastic film, and examples of the material of the film include polypropylene, polyethylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate.
[0021]
These materials may be appropriately selected and used according to the packaging purpose and packaging form. Polypropylene and polyethylene are suitable for collective packaging, and polystyrene and polyethylene terephthalate are suitable for individual packaging.
[0022]
Examples of the film type include a shrink film that shrinks by heat, a stretch film that can be wrapped and wrapped by rubber elasticity of the film, and a wrap film that utilizes self-adhesiveness. Similar to the above materials, a suitable type may be selected and used according to the packaging purpose and packaging form.
[0023]
When the light shielding means is irradiated for 168 hours at 10 ° C. with an illuminance of 2,000 lux, the total transmission energy ratio of visible light having a wavelength of 400 to 550 nm calculated by the following formula 1 is 0.1968 or less. It is preferable to carry out over the entire container with the material and color to be blocked, and in particular, those that block to 0.033 or less are preferable. If the total transmission energy ratio of visible light having a wavelength of 400 to 550 nm is 0.1968 or less, the light resistance of bacteria in the fermented milk filled and packaged in the container and the effect of suppressing discoloration and flavor deterioration of the product are improved. This is because it is particularly remarkable at 0.033 or less. When the total sum of transmitted energy ratios is different for each part of the container, for example, in a container colored with a plurality of colors, the above sum of the transmitted energy ratios can be achieved as an average value of the total sum of transmitted energy ratios. That's fine.
[0024]
[Expression 1]

[0025]
The sum of the transmission energy ratios is the sum of the energy ratios received at wavelengths of 400 to 550 nm, and since the magnitude of the energy of each wavelength is different, the intensity ratio of the wavelengths emitted by the light source and the transmittance between 400 to 550 nm are used. After calculating the energy ratio at each wavelength, it can be obtained by summing them. It can be said that the smaller the sum of the transmitted energy ratios, the less the energy received by the bacteria in the fermented milk filled and packaged in the container, and the higher the effect of suppressing the survival of the bacteria and the discoloration and flavor deterioration of the fermented milk.
The intensity ratio of the wavelengths emitted from the light source indicates the intensity ratio at each wavelength when the maximum intensity within 400 to 550 nm is 100.
[0026]
In the present invention, as a means for calculating the total transmission energy ratio, the calculation was performed by dividing 400 nm to 550 nm in 5 nm increments and totaling each transmission energy ratio. However, the calculation method is not limited to this. For example, it may be calculated by dividing 400 to 550 nm into 1 nm increments and summing the transmission energy ratios.
[0027]
However, if the delimiter range is changed, the value of the sum of the transmission energy ratios also changes. Therefore, in order to directly compare with the calculated value in Equation 1, it is necessary to correct the value. For example, when divided by 1 nm, the number of measurement points is 5 times and the total transmission energy ratio is 5 times compared to when divided by 5 nm, so the value when divided by 1 nm is 1/5. Then, both values may be compared.
[0028]
The material and color that can block the total transmission energy ratio at 400 to 550 nm to 0.1968 or less are not particularly limited as long as the wavelength range can be blocked. For example, black or black that can block all visible wavelengths can be used. Examples thereof include warm color pigments such as orange, red, yellow, and brown that can effectively block between 400 to 550 nm. Among these, black and warm color pigments are preferable because they can shield light from 400 to 550 nm to 0.1968 or less . Further, orange is preferable from the viewpoint of packaging of food and from the viewpoint of display.
[0029]
In the present invention, it is necessary to keep the ratio of the part that is not light-shielded to the container or the collective package (so-called exposed part) and the part that is hardly made low. The ratio is preferably 0.1968 or less , particularly 0.033 or less. Specifically, if the area of the exposed part is less than 5% (light shielding part 95% or more), a sufficient light resistance improvement effect can be obtained.
[0030]
When products are individually or collectively packaged, for example, when a material that blocks visible light such as an aluminum cap is used for a part of the product container, such as a cap, the entire product must be packaged. There is no. Further, it is not always necessary to wrap a product container bottom portion that is hardly irradiated with light during product distribution, and the area ratio of the light shielding portion may be calculated by subtracting the area of these portions. However, it is preferable to wrap the bottom as well because it is possible to avoid irradiation of light more reliably.
[0031]
As a fermented milk product in a container subjected to the light shielding means of the present invention, the survival rate of lactic acid bacteria in fermented milk when irradiated with light at 10 ° C. for 168 hours at an illumination intensity of 2000 lux is completely light-shielded. The fermented milk (control product) has a survival rate (survival) of lactic acid bacteria of 10% or more, preferably 80% or more. If it is 10% or more, the light resistance is sufficiently improved, it can withstand light exposure, etc. that can occur at the distribution stage, display at the store, etc., and can guarantee the number of viable bacteria, color, flavor, etc. This is because it is more prominent. Such fermented dairy products with light resistance, for example, are sufficiently allowed to be exposed to light at the distribution stage when displayed on the shelf of a convenience store for about two weeks, which is the shelf life of quality. To get.
[0032]
This survival rate is 10 ° C. at an illuminance of 2000 lux using a viable cell count before light irradiation of the fermented milk product in a container and a light stability tester (LST-300 type, manufactured by Tokyo Rika Kikai Co., Ltd.). The number of viable bacteria after irradiation for 168 hours may be measured, and the number of viable bacteria before and after irradiation may be calculated according to Equation 2 described below. The degree of improvement in the survival rate can be examined by completely shielding this value and comparing the other prescriptions and operations with the same control product.
[0033]
Manufacture of the fermented milk product of this invention can be implemented in accordance with a conventional method except providing the means which interrupts | blocks the light of 400-550 nm. For example, first, the skim milk solution is sterilized, inoculated with lactic acid bacteria, and homogenized to obtain fermented milk. Fermentation methods and conditions may be normal conditions and are not particularly limited. For example, if Lactobacillus casei is used, the bacterium may be inoculated into a medium containing dairy products and cultured at about 37 ° C. to a pH of about 3.5 to 4.5. As a culture method, a method suitable for culture of microorganisms used from stationary culture, stirring culture, shaking culture, aeration culture, and the like may be appropriately selected and used.
[0034]
Moreover, in this invention, you may mix | blend other food materials, ie, various saccharides, an emulsifier, a thickener, a thickener, a sweetener, a sour agent, fruit juice, etc. suitably in fermented milk. Specifically, sugars such as sucrose, isomerized sugar, glucose, fructose, palatinose, trehalose, lactose, xylose, sugar alcohols such as sorbitol, xylitol, erythritol, lactitol, palatinit, reduced starch syrup, reduced maltose starch syrup, sucrose fatty acid Emulsifiers such as esters, glycerin fatty acid esters, lecithin, thickeners (stabilizers) such as carrageenan, xanthan gum, guar gum, pectin, locust bean gum, acidulants such as citric acid, lactic acid, malic acid, lemon juice, orange juice, berries Examples include fruit juices such as system fruit juices. In addition, vitamins such as vitamin A, vitamin B, vitamin C, vitamin D, and vitamin E, and minerals such as calcium, iron, manganese, and zinc can be added.
[0035]
Furthermore, if we add thiols such as vitamin C, vitamin E, bayberry extract, chlorogenic acid, rutin, β-carotene, cysteine, etc. that we find as ingredients that can improve the light resistance of fermented milk, Since higher light resistance is obtained, it is preferable.
[0036]
The fermented dairy product of the present invention thus obtained can be any kind of product such as plain type, flavored type, fruit type, sweetness type, etc. Also, plain type, soft type, drink Any kind of product such as a type, a solid (hard) type, and a frozen type can be used.
[0037]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these. In addition, 5, 6, and 7 of the implementation goods in Table 1 are reference examples outside a claim.
(Test Example 1)
(Sample preparation)
Nonfat dry milk (solid content 15.2%, fat 0.2%, protein 5.7%) was sterilized at 121 ° C. for 3 seconds. 0.5% inoculum of Lactobacillus casei YIT9029 inoculum was inoculated and cultured until pH 3.6 was reached. After homogenizing the obtained fermented milk at 150 kg / cm ² , a syrup solution containing sucrose was added and mixed (final sucrose concentration 4.0%, SNF 3.1).
[0038]
(Light irradiation test)
A certain amount of the above fermented milk is taken in a cell (optical path length 1 cm), and the cell is placed in a spectral irradiator equipped with a constant temperature circulation type cell holder, and various visible wavelengths (400 nm, 450 nm, 500 nm, 550 nm) are irradiated in predetermined amounts. . Water was circulated at 10 ° C. in the thermostatic cell holder.
The number of living lactic acid bacteria before and after light irradiation was measured, and the survival rate of lactic acid bacteria was calculated according to Equation 2.
The results are shown in FIG.
[0039]
[Expression 2]

[0040]
From the results, it was found that the survival rate of lactic acid bacteria decreased by irradiating visible light of less than 550 nm.
[0041]
(Test Example 2)
The light transmittance with respect to each wavelength of the polystyrene container was measured.
[0042]
(Measurement method of transmittance)
A fixed amount of polystyrene pieces were taken from the polystyrene container, the light emitted from the light source was passed through a test piece (container) using an integrating sphere light transmittance measuring device, and the light after transmission was measured with a light receiver.
The results are shown in FIG. From FIG. 2, it was found that the polystyrene container transmits light of 400 to 700 nm by about 55 to 80%, and light of 400 to 550 nm also transmits about 55 to 75%.
[0043]
(Test Example 3)
Next, the light transmittance with respect to each wavelength of each colored film was measured.
[0044]
(Measurement method of transmittance)
A fixed amount of colored film was taken, and the light emitted from the light source was passed through a test piece (colored film) using an integrating sphere light transmittance measuring device, and the light after transmission was measured with a light receiver.
The results are shown in FIG. From FIG. 3, it was found that each colored film reduced the light transmission amount of 400 to 550 nm to about 40% or less. Further, those having a warm color have a particularly high light shielding degree.
[0045]
(Example 1)
(Light resistance test of fermented dairy products fully packed with colored films of different colors)
Nonfat dry milk (solid content 15.2%, fat 0.2%, protein 5.7%) was sterilized at 121 ° C. for 3 seconds. 0.5% inoculum of Lactobacillus casei YIT9029 inoculum was inoculated and cultured until pH 3.6 was reached. After homogenizing the obtained fermented milk at 150 kg / cm ² , a syrup solution containing sucrose was added and mixed (final sucrose concentration 4.0%, SNF 3.1).
The fermented milk was filled in a polystyrene container, and was fully packaged with each colored film shown in Table 1, and stored at 10 ° C. while irradiating with a light source (fluorescent lamp FL40SW) at an illuminance of 2000 lux for 168 hours.
The ultraviolet blocking film is a film that reduces the amount of transmission at a wavelength of 380 nm or less to about 10% or less.
[0046]
On the other hand, as a control product, fermented milk products filled in a polystyrene container covered with an aluminum foil so as to be completely shielded from light, and a fermented milk product filled in a polystyrene container not wrapped with a colored film were used.
Table 1 shows the color difference after storage compared to the completely light-shielded product after storage, the survival rate and flavor evaluation of lactic acid bacteria, and the total transmission energy ratio at 400 to 550 nm of each colored film calculated by the following formula 1.
[0047]
(Calculation of total transmission energy ratio)
The sum of the transmission energy ratios is the sum of the energy ratios received at wavelengths of 400 to 550 nm, and since the magnitude of the energy of each wavelength is different, the intensity ratio of the wavelengths emitted by the light source and the transmittance between 400 to 550 nm are used. After calculating the energy ratio at each wavelength, it can be obtained by summing them.
The intensity ratio of the wavelengths emitted from the light source indicates the intensity ratio at each wavelength when the maximum intensity within 400 to 550 nm is 100.
[0048]
[Expression 1]

[0049]
The light spectrum of the fluorescent lamp FL40SW used as the light source is shown in FIG.
[0050]
[Table 1]

[0051]
From the results, the one packaged with a colored film having an orange colored layer capable of blocking visible light of 400 to 550 nm (practical product 1) is not inferior to the completely light-shielded product (practical product 7), and has a survival rate of lactic acid bacteria. It had what was suppressed about discoloration and flavor deterioration.
Furthermore, a higher light resistance effect was confirmed in the film in which the white layer was superimposed on the orange color (Practical product 2) as compared with the film having only the orange color.
In addition, although slightly inferior to orange, red (practical product 3) and yellow (practical product 4) were also effective in improving the survival rate of lactic acid bacteria, suppressing discoloration, and further reducing the flavor.
[0052]
The green color (practical product 5) and blue color (practical product 6) are also inferior to warm colors such as orange, red, yellow, etc., but compared to no film (comparative product 1) and UV blocking film (comparative product 2). Improvement in survival rate and suppression of fading were observed.
From the above results, if the total transmission energy ratio is 0.27 or less, the viable count of 10% or more of the survival rate of lactic acid bacteria in a completely light-shielded product can be guaranteed, and the total transmission energy ratio is 0.033 or less. It was found that a viable count of 80% or more can be guaranteed.
[0053]
(Example 2)
(Light resistance test of fermented dairy products packaged entirely and partially with colored film)
Since it turned out that there exists an effect about the film colored with a certain specific color, it confirmed about the case where the packaging area of an effective colored film was changed next.
[0054]
As in Example 1, skim milk powder (solid content 15.2%, fat 0.2%, protein 5.7%) was sterilized at 121 ° C. for 3 seconds. 0.5% inoculum of Lactobacillus casei YIT9029 inoculum was inoculated and cultured until pH 3.6 was reached. After homogenizing the obtained fermented milk at 150 kg / cm ² , a syrup solution containing sucrose was added and mixed (final sucrose concentration 4.0%, SNF 3.1).
Fill the polystyrene container with the above fermented milk and unwrap the entire surface or part of it with a colored film with a white layer on orange (unwrapped about 5 to 20% of the side of the container). Light source (fluorescent lamp FL40SW) Was stored at 10 ° C. while being irradiated for 168 hours at an illuminance of 2000 lux.
Table 2 shows the color difference after storage compared to before storage, the survival rate of lactic acid bacteria, and the flavor evaluation (similar to Example 1).
[0055]
[Table 2]

[0056]
【The invention's effect】
According to the present invention, by reducing visible light having a wavelength of 400 to 550 nm with a light shielding material, for example, a colored film, it is possible to effectively prevent a decrease in the number of bacteria in the product due to light irradiation during distribution or the like.
In addition, according to the present invention, if two or more light-shielding materials, for example, colored layers of a colored film are stacked with different colors, visible light of 400 to 550 nm can be blocked more reliably. In addition, by using a white layer for the colored layer to be superimposed on the colored layer, packaging without any restrictions can be performed in terms of design in packaging of products.
Furthermore, according to the present invention, it is possible to effectively prevent a decrease in the number of bacteria in the product due to light irradiation, regardless of whether the milk-fermented product in the light-shielding container is individually or in a collective package.
[Brief description of the drawings]
FIG. 1 is a correlation diagram between the amount of light irradiation energy and the survival rate of lactic acid bacteria.
FIG. 2 is a correlation diagram between a change in wavelength of light projected to a polystyrene container and transmittance.
FIG. 3 is a change diagram of transmittance of each colored film according to wavelength.
FIG. 4 is an intensity ratio characteristic diagram with respect to the wavelength of a fluorescent lamp.

Claims (4)

The fermented milk a packaged fermented milk product of an optically transparent container state, and are not shielding means to said light permeable container blocks visible light with a wavelength of 400~550nm is performed, the light shielding means When the light shielding function of the light shielding material to be configured is irradiated with light source illuminance of 2,000 lux at 10 ° C. for 168 hours, the total transmission energy ratio of visible light having a wavelength of 400 to 550 nm calculated by the following formula 1 is 0. A fermented milk product in a light-shielding container (except for a completely light-shielded product) , characterized by being blocked to 1968 or lower .

  2. The fermented milk product in a light-shielding container according to claim 1, wherein the light-transmitting container material is a synthetic resin or glass. Shielding means for light transmitting container material, have been made by the exterior of the colored or colored film to the container material, the coloration orange, according to claim 1 or 2, wherein the red or features yellow der Rukoto Fermented dairy products in light-shielding containers. The fermented milk product in a light-shielding container according to claim 3 , wherein the colored film is individually or collectively packaged.

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