JP2500499B2 - Manufacturing method of rice cooked immediately after packaging - Google Patents

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、包装された即炊き米を
開封して洗米及び水浸漬せずに直ちに炊飯することので
きる、いわゆる包装即炊き米の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing so-called packaged ready-cooked rice which allows the packaged ready-cooked rice to be opened and immediately cooked without washing and soaking in water.

【０００２】[0002]

【従来の技術】従来、この種の製造方法に類似する早炊
き米の製造方法として、もち米を短時間水に浸漬し、も
ち米の水分含量を約３０〜４５％とし、これを短時間蒸
煮し、少なくとも表面部をα化した一部α化米をつく
り、次いでこれを約７５℃以下の温度で乾燥する方法
（特開昭５２−６１２４９号公報）が知られている。こ
の方法による早炊き米は、生米に水を加えて炊飯する場
合に比べ炊飯に際しての吸水が若干早く、それだけ水漬
け以降から炊飯終了迄の時間が短縮でき、さらに、全部
α化してから乾燥してつくった乾燥米に比べ、吸水乾燥
後の米がべたつかない長所がある。2. Description of the Related Art Conventionally, as a method for producing fast-cooking rice similar to this type of production method, glutinous rice is soaked in water for a short time to make the water content of glutinous rice about 30 to 45%, There is known a method (Japanese Patent Application Laid-Open No. 52-61249) in which steamed rice is prepared to partially gelatinize at least the surface of the rice, and then the rice is dried at a temperature of about 75 ° C. or lower. The fast-cooking rice produced by this method absorbs water a little faster than rice cooked by adding water to the cooked rice, which can shorten the time from the time of soaking until the end of cooking, and after drying all the rice, it is dried. It has the advantage that the rice after water absorption and drying is not sticky compared to the dry rice made by the above method.

【０００３】また、水浸漬を１〜１０時間程行なった水
浸漬米を粘液状（水に分散させて加熱粘化した澱粉、加
工澱粉、米粉さらには水に分散させたガム質などにより
粘状になった液）で被覆した後容器に充填密封し、１０
０℃以上の温度で加熱殺菌する方法も知られている。Further, water-immersed rice which has been soaked in water for about 1 to 10 hours is viscous (it is viscous due to starch dispersed in water, heat-viscosified starch, processed starch, rice flour, and gum dispersed in water). Liquid) and then filled and sealed in a container,
A method of heat sterilization at a temperature of 0 ° C. or higher is also known.

【０００４】さらに、水浸漬時間をなくすために、水浸
しない生米をそのままでまたは洗米してから粘状液で被
覆して、生米と粘状液との混合物の全体の水分含量を約
３８〜４７％に調整した改良方法も提案されている（特
公昭５７−４６８２４号公報）。Further, in order to eliminate the time of immersion in water, raw rice which is not soaked in water is washed as it is or after being washed with rice and then covered with a viscous liquid so that the total water content of the mixture of the raw rice and the viscous liquid is about 38. An improved method of adjusting the content to 47% has also been proposed (Japanese Patent Publication No. 57-46824).

【０００５】一方、特公昭５７−４４３０２号公報では
米粒の吸水性、膨脹率等の種々の点を勘案して胴割れ発
生の限度内において水分添加をし、貯蔵性，精米能率，
食味性を高めた胴割れがほとんどない水分添加米を得る
ための米粒の含有水分を補正するための水分添加方法が
提案されているが、これはタンクに揚穀装置を付設し
て、タンクの下部から揚穀装置へ、揚穀装置からタンク
上部へと流れる米粒群の循環路を形成し、この循環路に
水分添加装置を設け、該水分添加装置により循環する米
粒に数秒当り０．２３３％以下の水分を添加し、米粒の
含水率の増加を毎時０．６７％以下となるようにした方
法を開示している。On the other hand, in Japanese Examined Patent Publication No. 57-44302, water is added within the limit of occurrence of barrel cracking in consideration of various points such as water absorption and expansion rate of rice grains, and the storability, rice polishing efficiency,
A water addition method has been proposed to correct the water content of rice grains in order to obtain water-added rice with improved taste and which has almost no cracks in the body. A circulation path for the rice grains flowing from the bottom to the fried apparatus and from the fried apparatus to the upper part of the tank is formed, and a water addition device is provided in this circulation path, and 0.233% per few seconds is added to the rice particles circulated by the water addition device. Disclosed is a method in which the following water content is added to increase the water content of rice grains to 0.67% or less per hour.

【０００６】[0006]

【発明が解決しようとする課題】特開昭５２−６１２４
９号公報で開示された製造方法で作った早炊き米は米の
軟弱化によるべたべたがない代わりに、乾燥により含有
水分が少なくなっているために生米に直接水を加えて炊
飯してつくった米飯と比べると弾力が失われて食感が格
段に劣り、光沢も乏しいという問題がある。Problems to be Solved by the Invention JP-A-52-6124
The fast-cooked rice made by the manufacturing method disclosed in Japanese Patent No. 9 is not sticky due to the softening of rice, but the water content is reduced by drying, so the rice is cooked by adding water directly to it. Compared to cooked rice, there is a problem that elasticity is lost, texture is significantly inferior, and gloss is poor.

【０００７】水浸漬水を粘状液で被覆した後容器に充填
密封し、１００℃の温度で加熱殺菌する方法では水浸漬
を１〜１０時間ほど要するため余分な時間を要する問題
がある。In the method of coating water in water with a viscous liquid, filling and sealing in a container, and sterilizing by heating at a temperature of 100 ° C., there is a problem that extra time is required because immersion in water takes about 1 to 10 hours.

【０００８】特公昭５７−４６８２４号公報で開示され
た包装早炊き米の製造方法では、時間のかかる水浸漬は
しなくてもよいので、準備作業が簡単であり、加熱殺菌
に際し澱粉の構造的破損が殆どないため水を加えて炊飯
した場合に生米から直接炊飯して得られる米飯と劣ら
ず、弾力及び光沢のあるものとなり、数か月室温に依存
しても腐敗する心配がないなどの利点を有するものでは
あるが、澱粉などからなる粘状液を別々に用意しなけれ
ばならず、また、もち米の早炊きには有効であるかもし
れないが、普通米の洗米を要しない即炊き方法としては
必ずしも同様な食感の米飯が得られるとは考えられな
い。In the method for producing packaged pre-cooked rice disclosed in Japanese Patent Publication No. 57-46824, it is not necessary to immerse in water for a long time, so that the preparation work is simple and the starch is structurally structured during heat sterilization. Since there is almost no damage, when rice is cooked by adding water, it is as elastic and shiny as rice cooked directly from raw rice, and there is no worry of spoilage even if it depends on room temperature for several months. Although it has the advantage of, it is necessary to separately prepare a viscous liquid such as starch, and it may be effective for pre-cooking glutinous rice, but it does not require washing of ordinary rice. It is not always possible to obtain cooked rice with a similar texture as a method of instant cooking.

【０００９】元来、生米は傷みやすいため水分１６％以
下で流通され、炊飯時に洗米及び水浸漬が不可欠であっ
た。このような問題を解決するため前述した従来技術や
それ以外の一般的に知られた方法の中には洗米，水浸漬
を不要とする米の開発もなされてはいるが、炊飯時間の
短縮つまり早炊きのみが主たる目的とされる方法であっ
て、必ずしも米本来の旨味を考慮した方法ではなく、食
味を生かした良食米に適用するには不向きの方法と考え
られる。生米は元来、細菌数が高いため洗水及び水浸漬
を行なった高水分含有米はいたみやすいため流通するこ
とができず、乾燥状態で流通されている。そのため、利
用者が洗米と水浸漬を行なってから炊飯することが不可
欠であった。Originally, since raw rice is easily damaged, it is circulated with a water content of 16% or less, and washing rice and immersing it in water were indispensable when cooking rice. In order to solve such a problem, although the above-mentioned conventional techniques and other generally known methods have been developed for rice that does not require washing and soaking in water, shortening the cooking time It is a method whose main purpose is only early cooking, and is not necessarily a method that takes into consideration the original taste of rice, and is considered to be an unsuitable method for applying it to good-tasting rice that makes good use of its taste. Since raw rice originally has a high number of bacteria, it cannot be distributed because it has a high water content and has been washed and soaked in water, and therefore it is distributed in a dry state. Therefore, it was indispensable for the user to wash the rice and soak it in water before cooking.

【００１０】本発明は生米中より腐敗の原因となる菌類
を低減し、更に殺菌し、腐敗や食味品質の低下を招くお
それのない品質良好な即炊き米の製造方法を提供するこ
とを目的とする。It is an object of the present invention to provide a method for producing quick-cooked rice of good quality, which is capable of reducing fungi that cause spoilage in raw rice and further sterilizing it, without causing the deterioration of spoilage and taste quality. And

【００１１】本発明は前記課題に鑑み、特別の混入液を
必要とせずに工程が簡素で炊上がり状態も炊飯前に洗米
した場合と、ほぼ同一の品質を保持しうる効率的な即炊
き米の製造方法を提供するを目的とする。In view of the above problems, the present invention is an efficient instant cooked rice which can maintain substantially the same quality as when the rice is washed before cooking even in a cooked state without requiring a special mixed liquid. It aims at providing the manufacturing method of.

【００１２】[0012]

【課題を解決するための手段】本発明は生米と水を容器
に入れ、適度に加熱してから無菌処理された空気を該容
器中に吹き込むことにより微細気泡水を形成し、該微細
気泡水により水洗いして生米中の菌類を低減してから脱
水した後、包装し、加熱温度を変えながら数回加熱殺菌
を繰返して即炊き米を得るように構成した包装即炊き米
の製造方法である。According to the present invention, raw rice and water are placed in a container, heated appropriately and then air that has been sterilized is blown into the container to form fine bubble water. A method for producing cooked rice immediately after packaging, in which it is washed with water to reduce fungi in raw rice, dehydrated, then packaged, and cooked immediately by repeating heat sterilization several times while changing the heating temperature to obtain cooked rice. Is.

【００１３】[0013]

【実施例】第１工程 生米をタンクのような容器に入
れ、水道水を該容器内に注水してから該容器を３５℃〜
４０℃に加熱した後、無菌処理された空気を該容器に投
入することにより微細気泡水を形成し、該微細気泡水に
より水洗いする。[Example] First step Raw rice is placed in a container such as a tank, tap water is poured into the container, and then the container is heated to 35 ° C or higher.
After heating to 40 ° C., aseptically treated air is introduced into the container to form fine bubble water, which is washed with water.

【００１４】試験例では市販コシヒカリ３ｋｇをポリバ
ケツに入れ、無菌化処理をした微細気泡水により水洗し
た。水洗いは１分間に１回づつ水をかえながら５分手で
ゆるく攪拌しながら水洗いした。水洗いに用いた用水は
水道水並びにこれにエジェクタ−により空気を微細に懸
濁した分散水を使用し、水洗後脱水し、この一部を滅菌
樹脂袋に分取し、菌数測定用試料とした。この試料１ｇ
を滅菌容器中の滅菌食塩水５０ｃｃ中にとり、ストマッ
カ−にて５分摩砕した液を菌検液とし、この１ｍｌを標
準寒天培地を用いて３０℃´で２日間培養し、発現した
コロニ−数をもって洗米の菌数とした。これを５回行
い、気泡水洗浄工程で菌数が確実に低くなることを確認
した。また、気泡水を無菌処理された空気をエジェクト
することにより形成するため、無菌処理されない空気を
エジェクトする場合よりも菌数が著しく低減されたこと
も確認した。In the test example, 3 kg of commercially available Koshihikari was put in a poly bucket and washed with sterilized fine bubble water. Washing with water was carried out by changing the water once a minute for 5 minutes with gentle stirring by hand. As the water used for washing, tap water and dispersed water in which air is finely suspended by an ejector are used, washed with water and dehydrated, and a part of this is dispensed into a sterilized resin bag and used as a sample for bacterial count measurement. did. 1g of this sample
Was placed in 50 cc of sterilized saline in a sterilized container and ground for 5 minutes with a stomacher to give a bacterial test solution. 1 ml of this was cultured for 2 days at 30 ° C. in a standard agar medium to express colonies. The number was used as the number of bacteria for washing rice. This was repeated 5 times, and it was confirmed that the number of bacteria was surely lowered in the bubble water washing step. It was also confirmed that the number of bacteria was remarkably reduced as compared with the case of ejecting air that was not subjected to aseptic treatment, because the bubbly water was formed by ejecting air that was subjected to aseptic treatment.

【００１５】このように、水中に存在する微細な気泡が
船のスクリュ−を研削するが如く、水中の微細気泡の研
磨力を生米に適用したところ水洗時に米中の菌数を１０
² ／ｇ台に低減することが可能となった。これだけで適
切な包装条件と低温流通条件を適用することにより、２
週間程度の日持ちが可能である。しかし、夏場の３０℃
´台になるとこの菌数では約３日しか米の保存がきかな
い。つまり、気泡水洗浄工程により菌数の低減を図るこ
とができたが、更に流通期における品質の安定性を図る
にはグラム当たり菌数が０〜０．１台になることが必要
である。そこで次の第２工程が不可欠となる。As described above, the polishing power of fine bubbles in water is applied to raw rice so that the fine bubbles existing in water grind the screw of a ship.
It has become possible to reduce to ² / g level. By applying proper packaging conditions and low temperature distribution conditions alone, 2
It can last for a week. However, 30 ° C in summer
At this number, rice can only be stored for about 3 days with this number of bacteria. That is, although the number of bacteria could be reduced by the bubble water washing step, the number of bacteria per gram needs to be 0 to 0.1 in order to further stabilize the quality in the distribution period. Therefore, the following second step is indispensable.

【００１６】第２工程 洗米後、付着水を約１４〜１５％程度米粒に付着した状
態まで脱水してから包装し、前記付着水を保持したまま
６０℃で３時間、４５℃で２時間を３回繰返し、合計１
５時間に亘り加熱殺菌をして即炊き米を得る。Second step: After washing the rice, the attached water is dehydrated to a state of adhering to the rice grains by about 14 to 15% and then packaged, and the adhering water is kept at 60 ° C. for 3 hours and 45 ° C. for 2 hours. Repeat 3 times, total 1
Heat sterilize for 5 hours to immediately cook rice.

【００１７】米質に影響しないが殺菌法を検討した試験
例では３００ｇづつ脱水した米をケイナイロン（ＫＮ）
包装剤に採取し、真空包装，含気包装の包装条件で加熱
条件は温度を約６０℃で３時間、４５℃で２時間を３回
繰返し、合計１５時間に亘り加熱殺菌を繰返し、加熱手
段を湯と空気の二法で米品質と殺菌状況を比較した結
果、６０℃台であれば殺菌が十分にできることが知られ
たが、米粒の温度上昇速度が早い条件のものは粒割れが
ひどく高品価値がなくなった。また洗米後２時間水道水
に浸漬した後、脱水器にかけて直ちにビニ−ル袋に入れ
てシールし、６０℃で１時間加熱して得られた米を３０
℃の温蔵庫の中に２日間入れて菌を調べたところ乳酸菌
の発生が認められた。そこで米粒の温度上昇速度を遅く
し、且つ、浸漬工程中での菌の増殖を抑制し、水分の不
足状態を補うため米粒表面に約１４〜１５％程度の付着
水をつけたまま包装し、加熱空気中に温存する方法を検
討し、前工程の洗浄法の差と殺菌効果を比較した結果、
付着水を約１４〜１５％程度に付着させた状態で加熱殺
菌を行うことにより、ほぼ目的とする即炊き米の調整が
できた。また、乾燥殺菌の効果を上げるには第１工程に
おいて無菌処理された空気をエジェクトされた気泡水に
より菌数を低減しておくことが必須であることも裏づけ
られた。In a test example in which the sterilization method was examined although it did not affect the rice quality, 300 g of dehydrated rice was made into silica nylon (KN).
The sample is collected in a packaging material, and the heating conditions are vacuum packaging and air-containing packaging. The heating temperature is about 60 ° C. for 3 hours, and 45 ° C. for 2 hours 3 times, and heat sterilization is repeated for a total of 15 hours. As a result of comparing rice quality and sterilization condition by two methods of hot water and air, it was found that sterilization can be sufficiently performed at 60 ° C., but grain cracking is severe under conditions where the temperature rise rate of rice grain is fast. The high value is gone. After washing the rice for 2 hours, soak it in tap water, put it in a dehydrator and immediately put it in a vinyl bag for sealing, and heat it at 60 ° C. for 1 hour to obtain 30 pieces of rice.
Generation of lactic acid bacteria was observed when the bacteria were examined by putting them in a warm storage at ℃ for 2 days. Therefore, in order to slow down the temperature rise rate of rice grains, suppress the growth of bacteria during the dipping process, and to supplement the lack of water, the rice grain surface is packaged with about 14 to 15% of attached water attached, As a result of examining the method of preserving in heated air and comparing the difference in the cleaning method in the previous process and the sterilization effect,
By performing heat sterilization in a state in which about 14 to 15% of the adhered water was adhered, it was possible to prepare almost the intended cooked rice. Further, it was also confirmed that in order to improve the effect of the dry sterilization, it is essential to reduce the number of bacteria by aseptically treating air in the first step with ejected bubble water.

【００１８】さらに、乾燥による菌数の低減条件を検討
したところ、５０℃では殺菌不良となり効果がなかった
が、６０℃以上で著しい殺菌効果を示した。しかし、７
０℃台になると米粒の表面の色が黒ずみ、いわゆるレト
ルト現象などの組織変化をおこし、米粒どおしの付着が
おき、米粒の形がくずれ米品質の低下をきたした。した
がって、６０℃前後の加熱温度で３時間、４５℃で２時
間と３回繰返し１５時間に亘り加熱するように加熱変化
を与えると無菌効果があがり、即炊き米に組織変化を与
えない最適温度・時間であり、洗米せずに水を加えただ
けで即炊きした場合に、洗米して炊飯する米飯と変ら
ず、弾力，食味，香り及び光沢のある即炊き米であるこ
とが裏付けられた。Further, when the conditions for reducing the number of bacteria by drying were examined, bactericidal failure occurred at 50 ° C. and no effect was obtained, but a remarkable bactericidal effect was shown at 60 ° C. or higher. But 7
At 0 ° C, the surface of the rice grains turned dark, and the so-called retort phenomenon and other structural changes occurred, and the rice grains adhered to the rice grains, causing the rice grains to lose their shape and the quality of the rice to deteriorate. Therefore, when the heating temperature is changed to about 60 ° C. for 3 hours, 45 ° C. for 2 hours, and three times for 15 hours, the sterilization effect is improved, and the optimum temperature that does not cause the tissue change in cooked rice is obtained.・ It was time, and it was confirmed that when cooked immediately by adding water without washing rice, it is the same as the rice that is washed and cooked, and the rice is instantly cooked with elasticity, taste, aroma and gloss. .

【００１９】[0019]

【発明の効果】本発明は、生米を加熱温度をかえて数回
水とともに容器に入れ加熱した後、エジェクタにより無
菌処理された空気を容器に導入して微細気泡水を形成
し、該微細気泡水により水洗いして生米中の菌類を低減
してから脱水した後、包装し、加熱殺菌して即炊き米を
得るように構成したから、腐敗や食味品質の低下を招く
おそれがなく、しかも、炊飯前に洗米及び水浸漬の必要
がなく、洗米及び浸漬してして炊飯する米飯と変らない
弾力，食味，香り及び光沢のある即炊き米の製造方法を
提供できる。Industrial Applicability According to the present invention, raw rice is placed in a container with water several times while changing the heating temperature and heated, and then air aseptically treated by an ejector is introduced into the container to form fine bubble water. After washing with aerated water to reduce the fungi in the raw rice and dehydration, it was packaged, heat-sterilized and immediately cooked to obtain rice, so there is no risk of spoilage or deterioration in taste quality. Moreover, it is not necessary to wash and soak the rice before cooking, and it is possible to provide a method for producing instantly cooked rice having elasticity, taste, fragrance, and gloss that is the same as the cooked rice that is obtained by washing and soaking the rice.

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 生米と水を容器に入れ、適度に加熱して
から無菌処理された空気を該容器中に吹き込むことによ
り微細気泡水を形成し、該微細気泡水により水洗いして
生米中の菌類を低減してから脱水した後、包装し、加熱
温度を変えながら数回加熱殺菌を繰返して即炊き米を得
るように構成したことを特徴とする包装即炊き米の製造
方法。1. Raw rice and water are placed in a container, heated appropriately, and then air that has been sterilized is blown into the container to form fine bubble water, which is washed with water to obtain raw rice. A method for producing cooked rice immediately after packaging, comprising reducing the fungi in the product, dehydrating it, packaging it, and repeating heat sterilization several times while changing the heating temperature to obtain cooked rice immediately.