A method of improving the rheological properties of frozen dough

Abstract

The application provides a method for improving rheological properties of frozen dough, comprising the following steps: S1: taking flour and salt, uniformly mixing to obtain powder; S2: placing the powder into a dough cylinder, adding modified milk white albumin nanometer micellar coated with yeast and water, stirring until gluten network is formed, and the dough is uniform without raw powder inclusions; S3: alternately kneading the dough on both sides to obtain smooth and elastic dough; S4: placing the smooth and elastic dough into a preservative bag, sealing, and placing into a refrigerator at-40 DEG C for quick freezing for 90 min, so that the center temperature of the dough reaches-18 DEG C, and the dough is stored in the refrigerator for standby use. The modified milk white albumin nanometer micellar coated with yeast is used to improve the rheological properties and fermentation properties of the frozen dough, the milk white albumin can effectively form a more stable gluten network with the dough, so that the rheological properties are improved, and the solubility and water absorption capacity are improved by modification.

Description

Technical Field

[0001] This invention relates to the technical field of food processing, and more specifically to a method for improving the rheological properties of frozen dough. Background Technology

[0002] Frozen dough technology, a novel baking process developed in the late 1950s, utilizes freezing principles to quick-freeze dough at the semi-finished or finished product stage and store it in cold storage for a period of time. When needed, it undergoes thawing before being connected to subsequent processes and flows to produce fresh pasta products. It is characterized by high efficiency and safety, making it highly suitable for the standardization and industrialization of the food industry, as well as the modern business model requirements of promoting international chain operations. The mature application of this technology has significant economic and social implications. Dough is a viscoelastic material, possessing both the viscous properties of a viscous fluid and the elastic characteristics of an elastic solid. The rheological properties of dough are crucial, directly affecting processing quality and the final product quality. However, during frozen storage, temperature fluctuations cause ice crystals in frozen dough to continuously melt and recrystallize. The resulting recrystallized ice crystals are typically large, disrupting the gluten network structure and thus affecting the rheological properties of the frozen dough.

[0003] Lactalbumin is a tightly packed globulin with a molecular weight of approximately 14.2 kDa, composed of 123 amino acid residues. Its tertiary structure contains four disulfide bonds formed by eight cysteine ​​residues, located between positions 6 and 120, 28 and 111, 61 and 77, and 73 and 91, respectively. These four disulfide bonds maintain the protein's spatial structure, making it more stable than whey protein. Therefore, adding it to dough can effectively improve the dough's rheological properties.

[0004] However, lactalbumin has poor solubility, contains significant amphiphilic polypeptide fragments in its sequence, and its hydrophilicity is not particularly ideal. Therefore, the problem that this invention needs to solve is to enable it to not only improve the rheological properties of dough but also maintain its fermentation performance. Summary of the Invention

[0005] Technical Problem to be Solved: To address the aforementioned technical problems, the purpose of this invention is to provide a method for improving the rheological properties of frozen dough. This invention employs modified lactalbumin nanomicelles coated with yeast to enhance the rheological and fermentation properties of frozen dough. Lactalbumin is a tightly structured globulin, more stable than whey protein, and can effectively form a more stable gluten network with the dough, thereby improving its rheological properties. However, lactalbumin has relatively poor solubility. Therefore, this invention modifies it to improve its solubility and water absorption capacity. Through transglutaminase reaction, sugar chains are grafted onto lactalbumin. The lactalbumin molecule contains tryptophan, tryptophan, and cysteine, etc. The γ-hydroxylamine group of the tryptophan residue reacts with the enzymatically hydrolyzed konjac glucomannan, thereby improving its solubility and hydrophilicity. Because of the significant amphiphilic polypeptide fragments in the lactalbumin sequence, they can aggregate to form nanomicelles. These nanomicelles can encapsulate yeast, thereby reducing the impact of low temperature and maintaining the yeast's fermentation ability. At the same time, the glycans grafted onto them can provide energy substances for the yeast, which can be utilized to maintain its activity and fermentation ability.

[0006] Technical solution: A method for improving the rheological properties of frozen dough, wherein modified lactalbumin nanomicelles are added to the frozen dough, and the modified lactalbumin nanomicelles are coated with yeast.

[0007] Furthermore, the modified lactalbumin nanomicelles exhibit resistance to temperature changes.

[0008] Furthermore, the method for preparing the modified lactalbumin nanomicelles coated with yeast is as follows:

[0009] (1) Take lactic acid protein, add sodium diacetate and water and stir to prepare a lactic acid protein hydrate solution with a concentration of 50 mg / mL, wherein the amount of sodium diacetate added is 0.2 mg / mL;

[0010] (2) Add the enzymatically hydrolyzed konjac glucomannan to water and stir, then add the whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0011] (3) Homogenize three times at 20-30 MPa using a high-pressure homogenizer;

[0012] (4) Add transglutaminase and react at a constant temperature of 37℃ for 0.5-2 hours;

[0013] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 10-20 mg / mL;

[0014] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0015] (7) Add the activated yeast, stir magnetically at 25-30℃, and sonicate at 150-200W for 10 minutes to obtain modified lactic acid nanomicelles coated with yeast.

[0016] Furthermore, the enzymatic hydrolysis method for konjac glucomannan is as follows, by weight: take 3 parts of konjac glucomannan, add 100 parts of sodium citrate buffer with a concentration of 0.1 mol / L, allow to fully swell, add 0.001 parts of β-mannanase for enzymatic hydrolysis for 10-20 min, obtain the enzymatic hydrolysis product, freeze-dry and pass through a 120 mesh sieve.

[0017] Furthermore, the mass ratio of the enzymatically hydrolyzed konjac glucomannan to lactalbumin is (0.5-1):2.

[0018] Furthermore, the amount of transglutaminase added is quantified according to an enzyme activity of 10 U / g protein.

[0019] Furthermore, the mass-to-volume ratio of the activated yeast to the filtrate is (1-3) mg: 10 mL.

[0020] The above-mentioned method for improving the rheological properties of frozen dough includes the following steps:

[0021] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0022] S2: Place the powder in a mixing bowl, add 5-10 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0023] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0024] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0025] The frozen dough obtained by the above-mentioned method for improving the rheological properties of frozen dough.

[0026] Beneficial effects:

[0027] 1. This invention uses modified lactalbumin nanomicelles to encapsulate yeast to improve the rheological and fermentation properties of frozen dough. Lactalbumin is a tightly packed globulin with a molecular weight of approximately 14.2 kDa, composed of 123 amino acid residues. Its tertiary structure contains four disulfide bonds formed by eight cysteine ​​residues, located between positions 6 and 120, 28 and 111, 61 and 77, and 73 and 91, respectively. These four disulfide bonds maintain the protein's spatial structure, making it more stable than whey protein and effectively forming a more stable gluten network with the dough, thereby improving its rheological properties. However, lactalbumin has relatively poor solubility; therefore, this invention modifies it to improve its solubility and water absorption capacity.

[0028] 2. This invention utilizes a transglutaminase reaction to graft sugar chains onto lactalbumin. The lactalbumin molecule contains tryptophan, tryptophan, and cysteine. The γ-hydroxylamine group of the tryptophan residue reacts with the enzymatically hydrolyzed konjac glucomannan, thereby improving its solubility and hydrophilicity. Because the lactalbumin sequence contains significant amphiphilic polypeptide fragments, it can aggregate to form nanomicelles. These nanomicelles can encapsulate yeast, thus reducing the impact of low temperatures and maintaining the yeast's fermentation capacity. Simultaneously, the grafted sugar chains provide energy for the yeast, which it can utilize, maintaining its activity and fermentation power.

[0029] 3. In the dough freezing process, the modified lactic acid nanomicelles of this invention can not only improve the rheological properties of the dough, but also reduce the movement of free water in the dough, increase the viscosity of the unfrozen area, and reduce the formation of ice crystals, thereby reducing the damage to the gluten network. Detailed Implementation

[0030] This invention proposes a method for improving the rheological properties of frozen dough. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following will provide a more detailed description of the invention in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] Example 1

[0032] The enzymatic hydrolysis method of konjac glucomannan is as follows, by weight: take 3 parts of konjac glucomannan, add 100 parts of sodium citrate buffer with a concentration of 0.1 mol / L, swell fully, add 0.001 parts of β-mannanase for enzymatic hydrolysis for 15 min, obtain the enzymatic hydrolysis product, freeze-dry and pass through a 120 mesh sieve.

[0033] Example 2

[0034] A method for improving the rheological properties of frozen dough includes the following steps:

[0035] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0036] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0037] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0038] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0039] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0040] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0041] (2) Add 12.5 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0042] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0043] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0044] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0045] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0046] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0047] Example 3

[0048] A method for improving the rheological properties of frozen dough includes the following steps:

[0049] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0050] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0051] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0052] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0053] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0054] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0055] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0056] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0057] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0058] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0059] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0060] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0061] Example 4

[0062] A method for improving the rheological properties of frozen dough includes the following steps:

[0063] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0064] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0065] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0066] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0067] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0068] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0069] (2) Add 22 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0070] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0071] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0072] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0073] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0074] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0075] Example 5

[0076] A method for improving the rheological properties of frozen dough includes the following steps:

[0077] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0078] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0079] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0080] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0081] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0082] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0083] (2) Add 25 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0084] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0085] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0086] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0087] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0088] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0089] Example 6

[0090] A method for improving the rheological properties of frozen dough includes the following steps:

[0091] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0092] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0093] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0094] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0095] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0096] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0097] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0098] (3) Homogenize three times at 20 MPa using a high-pressure homogenizer;

[0099] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0100] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0101] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0102] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 30 °C and sonicate at 200 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0103] Example 7

[0104] A method for improving the rheological properties of frozen dough includes the following steps:

[0105] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0106] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0107] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0108] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0109] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0110] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0111] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0112] (3) Homogenize three times at 30 MPa using a high-pressure homogenizer;

[0113] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0114] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0115] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0116] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 30 °C and sonicate at 200 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0117] Example 8

[0118] A method for improving the rheological properties of frozen dough includes the following steps:

[0119] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0120] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0121] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0122] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0123] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0124] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0125] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0126] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0127] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 0.5 h.

[0128] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0129] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0130] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0131] Example 9

[0132] A method for improving the rheological properties of frozen dough includes the following steps:

[0133] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0134] S2: Place the powder in a mixing bowl, add 8 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0135] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0136] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0137] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0138] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0139] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0140] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0141] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 2 hours.

[0142] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0143] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0144] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0145] Example 10

[0146] A method for improving the rheological properties of frozen dough includes the following steps:

[0147] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0148] S2: Place the powder in a mixing bowl, add 5 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0149] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0150] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0151] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0152] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0153] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0154] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0155] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0156] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0157] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0158] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0159] Example 11

[0160] A method for improving the rheological properties of frozen dough includes the following steps:

[0161] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0162] S2: Place the powder in a mixing bowl, add 10 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0163] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0164] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0165] The preparation method of yeast-coated modified lactalbumin nanomicelles is as follows:

[0166] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0167] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0168] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0169] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0170] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0171] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0172] (7) Add the activated yeast. The mass-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25 °C and sonicate at 150 W for 10 min to obtain modified lactic acid nanomicelles coated with yeast.

[0173] Comparative Example 1

[0174] The difference between this comparative example and Example 3 is that lactic acid protein and yeast were added directly, with the amounts of lactic acid protein and yeast being the same as in Example 3, as detailed below:

[0175] A method for improving the rheological properties of frozen dough includes the following steps:

[0176] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0177] S2: Place the powder in the mixing bowl, add the whey protein, yeast and 55 parts water, and stir until the gluten network is formed, the dough is uniform and there is no raw flour mixed in.

[0178] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0179] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0180] Comparative Example 2

[0181] The difference between this comparative example and Example 3 is that the modified lactalbumin nanomicelles and yeast were added separately, as detailed below:

[0182] A method for improving the rheological properties of frozen dough includes the following steps:

[0183] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0184] S2: Place the powder in the mixing bowl, add modified lactic acid nano micelles, yeast and 55 parts water, and stir until the gluten network is formed, the dough is uniform and there is no raw flour mixed in;

[0185] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0186] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0187] The preparation method of modified lactalbumin nanomicelles is as follows:

[0188] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0189] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0190] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0191] (4) Add transglutaminase. The amount of transglutaminase added is quantified according to the enzyme activity of 10 U / g protein. The reaction is carried out at a constant temperature of 37℃ for 1 hour.

[0192] (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 15 mg / mL;

[0193] (6) The filtrate was obtained by filtration through a 0.8 μm microporous membrane;

[0194] (7) Stir magnetically at 25℃ and sonicate at 150W for 10 minutes to obtain modified milk albumin nanomicelles.

[0195] Comparative Example 3

[0196] The difference between this comparative example and Example 3 is that the transglutaminase reaction is not used, as detailed below:

[0197] A method for improving the rheological properties of frozen dough includes the following steps:

[0198] S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder;

[0199] S2: Place the powder in the mixing bowl, add 8 parts of the whey protein mixture and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in.

[0200] S3: Knead the dough alternately on both sides until you get a smooth and elastic dough;

[0201] S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

[0202] The preparation method of the lactalbumin mixture is as follows:

[0203] (1) Take 50 mg of lactalbumin, add 0.2 mg of sodium diacetate and 1 mL of water and stir to prepare a lactalbumin hydrate solution with a concentration of 50 mg / mL;

[0204] (2) Add 18 mg of enzymatically hydrolyzed konjac glucomannan to water and stir, then add whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL;

[0205] (3) Homogenize three times at 25 MPa using a high-pressure homogenizer;

[0206] (4) Dilute with water to a mass concentration of 15 mg / mL;

[0207] (5) Filter the solution through a 0.8 μm microporous membrane to obtain the filtrate;

[0208] (6) Add the activated yeast. The mass-to-volume ratio of the activated yeast to the filtrate is 2 mg: 10 mL. Stir magnetically at 25°C and sonicate at 150 W for 10 min.

[0209] Frozen dough was taken out after 15, 30, 45 and 60 days of freezing and thawed in a 30°C water bath until the core temperature reached 25°C, and various indicators were tested.

[0210] Dough extensibility testing: The extensibility of the mixed flour dough was measured using an extensometer according to American Grain Council (AACC) standard AACC54-21. The results are shown in Table 1 below.

[0211]

[0212]

[0213] As shown in Table 1, the addition of modified lactic acid nanomicelles to coat yeast significantly improved the tensile and extensibility properties of the dough. Furthermore, the quality did not decline significantly with increasing freezing time. This is mainly because the modified lactic acid nanomicelles increase the overall viscosity of the dough. Simultaneously, the modified lactic acid nanomicelles possess excellent water absorption properties, enabling the redistribution of moisture in the dough and cross-linking with gluten protein molecules to form a more stable and beneficial network structure. This reduces the damage to the gluten network caused by freezing ice crystals, thereby improving the rheological properties of the dough. With prolonged freezing time, the comparative doughs, especially the frozen dough prepared in Comparative Example 1, hardened, and their extensibility decreased, ultimately leading to an increased stretch ratio. An excessively high stretch ratio indicates that the dough has excessively strong gluten, making it difficult for the carbon dioxide produced during fermentation to support the air bubbles, thus preventing the dough from rising properly.

[0214] Carbon dioxide production was achieved using carbon dioxide absorption titration.

[0215] Determination of the moisture content of freezeable water: The change in heat flow during the heating process of frozen dough was tested using a differential calorimeter, and the moisture content was calculated.

[0216] Table 2 Fermentation characteristics of frozen dough

[0217]

[0218]

[0219] As can be seen from Table 2, the fermentation performance of each embodiment is very good. Even after 60 days of storage, the gas production and expansion are still good. This is mainly because the solubility of the modified lactalbumin increases and its hydrophilicity improves, allowing it to adsorb more water. At the same time, the micelles can protect the yeast cells from the effects of low temperature, and the grafted sugars can be utilized by the yeast to maintain its fermentation performance.

Claims

1. A method for improving the rheological properties of frozen dough, characterized in that, Modified lactic acid nanomicelles, which are coated with yeast, are added to frozen dough. The method for preparing the modified lactalbumin nanomicelles coated with yeast is as follows: (1) Take lactic acid protein, add sodium diacetate and water and stir to prepare a lactic acid protein hydrate solution with a concentration of 50 mg / mL, wherein the amount of sodium diacetate added is 0.2 mg / mL; (2) Add the enzymatically hydrolyzed konjac glucomannan to water and stir, then add the whey protein hydrate to obtain a mixed solution with a concentration of 50 mg / mL; (3) Homogenize three times using a high-pressure homogenizer at 20-30 MPa; (4) Add transglutaminase and react at a constant temperature of 37℃ for 0.5-2 h; (5) Place in an 80℃ constant temperature water bath to inactivate the enzyme for 10 min, cool, and dilute with water to a mass concentration of 10-20 mg / mL; (6) Filter the solution through a 0.8 μm microporous membrane to obtain the filtrate; (7) Add the activated yeast, stir magnetically at 25-30℃, and sonicate at 150-200W for 10 minutes to obtain modified lactic acid nanomicelles coated with yeast.

2. The method for improving the rheological properties of frozen dough according to claim 1, characterized in that, The modified lactalbumin nanomicelles exhibit resistance to temperature changes.

3. The method for improving the rheological properties of frozen dough according to claim 1, characterized in that, The enzymatic hydrolysis method of konjac glucomannan is as follows, by weight: take 3 parts of konjac glucomannan, add 100 parts of sodium citrate buffer with a concentration of 0.1 mol / L, swell fully, add 0.001 parts of β-mannanase for enzymatic hydrolysis for 10-20 min, obtain the enzymatic hydrolysis product, freeze-dry and pass through a 120 mesh sieve.

4. The method for improving the rheological properties of frozen dough according to claim 1, characterized in that, The mass ratio of the enzymatically hydrolyzed konjac glucomannan to lactalbumin is (0.5-1):

2.

5. A method for improving the rheological properties of frozen dough according to claim 1, characterized in that, The amount of transglutaminase added was quantified according to an enzyme activity of 10 U / g protein.

6. The method for improving the rheological properties of frozen dough according to claim 1, characterized in that, The mass-to-volume ratio of the activated yeast to the filtrate was (1-3) mg:10 mL.

7. A method for improving the rheological properties of frozen dough according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Take 100 parts flour and 1 part salt, mix them evenly to make powder; S2: Place the powder in a mixing bowl, add 5-10 parts of modified lactic acid nano micelles containing yeast and 55 parts of water, and stir until the gluten network is formed, the dough is uniform, and there is no raw flour mixed in. S3: Knead the dough alternately on both sides until you get a smooth and elastic dough; S4: Place the smooth and elastic dough in a plastic bag, seal it, and freeze it in a -40℃ freezer for 90 minutes to bring the center temperature of the dough to -18℃. Store it frozen for later use.

8. Frozen dough obtained by the method for improving the rheological properties of frozen dough according to any one of claims 1-7.

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