WO2018042741A1 - Bread improving agent and method for producing bread - Google Patents

Abstract

Provided are a bread improving agent and a method for producing a bread, whereby a bread having an appreciable bread-making suitability and excellent qualities such as texture can be obtained even in the case of using a wheat flour for bread having a high ash content and being less suitable for bread-making. The bread improving agent comprises, as a starting material, a high-gluten wheat flour and/or a semi-high gluten wheat flour having a ratio of the soluble protein content to the ash content of 17.0 or less and also comprises, as an active ingredient, a pregelatinized, acetylated and swelling-controlled starch having an acetyl group content of 2.0-2.5 mass% and showing a paste viscosity at 6 mass% of 200 mPa^.s or less. A bread is produced by preparing a bread dough which comprises a high-gluten wheat flour and/or a semi-high gluten wheat flour having a ratio of the soluble protein content to the ash content of 17.0 or less and also comprises a pregelatinized, acetylated and swelling-controlled starch having an acetyl group content of 2.0-2.5 mass% and showing a paste viscosity at 6 mass% of 200 mPa^.s or less, swelling the obtained bread dough by fermentation and then heating the same.

Description

Bread improver and bread production method

The present invention relates to a bread improving agent and a bread production method for producing a bread having good workability of dough and excellent quality.

Wheat flour is one of the most important raw materials for making bread, and the flour used in bread is said to be better if it has a higher protein content and a lower ash content.

The first reason is gluten. Standard bread flour contains about 12% protein, about 85% of which is glutenin and gliadin, the storage proteins of wheat endosperm, and these proteins are added to the water added during mixing. When hydrated, it forms gluten. Gluten is both elastic and sticky, and at the same time it is somewhat soft and fluid, and the gluten that is stretched together wraps starch to form a film and wraps around the carbon dioxide produced by yeast. , Keep the shape of the bread. Furthermore, in addition to glutenin and gliadin, soluble proteins such as albumin and globulin contribute to the production of high-quality and smooth dough. For this reason, it is generally considered that a higher protein content is preferable as bread flour.

On the other hand, ash content is one of the important indicators of flour quality. When wheat flour is burned at a high temperature, its main components such as protein, starch, and lipid will not burn, but some will remain as ash without burning. This is called ash, and its substance is a mineral such as phosphorus, potassium, magnesium, calcium, or iron contained in flour. Ash content inhibits the activity of enzymes that are effective for bread production, so if the content is large, problems such as stickiness of bread dough and deterioration of the mouth-feel of bread occur. In addition, wheat flour with a high ash content also has a high content of contaminating proteins and enzymes, which have the effect of inhibiting the formation of gluten and lowering the quality of gluten. It becomes a bread that is easy to stick. For this reason, it is generally considered that a lower ash content is preferable as flour for bread.

However, in the process of milling wheat flour, it is not always possible to obtain flour with high protein content and low ash content. In other words, in the flour milling process, the endosperm part, which is the main component of the flour, is separated through a step-by-step roll / sieving process. It is inevitable to mix germs. And if it is going to obtain quality wheat flour with few mixing of the outer skin and the part containing a germ, a yield will also worsen. In this respect, in the Japanese market, good quality products with low ash content produced using milling technology have become the mainstream, but it is expensive. In overseas markets, bread flour is often used because it has a high ash content and is not considered to be suitable for breadmaking. Therefore, even when flour with a high ash content is used, there has been a demand for a technique for obtaining bread having a good quality such as texture and having a good bread-making suitability.

With regard to such a problem, for example, Patent Document 1 discloses bread making characterized in that wheat flour having an ash content of 0.5 to 3% by mass is subjected to wet heat treatment at a product temperature of 82 to 97 ° C. for 5 to 60 seconds. A method for producing wheat flour is disclosed. And when the said bread flour is used, it is described that the same bread-making property and food texture as when using the normal bread flour are obtained.

Also, for example, in Patent Document 2, one or more polysaccharides selected from pullulan, gum arabic and arabinoxylan are blended at a ratio of 0.1 to 1 part by mass with respect to 1 part by mass of trehalose. A bread improver characterized by the following is disclosed: And, when the bread improver is used, when the bread is produced using flours with low protein content such as gluten and low bread-making suitability, the ingredients other than bread flour are mixed. Even when bread is produced using bread-making ingredients with a reduced gluten content as a whole, high-quality bread with a large bread volume and excellent appearance, internal phase, texture and taste is a good process. It is described that it can be manufactured smoothly.

Also, for example, Patent Document 3 discloses a plastic emulsified oil composition for kneading bread, characterized in that it contains glucomannan and glycerin fatty acid ester in the aqueous phase. When the composition is used, even when flour with a high ash content is used, the obtained dough is not sticky and has good extensibility, and the texture of the bread obtained using the dough Is also described as being good.

Further, for example, Patent Document 4 discloses a water-in-oil emulsified fat composition for bread kneading, which contains a proteolytic enzyme, a glycerin organic acid fatty acid ester, an oxidizing agent, and a gelatinized swelling-inhibited starch. . When the composition is used, even when flour with a high ash content is used, the obtained dough is not sticky and has good extensibility, and the texture of the bread obtained using the dough Is also described as being good.

JP 2007-125006 A JP 2011-223907 A International Publication No. 2012/108377 JP 2010-200696 A

However, in the method described in Patent Document 1, when ordinary wheat flour is used, only a portion of the flour is wet-heat treated and high ash content flour is used. When flour with an ash content was used, a sufficient effect was not obtained. In addition, the method described in Patent Document 2 is intended to improve bread-making properties when wheat flour having a low protein content is used. Bread-making when bread flour having a high ash content is used. It was not a technique to improve the sex. Moreover, in the method of the said patent documents 3 and 4, it was necessary to use a specific emulsifier, and there existed a problem that it was not accepted by the consumer who does not like the use.

In view of the above prior art, the object of the present invention is to have a high ash content, and even when using flour for bread that is difficult to say that bread making is high, bread making suitability is not inferior, such as texture. An object of the present invention is to provide a bread improving agent and a method for producing bread, which can obtain bread of good quality.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention applied a specific pregelatinized acetylated swelling-suppressing starch to a strong powder or semi-strong powder that has a high ash content and is difficult to say that bread-making ability is high. By blending, it was found that a dough without stickiness and good extensibility was obtained, and the resulting bread had a soft feeling, moist feeling, mouthfeel, etc., and the present invention was completed. .

That is, the bread improver of the present invention is a bread improver containing a strong flour and / or semi-strong flour having a soluble protein content / ash content value of 17.0 or less as a raw material, and has an acetyl group content of 2.0. It is characterized by comprising an α-acetylated swelling-suppressed starch having an active ingredient of ~ 2.5% by mass and a paste viscosity of 6% by mass of 200 mPa · s or less.

In the bread improving agent of the present invention, it is preferable that the pregelatinized acetylated swelling-suppressed starch is a pregelatinized acetylated crosslinked starch.

The bread production method of the present invention includes a strong flour and / or a semi-strong flour having a soluble protein content / ash content value of 17.0 or less, and further has an acetyl group content of 2.0 to 2.5% by mass. The bread dough containing the gelatinization acetylation swelling suppression starch from which the paste viscosity of 6 mass% will be 200 mPa * s or less is prepared, this is fermented and expanded, It heat-processes, It is characterized by the above-mentioned.

In the bread manufacturing method of the present invention, it is preferable to contain 0.2 to 15% by mass of the pregelatinized acetylated swelling-suppressing starch in the total amount of starchy raw material of the bread.

Further, it is preferable that the pregelatinized acetylated swelling-suppressed starch is obtained by subjecting the raw material starch to acetylation treatment and swelling inhibition treatment, and then pregelatinizing with a drum dryer.

Further, it is preferable that the pregelatinized acetylated swelling-suppressed starch is a pregelatinized acetylated crosslinked starch.

According to the bread improving agent of the present invention, even when using bread flour that has a high ash content and high breadmaking suitability, the breadmaking suitability is inferior and the quality such as texture is good. Can get a good bread. Specifically, a dough having no stickiness and good extensibility can be prepared, and the texture of bread such as soft feeling, moist feeling, and mouthfeel becomes good.

In addition, according to the bread manufacturing method of the present invention, using a flour for bread which has a high ash content and is not highly suitable for bread making, a specific pregelatinized acetylated swelling inhibiting starch is added thereto. As a result, it is possible to obtain a bread having a good quality such as a texture without having an inferior bread-making suitability. Specifically, a dough that is not sticky and has good extensibility can be prepared, and after the dough is fermented and expanded, heat treatment is performed to obtain a bread having a soft texture, a moist feeling, a mouthfeel, etc. be able to.

The pregelatinized acetylated swelling-suppressed starch used in the present invention has an acetyl group content of 2.0 to 2.5% by mass and a paste viscosity of 6% by mass of 200 mPa · s or less. There are no particular restrictions on the type of raw starch, the method of α-izing, the method of acetylation, the method of inhibiting swelling, and the like.

The raw material starch may be any starch that can be used for food. Examples include starch. Among these, corn starch or tapioca is preferable from the viewpoint of cost and effect. Further, in any starch, in addition to ordinary starch, those modified in breeding techniques or genetic engineering techniques such as urch seeds, waxy seeds, and high amylose seeds may be used.

Starch acetylation can be performed using a conventionally known acetylating agent, for example, acetic anhydride, vinyl acetate monomer or the like. At that time, by appropriately adjusting conditions such as the addition amount of the acetylating agent to be used, reaction time, reaction temperature, reaction pH and the like, a desired acetyl group content, for example, 2.0 to 2.5% by mass in the present invention. Can be adjusted. It is not preferable that the acetyl group content is less than 2.0% by mass because the effects of soft feeling and moist feeling tend to be hardly obtained. In addition, the acetyl group content of the acetylated starch is preferably 2.5% by mass or less in consideration of the efficiency of the acetylation reaction by the acetylating agent and the standards of food hygiene law foods and additives. .

The acetyl group content can be measured, for example, as follows.

(Measurement method of acetyl group content)
Weigh accurately 5.0 g of sample, suspend in 50 mL of water, add a few drops of phenolphthalein test solution, add 0.1 mol / L sodium hydroxide solution dropwise until the solution turns slightly red, then add 0.45 mol / L water. Add exactly 25 mL of sodium oxide solution, cap and shake vigorously for 30 minutes, being careful not to let the temperature rise above 30 ° C. Titrate excess sodium hydroxide with 0.2 mol / L hydrochloric acid. The end point is when the slight red color of the liquid disappears. Separately, perform a blank test to correct. A free acetyl group content is calculated | required by following formula (1), and also dry matter conversion is performed.

Acetyl group content (mass%) = (ef) × n × 0.043 × 100 / w (1)
(In the above formula (1), e: blank test titration (mL), f: sample titration (mL), n: normality of 0.2 mol / L hydrochloric acid, w: dry sample weight (g) It shall be.)

The suppression of starch swelling means that the starch is processed in some way so that the swelling of the starch particles is suppressed when the starch is heated and expanded. Examples of the treatment include cross-linking treatment and wet heat treatment. Etc. are exemplified.

The starch can be crosslinked using a conventionally known crosslinking agent. Examples of the crosslinking treatment include phosphoric acid crosslinking treatment using sodium trimetaphosphate and phosphoryl chloride, adipic acid crosslinking treatment using adipic acid with acetic anhydride, acrolein crosslinking treatment using acrolein, and epichlorohydrin crosslinking treatment using epichlorohydrin. Etc. In that case, it can adjust so that it may become a desired crosslinking degree by adjusting suitably conditions, such as the addition amount of the crosslinking agent to be used, reaction time, reaction temperature, reaction pH. This degree of crosslinking correlates well with the starch viscosity of the starch. That is, the swelling of starch is suppressed by increasing the degree of crosslinking, and the paste viscosity can be suppressed. Therefore, it can be adjusted to a desired paste viscosity by appropriately adjusting the conditions such as the addition amount of the crosslinking agent, the reaction time, the reaction temperature, and the reaction pH.

Also, the wet heat treatment of starch can be performed by heat treatment in the presence of insufficient moisture to gelatinize the starch. For example, it is obtained by adjusting the water content of starch to about 20 to 25% and treating it at about 100 to 130 ° C. for about 0.5 to 5 hours. At this time, if the amount of water is increased within a range where gelatinization does not occur, and the heating temperature is increased to increase the treatment time, the swelling is further suppressed. Therefore, by appropriately setting conditions such as the moisture content of starch, the heating temperature, and the heating time, the suppression of swelling can be adjusted to a desired degree, and thus the desired paste viscosity can be adjusted.

The starch swelling suppression treatment is preferably a crosslinking treatment from the viewpoint of production cost and ease of production.

The above-mentioned α-acetylated swelling-suppressed starch used in the present invention needs to have a paste viscosity of 6% by mass of 200 mPa · s or less. In addition, as for the paste viscosity of 6 mass%, it is more preferable that it is 150 mPa * s or less. If the paste viscosity exceeds 200 mPa · s, the dough is sticky, workability is lowered, and the produced bread tends to be unsatisfactory, which is not preferable.

The paste viscosity of 6% by mass of starch can be measured, for example, as follows using a paste viscosity measuring device (for example, Rapid Visco Analyzer: RVA, model RVA-4 manufactured by Newport Scientific).

(Measurement method of paste viscosity)
Put 1.8 g of sample starch in terms of solid content into an aluminum can, add purified water to a total amount of 30 g (6% by mass), set a paddle, and measure the viscosity under the conditions shown in Table 1 below. . And let the maximum viscosity in the viscosity data obtained at the time of 160 rpm rotation be the paste viscosity of 6 mass%.

The gelatinization of starch can be performed by employing a general method used for heat gelatinization of starch. Specifically, a heat gelatinization method using a drying device such as a drum dryer, a jet cooker, an extruder, a paddle dryer, or a spray dryer is known. In particular, it is preferable to perform the alpha treatment with a drum dryer from the viewpoint of efficiently producing an alpha starch with a high alpha conversion rate. Moreover, it is preferable to perform gelatinization of starch with respect to the starch which the process of acetylation and swelling suppression was performed.

The pregelatinized acetylated swelling-suppressed starch used in the present invention is subjected to other processing in addition to the above-described pregelatinization, acetylation, and swelling suppression as long as the effects of the present invention are not impaired. It may be. Specifically, it has been subjected to processing such as esterification, etherification, oxidation, fat processing, ball mill processing, pulverization processing, heating processing, hot water processing, bleaching processing, acid processing, alkali processing, enzyme processing, etc. There may be.

On the other hand, bread is generally made from flour and / or flour-derived flour, and after adding dough to water, yeast, salt, yeast food and other necessary auxiliary materials, It is manufactured by performing heat treatment such as baking, frying, steaming and boiling. Specific examples include breads such as pullman, French breads such as baguette and batar, various rolls such as sweet rolls and table rolls, pizza, naan, bagels, English muffins, buns, brioche, sweet breads, prepared breads, etc. It is done. Secondary materials used as necessary include, for example, fats and oils, sugars, sweeteners, thickening stabilizers, coloring agents, antioxidants, dextrin, milk and dairy products, cheeses, distilled liquor, brewed liquor, various liqueurs , Emulsifiers, swelling agents, inorganic salts, baking powder, cacao and cacao products, coffee and coffee products, herbs, beans, proteins, preservatives, bitter agents, acidulants, pH adjusters, shelf life improvers, fruits, fruit juice, jam , Fruit sauces, seasonings, spices, fragrances, various food ingredients and food additives.

In the present invention, the α-acetylated swelling-suppressed starch described above is used as an active ingredient for bread improvement. That is, the above-mentioned α-acetylated swelling-suppressed starch is added to bread ingredients together with other materials such as wheat flour to improve bread-making properties. However, it is preferable that the present invention is applied to breads containing strong flour and / or quasi-strong flour with a soluble protein content / ash content value of 17.0 or less among the breads, The value of / ash content is more preferably 16.0 or less, and the value of soluble protein content / ash content is most preferably 14.0 or less. That is, as shown in the examples described later, in the bread using the flour for bread that has a high ash content and high breadmaking suitability, the effect of improving the handling workability and texture of the dough is remarkable. It is because it is demonstrated to.

In the present specification, “strong flour” and “quasi-strong flour” are used in the meaning usually understood by those skilled in the art as wheat flour for bread. More specifically, “strong flour” has a protein content of 11. The term “semi-strong powder” means that the protein content is about 11.0 to 12.5% by mass.

The protein content of wheat flour can be measured, for example, as follows.

(Measurement method of protein content of wheat flour)
(1-1) 0.5 g of a wheat flour sample in terms of anhydride is placed in a Kjeldahl tube manufactured by Ticator (Sweden), and a decomposition accelerator [“Keltab Cu4.5” manufactured by Foss Japan KK; (component) potassium sulfate: Copper sulfate = 4.5 g: 0.5 g (mass ratio)] 2 tablets and 15 mL of concentrated sulfuric acid are added.
(1-2) For decomposition, use a Kjeldahl decomposition apparatus (FOSS Tecator Digester 8) and leave it at 420 ° C. for 30 to 60 minutes until the contents become clear blue-green. Add 2 mL with Komagome pipette. Further, the decomposition reaction is carried out at 420 ° C. for 1 hour and the mixture is allowed to cool for 10 minutes.
(1-3) Distillation, titration, and nitrogen calculation are performed with a Keltec distillation titration system (Actac “Super Kell 1500”) to obtain a nitrogen content (mass%).
(1-4) The protein content (% by mass) is calculated by multiplying the nitrogen content value obtained in (1-3) above by the nitrogen protein conversion factor (5.70).

The soluble protein of wheat flour is considered to contain albumin, globulin and the like as well as glutenin and gliadin that form gluten that is soluble in dilute acid. The higher the content, the better and smooth bread dough can be made, and it can be said that the bread-making ability is high.

The soluble protein content of wheat flour can be measured, for example, as follows.

(Method for measuring soluble protein content of wheat flour)
(2-1) Precisely weigh about 2 g of a flour sample in terms of anhydride in a 100 mL beaker.
(2-2) Add 40 mL of 0.05N acetic acid and stir for 60 minutes at room temperature using a stirrer.
(2-3) The obtained suspension was transferred to a centrifuge tube, the beaker was washed with 40 mL of 0.05 N acetic acid, the washing solution was transferred to the same centrifuge tube, and centrifuged at 4,220 × G for 5 minutes. Then, it is filtered using a filter paper, and the filtrate is recovered.
(2-4) Mix the filtrate obtained in (2-3) above and make up to 100 mL.
(2-5) 25 mL of the liquid obtained in (2-4) above was put into a Kjeldahl tube manufactured by Ticator (Sweden) with a whole pipette, and a decomposition accelerator [“Keltab Cu4.5” manufactured by Foss Japan Co., Ltd .; (Component) Potassium sulfate: Copper sulfate = 4.5 g: 0.5 g (mass ratio)] Add 2 tablets and 15 mL of concentrated sulfuric acid.
(2-6) Decomposition is carried out using a Kjeldahl decomposition apparatus (FOSS Tecator Digester 8), left at 420 ° C. for 30 to 60 minutes until the contents become transparent blue-green, and allowed to cool for 10 minutes, then hydrogen peroxide Add 2 mL with Komagome pipette. Further, the decomposition reaction is carried out at 420 ° C. for 1 hour and the mixture is allowed to cool for 10 minutes.
(2-7) Distillation, titration, and nitrogen calculation are performed with a Keltec distillation titration system (Actac "Super Kel 1500") to obtain a nitrogen content (% by mass).
(2-8) The soluble protein content (mass%) is calculated by multiplying the nitrogen content value obtained in (2-7) above by the nitrogen protein conversion factor (5.70).

As described above, the ash content of wheat flour is a mineral such as phosphorus, potassium, magnesium, calcium, and iron. In addition, wheat with a high ash content also tends to have a high content of foreign substances including contaminating enzymes, which is an index for judging the suitability for breadmaking. In order of decreasing ash content, first flour (ash content 0.3 to 0) .4 mass%), second-class powder (ash content around 0.5% by mass), and third-class powder (ash content around 1.0% by mass) for convenience and are classified by grade and sold in the market Most flours are in these ash content ranges.

The ash content of the strong flour and / or semi-strong flour used as a raw material for bread to which the present invention is applied is preferably 0.55% by mass or more in terms of anhydride, and preferably 0.65% by mass or more. More preferred. The “ash content” in the present invention means an ash content in terms of anhydride measured by the direct ashing method shown below, unlike the ash content in the above-mentioned classification of wheat flour.

(Measurement method of ash content of wheat flour (anhydrous equivalent))
Precisely weigh an appropriate amount of sample in an ashing container (W0g) [W1g (anhydride equivalent)], perform the necessary pretreatment, and put it in an electric furnace that has reached a temperature of 550 to 600 ° C. Ash until white or near color. After ashing, the ashing container is taken out), allowed to cool to a temperature close to 200 ° C., transferred to a desiccator, returned to room temperature, and weighed. The same operation (incineration, cooling, weighing) is repeated until a constant weight (W2g) is reached.

From the value obtained by the above method, it is obtained by the following formula (2).
Ash content (%) = (W2-W0) / W1 × 100 (2)

In this specification, “value of soluble protein content / ash content” can be said to be an index indicating the quality of flour. That is, flour with a high value indicates that the flour in the flour is a good quality flour with a high gluten content, and flour with a low value indicates that the gluten content in the flour with respect to the contaminants in the flour. Indicates that the flour is of poor quality.

The bread to which the present invention is applied is obtained by producing a bread by blending a predetermined amount of the above-described pregelatinized swelling-suppressed starch with bread containing the above-described strong flour and / or semi-strong flour as a raw material. As a manufacturing method thereof, a conventionally known general method may be adopted, and there is no particular limitation. That is, it is produced by preparing bread dough containing the above-described strong flour and / or quasi-strong flour and further containing the above-described pregelatinized acetylation-swelling starch, fermenting and then heat-treating it. do it. For example, the present invention can be applied to any bread making method such as the straight rice method, the middle seed method, the water seed method, the refrigeration method, and the hot water seed method. Moreover, it is applicable also to the bread-making method which prepares and uses frozen bread dough.

The addition amount of the above-mentioned pregelatinized acetylation-swelling starch is preferably 0.2 to 15% by mass, more preferably 0.5 to 10% by mass in the total amount of starchy starch material. Moreover, it is preferable to contain 80 mass% or more in the whole quantity of the starch raw material of bread | pan, and, as for the said strong powder and / or semi-strong powder, it is more preferable to contain 90 mass% or more. If the pregelatinized acetylated swelling-inhibiting starch is less than 0.2% by mass, the effect of improving dough workability and the texture of bread tends to be poor, such being undesirable. On the other hand, when the content exceeds 15% by mass, the dough viscosity tends to decrease, resulting in a decrease in the volume of bread after manufacture or a hard texture. Moreover, when the said strong flour and / or semi-strong flour is less than 80 mass% of the total amount of starchy raw material of bread, bread-making property will worsen and it will become difficult to obtain a favorable food texture of bread, which is not preferable.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

[Sample preparation]
・ Samples 1 to 5
Water was added to tapioca to prepare a slurry containing 30-40% by mass of tapioca. After heating this slurry to 30 ° C., 2 parts by mass of sodium sulfate was dissolved with respect to 100 parts by mass of the dry mass of starch. Furthermore, after adding sodium hydroxide and adjusting to pH 11-12, with respect to 100 mass parts of dry mass of starch, 0.5 mass part in sample 1, 0.05 mass part in sample 2, 0 in sample 3 0.04 part by mass, 0.03 part by mass for sample 4, and 0.02 part by mass phosphoryl chloride for sample 5 were added and reacted for 1 hour. Next, after adding sulfuric acid to adjust the pH to 9 to 10, while maintaining the pH, 7 parts by mass of vinyl acetate monomer was added to 100 parts by mass of the dry starch and reacted for 30 minutes. Further, sulfuric acid was added to adjust the pH to 5 to 6, followed by washing with water and dehydration. Water was added to the obtained product to prepare a slurry containing 30 to 40% by mass of the product, and this slurry was dried with a double drum dryer set at a surface temperature of 158 ° C. Got.

・ Sample 6
Water was added to tapioca to prepare a slurry containing 30-40% by mass of tapioca. After heating this slurry to 30 ° C., 2 parts by mass of sodium sulfate was dissolved with respect to 100 parts by mass of the dry mass of starch. Further, sodium hydroxide was added to adjust the pH to 11 to 12, and 0.05 parts by mass of phosphoryl chloride was added to 100 parts by mass of the dry starch, followed by reaction for 1 hour. Sulfuric acid was added to adjust to pH 5-6, followed by washing with water and dehydration. Water was added to the obtained product to prepare a slurry containing 30 to 40% by mass of the product, and this slurry was dried with a double drum dryer set at a surface temperature of 158 ° C. to obtain Sample 6. It was.

・ Sample 7
Sample 2 was prepared in the same manner as Sample 2, except that 1.5 parts by weight of vinyl acetate monomer was added instead of adding 7 parts by weight of vinyl acetate monomer to 100 parts by weight of dry starch. Sample 7 was obtained.

・ Sample 8
100 parts by mass of tapioca was added to 120 parts by mass of water to form a slurry, and 0.5% by mass of sodium trimetaphosphate was added while maintaining a pH of 11.3 to 11.5 by adding a 3% aqueous solution of caustic soda under stirring. Was reacted for 5 hours, adjusted to pH 9.5 with sulfuric acid, and cooled to 25 ° C. Next, 3 parts of aqueous caustic soda was added to maintain the pH at 9.0 to 9.5, 6 parts by mass of acetic anhydride was added to acetylate, neutralized with sulfuric acid, washed with water, and dehydrated. Water was added to the obtained product to prepare a slurry containing 30 to 40% by mass of the product, and this slurry was dried with a double drum dryer set at a surface temperature of 158 ° C. to obtain Sample 8. It was.

・ Sample 9
Sample 2 was prepared in the same manner as Sample 2, except that 8 parts by weight of vinyl acetate monomer was added instead of 7 parts by weight of vinyl acetate monomer with respect to 100 parts by weight of the dry starch mass. 9 was obtained.

・ Sample 10
In the preparation of Sample 1, corn starch was used instead of tapioca, and instead of adding 0.5 parts by mass of phosphoryl chloride to 100 parts by mass of dry starch (corn starch), 0.8 parts by mass of trimetaline Sample 10 was obtained in the same manner as Sample 1, except that sodium acid was added.

・ Sample 11
In the preparation of Sample 1, potato starch was used instead of tapioca, and instead of adding 0.5 parts by mass of phosphoryl chloride to 100 parts by mass of the dry mass of starch (potato starch), 1 part by mass of trimetaline Sample 11 was obtained in the same manner as Sample 1, except that sodium acid was added.

・ Sample 12
100 parts of commercially available tapioca was added to 120 parts of water in which 20 parts of sodium sulfate had been dissolved to form a slurry. Under stirring, 30 parts of a 4% aqueous sodium hydroxide solution, 5 parts of propylene oxide, and 0.4 parts of sodium trimetaphosphate were added at 41 ° C. After reacting for 20 hours, the mixture was neutralized with sulfuric acid, washed with water and dehydrated. Water was added to the obtained product to prepare a slurry containing 30 to 40% by mass of the product, and this slurry was dried with a double drum dryer set at a surface temperature of 158 ° C. to obtain Sample 12. It was.

The hydroxypropyl group (HP group) content was measured by the following method.

0.05 g of sample starch was accurately weighed, 25 mL of 0.5 mol / L sulfuric acid was added and dissolved by heating in a boiling water bath, and after cooling, water was added to make 100 mL. 1.0 mL of the sample starch solution was accurately weighed, 8 mL of sulfuric acid was added while cooling with cold water, stirred, heated in boiling water for exactly 3 minutes, and immediately cooled in ice water. After cooling, 0.6 mL of ninhydrin reagent was added along the tube wall, stirred immediately, and allowed to react for 100 minutes in a 25 ° C. water bath. To this was added 15 mL of sulfuric acid, and the mixture was gently stirred, and the absorbance at 590 nm was measured after 5 minutes. As the control solution, raw starch derived from the same plant was used, and the same operation as in the test solution was performed. Furthermore, in order to prepare a calibration curve, propylene glycol was prepared to be 0, 15, 30, and 60 μg / mL, and these liquids were subjected to the same operation as in the case of the test liquid. From the calibration curve, the propylene glycol concentration (μg / mL) in the test solution and the control solution was determined, and the hydroxypropyl group content was determined by the following formula (3).

Hydroxypropyl group content (mass%) = (fe) × 0.007763 / w (3)
(In the above formula (3), f: propylene glycol concentration (μg / mL) in the test solution, e: propylene glycol concentration (μg / mL) in the control solution, w: dry substance amount (g) of the sample starch. means.)

・ Sample 13
Water was added to tapioca to prepare a slurry containing 30-40% by mass of tapioca. After heating this slurry to 30 ° C., 2 parts by weight of sodium sulfate is dissolved with respect to 100 parts by weight of the dry starch, and the pH is adjusted to 11-12 by adding sodium hydroxide, etc., and then the starch is dried. 0.05 parts by mass of phosphoryl chloride was added to 100 parts by mass of mass and reacted for 1 hour. After adjusting the pH to 9 to 10 by adding sulfuric acid, 7 parts by weight of vinyl acetate monomer was added to 100 parts by weight of the dry starch while maintaining the pH and reacted for 30 minutes. Further, sulfuric acid was added to adjust to pH 5-6, and then washed with water, dehydrated and dried to obtain Sample 13.

Table 2 below summarizes the characteristics of each prepared starch sample.

[Test Example 1]
<Manufacture of bread 1>
Strong powder sample A (protein content: 14.3 mass%, soluble protein content: 8.6 mass%, ash content: 0.68 mass%, soluble protein content / ash content value: 12.6), and Samples 2, 5, 6, 10-12 were blended as test starches (or no starch added as a control) to produce a pullman bread. Specifically, it was produced as follows.

Powerful powder sample A 70 parts by weight, raw yeast 2.2 parts by weight, emulsifier 0.3 parts by weight, yeast food 0.1 part by weight, and water 40 parts by weight are put into a bowl, and mixed at a low speed for 3 minutes with a hook. A medium dough was obtained. The kneading temperature was 24 ° C. This medium seed dough was put in a plastic case and subjected to seed fermentation for 4 hours with a proofer having a temperature of 27 ° C. and a relative humidity of 75%. The temperature after fermentation was 28 ° C. This medium seed dough, strong powder sample A 30 parts by weight, test starch 5 parts by weight (or no starch added as a control), upper white sugar 6 parts by weight, skim milk powder 2 parts by weight, salt 2 parts by weight, and water 28 parts by weight The mixture was put into a bowl and mixed for 2 minutes at low speed and 2 minutes at medium speed. 6 parts by weight of margarine was added and mixed for 2 minutes at medium speed and 6 minutes at high speed. The resulting bread dough was adjusted at the time of mixing so that the kneading temperature was 27 ° C. Then, the floor time was taken for 20 minutes, and it divided and rounded to 240g. Next, after taking a bench time of 20 minutes, mold the mold, put 6 pieces into a U-shape, put them in a 3 斤 -type pullman mold, and perform fermentation for 45 minutes at 38 ° C and a relative humidity of 85%. Was baked in a fixed kiln for 40 minutes to obtain a pullman type bread.

<Evaluation>
The obtained pullman type bread was evaluated for dough workability (a dough with less stickiness and extensibility is better workability) and a texture (soft feeling, moist feeling, mouthfeel) after 4 days of manufacture. It was. The evaluation was performed according to the following evaluation criteria, and the dough workability was evaluated by two panelists, and the texture was evaluated by ten panelists, and the average value of each score was shown.

(Workability)
When the dough workability of the control Pullman type bread produced without adding the test starch is 1 point, the workability is slightly superior: +2 points, workability is excellent: +3 points, very workability Is excellent: +4 points, work is remarkably excellent: +5 points, workability is equal or inferior: Evaluation was made on the basis of 1 point.

(Soft feeling)
When the softness of the control Pullman type bread produced without adding the test starch is 0 points, the softness is slightly strong: +1 point, soft: +2 points, very soft: +3 points, slightly Inferior soft feeling: -1 point, poor soft feeling: -2 points, very poor soft feeling: -3 points.

(Moist feeling)
When the control Pullman type bread made without adding the test starch is 0 points, it is slightly moist: +1 point, moist: +2 points, very moist: +3 points Slightly moist feeling was inferior: -1 point, moist feeling was inferior: -2 points, very moist feeling was inferior: -3 points.

(Spoken)
Slightly good mouthfeel: +1, good mouthfeel: +2 points, very good mouthfeel: +3 points Slightly bad mouth: -1 points, bad mouth: -2 points, very bad mouth: -3 points.

The results are shown in Table 3.

As a result, when the strong powder sample A (soluble protein content / ash content value: 12.6) was used, the following became clear.

(1) When starch sample 2 (source: tapioca), starch sample 10 (source: corn starch), or starch sample 11 (source: potato starch) is added, it has excellent workability and soft feeling regardless of those sources. , Moist feeling, good mouthfeel. In particular, in the starch sample 2, the workability and texture improvement effects were more remarkable.
(2) Starch sample 5 having a viscosity of more than 200 mPa · s has been softened and moist but good evaluation has been obtained, but the mouthfeel is insufficient and the texture is slightly fluffy. Met. Moreover, the workability improvement effect was not obtained.
(3) The starch sample 6 that was not subjected to acetylation treatment had a soft and moist feeling and a hard and crunchy texture. Moreover, the workability improvement effect was poor.
(4) In the starch sample 12 which is hydroxypropylated tapioca, although the improvement effect of workability was recognized, the texture was slightly soft and the mouthfeel was bad.

[Test Example 2]
<Manufacture of bread 2>
Strong powder sample B instead of strong powder sample A (protein content: 13.4 mass%, soluble protein content: 9.75 mass%, ash content: 0.61 mass%, soluble protein content / ash content value: 16.0 ) Was used in the same manner as in Test Example 1, and any one of the starch samples of Samples 1 to 13 was added as a test starch (or no starch added as a control) to produce a pullman-type bread. .

<Evaluation>
The obtained pullman bread was evaluated in the same manner as in Test Example 1 with reference to the control pullman bread produced without adding the test starch.

The results are shown in Table 4.

As a result, when the strong powder sample B (value of soluble protein content / ash content: 16.0) was used, the following became clear.

(1) When starch samples 1 to 3, 9 (source: tapioca), starch sample 10 (source: corn starch), or starch sample 11 (source: potato starch) are added, workability is improved regardless of the sources. Excellent, soft feeling, moist feeling and good mouthfeel. In particular, in the starch sample 2, the workability improvement effect was more remarkable and the texture was excellent.
(2) Starch samples 4 and 5 having a viscosity higher than 200 mPa · s have been evaluated for softness and moistness, but lack of mouthfeel and slightly fluffy. It was a texture. Moreover, the workability improvement effect was poor.
(3) The starch sample 6 that was not subjected to acetylation treatment had a soft and moist feeling and a hard and crunchy texture. Moreover, the workability improvement effect was poor.
(4) In the starch samples 7 and 8 having a low acetyl group content, the evaluation of soft feeling and moist feeling was slightly low, and a good texture was not obtained. Moreover, the workability improvement effect was poor.
(5) In the starch sample 12, which is hydroxypropylated tapioca, the texture was slightly soft and the mouthfeel was poor. Moreover, the workability improvement effect was poor.
(6) The starch sample 13 that was not subjected to the pregelatinization treatment was poor in workability, and the texture improvement effect was not good throughout.

[Test Example 3]
<Manufacture of bread>
Strong powder sample C instead of strong powder sample A (protein content: 13.1 mass%, soluble protein content: 8.3%, ash content: 0.47 mass%, soluble protein content / ash content value: 17.6) In the same manner as in Test Example 1 except that was used, any one of the starch samples of Samples 1 to 13 was blended as a test starch (or no starch added as a control) to produce a pullman-type bread.

<Evaluation>
The obtained pullman bread was evaluated in the same manner as in Test Example 1 with reference to the control pullman bread produced without adding the test starch.

The results are shown in Table 5.

As a result, when the strong flour sample C (soluble protein content / ash content value: 17.6) was used, any of the starch samples 1 to 13 had excellent workability improvement effect compared to the control. I couldn't. This was because there was no problem in dough workability because a high-quality strong powder having a high value of soluble protein content / ash content was used.

According to the above results, according to the starch samples 1 to 3 and 9 to 11 belonging to the scope of the present invention, when using strong powder of poor quality, the texture such as soft feeling, moist feeling, mouthfeel, etc. It has been clarified that the effect of improving the fabric workability can be obtained.

Claims (6)

1. A bread improver comprising a strong flour and / or semi-strong flour having a soluble protein content / ash content value of 17.0 or less as a raw material, and having an acetyl group content of 2.0 to 2.5% by mass, 6 A bread improving agent comprising, as an active ingredient, pregelatinized acetylated swelling-suppressed starch having a mass% paste viscosity of 200 mPa · s or less.
2. The bread improver according to claim 1, wherein the pregelatinized acetylated swelling-suppressed starch is pregelatinized cross-linked starch.
3. It contains a strong powder and / or a semi-strong powder having a soluble protein content / ash content value of 17.0 or less, and further has an acetyl group content of 2.0 to 2.5% by mass and a paste viscosity of 6% by mass of 200 mPa A method for producing bread characterized by preparing bread dough containing pregelatinized acetylated and swelling-suppressed starch that is s or less, fermenting and expanding the bread dough, followed by heat treatment.
4. The method for producing bread according to claim 3, wherein the pregelatinized acetylated swelling-suppressing starch is contained in an amount of 0.2 to 15% by mass in the total amount of starchy raw material of the bread.
5. The method for producing bread according to claim 3 or 4, wherein the pregelatinized acetylated swelling-suppressed starch is obtained by subjecting a raw material starch to acetylation treatment and swelling inhibition treatment and then alphalyzing with a drum dryer.
6. The method for producing bread according to any one of claims 3 to 5, wherein the pregelatinized acetylation-swelling starch is pregelatinized acetylated crosslinked starch.