JP7625368B2 - Flour for spring roll wrappers - Google Patents

Description

The present invention relates to wheat flour for producing spring roll wrappers. The present invention also relates to spring roll wrappers using wheat flour for spring roll wrappers, and a method for producing the same. The present invention also relates to spring rolls using wheat flour for spring roll wrappers, and a method for producing the same.

Wheat flour is a type of cereal made by grinding wheat, and is used as an ingredient in a variety of foods. In recent years, wheat flour has been developed for a variety of uses, including bread, cakes, and noodles.
Known examples of wheat flour for noodles include those described in Patent Documents 1 and 2. Patent Document 1 describes that by blending strong wheat flour having a specific particle size, wheat flour products with excellent suitability for secondary processing can be obtained. Specifically, Patent Document 1 describes using strong wheat as the raw material, wheat flour in which grains with a particle size of 50 to 160 μm account for 70% by mass or more and grains with a particle size of 50 to 110 μm account for 55% by mass or more.

Patent Document 2 also proposes wheat flour made from a specific variety of soft wheat and with a specific average particle size and amount of starch loss, as wheat flour specialized for making udon noodles.

JP 2007-014224 A JP 2015-159759 A

The object of the present invention is to develop an excellent wheat flour for producing spring roll wrappers. Spring roll wrappers are similar to gyoza, shumai, and wonton wrappers in that they are made from wheat flour, but differ from gyoza wrappers in that they are produced by baking. Spring roll wrappers must be thin yet strong enough to wrap the filling (stuffing), and must have a good texture after deep-frying. Furthermore, it is particularly preferable for the texture of the wrappers to be excellent even when they are eaten some time after deep-frying, or when they are eaten after being frozen and thawed.

In view of this situation, the object of the present invention is to provide an excellent wheat flour for producing spring roll wrappers that are not only easy to work with, such as for filling, but also have a good texture when deep-fried.

The inventors conducted extensive research into wheat flour that could solve the above problems, and discovered that wheat flour with a specific range of viscosity when heated can produce excellent spring roll wrappers, which led to the completion of the present invention.

The present invention includes, but is not limited to, the following inventions.
[1] Wheat flour for spring roll wrappers having a maximum viscosity when heated of 100 to 275 mPa·s, wherein the maximum viscosity of the wheat flour when heated is the maximum value measured at 160 rpm at 95°C after heating 30 g of a solution obtained by adding water to 1.8 g of wheat flour as a solid content.
[2] The wheat flour according to [1], having a protein content of 6.0 to 15.0% by mass.
[3] The wheat flour according to [1] or [2], having a protein content of 10.0 to 15.0% by mass.
[4] The wheat flour according to [2], having a protein content of less than 10.0% by mass and a maximum viscosity when heated of 200 mPa·s or less.
[5] The wheat flour according to any one of [1] to [4] for producing frozen spring roll wrappers.
[6] A spring roll wrapper made from the wheat flour according to any one of [1] to [5].
[7] A method for producing spring roll wrappers, comprising a step of obtaining baked dough using the wheat flour according to any one of [1] to [5] as a raw material.
[8] A method for producing spring rolls, comprising a step of wrapping ingredients in the spring roll wrapper made from the wheat flour according to any one of [1] to [5].
[9] A method for producing frozen spring rolls, comprising a step of wrapping ingredients in the spring roll wrapper made from the wheat flour according to any one of [1] to [5], and freezing the resulting spring rolls.

The present invention provides excellent wheat flour for spring roll wrappers. In other words, the wheat flour for spring roll wrappers of the present invention makes it easy to produce spring roll wrappers, which are baked dough, and also provides spring roll wrappers that are strong enough to wrap ingredients.

Spring rolls made from the wheat flour for spring roll wrappers of the present invention have an excellent texture after deep frying, and the excellent texture is maintained even after freezing.

1 is a graph showing the measurement conditions for maximum viscosity upon heating.

The present invention relates to wheat flour for producing spring roll wrappers. Spring roll wrappers are a type of noodle strip (noodle skin), but differ from wrappers for dumplings, wontons, etc. in that they are already baked. Spring rolls are often cooked by deep-frying, and in the present invention, the concept of spring roll wrappers includes both wrappers before cooking, such as deep-frying, and cooked wrappers.

The wheat flour for spring roll wrappers according to the present invention has a maximum viscosity of 100 to 275 mPa·s when heated. In the present invention, the maximum viscosity of wheat flour when heated is the maximum value of the viscosity measured at 160 rpm at 95°C after heating 30 g of a solution obtained by adding water to 1.8 g of wheat flour as a solid content. In addition, a Rapid Visco Analyzer (RVA4500, Perten Instruments) can be used as a viscosity measuring device. If the maximum viscosity when heated is less than 100 mPa·s, the strength of the spring roll wrapper after baking is weak, and it may be easily torn when peeled off from the drum-type baking machine and may also be easily torn when wrapping ingredients. On the other hand, if the maximum viscosity when heated exceeds 275 mPa·s, the skin of the spring roll becomes chewy when eaten, and the crispness is not felt. In the present invention, the lower limit of the maximum viscosity when heated is preferably 150 mPa·s, more preferably 160 mPa·s, and may be 180 mPa·s or 190 mPa·s. The upper limit is preferably 260 mPa·s, and more preferably 250 mPa·s.

In the present invention, the protein content of the wheat flour for the spring roll wrappers is not particularly limited, and may be a general protein content for wheat flour, preferably 6.0 to 15.0% by mass, more preferably 7.0 to 14.0% by mass, and even more preferably 7.4 to 13.5% by mass. When the protein content is in this range, spring roll wrappers can be produced that have a suitable hardness and texture when eaten, while also having a certain degree of strength.

In a preferred embodiment of the present invention, the protein content of the wheat flour for the spring roll wrappers is 10.0 to 15.0% by mass. When the protein content is 10.0 to 15.0% by mass, the strength of the spring roll wrappers after baking is increased, and they are less likely to break when removed from the drum-type baking machine and when the ingredients are wrapped around them. The lower limit of the protein content is more preferably 11.5% by mass, and even more preferably 12.0% by mass. The upper limit is more preferably 14.0% by mass, and even more preferably 13.5% by mass. When the protein content is 10.0 to 15.0% by mass, the maximum viscosity during heating is preferably 180 to 260 mPa·s, and even more preferably 190 to 250 mPa·s.

In another embodiment, the protein content of the wheat flour for spring roll wrappers according to the present invention is 6.0% by mass or more and less than 10.0% by mass. 7.0 to 9.4% by mass is more preferable, and 7.4 to 8.7% by mass is even more preferable. When the protein content is less than 10.0% by mass, the maximum viscosity during heating is preferably 150 to 275 mPa·s, more preferably 160 to 235 mPa·s, and even more preferably 160 to 220 mPa·s. From the viewpoint of improving the texture of the spring roll wrappers, it is most preferable that the viscosity is 200 mPa·s or less.

In the present invention, the ash content of the wheat flour is not particularly limited. In a preferred embodiment, the ash content of the wheat flour according to the present invention is 0.90% by mass or less, more preferably 0.20 to 0.75% by mass, and even more preferably 0.30 to 0.50% by mass.

Wheat flour can be produced by standard methods, for example by adding water and tempering wheat grains that have been refined in the usual way, and then, if necessary, carrying out processes such as breaking, grading, and purification, and adjusting the particle size composition using a grinder.

The wheat flour used for the spring roll wrapper of the present invention is not particularly limited in terms of the origin or variety of the wheat used as the raw material. For example, it may be hard, medium or soft wheat, or it may be hexaploid or two-grain wheat. In the present invention, wheat flour can be produced from one type of wheat, or two or more types of wheat can be combined to produce wheat flour. The wheat flour of the present invention can also be produced by combining the wheat flours produced. Whole wheat flour may be used in the present invention. Wheat is classified into hard, medium and soft wheat based on the hardness of the seeds (hardness/softness). Hard wheat is often vitreous with high protein content and amber-colored seeds, while soft wheat is often powdery with low protein content and whitish seeds. Medium wheat has properties intermediate between hard and soft wheat. The hardness/softness of the seeds is determined by mutations in the genes of two proteins, puroindoline-a and puroindoline-b. The wild type is soft, and mutations in these genes result in hard seeds.

In a preferred embodiment, the wheat flour for spring roll wrappers according to the present invention has a median diameter of 20 to 90 μm. The median diameter is the particle size at which the cumulative 50% is determined from the particle size distribution based on volume. In the present invention, the median diameter of wheat flour for spring roll wrappers is more preferably 23 to 80 μm, and even more preferably 25 to 75 μm. By using such wheat flour for spring roll wrappers, the workability during the manufacture of spring roll wrappers can be further improved. In one embodiment, the wheat flour for the present invention has a protein content of 10.0 to 15.0 mass%, and the median diameter is preferably 30 to 90 μm, more preferably 33 to 80 μm, and even more preferably 35 to 75 μm. In another embodiment, the wheat flour for the present invention has a protein content of less than 10.0 mass%, and the median diameter is preferably 20 to 70 μm, more preferably 23 to 60 μm, and even more preferably 25 to 50 μm.

In the present invention, the volumetric particle size distribution of wheat flour can be measured using a laser diffraction particle size distribution measuring device. Specifically, the volumetric particle size distribution (cumulative distribution or frequency distribution) is obtained by Fraunhofer diffraction using a laser diffraction particle size distribution measuring device.

The median diameter of the wheat flour can be changed by adjusting the conditions for grinding and sorting the wheat. For example, a mill such as an impact mill, airflow mill, or roll mill can be used to grind the wheat. For example, a roll mill can be used for roll grinding, a jet mill can be used for airflow grinding, and a hammer mill, pin mill, or turbo mill can be used for impact grinding. A mill that combines multiple grinding methods (such as a cyclone mill or a relative flow mill) can also be used. These mills can be used alone or in combination. The wheat flour for the spring roll wrapper of this embodiment can be obtained by classifying the ground wheat flour using a sieve or air classification to adjust the desired median diameter, or by grinding the ground wheat flour using a mill with a classification function. The wheat flour for the spring roll wrapper of this embodiment can also be adjusted to the desired median diameter by passing the wheat flour through multiple sieves with different openings, starting with the coarse opening, and adjusting the blending ratio of the fraction remaining on each sieve and the fraction that passed through all the sieves.

In a preferred embodiment, the wheat flour for spring roll wrappers according to the present invention has a damaged starch content of 3 to 11% by mass. In the present invention, the damaged starch content of the wheat flour for spring roll wrappers is more preferably 10% by mass or less, even more preferably 9% by mass or less, and even more preferably 8% by mass or less. By using such wheat flour for spring roll wrappers, the workability during the manufacture of spring roll wrappers can be further improved. In one embodiment, the wheat flour for the present invention has a protein content of 10.0 to 15.0% by mass, and the damaged starch content is preferably 4 to 11% by mass, more preferably 4.5 to 9% by mass, and even more preferably 5 to 8% by mass. In another embodiment, the wheat flour for the present invention has a protein content of less than 10.0% by mass, and the damaged starch content is preferably 3 to 7% by mass, more preferably 3 to 6% by mass, and even more preferably 3.5 to 5.5% by mass.

The wheat flour for spring roll wrappers according to the present invention may be used alone as the grain flour to produce spring roll wrappers, or may be blended with other grain flours and starches, as long as it does not adversely affect the effects of the present invention. For example, one or more grain flours selected from rice flour, buckwheat flour, barley flour, rye flour, oat flour, corn flour, barnyard millet flour, foxtail millet flour, soy flour, and white sorghum flour may be used. Wheat bran may also be included. These grain flours may be subjected to heat treatment, etc. Examples of starches include one or more selected from wheat starch, barley starch, rye starch, oat starch, and other wheat starches, corn starch, rice starch, bean starch, potato starch, sweet potato starch, tapioca starch, water chestnut starch, chestnut starch, sago starch, yam starch, lotus root starch, arrowhead starch, bracken starch, lily of the valley starch, and amylomaize starch. Processed starches obtained by subjecting these starches to physical and/or chemical processing, either alone or in combination, may also be used.

When manufacturing spring roll wrappers using the wheat flour for spring roll wrappers of the present invention as a raw material, auxiliary ingredients may be further used. Examples of auxiliary ingredients used in the present invention include protein materials such as soy protein, wheat protein, egg yolk powder, egg white powder, whole egg powder, and skim milk powder; fats and oils such as animal and vegetable oils and oil powders; kansui, dietary fiber, leavening agents, thickeners, emulsifiers, salt, sugars, sweeteners, spices, seasonings, vitamins, minerals, colorings, and flavorings. These auxiliary ingredients can be used alone or in combination.

The spring roll wrapper of the present invention is produced using the wheat flour for spring roll wrappers described above as a raw material. By using the wheat flour for spring roll wrappers of the present invention, the wrappers are less likely to break during production, and spring roll wrappers can be produced efficiently.

The spring roll wrapper of the present invention can be manufactured by a known manufacturing method. In one embodiment of the present invention, the spring roll wrapper is manufactured by mixing wheat flour for spring roll wrappers, water, and salt to prepare a dispersion, and baking a noodle sheet of a predetermined thickness from the dispersion using a baking machine. The noodle sheet is then cut to a predetermined size or a die-cutting machine is used to manufacture the spring roll wrapper. Baking when manufacturing the spring roll wrapper can also be performed by a conventional method, and for example, a drum-type baking machine or the like can be suitably used.

When producing the spring roll wrappers of the present invention, the mixing ratio of wheat flour for spring roll wrappers and water is, for example, preferably 25 to 500 parts by weight of water per 100 parts by weight of wheat flour, and may be 50 to 300 parts by weight or 100 to 200 parts by weight. Note that in this mass ratio, the water contained in the wheat flour constitutes "wheat flour" and not "water."

The spring rolls according to the present invention are produced using the spring roll wrappers described above. Because the wheat flour for spring rolls according to the present invention is used for the spring roll wrappers, the wrappers are less likely to tear when wrapping the filling (stuffing) or when cooking, and the spring rolls can be produced efficiently. The resulting spring rolls have a moderate hardness and a good crispness and crunchiness.

The spring roll according to the present invention is produced by wrapping the filling (stuffing) in the above-mentioned spring roll wrapper and cooking it by deep-frying or the like. The cooking method is not particularly limited, but cooking methods other than deep-frying may be used, as long as the wrapper is gelatinized until it is ready to eat.

The spring rolls and spring roll wrappers according to the present invention may be stored and/or distributed refrigerated or frozen, and in particular, according to the present invention, it is possible to obtain tasty spring rolls even when frozen.

From one perspective, the present invention can be understood as a method for improving the texture of spring rolls by using the above-mentioned wheat flour for spring roll wrappers. According to the present invention, it is possible to produce spring rolls that have a moderate hardness and a good crispness and crunchiness.

The present invention will be described in more detail below based on specific experiments. Note that the following experiments are representative examples of the present invention, and the present invention is not limited to the following examples. Furthermore, unless otherwise specified, concentrations and the like in this specification are based on mass, and numerical ranges are described as including their endpoints.

Wheat flour In the following experiments, nine types of wheat flour samples with different ingredients and physical properties were used, as shown in Table 1. The physical properties of the wheat flour samples were analyzed as follows.

(1) Maximum Viscosity When Heated The viscosity of wheat flour when heated was measured using a Rapid Visco Analyzer (RVA4500, Perten Instruments). Specifically, 1.8 g of wheat flour as a solid content was placed in a container, water was added to a total of 30.0 g, and the viscosity was measured by changing the temperature under the following conditions. When the temperature was increased from 50°C to 95°C and maintained at 95°C, the viscosity increased to a peak and then decreased. The viscosity at this peak was evaluated as the viscosity when heated.
(Measurement conditions)
Time (sec) Temperature (℃) Rotational speed (rpm)
0~10 50℃ 960
10-282 Temperature rise from 50℃ to 95℃ 160
282-432 Maintain at 95℃ 160
432-660 Cool from 95℃ to 50℃ 160
(2) Moisture content of wheat flour 10 g of wheat flour was weighed into an aluminum container and dried at 130° C. for 1 hour in a blower dryer. The weight of the dried sample was subtracted from the weight of the sample before drying to calculate the moisture content of the sample.

(3) Protein content of wheat flour: Calculated by multiplying the nitrogen content determined by the Kjeldahl method by the nitrogen-protein conversion factor (5.70).

(4) Ash content of wheat flour: Measured by the direct ashing method based on AACC08-02.
(5) Median diameter of wheat flour
The measurement was performed using a laser diffraction particle size analyzer. Specifically, a laser diffraction particle size distribution analyzer HELOS & RODOS (manufactured by Nippon Laser) was used to determine the cumulative 50% particle size from the volume-based distribution (frequency distribution) by Fraunhofer diffraction.

(6) Damaged starch content of wheat flour The damaged starch content was measured based on AACC76-31 using a commercially available measurement kit (Starch Damage Assay Kit, MegaZyme). Specifically, 1 mL of α-amylase solution (derived from Aspergillus oryae, 50 unit/mL) pre-incubated at 40 ° C for 10 minutes was added to 100 mg of each wheat flour sample, stirred, and then treated at 40 ° C for 10 minutes. Next, 5 mL of citric acid-phosphoric acid aqueous solution (pH 2.5) was added to stop the reaction, and the mixture was centrifuged (1000 × g, 5 minutes) to obtain a supernatant. Amyloglucosidase solution (derived from Aspergillus niger, 2 unit/0.1 mL) was added to 0.1 mL of this supernatant, and the mixture was treated at 40 ° C for 20 minutes, and the absorbance was measured at 510 nm. The amount of glucose produced was calculated from the absorbance obtained, and the damaged starch content in the sample was calculated.

Preparation and evaluation of spring rolls After mixing water and salt and completely dissolving them, wheat flour was added to prepare a dispersion. Water, salt, and wheat flour were used in the amounts shown in the table below, but the amount of water added was adjusted so that the viscosity of the dispersion was almost the same.

The dispersion was baked into a noodle strip with a thickness of 0.50 to 0.55 mm using a drum-type baking machine, and then cut into a size of 190 mm x 190 mm to produce spring roll wrappers. A pre-cooked filling (stuffing) was placed on the spring roll wrapper and wrapped to produce spring rolls for deep frying.

Next, frozen spring rolls were prepared from the fried spring rolls. They were completely frozen at -40°C and then frozen for 14 days at -20°C. (a) ones were frozen as is, and (b) ones were deep-fried at 170-180°C and then frozen.

(a) The frozen spring rolls that had been frozen as is were fried at 170-180°C for 5 minutes, and the texture was evaluated immediately after frying and after leaving to stand at 25°C for 3 hours. (b) The frozen spring rolls that had been fried and then frozen were reheated in a 500W microwave for 30 seconds and left to thaw naturally for 5 hours, and their texture was evaluated.

In this experiment, the dough of the spring roll wrapper was evaluated by a sensory evaluation by a panel of five experts. Specifically, the dough was evaluated on a five-point scale based on the following evaluation criteria, and the average score was calculated. The texture of the spring roll wrapper was evaluated by a panel of ten experts. Specifically, the dough was evaluated on a five-point scale based on the following evaluation criteria, and the average score was calculated. The higher the numerical value for each evaluation, the better the result.
(Spring roll wrapper dough evaluation criteria)
・5 points: The dough does not tear when peeled off from the baking machine, and does not tear even when pulled very hard when wrapping ingredients. ・4 points: The dough hardly tears when peeled off from the baking machine, and does not tear even when pulled hard when wrapping ingredients. ・3 points: The dough rarely tears when peeled off from the baking machine, and can be used to wrap ingredients. ・2 points: The dough tears easily when peeled off from the baking machine, and tears easily when wrapping ingredients. ・1 point: The dough tears when peeled off from the drum-type baking machine, and ingredients cannot be wrapped. (Spring roll wrapper texture evaluation criteria)
・5 points: Moderate hardness, good crispness, and a nice crunchiness ・4 points: Hard, crisp, and a pleasant crunchiness ・3 points: Slightly hard, crisp, and slightly crisp ・2 points: Chewy texture, no crunchiness ・1 point: Chewy texture, no crunchiness at all

As shown in Table 2, in Test Examples 1 to 5, in which wheat flour with a maximum viscosity when heated of 167 to 248 mPa·s (Wheat flour A, B, F, G, H) was blended into the spring roll wrappers, the dough was evaluated as good, and the skin was evaluated as good in texture, whether it was frozen and then fried, or frozen after frying and then heated in a microwave oven or naturally thawed. On the other hand, in Test Examples 6 to 9, in which wheat flour with a maximum viscosity when heated of 291 mPa·s or more (Wheat flour C, D, E, I) was blended into the spring roll wrappers, the skin had a chewy texture and was not crispy in the spring rolls that had been frozen and then fried for 3 hours, and the spring rolls that had been frozen after frying and then heated in a microwave oven or naturally thawed. Furthermore, in Test Examples 7 and 9, the skin had a chewy texture and was not crispy, even in the spring rolls that had been frozen and then fried immediately after frying.

These results suggest that by using the wheat flour of the present invention for spring roll wrappers, they are less likely to tear when removed from the drum-type baking machine, and are also less likely to tear when wrapping ingredients around them. Additionally, spring rolls that are fried after being frozen, or fried and then frozen, then heated in a microwave oven or thawed naturally, have good hardness and crispness in the wrappers, providing a crispy texture.

Comparing Test Examples 1 to 5, which had good dough and texture evaluations, Test Examples 1 and 2, in which wheat flour with a protein content of 10% or more by mass (Wheat Flour A and B) was blended into the spring roll wrapper, had better results in the dough evaluation than Test Examples 3 to 5, in which wheat flour with a protein content of less than 10% by mass (Wheat Flour F, G, and H) was blended into the spring roll wrapper. These results suggest that when the protein content is set to 10.0 to 15.0% by mass, the strength of the spring roll wrapper after baking is increased, it is less likely to tear when removed from the drum-type baking machine, and it is also less likely to tear when wrapping ingredients.

In addition, when comparing Test Examples 3 to 5, the spring rolls immediately after frying after freezing were better in hardness and crispness in Test Examples 3 and 5 than in Test Example 4, and had a crispy texture. This suggests that even if the protein content of wheat flour for spring roll wrappers is less than 10% by mass, if the maximum viscosity during heating is lower, the texture of the spring roll wrappers immediately after frying after freezing will be more favorable.

Claims (8)

A wheat flour for spring roll wrappers having a protein content of 11.5 to 15.0% by mass and a maximum viscosity upon heating of 100 to 275 mPa s,
Here, the wheat flour has a maximum viscosity when heated, which is the maximum value of the viscosity measured at 160 rpm at 95°C after heating 30 g of a solution obtained by adding water to 1.8 g of wheat flour as a solid content. The flour according to claim 1 for producing frozen spring roll wrappers. The wheat flour according to claim 1, having a damaged starch content of 3 to 11% by mass. A spring roll wrapper made from the wheat flour according to any one of claims 1 to 3 . A method for producing spring roll wrappers, comprising a step of obtaining baked dough using the wheat flour according to any one of claims 1 to 3 as a raw material. A method for producing spring roll wrappers, comprising a step of obtaining baked dough using the wheat flour according to any one of claims 1 to 3 as a raw material (excluding the method of adjusting the pH of the dough to a range of 3.0 to 5.5 or 8.0 to 10.5 and then re-adjusting the pH of the dough to a range of 6.0 to 7.5). A method for producing spring rolls, comprising a step of wrapping ingredients in the spring roll wrapper made from the wheat flour according to any one of claims 1 to 3 . A method for producing frozen spring rolls, comprising a step of wrapping ingredients in the spring roll wrapper made from the wheat flour according to any one of claims 1 to 3, and freezing the resulting spring rolls.

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