【発明の詳細な説明】[Detailed description of the invention]
本発明は、凍結苺の製造方法に関する。
苺は、生果用、またはジヤム等の加工用、製菓
用、飲食品用材料として用途の広いものである
が、収穫時期が限られかつ非常に変質しやすいも
のであるため、凍結保存することが行なわれてい
る。この凍結保存においては、凍結による変性を
防止し、解凍した際に生の苺と比較して遜色のな
い色調、艶等の品質が維持されていることが要求
されており、斯る要求に対して従来、砂糖を苺に
まぶして凍結する方法が採られてきた。
然し乍ら、砂糖を苺にまぶして凍結された凍結
苺は、苺をそのまま凍結したものより多少の凍結
変性防止効果はあるものの、解凍した場合、生の
苺に比較して脱色されたように色調、艶が悪くな
るという問題を有していた。
本発明者は、叙上の点に鑑み、凍結保存後解凍
した際に生の苺と比較して色調、艶が何等遜色の
ない凍結苺を提供することを目的として種々検討
した結果、従来用いられている糖類の他に粉末状
の増粘剤を用いることにより凍結保存後解凍して
も、生の苺と比較して色調、艶が何等遜色のない
凍結苺が得られることを見出し、本発明に到達し
た。
すなわち、本発明は糖類と増粘剤の混合粉末を
苺にまぶした後、これを凍結することを特徴とす
る凍結苺の製造方法を提供するものである。
以下に本発明の凍結苺の製造方法について詳説
する。
本発明において用いられる苺は、生の苺であれ
ば特に限定はなく、通常へた取りし、水洗したも
のが用いられる。
また、本発明で用いられる糖類としては、粉末
状であれば特に制限されるものではないが、水に
溶けやすいものが好ましく、例えば、砂糖、結晶
ぶどう糖、粉末水あめ等が挙げられる。増粘剤と
しては、粉末状で、吸水することにより粘稠性を
呈するものであれば良いが、好ましいものとして
は、例えば、キサンタンガム、ローカストビーン
ガム、グアーガム、α化澱粉等が挙げられる。
尚、上記糖類及び上記増粘剤は、各々、１種或
いは２種以上混合して用いても良い。
本発明では上記の糖類と増粘剤の混合粉末を苺
にまぶす。
混合粉末を調製する際の糖類と増粘剤の混合割
合は、苺と混合粉末の総重量に対し、糖類は５〜
50重量％、更に好ましくは20〜40重量％で、増粘
剤は0.1〜５重量％、更に好ましくは0.5〜３重量
％である。糖類が５重量％未満であると添加効果
が少なく、50重量％を超えると苺に付着せずに流
れ落ちる傾向があるので好ましくなく、また、増
粘剤が0.1重量％未満であると効果が少なく、５
重量％を超えると粘度が高くなり過ぎ作業性が悪
くなる傾向があるので好ましくない。
上記糖類と上記増粘剤との混合は、例えば混合
撹拌機に糖類と増粘剤を入れて均一に混合する方
法によれば良く、均一な混合粉末が得られれば、
その手段には制限されない。
而して、本発明は、先ず、上述の如く調製し
た、糖類と増粘剤の混合粉末を苺にまぶすもので
ある。そのまぶし方は、上記混合粉末を苺の表面
全体に均一にまぶすことのできる方法であれば特
に制限されないが、混合粉末をまぶした後、放置
又は撹拌して苺の水分の10％以上を混合粉末に吸
水させるのが凍結変性を防止する上で効果的であ
るので好ましい。
尚、特開昭52−41255号公報に提案されている
ように、糖類や増粘剤等を含有する溶液に苺を浸
漬（又は苺の表面に溶液を塗布）し、苺を糖類や
増粘剤等で被覆することも考えられるが、糖類及
び増粘剤を溶かすと溶液の粘度が著しく上昇し、
したがつて溶液の糖類及び増粘剤の濃度をあまり
高くすることはできないので、この方法では苺か
ら吸水できる程の糖類及び増粘剤を苺の表面に被
覆することはできず、この方法で被覆した苺は、
凍結すると、色調、艶等が悪化する。
次いで、上記混合粉末をまぶした苺を凍結す
る。この凍結は、常法通り行なえば良く、例え
ば、苺をプラスチツク製の袋に詰め、−20℃で凍
結する等の方法により凍結する。
本発明法により、叙上の如くして凍結された苺
は、凍結保存後解凍した際に生の苺と比較して色
調、艶が遜色のないものであり、その色調、艶の
保持がどのような機構作用によりなされるのかは
明らかではないが、恐らく糖類と増粘剤とからな
る混合粉末が苺の水分を吸収保持すること（苺を
脱水すること）により、凍結時の氷結膨張による
苺の組織破壊を防止することによるものと考えら
れる。
なお、本発明によれば、苺の水分の吸収保持力
が高いものとなるので、凍結解凍後苺の肉質軟化
が従来の単に糖類のみまぶしたものより一段と少
くなるという効果もある。
以下に本発明の試験例及び実施例を示し、本発
明の効果を具体的に明らかにする。
試験例 １
へた取りし、水洗した苺385ｇに砂糖115ｇをま
ぶした後プラスチツク製袋に入れて凍結したもの
（対照品）、及び上記と同様の苺385ｇに、それぞ
れ下記表−１に示す配合で均一に混合した砂糖と
ガム質の混合粉末をまぶし、プラスチツク製袋に
入れてから室温で３時間放置した後凍結したもの
（試験品〜）について、それぞれ解凍し、そ
の時の色調、艶等の状態を観察した。その結果、
対照品は、液汁がプラスチツク製袋の底部に溜
り、苺は脱色されたように色調、艶が悪かつた
が、本発明の製造方法による試験品〜は、液
汁の分離もなく、生の苺特有の色調を有し、艶も
あり良好な状態であつた。
The present invention relates to a method for producing frozen strawberries. Strawberries have a wide range of uses, including as fresh fruit, for processing jams and other products, for confectionery, and as an ingredient for food and beverages.However, as the harvest period is limited and they are extremely susceptible to deterioration, they must be frozen and preserved. is being carried out. In this cryopreservation, it is required to prevent denaturation due to freezing and to maintain quality such as color tone and gloss comparable to that of fresh strawberries when thawed. Traditionally, strawberries were sprinkled with sugar and frozen. However, although frozen strawberries made by sprinkling sugar on strawberries are more effective in preventing freeze denaturation than strawberries that are frozen as is, when thawed they have a color tone that looks bleached compared to fresh strawberries. The problem was that the gloss deteriorated. In view of the above points, the present inventor has conducted various studies with the aim of providing frozen strawberries that are comparable in color tone and luster to fresh strawberries when thawed after cryopreservation. We discovered that by using a powdered thickener in addition to the sugars that are commonly used, it is possible to obtain frozen strawberries that are comparable in color and gloss to fresh strawberries, even after thawing after frozen storage. The invention has been achieved. That is, the present invention provides a method for producing frozen strawberries, which comprises coating strawberries with a mixed powder of sugars and a thickener, and then freezing the mixture. The method for producing frozen strawberries of the present invention will be explained in detail below. The strawberries used in the present invention are not particularly limited as long as they are fresh strawberries, and those that have been peeled and washed with water are usually used. Furthermore, the saccharides used in the present invention are not particularly limited as long as they are in powder form, but those that are easily soluble in water are preferred, and examples thereof include sugar, crystalline glucose, powdered starch syrup, and the like. The thickener may be any powdery one that becomes viscous upon absorption of water, but preferred examples include xanthan gum, locust bean gum, guar gum, and pregelatinized starch. The saccharides and the thickeners may be used alone or in combination of two or more. In the present invention, strawberries are sprinkled with a mixed powder of the above sugars and thickener. When preparing mixed powder, the mixing ratio of sugars and thickener is 5 to 5% of the total weight of strawberries and mixed powder.
50% by weight, more preferably from 20 to 40% by weight, and the thickener from 0.1 to 5% by weight, more preferably from 0.5 to 3% by weight. If the sugar content is less than 5% by weight, the added effect will be small; if it exceeds 50% by weight, it will tend to run off without adhering to the strawberries, which is undesirable; and if the content of the thickener is less than 0.1% by weight, the effect will be low. ,5
If it exceeds % by weight, the viscosity tends to become too high and workability tends to deteriorate, which is not preferable. The saccharide and the thickener may be mixed by, for example, a method in which the saccharide and the thickener are placed in a mixer and mixed uniformly, and if a uniform mixed powder is obtained,
There are no restrictions on the means. Accordingly, in the present invention, first, strawberries are sprinkled with a mixed powder of sugars and a thickener prepared as described above. The method of sprinkling is not particularly limited as long as the above mixed powder can be uniformly sprinkled over the entire surface of the strawberries, but after sprinkling the mixed powder, leave it to stand or stir to mix at least 10% of the moisture in the strawberries. It is preferable to allow the powder to absorb water since this is effective in preventing freeze denaturation. Furthermore, as proposed in Japanese Patent Application Laid-open No. 52-41255, strawberries are soaked in a solution containing sugars, thickeners, etc. (or the solution is applied to the surface of the strawberries). It is also possible to coat the solution with an agent, but dissolving sugars and thickeners will significantly increase the viscosity of the solution.
Therefore, it is not possible to make the concentration of sugars and thickeners in the solution too high, so this method cannot coat the surface of strawberries with enough sugars and thickeners to absorb water from the strawberries. The covered strawberries are
When frozen, the color tone, luster, etc. deteriorate. Next, the strawberries coated with the mixed powder are frozen. This freezing may be carried out in a conventional manner, for example, by packing the strawberries into a plastic bag and freezing at -20°C. Strawberries frozen as described above using the method of the present invention have a color tone and gloss comparable to those of fresh strawberries when thawed after cryopreservation. Although it is not clear whether this is done through such a mechanism, it is probably due to the mixed powder consisting of sugars and thickeners absorbing and retaining the moisture in the strawberries (dehydrating the strawberries), causing the strawberries to freeze and expand during freezing. This is thought to be due to the prevention of tissue destruction. In addition, according to the present invention, since the water absorption and retention capacity of strawberries is high, there is also the effect that the softening of the flesh of strawberries after freezing and thawing is much less than that of conventional strawberries that are simply sprinkled with sugar. Test examples and examples of the present invention will be shown below to specifically clarify the effects of the present invention. Test Example 1 385 g of strawberries that had been peeled and washed with water were sprinkled with 115 g of sugar, then placed in a plastic bag and frozen (control product), and 385 g of the same strawberries as above were mixed with the formulations shown in Table 1 below. Sprinkle with sugar and gummy mixed powder mixed uniformly in a plastic bag, leave it at room temperature for 3 hours, then thaw each frozen product (test product ~) and check the color tone, gloss, etc. I observed the condition. the result,
In the control product, the sap accumulated at the bottom of the plastic bag, and the strawberries had a poor color tone and luster, as if they had been bleached, but in the test products produced by the manufacturing method of the present invention, there was no separation of the sap, and the strawberries were raw. It had a unique color tone, was glossy, and was in good condition.
【表】
試験例 ２
下記表−２に示す如く、苺に対する砂糖の使用
量が変化するように下記表−２に示す配合の混合
粉末を用いて、苺にまぶした時の状態を観察し
た。その結果、試験品は、砂糖の量が少なく苺
に混合粉末が均一にまぶされていなかつた。試験
品及びは、苺に混合粉末が均一にまぶされて
いた。試験品は、苺に混合粉末が均一にまぶさ
れていたが、この場合、砂糖の量が多過ぎて底に
砂糖が残つた。
また、苺に混合粉末をまぶした後室温に３時間
放置することにより、苺からの脱水で溶解して粘
性物となつた混合粉末を水洗いした際の苺重量を
測定し、予め測定してあつた脱水前の苺重量と比
較して脱水率を得たので、表−２に示す。
尚、試験品〜をプラスチツク製袋に入れて
凍結後解凍した際の状態を観察した結果〜の
順で、色調、艶がよかつた。[Table] Test Example 2 As shown in Table 2 below, mixed powders having the formulations shown in Table 2 below were used to vary the amount of sugar used for each strawberry, and the state when sprinkled on strawberries was observed. As a result, the test product had a small amount of sugar and the strawberries were not evenly coated with the mixed powder. In the test product, the mixed powder was evenly sprinkled on the strawberries. In the test product, the mixed powder was evenly sprinkled on the strawberries, but in this case, the amount of sugar was too large and sugar remained at the bottom. In addition, by sprinkling the mixed powder on strawberries and leaving it at room temperature for 3 hours, the weight of the strawberries was measured when the mixed powder, which had been dissolved by dehydration from the strawberries and became a viscous substance, was washed with water. The dehydration rate was obtained by comparing the weight of the strawberries before dehydration, and is shown in Table 2. In addition, the results of observing the state of the test products ~ when placed in plastic bags and thawed after freezing showed that the color tone and gloss were good in the order ~.
【表】
実施例 １
へたを取り水洗した苺380ｇに、砂糖120ｇ（24
重量％）及びグアールガム３ｇとエコーガム３ｇ
（合計で1.2重量％）を均一に混合した混合粉末
を、表面に均一にまぶし、室温で３時間放置した
後、これをプラスチツク製袋に入れて、常法によ
り−20℃で凍結した。得られた凍結苺を解凍して
観察したところ、生の苺と同様の色調、艶を有し
ており良好であつた。
実施例 ２
へたを取り水洗した苺380ｇに、砂糖120ｇ（23
重量％）とα化澱粉20ｇ（４重量％）を均一に混
合したものを苺の表面に均一にまぶし、苺がつぶ
れないようにゆつくりと15分間撹拌した後、これ
をプラスチツク製袋に入れて、常法により−20℃
で凍結した。得られた凍結苺を解凍して観察した
ところ、実施例１における結果と同様な結果が得
られた。[Table] Example 1 Add 120 g of sugar (24 g
weight%) and 3 g of guar gum and 3 g of echo gum
(1.2% by weight in total) was uniformly sprinkled on the surface and left at room temperature for 3 hours, then placed in a plastic bag and frozen at -20°C by a conventional method. When the obtained frozen strawberries were thawed and observed, they were found to have a good color tone and gloss similar to those of fresh strawberries. Example 2 Add 120g of sugar to 380g of strawberries that have been hulled and washed with water.
Sprinkle a uniform mixture of 20g (4% by weight) of pregelatinized starch and 20g (4% by weight) of pregelatinized starch on the surface of the strawberries, stir gently for 15 minutes so as not to crush the strawberries, and then place the mixture in a plastic bag. and -20℃ using the usual method.
It was frozen. When the obtained frozen strawberries were thawed and observed, results similar to those in Example 1 were obtained.