阅读说明：本技术 一种利用天然酵头制作老式面包的方法 (Method for making old bread by using natural yeast ) 是由 苏浩轩 苏魁 孙汉巨 叶永康 何述栋 苏露 于 2020-12-29 设计创作，主要内容包括：一种利用天然酵头制作老式面包的方法,选择和培养来自水果、干果、谷物的复合天然酵母菌种,经过适应性培养,制作了天然酵头；将小麦面粉、谷朊粉、小麦胚芽粉进行双螺杆挤出处理制得半熟化面团,然后对半熟化面团进行天然酵母、根霉、曲霉复合菌种发酵,制得面包改良剂A；利用五碳糖-木糖、六碳糖-葡萄糖、二糖-麦芽糖与牛奶复合酶解液进行美拉德反应,得到了面包改良剂B；然后,将面包改良剂A、面包改良剂B添加于面包生产,利用天然酵头发酵面团生产得到老式面包产品。本发明制得的老式面包,口感松软,面香纯正；天然酵母培养和面包改良剂加工均采用生物工程方法,面包的风味和品质稳定,具有较长的货架期。(A method for preparing old bread with natural yeast comprises selecting and culturing compound natural yeast strain from fruit, dried fruit, and grain, and preparing natural yeast by adaptive culture; carrying out double-screw extrusion treatment on wheat flour, wheat gluten and wheat germ powder to prepare semi-cured dough, and then carrying out fermentation on the semi-cured dough by using natural yeast, rhizopus and aspergillus composite strains to prepare a bread improver A; carrying out Maillard reaction on pentose-xylose, hexose-glucose, disaccharide-maltose and the milk composite enzymatic hydrolysate to obtain a bread improver B; then, adding the bread improver A and the bread improver B into bread production, and fermenting dough by utilizing the natural fermentation heads to produce an old bread product. The old bread prepared by the invention has soft taste and pure flour fragrance; the natural yeast culture and the bread modifier processing both adopt a bioengineering method, the flavor and the quality of the bread are stable, and the bread has a longer shelf life.)

1. A method for making old bread by using natural yeast heads is characterized in that: comprises the following steps:

step 1: mixing 4-6 parts by weight of fruits, 2-3 parts by weight of dried fruits and 2-3 parts by weight of grains, then putting the mixture into a sterilized glass bottle, pouring purified water with the mass of 3-5 times that of the mixture into the glass bottle, then putting white granulated sugar with the mass of 0.25-0.50 time that of the mixture into the glass bottle, uniformly stirring, sealing the glass bottle, placing the glass bottle in an environment with the temperature of 28-32 ℃, opening the bottle cap 1-2 times per day, and standing and culturing for 3-7 d; then filtering the mixture in the glass bottle by a filter screen of 80-120 meshes in an environment with the cleanliness of 1 ten thousand grade, and collecting filtrate, namely the natural yeast culture solution;

step 2: placing the natural yeast culture solution into a transparent glass bottle or plastic bottle, placing the transparent glass bottle or plastic bottle in an environment with the temperature of 28-32 ℃ and the illumination intensity of 2500-;

and step 3: mixing the natural yeast culture solution subjected to illumination adaptive culture with edible alcohol according to the mass ratio of 100:7-9, placing the mixed solution in an environment with the temperature of 28-32 ℃, standing and culturing for 45-90min, and carrying out alcohol-resistant adaptive culture on natural yeast to obtain a natural yeast culture solution for alcohol-resistant adaptive culture of the natural yeast;

and 4, step 4: mixing 55-65 parts by weight of wheat flour, 30-35 parts by weight of purified water, 3-5 parts by weight of white granulated sugar and 0.5-2.5 parts by weight of natural yeast culture solution for alcohol-resistant adaptive culture of natural yeast, stirring uniformly and kneading into dough; placing the dough in an environment with the temperature of 28-32 ℃ and the cleanliness of 1 ten thousand grade, and performing static culture for 3-6h to obtain a natural yeast head;

and 5: mixing 38-42 parts by weight of purified water, 40-50 parts by weight of wheat flour, 5-10 parts by weight of wheat gluten and 5-10 parts by weight of wheat germ powder, stirring and homogenizing, adding the mixed material into a double-screw extruder at a uniform speed, controlling the temperature of a feeding section to be 50-60 ℃, the temperature of an extrusion section to be 65-70 ℃, the temperature of a metering section to be 75-80 ℃, the rotation speed of a screw to be 150r/min and the feeding speed to be 200-; collecting the extruded material, and cooling to 25-35 deg.C; then mixing the extruded material and the microbial strains according to the mass ratio of 100:1-5, uniformly stirring, putting the inoculated material in an environment with the temperature of 28-32 ℃ and the cleanliness of 1 ten thousand grade, and performing static culture for 12-18h to obtain a culture; then, the culture is subjected to vacuum sealing packaging, and then is subjected to ultrahigh pressure treatment to obtain a bread improver A; the microbial strain is formed by mixing 90-95 parts by weight of natural yeast heads, 1-3 parts by weight of rhizopus spores and 1-3 parts by weight of aspergillus oryzae spores;

step 6: adding pepsin, trypsin and lactase into milk raw material, keeping pH of the solution at 6.8-7.5 and temperature at 30-40 deg.C, and performing enzymolysis for 2-4 hr to obtain a complex enzymolysis solution; then mixing 100 parts by weight of the composite enzymolysis liquid, 1-5 parts by weight of xylose, 2-10 parts by weight of glucose and 1-5 parts by weight of maltose, heating the mixed material to 80-90 ℃, and preserving heat for 60-120min to obtain a Maillard reaction product; then concentrating the Maillard reaction product to 25-30% of the original volume to obtain a bread improver B;

and 7: mixing 50-60 parts by weight of wheat flour, 35-40 parts by weight of purified water, 4-6 parts by weight of white granulated sugar, 0.5-0.75 part by weight of salt and 1.5-3.0 parts by weight of natural yeast starter uniformly, kneading into dough, placing in an environment with the temperature of 35-40 ℃, the relative humidity of 60-80% and the cleanliness of 1 ten thousand grade, and performing static culture for 80-100min to obtain a first section of fermented dough; mixing 100 parts by weight of first-stage fermented dough, 2.5-10 parts by weight of bread improver A, 1.5-5.0 parts by weight of bread improver B, 1-5 parts by weight of milk powder, 10-20 parts by weight of egg liquid, 2.5-5.0 parts by weight of butter and 0-0.5 part by weight of vegetable oil uniformly, kneading into dough, placing in an environment with the temperature of 35-40 ℃, the relative humidity of 60-80% and the cleanliness of 1 ten thousand, and standing and culturing for 25-50min to obtain second-stage fermented dough; uniformly dividing the second stage fermented dough into flour blocks of 45-65 g/piece, placing in an environment with a temperature of 35-40 deg.C, a relative humidity of 60-80% and a cleanliness of 1 ten thousand, and standing for 10-20 min; and then putting the molded dough blocks into an oven, and baking to obtain the old bread product.

2. The method of making bread using natural sourdough as claimed in claim 1, wherein: the fruit is at least one of apple, pear, peach and kiwi fruit; the dried fruit is at least one of raisin, dried blueberry and dried red date; the cereal is at least one of dried wheat grain and oat grain.

3. The method of making bread using natural sourdough as claimed in claim 1, wherein: the ultrahigh pressure treatment is carried out at the temperature of 5-30 ℃, water is used as a pressure medium, and the ultrahigh pressure treatment is carried out at the pressure of 250-500MPa, and the pressure maintaining time is 10-20 min.

4. The method of making bread using natural sourdough as claimed in claim 1, wherein: the milk raw material is one of pasteurized milk, UHT pasteurized milk and reconstituted milk.

5. The method of making bread using natural sourdough as claimed in claim 1, wherein: the enzyme activity of the pepsin is 5-10 ten thousand U, and the addition amount of the pepsin is 0.1-0.5 percent of the mass of the milk raw material; the enzyme activity of the trypsin is 5-10 ten thousand U, and the addition amount is 0.1-0.5% of the mass of the milk raw material; the enzymatic activity of the lactase is 5-10 ten thousand U, and the addition amount is 0.1-0.5% of the mass of the milk raw material.

6. The method of making bread using natural sourdough as claimed in claim 1, wherein: in step 7, baking at the temperature of 170-.

Technical Field

The invention belongs to the technical field of food processing, and relates to a method for making old bread by using natural yeast.

Background

Bread is a food made by milling five cereals and heating, and is generally a baked food prepared by using wheat flour as a main raw material, using yeast, eggs, grease, sugar, salt and the like as auxiliary materials, adding water to prepare dough, and performing processes such as cutting, forming, proofing, baking, cooling and the like. Through the development of thousands of years, bread gradually becomes one of the main foods of people in various countries in the world, and has various varieties and flavors.

The old bread is a product just coming into the way of bread industrial production, and the production method is 'middle standard and middle standard', and the old bread is fragrant and soft in taste, rapid in entrance and slightly sour. With the development of the times, the bread varieties are infinite, but the old bread is not eliminated by society, but becomes the best taste in the memory of many people, namely simple and happy, and has the old flavor in the memory of consumers.

Natural yeast refers to a variety of fungi that cover grains, fruits and in nature. The natural yeast has better flavor than common yeast because the natural yeast can make flour fully absorb moisture and the ripening time is long, and on the other hand, the natural yeast is a plurality of bacteria, and each bacteria can emit different fragrance when baking, so that the flavor of the bread is more diversified.

Disclosure of Invention

The invention aims to provide a method for making old bread by using natural yeast heads.

In order to achieve the above objects and other related objects, the present invention provides the following technical solutions: a method for making old bread by using natural yeast comprises the following steps:

step 1: mixing 4-6 parts by weight of fruits, 2-3 parts by weight of dried fruits and 2-3 parts by weight of grains, then putting the mixture into a sterilized glass bottle, pouring purified water with the mass of 3-5 times that of the mixture into the glass bottle, then putting white granulated sugar with the mass of 0.25-0.50 time that of the mixture into the glass bottle, uniformly stirring, sealing the glass bottle, placing the glass bottle in an environment with the temperature of 28-32 ℃, opening the bottle cap 1-2 times per day, and standing and culturing for 3-7 d; then filtering the mixture in the glass bottle by a filter screen of 80-120 meshes in an environment with the cleanliness of 1 ten thousand grade, and collecting filtrate, namely the natural yeast culture solution;

step 2: placing the natural yeast culture solution into a transparent glass bottle or plastic bottle, placing the transparent glass bottle or plastic bottle in an environment with the temperature of 28-32 ℃ and the illumination intensity of 2500-;

and step 3: mixing the natural yeast culture solution subjected to illumination adaptive culture with edible alcohol according to the mass ratio of 100:7-9, placing the mixed solution in an environment with the temperature of 28-32 ℃, standing and culturing for 45-90min, and carrying out alcohol-resistant adaptive culture on natural yeast to obtain a natural yeast culture solution for alcohol-resistant adaptive culture of the natural yeast;

and 4, step 4: mixing 55-65 parts by weight of wheat flour, 30-35 parts by weight of purified water, 3-5 parts by weight of white granulated sugar and 0.5-2.5 parts by weight of natural yeast culture solution for alcohol-resistant adaptive culture of natural yeast, stirring uniformly and kneading into dough; placing the dough in an environment with the temperature of 28-32 ℃ and the cleanliness of 1 ten thousand grade, and performing static culture for 3-6h to obtain a natural yeast head;

and 5: mixing 38-42 parts by weight of purified water, 40-50 parts by weight of wheat flour, 5-10 parts by weight of wheat gluten and 5-10 parts by weight of wheat germ powder, stirring and homogenizing, adding the mixed material into a double-screw extruder at a uniform speed, controlling the temperature of a feeding section to be 50-60 ℃, the temperature of an extrusion section to be 65-70 ℃, the temperature of a metering section to be 75-80 ℃, the rotation speed of a screw to be 150r/min and the feeding speed to be 200-; collecting the extruded material, and cooling to 25-35 deg.C; then mixing the extruded material and the microbial strains according to the mass ratio of 100:1-5, uniformly stirring, putting the inoculated material in an environment with the temperature of 28-32 ℃ and the cleanliness of 1 ten thousand grade, and performing static culture for 12-18h to obtain a culture; then, the culture is subjected to vacuum sealing packaging, and then is subjected to ultrahigh pressure treatment to obtain a bread improver A; the microbial strain is formed by mixing 90-95 parts by weight of natural yeast heads, 1-3 parts by weight of rhizopus spores and 1-3 parts by weight of aspergillus oryzae spores;

step 6: adding pepsin, trypsin and lactase into milk raw material, keeping pH of the solution at 6.8-7.5 and temperature at 30-40 deg.C, and performing enzymolysis for 2-4 hr to obtain a complex enzymolysis solution; then mixing 100 parts by weight of the composite enzymolysis liquid, 1-5 parts by weight of xylose, 2-10 parts by weight of glucose and 1-5 parts by weight of maltose, heating the mixed material to 80-90 ℃, and preserving heat for 60-120min to obtain a Maillard reaction product; then concentrating the Maillard reaction product to 25-30% of the original volume to obtain a bread improver B;

and 7: mixing 50-60 parts by weight of wheat flour, 35-40 parts by weight of purified water, 4-6 parts by weight of white granulated sugar, 0.5-0.75 part by weight of salt and 1.5-3.0 parts by weight of natural yeast starter uniformly, kneading into dough, placing in an environment with the temperature of 35-40 ℃, the relative humidity of 60-80% and the cleanliness of 1 ten thousand grade, and performing static culture for 80-100min to obtain a first section of fermented dough; mixing 100 parts by weight of first-stage fermented dough, 2.5-10 parts by weight of bread improver A, 1.5-5.0 parts by weight of bread improver B, 1-5 parts by weight of milk powder, 10-20 parts by weight of egg liquid, 2.5-5.0 parts by weight of butter and 0-0.5 part by weight of vegetable oil uniformly, kneading into dough, placing in an environment with the temperature of 35-40 ℃, the relative humidity of 60-80% and the cleanliness of 1 ten thousand, and standing and culturing for 25-50min to obtain second-stage fermented dough; uniformly dividing the second stage fermented dough into flour blocks of 45-65 g/piece, placing in an environment with a temperature of 35-40 deg.C, a relative humidity of 60-80% and a cleanliness of 1 ten thousand, and standing for 10-20 min; and then putting the molded dough blocks into an oven, and baking to obtain the old bread product.

The preferable technical scheme is as follows: the fruit is at least one of apple, pear, peach and kiwi fruit; the dried fruit is at least one of raisin, dried blueberry and dried red date; the cereal is at least one of dried wheat grain and oat grain.

The preferable technical scheme is as follows: the ultrahigh pressure treatment is carried out at the temperature of 5-30 ℃, water is used as a pressure medium, and the ultrahigh pressure treatment is carried out at the pressure of 250-500MPa, and the pressure maintaining time is 10-20 min.

The preferable technical scheme is as follows: the milk raw material is one of pasteurized milk, UHT pasteurized milk and reconstituted milk.

The preferable technical scheme is as follows: the enzyme activity of the pepsin is 5-10 ten thousand U, and the addition amount of the pepsin is 0.1-0.5 percent of the mass of the milk raw material; the enzyme activity of the trypsin is 5-10 ten thousand U, and the addition amount is 0.1-0.5% of the mass of the milk raw material; the enzymatic activity of the lactase is 5-10 ten thousand U, and the addition amount is 0.1-0.5% of the mass of the milk raw material.

The preferable technical scheme is as follows: in step 7, baking at the temperature of 170-.

Due to the application of the technical scheme, compared with the prior art, the invention has the advantages that:

1. the invention selects and cultures the composite natural yeast strains from fruits, dried fruits and grains, and comprehensively utilizes the production advantages of the composite natural yeast strains.

2. The invention carries out illumination and alcohol-resistant adaptive culture on the composite natural yeast strain and optimizes the structure of natural yeast flora.

3. The bread improver A is prepared by carrying out double-screw extrusion treatment on wheat flour, wheat gluten and wheat germ powder to prepare semi-cured dough, and then carrying out composite strain fermentation of natural yeast, rhizopus and aspergillus on the semi-cured dough and ultrahigh pressure treatment; the bread improver A is rich in short-chain carbohydrate, protein, peptide, amino acid and the like, and is beneficial to optimizing the tissue structure and the mouthfeel of bread.

4. The invention utilizes pentose-xylose, hexose-glucose, disaccharide-maltose and milk composite enzymolysis liquid to carry out Maillard reaction to obtain the bread improver B rich in Maillard flavor peptide, and the bread improver B is added into bread production to be beneficial to optimizing the bread flavor.

5. The old bread prepared by the invention has soft taste and pure flour fragrance; the natural yeast culture and the bread modifier processing both adopt a bioengineering method, the flavor and the quality of the bread are stable, and the bread has a longer shelf life.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Example 1: method for making old bread by using natural yeast

A method for making old bread by using natural yeast heads is characterized by comprising the following technical steps.

(1) Preparation of Natural Yeast culture solution

Mixing 5 parts by weight of fruits, 2.5 parts by weight of dried fruits and 2.5 parts by weight of grains, putting the mixture into a sterilized glass bottle, pouring 4 times of food-grade purified water, then adding 0.3 times of white granulated sugar, uniformly stirring, sealing the glass bottle, placing the glass bottle in an environment with the temperature of 30 ℃, and standing and culturing for 5 days; opening the bottle cap 1-2 times every day, filling fragrant alcohol smell and many bubbles when opening the bottle cap, filtering the mixed material in the glass bottle through a 100-mesh filter screen in an environment with cleanliness of 1 ten thousand, and collecting filtrate, namely the natural yeast culture solution for later use.

The fruit is fresh particles of one or more of apples, pears, peaches and kiwi fruits without silt, mechanical damage and plant diseases and insect pests on the surface. This example is specifically a kiwi fruit pulp pellet.

The dried fruit is one or more of raisins, dried blueberries and dried red dates without silt, mechanical damage and plant diseases and insect pests on the surface. The embodiment is specifically the dried blueberries.

The grain is dry wheat grains or oat grains without silt, mechanical damage and plant diseases and insect pests on the surface. This example is specifically a dried wheat grain.

(2) Illumination adaptive culture of natural yeast

Placing the natural yeast culture solution in the step (1) into a transparent glass bottle or plastic bottle, placing in an environment with the temperature of 30 ℃ and the illumination intensity of 4000Lx, standing and culturing for 60min, and carrying out illumination adaptive culture on the natural yeast.

(3) Alcohol-resistant adaptive culture of natural yeast

Mixing the natural yeast culture solution subjected to the illumination adaptive culture in the step (2) and edible alcohol according to the mass ratio of 100:8, placing the mixed solution in an environment with the temperature of 30 ℃, standing and culturing for 80min, and carrying out the alcohol-resistant adaptive culture of the natural yeast.

(4) Making natural yeast heads

Mixing 60 parts by weight of wheat flour, 32 parts by weight of food-grade purified water, 4 parts by weight of white granulated sugar and 1.5 parts by weight of the natural yeast culture solution subjected to alcohol-tolerant adaptive culture in the step (3), fully stirring and kneading uniformly to prepare dough; and (3) placing the dough in an environment with the temperature of 30 ℃ and the cleanliness of 1 ten thousand grade, and standing and culturing for 4h to obtain the natural yeast sourdough for later use.

(5) Bread improver A for making bread

And (5) extruding. Mixing 40 parts by weight of food-grade purified water, 45 parts by weight of wheat flour, 8 parts by weight of wheat gluten and 8 parts by weight of wheat germ powder, and fully stirring and homogenizing; adding the mixed material into a double-screw extruder at a uniform speed, controlling the temperature of a feeding section to be 55 ℃, the temperature of an extrusion section to be 68 ℃, the temperature of a metering section to be 77 ℃, the rotating speed of a screw to be 120r/min and the feeding speed to be 250g/min, and carrying out extrusion processing; collecting the extruded materials, and cooling to 30 ℃ for later use.

And (5) standing and culturing. Mixing the extruded material and microbial strains according to the mass ratio of 100:3, and fully stirring and uniformly mixing; and (3) placing the inoculated material in an environment with the temperature of 30 ℃ and the cleanliness of 1 ten thousand grade, and performing static culture for 15h to obtain a culture for later use. The microbial strain is a mixed strain of yeast, rhizopus and aspergillus oryzae, and comprises 92 parts by weight of (4) natural yeast starter, 2 parts by weight of rhizopus spores and 2 parts by weight of aspergillus oryzae spores.

And (4) ultrahigh pressure treatment. Putting the culture after the static culture into a food-grade plastic bag, carrying out heat sealing in an environment with vacuum gauge pressure of-0.09-0.10 MPa, then putting the plastic bag into food ultrahigh pressure equipment, carrying out ultrahigh pressure treatment at the temperature of 20 ℃ by using water as a pressure medium and keeping the pressure for 15min under 400 MPa; and then the pressure is removed, and the materials are taken out to obtain the bread improver A for later use.

(6) Bread improver B

The milk raw material is one of pasteurized milk, UHT pasteurized milk and reconstituted milk. This example is specifically pasteurized milk.

And (4) performing compound enzymolysis. Adding pepsin, trypsin and lactase into milk raw material, keeping pH7.2 and temperature 35 deg.C, and performing enzymolysis for 3 hr to obtain complex enzyme hydrolysate. The pepsin has the enzyme activity of 8 ten thousand U, and the addition amount is 0.3 percent of the mass of the milk. The trypsin has the enzyme activity of 6 ten thousand U, and the addition amount is 0.3 percent of the mass of the milk. The lactase has the enzyme activity of 6 ten thousand U, and the addition amount is 0.3 percent of the mass of the milk.

And (4) carrying out a Maillard reaction. Mixing 100 parts by weight of the composite enzymolysis liquid, 3 parts by weight of xylose, 6 parts by weight of glucose and 3 parts by weight of maltose; putting the mixed material into a temperature-controllable heating and stirring device with a steam condensation recovery device, starting stirring, keeping the stirring speed at 60r/min, heating to 85 ℃, and preserving heat; heating and stirring for reaction for 90min to obtain Maillard reaction product for later use.

And (4) concentrating in vacuum. And (3) putting the Maillard reaction product into vacuum reduced pressure concentration equipment, and boiling and concentrating the product to 26 percent of the original volume under the condition of vacuum gauge pressure of-0.09 to-0.10 MPa to obtain a concentrated solution, namely the bread improver B for later use.

(7) Old bread making method

And (5) performing primary fermentation. The preparation method comprises the steps of fully and uniformly mixing 55 parts by weight of wheat flour, 36 parts by weight of food-grade pure water, 5 parts by weight of white granulated sugar, 0.65 part by weight of salt and 2.0 parts by weight of natural yeast starter, kneading the materials into dough, placing the dough in an environment with the temperature of 36 ℃, the relative humidity of 70% and the cleanliness of 1 ten thousand grade, and performing standing culture for 90min to obtain a first-stage fermented dough.

And (5) performing secondary fermentation. Fully and uniformly mixing 100 parts by weight of first-stage fermented dough, 5 parts by weight of bread improver A, 3.0 parts by weight of bread improver B, 3 parts by weight of milk powder, 15 parts by weight of egg liquid, 4.0 parts by weight of butter and 0.2 part by weight of vegetable oil, kneading into dough, placing in an environment with the temperature of 36 ℃, the relative humidity of 70% and the cleanliness of 1 ten thousand, and standing and culturing for 40min to obtain second-stage fermented dough.

And (5) molding. Uniformly dividing the second stage fermented dough into dough pieces of 45-65 g/piece, making the dough pieces into desired shape such as round, square, roll, etc., placing the formed dough pieces in an environment with temperature of 36 deg.C, relative humidity of 70% and cleanliness of 1 ten thousand grade, and standing for 15 min.

And (5) baking. And (3) putting the formed dough blocks into an oven, and baking for 25min at the temperature of 175 ℃ to obtain the old bread product.

The prepared old bread is soft in taste and pure in flour fragrance; the natural yeast culture and the bread modifier processing both adopt a bioengineering method, the flavor and the quality of the bread are stable, and the bread has a longer shelf life.

Example 2: method for making old bread by using natural yeast

A method for making old bread by using natural yeast comprises the following steps:

step 1: mixing 4 parts by weight of fruits, 2 parts by weight of dried fruits and 2 parts by weight of grains, then putting the mixture into a sterilized glass bottle, pouring 3 times of purified water of the mixture quality into the glass bottle, then putting 0.25 times of white granulated sugar of the mixture quality into the glass bottle, sealing the glass bottle after uniformly stirring, placing the glass bottle in an environment at the temperature of 28 ℃, opening the bottle cap 1 time every day, and standing and culturing for 3 d; then filtering the mixture in the glass bottle by a 80-mesh filter screen in an environment with the cleanliness of 1 ten thousand grade, and collecting filtrate, namely the natural yeast culture solution;

step 2: placing natural yeast culture solution into transparent glass bottle or plastic bottle, standing and culturing at 28 deg.C and illumination intensity of 2500Lx for 45min, and performing illumination adaptive culture to obtain illumination adaptive cultured natural yeast culture solution;

and step 3: mixing the natural yeast culture solution subjected to illumination adaptive culture with edible alcohol according to the mass ratio of 100:7, placing the mixed solution in an environment with the temperature of 28 ℃, standing and culturing for 45min, and carrying out alcohol-resistant adaptive culture on the natural yeast to obtain the natural yeast culture solution subjected to alcohol-resistant adaptive culture on the natural yeast;

and 4, step 4: mixing 55 parts by weight of wheat flour, 30 parts by weight of purified water, 3 parts by weight of white granulated sugar and 0.5 part by weight of natural yeast culture solution for alcohol-resistant adaptive culture of natural yeast, stirring uniformly and kneading into dough; placing the dough in an environment with the temperature of 28 ℃ and the cleanliness of 1 ten thousand grade, and performing standing culture for 3 hours to obtain a natural yeast head;

and 5: mixing 38 parts by weight of purified water, 40 parts by weight of wheat flour, 5 parts by weight of wheat gluten and 5 parts by weight of wheat germ powder, stirring and homogenizing, adding the mixed material into a double-screw extruder at a uniform speed, and performing extrusion processing by controlling the feeding section temperature of 50 ℃, the extrusion section temperature of 65 ℃, the metering section temperature of 75 ℃, the screw rotating speed of 100r/min and the feeding speed of 200 g/min; collecting the extruded materials, and cooling to 25 ℃; then mixing the extruded material and the microbial strains according to the mass ratio of 100:1, uniformly stirring, putting the inoculated material in an environment with the temperature of 28 ℃ and the cleanliness of 1 ten thousand grade, and standing and culturing for 12h to obtain a culture; then, the culture is subjected to vacuum sealing packaging, and then is subjected to ultrahigh pressure treatment to obtain a bread improver A; the microbial strain is formed by mixing 90 parts by weight of natural yeast heads, 1 part by weight of rhizopus spores and 1 part by weight of aspergillus oryzae spores;

step 6: adding pepsin, trypsin and lactase into milk raw material, keeping pH of the solution at 6.8 and 30 ℃, and performing enzymolysis for 2h to obtain a compound enzymatic hydrolysate; then mixing 100 parts by weight of the composite enzymolysis liquid, 1 part by weight of xylose, 2 parts by weight of glucose and 1 part by weight of maltose, heating the mixed material to 80 ℃ and preserving heat for 60min to obtain a Maillard reaction product; then concentrating the Maillard reaction product to 25% of the original volume to obtain a bread improver B;

and 7: uniformly mixing 50 parts by weight of wheat flour, 35 parts by weight of purified water, 4 parts by weight of white granulated sugar, 0.5 part by weight of salt and 1.5 parts by weight of natural yeast starter, kneading into dough, placing the dough in an environment with the temperature of 35 ℃, the relative humidity of 60% and the cleanliness of 1 ten thousand grade, and standing and culturing for 80min to obtain a first section of fermented dough; uniformly mixing 100 parts by weight of first-stage fermented dough, 2.5 parts by weight of bread improver A, 1.5 parts by weight of bread improver B, 1 part by weight of milk powder, 10 parts by weight of egg liquid and 2.5 parts by weight of butter, kneading into dough, placing in an environment with the temperature of 35 ℃, the relative humidity of 60% and the cleanliness of 1 ten thousand, and performing standing culture for 25min to obtain second-stage fermented dough; uniformly dividing the second-stage fermented dough into flour blocks of 45 g/piece, then placing the flour blocks in an environment with the temperature of 35 ℃, the relative humidity of 60% and the cleanliness of 1 ten thousand grade, and standing for 10 min; and then putting the molded dough blocks into an oven, and baking to obtain the old bread product.

The preferred embodiment is: the fruits are apple and pear pulps according to the ratio of 1: 1 in a mass ratio; the dried fruits are raisins; the cereal is dry oat particles.

The preferred embodiment is: the ultrahigh pressure treatment is carried out at the temperature of 5 ℃, water is used as a pressure medium, the 250MPa ultrahigh pressure treatment is adopted, and the pressure maintaining time is 10 min.

The preferred embodiment is: the milk raw material is UHT sterilized milk.

The preferred embodiment is: the enzyme activity of the pepsin is 5 ten thousand U, and the addition amount of the pepsin is 0.5 percent of the mass of the milk raw material; the enzyme activity of the trypsin is 5 ten thousand U, and the addition amount of the trypsin is 0.5 percent of the mass of the milk raw material; the enzymatic activity of the lactase is 5 ten thousand U, and the addition amount of the lactase is 0.5 percent of the mass of the milk raw material.

The preferred embodiment is: and 7, baking for 30min at the temperature of 170 ℃ to obtain the old bread product.

Example 3: method for making old bread by using natural yeast

A method for making old bread by using natural yeast comprises the following steps:

step 1: mixing 6 parts by weight of fruits, 3 parts by weight of dried fruits and 3 parts by weight of grains, then putting the mixture into a sterilized glass bottle, pouring 5 times of purified water of the mixture into the glass bottle, then putting 0.50 times of white granulated sugar of the mixture into the glass bottle, sealing the glass bottle after uniformly stirring, placing the glass bottle in an environment with the temperature of 32 ℃, opening the bottle cap 2 times a day, and standing and culturing for 7 d; then filtering the mixture in the glass bottle by a 120-mesh filter screen in an environment with the cleanliness of 1 ten thousand grade, and collecting filtrate, namely the natural yeast culture solution;

step 2: placing natural yeast culture solution into transparent glass bottle or plastic bottle, placing in environment with illumination intensity of 5000Lx at 32 deg.C, standing for 90min, and performing illumination adaptive culture of natural yeast to obtain illumination adaptive culture solution;

and step 3: mixing the natural yeast culture solution subjected to illumination adaptive culture with edible alcohol according to the mass ratio of 100:9, placing the mixed solution in an environment with the temperature of 32 ℃, standing and culturing for 90min, and carrying out alcohol-resistant adaptive culture on the natural yeast to obtain the natural yeast culture solution subjected to alcohol-resistant adaptive culture on the natural yeast;

and 4, step 4: mixing 65 parts by weight of wheat flour, 35 parts by weight of purified water, 5 parts by weight of white granulated sugar and 2.5 parts by weight of natural yeast culture solution for alcohol-resistant adaptive culture of natural yeast, stirring uniformly and kneading into dough; placing the dough in an environment with the temperature of 32 ℃ and the cleanliness of 1 ten thousand grade, and standing and culturing for 6h to obtain a natural yeast head;

and 5: mixing 42 parts by weight of purified water, 50 parts by weight of wheat flour, 10 parts by weight of wheat gluten and 10 parts by weight of wheat germ powder, stirring and homogenizing, adding the mixed material into a double-screw extruder at a uniform speed, and performing extrusion processing by controlling the temperature of a feeding section at 60 ℃, the temperature of an extrusion section at 70 ℃, the temperature of a metering section at 80 ℃, the rotation speed of a screw at 150r/min and the feeding speed at 300 g/min; collecting the extruded material, and cooling to 35 ℃; then mixing the extruded material and the microbial strains according to the mass ratio of 100:5, uniformly stirring, putting the inoculated material in an environment with the temperature of 32 ℃ and the cleanliness of 1 ten thousand grade, and standing and culturing for 18h to obtain a culture; then, the culture is subjected to vacuum sealing packaging, and then is subjected to ultrahigh pressure treatment to obtain a bread improver A; the microbial strain is formed by mixing 95 parts by weight of natural yeast heads, 3 parts by weight of rhizopus spores and 3 parts by weight of aspergillus oryzae spores;

step 6: adding pepsin, trypsin and lactase into milk raw material, keeping pH of the solution at 7.5 and 40 ℃, and performing enzymolysis for 4h to obtain a compound enzymatic hydrolysate; then mixing 100 parts by weight of the composite enzymolysis liquid, 5 parts by weight of xylose, 10 parts by weight of glucose and 5 parts by weight of maltose, heating the mixed material to 90 ℃, and preserving heat for 120min to obtain a Maillard reaction product; then concentrating the Maillard reaction product to 30% of the original volume to obtain a bread improver B;

and 7: uniformly mixing 60 parts by weight of wheat flour, 40 parts by weight of purified water, 6 parts by weight of white granulated sugar, 0.75 part by weight of salt and 3.0 parts by weight of natural yeast starter, kneading into dough, placing the dough in an environment with the temperature of 40 ℃, the relative humidity of 80% and the cleanliness of 1 ten thousand grade, and standing and culturing for 100min to obtain a first section of fermented dough; uniformly mixing 100 parts by weight of first-stage fermented dough, 10 parts by weight of bread improver A, 5.0 parts by weight of bread improver B, 5 parts by weight of milk powder, 20 parts by weight of egg liquid, 5.0 parts by weight of butter and 0.5 part by weight of vegetable oil, kneading into dough, placing in an environment with the temperature of 40 ℃, the relative humidity of 80% and the cleanliness of 1 ten thousand, and standing and culturing for 50min to obtain second-stage fermented dough; uniformly dividing the second-stage fermented dough into flour blocks of 65 g/piece, then placing the flour blocks in an environment with the temperature of 40 ℃, the relative humidity of 80% and the cleanliness of 1 ten thousand grade, and standing for 20 min; and then putting the molded dough blocks into an oven, and baking to obtain the old bread product.

The preferred embodiment is: the fruit is kiwi fruit; the dried fruits are dried red dates; the cereal is dried wheat grains and oat grains in a ratio of 1: 1 in a mass ratio.

The preferred embodiment is: the ultrahigh pressure treatment is carried out at 30 ℃, water is used as a pressure medium, 500MPa ultrahigh pressure treatment is adopted, and the pressure maintaining time is 20 min.

The preferred embodiment is: the milk raw material is recovered milk.

The preferred embodiment is: the enzyme activity of the pepsin is 10 ten thousand U, and the addition amount of the pepsin is 0.1 percent of the mass of the milk raw material; the enzyme activity of the trypsin is 10 ten thousand U, and the addition amount of the trypsin is 0.1 percent of the mass of the milk raw material; the enzymatic activity of the lactase is 10 ten thousand U, and the addition amount of the lactase is 0.1 percent of the mass of the milk raw material.

The preferred embodiment is: and 7, baking at the temperature of 180 ℃ for 20min to obtain the old bread product.

The foregoing is illustrative of the preferred embodiment of the present invention and is not to be construed as limiting thereof in any way, and any modifications or variations thereof that fall within the spirit of the invention are intended to be included within the scope thereof.