阅读说明：本技术 一种含麦麸的全麦面包及其制备方法 (Whole wheat bread containing wheat bran and preparation method thereof ) 是由 谭斌 张笃芹 汪丽萍 于 2021-05-24 设计创作，主要内容包括：本发明公开了一种含麦麸的全麦面包及其制备方法。该全麦面包包括以下重量份的原料：小麦粉80～100份,固态发酵麦麸16～54份,面筋2.4～7.7份,羟丙基甲基纤维素1.9～6.1份,TG酶0.3～0.8份,葡萄糖氧化酶0.08～0.12份,谷胱甘肽0.12～0.50份,维生素0.1～0.3份,黄油2～5份及饮用水适量。本发明采用混菌固态发酵麦麸回添至小麦粉制作全麦面包,提高了麦麸中多酚类物质和可溶性膳食纤维含量,降低了植酸水平,此外,利用混菌固态发酵麦麸对全麦面团的复合发酵作用,赋予了全麦面包以更大的比体积、更均匀的气孔结构和更柔软的质构。(The invention discloses whole wheat bread containing wheat bran and a preparation method thereof. The whole wheat bread comprises the following raw materials in parts by weight: 80-100 parts of wheat flour, 16-54 parts of solid-state fermented wheat bran, 2.4-7.7 parts of gluten, 1.9-6.1 parts of hydroxypropyl methyl cellulose, 0.3-0.8 part of TG enzyme, 0.08-0.12 part of glucose oxidase, 0.12-0.50 part of glutathione, 0.1-0.3 part of vitamin, 2-5 parts of butter and a proper amount of drinking water. The whole wheat bread is made by adding the mixed bacteria solid state fermentation wheat bran back to the wheat flour, so that the contents of polyphenol substances and soluble dietary fibers in the wheat bran are improved, the phytic acid level is reduced, and in addition, the whole wheat bread is endowed with larger specific volume, more uniform pore structure and softer texture by utilizing the compound fermentation effect of the mixed bacteria solid state fermentation wheat bran on the whole wheat dough.)

1. The wheat bran-containing whole wheat bread is characterized by comprising the following raw materials in parts by weight: 80-100 parts of wheat flour, 16-54 parts of solid-state fermented wheat bran, 2.4-7.7 parts of gluten, 1.9-6.1 parts of hydroxypropyl methyl cellulose, 0.3-0.8 part of TG enzyme, 0.08-0.12 part of glucose oxidase, 0.12-0.50 part of glutathione, 0.1-0.3 part of vitamin, 2-5 parts of butter and a proper amount of drinking water.

2. The wheat bran-containing whole wheat bread as claimed in claim 1, wherein the solid state fermented wheat bran is produced by mixed bacteria solid state fermentation;

the mixed bacteria comprise saccharomyces cerevisiae, lactobacillus plantarum and bacillus according to the mass ratio of 2-9: 2-6: 1-2, or comprise saccharomyces cerevisiae, lactobacillus plantarum and mould according to the mass ratio of 2-9: 2-6: 1-4.

3. The wheat bran-containing whole wheat bread as claimed in claim 2, wherein the conditions of the mixed bacteria solid state fermentation are: shaking and mixing wheat bran and mixed bacteria liquid, and fermenting and culturing for 8-48 h at 25-38 ℃, wherein the material-liquid ratio of the wheat bran to the mixed bacteria liquid is 1: 0.3-1 (w/v); the preparation of the mixed bacteria liquid comprises the following steps: adding 0.2-0.8 g of mixed bacterial sludge in total mass into every 50mL of sterile water.

4. Wheat bran-containing whole wheat bread as claimed in claim 2 or 3 wherein the bacillus is bacillus licheniformis or bacillus subtilis; the mould is Aspergillus oryzae or Rhizopus oryzae.

5. The wheat bran-containing whole wheat bread as claimed in claim 1, wherein the TG enzyme activity is 50000U/g; the activity of the glucose oxidase is 10000U/g.

6. A process for preparing a whole wheat bran-containing bread as claimed in any one of claims 1 to 5, comprising the steps of:

mixing wheat flour, solid-state fermented wheat bran, gluten, hydroxypropyl methyl cellulose, TG enzyme, glucose oxidase, glutathione and vitamins according to the formula amount to obtain mixed powder, then adding a proper amount of drinking water, stirring for 3-5 min, adding butter, and stirring for 2-4 min to obtain whole wheat dough;

performing primary fermentation;

secondary fermentation;

baking and cooling to obtain the product.

7. The preparation method according to claim 6, wherein the weight ratio of the mixed powder to the drinking water is 100: 40-55.

8. The method according to claim 6, wherein the conditions for one proofing are as follows: and standing and fermenting the whole wheat dough obtained by the preparation in a proofing box with the temperature of 37 ℃ and the relative temperature of 78% for 30-50 min.

9. The method according to claim 6, wherein the conditions for the secondary fermentation are as follows: and (3) placing the dough after the primary fermentation into a mold, and standing and fermenting for 20-40 min in a fermentation box with the temperature of 37 ℃ and the relative temperature of 78%.

10. The method according to claim 6, wherein the baking conditions are: baking at 140 ℃ for 10-20 min, and then adjusting the temperature to 210 ℃ for baking for 10-20 min.

Technical Field

The invention belongs to the technical field of food processing, and particularly relates to whole wheat bread containing wheat bran and a preparation method thereof.

Background

With the improvement of health consciousness of residents, whole wheat food receives more and more attention. The whole wheat contains rich dietary fiber, plant physiological active substances, mineral elements and other nutrient substances, and has an important effect on improving the public dietary level and the nutritional status. However, wheat bran, as a main functional active ingredient in whole wheat, contains relatively high insoluble dietary fiber and phytic acid, so that the whole wheat product has rough taste and bitter taste, and meanwhile, due to the uneven lamellar structure of the wheat bran and the dilution effect on gluten in wheat, the stomatal tissue of whole wheat dough is easily damaged, so that the problems of small volume, hard texture, dark color and the like of the whole wheat product are brought. In order to fully utilize the advantages of the nutritional resources of the wheat bran and improve the public dietary level and the current situation of nutrition, the wheat bran needs to be modified, and the processing quality such as the fermentation capacity of the whole wheat product is enhanced on the basis of improving the nutritional quality.

The solid state fermentation refers to a fermentation process which is carried out under the condition of no or almost no free water and contains a solid substrate, and the most important characteristic is that a plurality of microorganisms (fungi and bacteria) can be simultaneously used for mixed fermentation, and the metabolic synergistic effect among various microorganisms is fully utilized to achieve a higher modification effect or obtain more target products. Because the solid fermentation is carried out on a solid substrate with extremely low water content, the substrate concentration is high, the water activity is low, and microorganisms can easily form dominant strains, so the method has higher fermentation capacity, strong production stability, low catabolism repression and low requirement on sterility, and is a biological processing technology with great advantages. At present, solid state fermentation is widely used in industrial production, and particularly widely applied in the production fields of bioactive secondary metabolites (including enzyme preparations, organic acids, mycotoxins and antibiotics), probiotics, spores, feed and the like.

At present, no relevant literature report is found on the preparation of whole wheat bread by performing solid state fermentation on wheat bran and adding the wheat bran back to wheat flour.

Disclosure of Invention

The first object of the present invention is to provide whole wheat bread containing wheat bran, which is made by adding wheat bran obtained by solid state fermentation of mixed fungi back to wheat flour. The mixed bacteria solid fermentation improves the contents of polyphenols and soluble dietary fibers in the wheat bran, reduces the phytic acid level, and in addition, the whole wheat bread is endowed with larger specific volume, more uniform pore structure and softer texture by utilizing the compound fermentation effect of the mixed bacteria solid fermentation wheat bran on the whole wheat dough.

The second purpose of the invention is to provide a preparation method of the whole wheat bread containing wheat bran.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

in a first aspect, the invention provides whole wheat bread containing wheat bran, which comprises the following raw materials in parts by weight: 80-100 parts of wheat flour, 16-54 parts of solid-state fermented wheat bran, 2.4-7.7 parts of gluten, 1.9-6.1 parts of hydroxypropyl methyl cellulose, 0.3-0.8 part of TG enzyme (glutamine transaminase), 0.08-0.12 part of glucose oxidase, 0.12-0.50 part of glutathione, 0.1-0.3 part of vitamin, 2-5 parts of butter and a proper amount of drinking water.

Further, the solid-state fermented wheat bran is prepared by mixed-bacterium solid-state fermentation; the mixed bacteria comprise saccharomyces cerevisiae, lactobacillus plantarum and bacillus according to the mass ratio of 2-9: 2-6: 1-2, or comprise saccharomyces cerevisiae, lactobacillus plantarum and mould according to the mass ratio of 2-9: 2-6: 1-4.

Preferably, the mixed bacteria are composed of saccharomyces cerevisiae, lactobacillus plantarum and bacillus according to the mass ratio of 4-9: 3-4: 1, or composed of saccharomyces cerevisiae, lactobacillus plantarum and mould according to the mass ratio of 4-9: 3-4.

According to the invention, saccharomyces cerevisiae, lactobacillus plantarum and bacillus or mould are compounded to carry out solid-state fermentation biological modification on wheat bran, so that the content and effectiveness of bioactive substances such as soluble dietary fibers and phenolic substances in the wheat bran are obviously improved, and a whole wheat product is endowed with higher nutritional value. Furthermore, compared with the wheat bran without treatment, the solid-state fermented wheat bran is added back to the whole wheat bread preparation process by the wheat flour, the effect is similar to that of the traditional sour dough, the saccharomyces cerevisiae and the lactobacillus plantarum can continuously utilize the nutrient substances in the whole wheat dough to carry out reproduction and metabolism, and the dough is subjected to compound fermentation to expand the volume and form a spongy pore structure; the cellulase produced by metabolism of bacillus and mould can effectively decompose insoluble dietary fiber in wheat bran, produce more carbohydrates which can be used by growth of saccharomycetes and lactic acid bacteria, reduce rough texture of the wheat bran, and be beneficial to formation and maintenance of dough bubbles in the whole wheat bread making process.

According to the specific embodiment of the invention, the conditions of the mixed bacteria solid state fermentation are as follows: shaking and mixing wheat bran and mixed bacteria liquid, and fermenting and culturing for 8-48 h at 25-38 ℃, wherein the material-liquid ratio of the wheat bran to the mixed bacteria liquid is 1: 0.3-1 (w/v); the preparation of the mixed bacteria liquid comprises the following steps: adding 0.2-0.8 g of mixed bacterial sludge in total mass into every 50mL of sterile water.

According to the specific embodiment of the invention, before use, the saccharomyces cerevisiae, lactobacillus plantarum, bacillus or mould used in the invention can be activated according to the method known in the art to obtain the strain with vigorous activity, so as to improve the biological modification effect on wheat bran. For example, the strain activation can be performed as follows:

activation of saccharomyces cerevisiae (aerobic): inoculating saccharomyces cerevisiae into a yeast leaching peptone glucose broth culture medium without agar, activating for 1-2 generations, centrifuging for 3-5 min at 3000-4000 r/min, and washing with 0.8% sterile normal saline to obtain precipitated white saccharomyces cerevisiae bacterial sludge. The preparation method of the agar-free yeast leaching peptone glucose broth culture medium comprises the following steps: mixing peptone 10g, yeast extract powder 5g and glucose 20g, adding into 1000mL distilled water, heating to boil and dissolve, placing into a triangular flask, sealing, and autoclaving at 121 deg.C for 20 min.

Activation of lactobacillus plantarum (aerobic): inoculating lactobacillus plantarum into an MRS broth culture medium without agar, activating for 1-2 generations, centrifuging for 3-5 min at 3000-4000 r/min, and washing with 0.8% sterile normal saline to respectively obtain precipitated white lactobacillus plantarum bacterial sludge. The preparation method of the agar-free MRS broth culture medium comprises the following steps: 10g of peptone, 5g of beef powder, 20g of glucose, 4g of yeast powder, 5g of sodium acetate, 2g of dipotassium hydrogen phosphate, 0.2g of magnesium sulfate, 2g of triammonium citrate, 0.05g of manganese sulfate and 1mL of Tween 80, mixing, adding 1000mL of distilled water, heating, boiling, dissolving, filling into a triangular flask, sealing, and sterilizing at 121 ℃ for 20min under high pressure.

Activation of bacillus (e.g., bacillus licheniformis, bacillus subtilis, all aerobic): respectively inoculating bacillus licheniformis and bacillus subtilis into a beef extract peptone culture medium without agar, activating for 1-2 generations, centrifuging for 3-5 min at 3000-4000 r/min, washing with 0.8% sterile normal saline, and respectively obtaining precipitated bacillus licheniformis and bacillus subtilis sludge. The preparation method of the agar-free beef extract peptone culture medium comprises the following steps: mixing 3g of beef extract, 10g of peptone and 5g of sodium chloride, adding into 1000mL of distilled water, heating to boil and dissolve, filling into a triangular flask, sealing, and autoclaving at 121 ℃ for 20 min.

Activation of mold (e.g., Aspergillus oryzae, Rhizopus oryzae, all aerobic): respectively inoculating aspergillus oryzae and rhizopus oryzae into a Chachi liquid culture medium and a potato glucose liquid culture medium, activating for 1-2 generations, centrifuging for 3-5 min at a speed of 3000-4000 r/min, and washing with 0.8% sterile normal saline to respectively obtain precipitated aspergillus oryzae and rhizopus oryzae bacterial sludge. The preparation method of the Chashi liquid culture medium comprises the following steps: 30g of sucrose, 3g of sodium nitrate, 0.5g of magnesium sulfate heptahydrate, 0.5g of potassium chloride, 0.01g of ferric sulfate tetrahydrate and 1g of potassium hydrogen phosphate, mixing, adding into 1000mL of distilled water, heating to boil and dissolve at the pH value of 6.0-6.5, filling into a triangular flask, sealing, and autoclaving at 121 ℃ for 20 min. The preparation method of the potato glucose liquid culture medium comprises the following steps: 1.0L potato extractive solution (peeled potato 200g, cut into small pieces, adding water 1.0L, boiling for 30min, filtering to remove potato pieces, adding filtrate to 1.0L) and glucose 20g, mixing, adding into 1000mL distilled water, heating to boil and dissolve, placing into triangular flask and sealing, and autoclaving at 121 deg.C for 20 min.

According to the specific embodiment of the invention, in order to achieve a better wheat bran modification effect, the wheat bran can be pretreated, namely, the wheat bran is sieved, cleaned and dried to remove other impurities in the material, the wheat bran is milled and sieved by a 40-80 mesh sieve to obtain wheat bran powder with uniform particle size, and the wheat bran powder is subjected to autoclaving treatment at 121 ℃.

Furthermore, in the formula of the whole wheat bread, the activity of the used TG enzyme is 50000U/g; the activity of the glucose oxidase is 10000U/g.

The vitamins include, but are not limited to, vitamin B, vitamin C, vitamin D, vitamin E, and the like.

In a second aspect, the present invention provides a method for preparing the above whole wheat bread containing wheat bran, comprising the steps of:

mixing wheat flour, solid-state fermented wheat bran, gluten, hydroxypropyl methyl cellulose, TG enzyme, glucose oxidase, glutathione and vitamins according to the formula amount to obtain mixed powder, then adding a proper amount of drinking water, stirring for 3-5 min, adding butter, and stirring for 2-4 min to obtain whole wheat dough;

performing primary fermentation;

secondary fermentation;

baking and cooling to obtain the product.

Optionally, the weight ratio of the mixed powder to the drinking water is 100: 40-55.

Optionally, the conditions of one proofing are as follows: and standing and fermenting the whole wheat dough obtained by the preparation in a proofing box with the temperature of 37 ℃ and the relative temperature of 78% for 30-50 min.

Optionally, the conditions of the secondary fermentation are as follows: and (3) placing the dough after the primary fermentation into a mold, and standing and fermenting for 20-40 min in a fermentation box with the temperature of 37 ℃ and the relative temperature of 78%.

Optionally, the baking conditions are: baking at 140 ℃ for 10-20 min, and then adjusting the temperature to 210 ℃ for baking for 10-20 min.

Optionally, sugar and/or salt can be added during whole wheat bread making process according to personal taste, wherein the sugar is one or more of trehalose, sucrose, maltose, arabinose, cyclodextrin, arabinoxylan and sugar alcohol.

The invention has the beneficial effects that:

the invention utilizes saccharomycetes, lactic acid bacteria, bacillus/mould mixed bacteria to perform solid state fermentation on wheat bran, and the solid state fermentation wheat bran is added back to wheat flour to prepare the whole wheat bread. The content of essential amino acids and polyphenols in the wheat bran is increased by adopting mixed bacteria solid state fermentation, the phytic acid level is reduced, and the content of soluble dietary fiber can be obviously increased. The wheat bran solid-state fermented by the strain of the invention has the polyphenol content increased to more than 5.56 times of that of the unfermented wheat bran, the phytic acid content at least reduced to 21.99 percent of the original wheat bran, and the soluble dietary fiber content increased to more than 15.87 percent. After the solid-state fermented wheat bran is added back to the wheat flour, in the bread preparation process, the whole wheat dough can be proofed directly by using the existing strains in the solid-state fermented wheat bran without adding additional active yeast, the specific volume of the finally prepared whole wheat bread is more than 3.50mL/g, the pore density is more than 30%, the hardness is lower than 600, and the sensory quality is obviously improved.

Drawings

FIG. 1 is a comparison of the appearance of whole wheat bread made from different mixed-fungus solid-state fermented wheat bran powder.

Detailed Description

The invention is further illustrated below with reference to specific embodiments and the accompanying drawings. These examples are only illustrative and not intended to limit the scope of the present invention. The methods described in the following examples are conventional methods unless otherwise specified; the materials are commercially available, unless otherwise specified.

The strains used in the invention are all commercially available strains and are derived from China industrial microorganism strain preservation management center (CICC), wherein the number of the saccharomyces cerevisiae strain is CICC 1223, the number of the lactobacillus plantarum strain is CICC22696, the number of the bacillus licheniformis strain is CICC 10037, the number of the bacillus subtilis strain is CICC10023, the number of the aspergillus oryzae strain is CICC 41737, the number of the rhizopus oryzae strain is CICC 40282, the number of the aspergillus niger strain is CICC 2041, the number of the trichoderma koningii strain is CICC 13011, the number of the good-eating Neurospora strain is CICC 40204, the number of the aspergillus awamori strain is CICC 2040, and the number of the trichoderma reesei 13052.

The agar-free CYA culture medium, the yeast extract peptone glucose broth culture medium, the agar-free MRS broth culture medium, the agar-free beef extract peptone, the Chashi liquid culture medium, the potato glucose liquid culture medium, the MEB culture medium and the PDA culture medium can be purchased externally or prepared automatically.

Example 1 Yeast-Lactobacillus-Bacillus, Yeast-Lactobacillus-mold Mixed solid fermentation wheat bran to make Whole wheat bread (YPLB, YPSB, YPAB, YPRB)

(1) Activation of saccharomyces cerevisiae (aerobic): inoculating saccharomyces cerevisiae into a yeast leaching peptone glucose broth culture medium without agar, activating for 1-2 generations, centrifuging for 3-5 min at 3000-4000 r/min, and washing with 0.8% sterile normal saline to obtain precipitated white saccharomyces cerevisiae bacterial sludge.

(2) Activation of lactobacillus plantarum (aerobic): the freeze-dried powder of the lactobacillus plantarum is respectively subjected to activation culture in an agar-free MRS culture medium, is subjected to constant-temperature oscillation activation culture for 18h at 37 ℃ in a constant-temperature incubator, is then centrifuged for 5min at 3000r/min, and is washed for 3 times by using 0.8% sterile physiological saline to respectively obtain white bacterial sludge of the lactobacillus plantarum and pediococcus pentosaceus.

(3) Activation of bacillus licheniformis and bacillus subtilis (aerobic): respectively performing activated culture on freeze-dried powder of the bacillus licheniformis and the bacillus subtilis in agar-free MRS culture medium, performing vibration activated culture for 18h at constant temperature of 30 ℃ in a constant-temperature incubator, centrifuging for 5min at 3000r/min, and washing for 3 times by using 0.8% sterile physiological saline to respectively obtain white bacterial sludge of the bacillus licheniformis and the bacillus subtilis.

(4) Activation of aspergillus oryzae (aerobic): activating and culturing Aspergillus oryzae lyophilized powder in Chachi liquid culture medium, shaking and activating and culturing at 28 deg.C for 18h in a constant temperature incubator, centrifuging at 3000r/min for 5min, and washing with 0.8% sterile physiological saline for 3 times to obtain white flocculent Aspergillus oryzae bacterial sludge.

(5) Activation of rhizopus oryzae (aerobic): the freeze-dried powder of the rhizopus oryzae is subjected to activation culture in a potato glucose liquid culture medium, is subjected to constant-temperature oscillation activation culture for 18h in a constant-temperature incubator at the constant temperature of 28 ℃, is then centrifuged for 5min at 3000r/min, and is washed for 3 times by using 0.8% sterile physiological saline to obtain white clitocybe mud of the rhizopus oryzae.

(6) Preparing mixed bacterium suspension: the method comprises the steps of mixing saccharomyces cerevisiae, lactobacillus plantarum and bacillus licheniformis in a ratio of 5:6:1, saccharomyces cerevisiae, lactobacillus plantarum and bacillus subtilis in a ratio of 9:4:1, saccharomyces cerevisiae, lactobacillus plantarum and aspergillus oryzae in a ratio of 8:3:3 and saccharomyces cerevisiae, lactobacillus plantarum and rhizopus oryzae in a ratio of 4:3:1, and adding 10mL of sterile water into 0.1g of mixed bacteria mud to respectively prepare mixed bacteria suspensions for later use.

(7) Wheat bran pretreatment: sieving testa Tritici, cleaning, drying to remove other impurities, grinding, sieving with 60 mesh sieve to obtain testa Tritici powder with uniform particle size, packaging 100g each part in triangular flask for fermentation, and autoclaving at 121 deg.C for 20 min.

Preparing mixed-bacterium solid-state fermented wheat bran: and (3) adding 100mL of the mixed bacteria suspension (the material-liquid ratio is 1:1(w/v)) obtained in the step (6) into each part of the treated wheat bran, and culturing for 18h at 30 ℃ in a constant-temperature incubator to obtain the wheat bran powder subjected to mixed bacteria solid state fermentation.

Wheat bran powder obtained by solid state fermentation of a saccharomyces cerevisiae-lactobacillus plantarum-bacillus licheniformis mixed strain is marked as YPL; wheat bran powder solid-state fermented by a saccharomyces cerevisiae-lactobacillus plantarum-bacillus subtilis mixed strain is marked as YPS, and wheat bran powder solid-state fermented by a saccharomyces cerevisiae-lactobacillus plantarum-aspergillus oryzae mixed strain is marked as YPA; wheat bran powder obtained by solid state fermentation of Saccharomyces cerevisiae-Lactobacillus plantarum-Rhizopus oryzae is labeled YPR.

(8) Preparing whole wheat bread dough: taking 300g of wheat flour; 75g of four solid-state fermented wheat bran powders; 19.50g of gluten; 7.50g of hydroxypropyl methyl cellulose; TG enzyme 1.85 g; 0.30g of glucose oxidase; 0.75g of glutathione; 0.80g of vitamin is added with 200mL of water, the mixture is slowly stirred for 5min, then 15g of butter is added, the mixture is slowly stirred for 4min, the dough is made to be cohesive and smooth and not stick to a pot, and the mixture is stirred at a medium speed for 5min, so that the whole wheat bread dough is obtained preliminarily.

(9) Primary fermentation: standing the whole wheat dough in a proofing box with the relative temperature of 78% at 37 ℃ for 40min, fermenting, taking out, placing in a stirrer, stirring at a medium speed, adding 12g of sugar and 4g of salt into the whole wheat dough under stirring, adding 40mL of drinking water, and stirring at the medium speed for 8min until the dough is uniformly mixed.

(10) And (3) secondary fermentation: and placing the formed uniform dough into a square mold, standing and fermenting for 40min in a fermenting box with the temperature of 37 ℃ and the relative temperature of 78% for the second time, and finally fermenting and maturing the dough (the volume is 2-3 times as large as the original volume, and the dough is pressed by fingers to be sunken without rebounding and collapsing).

(11) Baking the whole wheat bread: baking the fermented and mature whole wheat dough at 140 ℃ for 15min, then adjusting the temperature to 210 ℃ for baking for 10min, demolding and cooling to room temperature to obtain the whole wheat bread prepared by the saccharomyces cerevisiae-lactobacillus plantarum-bacillus licheniformis, the saccharomyces cerevisiae-lactobacillus plantarum-bacillus subtilis, the saccharomyces cerevisiae-lactobacillus plantarum-aspergillus oryzae and the saccharomyces cerevisiae-lactobacillus plantarum-rhizopus oryzae mixed solid fermentation wheat bran addition method, which is respectively marked as YPLB, YPSB, YPAB and YPRB.

COMPARATIVE EXAMPLE 1 Yeast-Aspergillus niger Mixed bacteria solid fermentation Whole wheat bread (YNB)

(1) Activation of saccharomyces cerevisiae (aerobic): activating and culturing lyophilized powder of Saccharomyces cerevisiae in agar-free culture medium of yeast extract peptone glucose broth, performing activation culture at 28 deg.C for 18h, centrifuging at 3000r/min for 5min, and washing with 0.8% sterile physiological saline for 3 times to obtain white bacterial sludge.

(2) Activation of Aspergillus niger (aerobic): activating and culturing Aspergillus niger lyophilized powder in agar-free CYA culture medium, performing shake activation culture at constant temperature of 30 deg.C for 18h in a constant temperature incubator, centrifuging at 3000r/min for 5min, and washing with 0.8% sterile physiological saline for 3 times to obtain Aspergillus niger precipitate.

(3) Preparing mixed bacterium suspension: mixing the saccharomyces cerevisiae and the aspergillus niger in a mass ratio of 5:2, and adding 10mL of sterile water into each 0.1g of mixed bacteria mud to prepare mixed bacteria suspension for later use.

(4) Wheat bran pretreatment: sieving testa Tritici, cleaning, drying to remove other impurities, grinding, sieving with 60 mesh sieve to obtain testa Tritici powder with uniform particle size, packaging 100g each part in triangular flask for fermentation, and autoclaving at 121 deg.C for 20 min.

(5) Solid-state fermentation of wheat bran: and (3) adding 100mL of the mixed bacteria suspension obtained in the step (4) into each part of wheat bran obtained in the step (5), and culturing for 18h at 30 ℃ in a constant-temperature incubator to obtain wheat bran powder subjected to mixed bacteria solid fermentation, wherein the wheat bran powder is marked as YN.

(6) Preparing whole wheat bread dough: taking 300g of wheat flour; performing solid state fermentation on 75g of wheat bran; 19.50g of gluten; 7.50g of hydroxypropyl methyl cellulose; TG enzyme 1.85 g; 0.30g of glucose oxidase; 0.75g of glutathione; 0.80g of vitamin is added with 200mL of water, the mixture is slowly stirred for 5min, then 15g of butter is added, the mixture is slowly stirred for 4min, the dough is made to be cohesive and smooth and not stick to a pot, and the mixture is stirred at a medium speed for 5min, so that the whole wheat bread dough is obtained preliminarily.

(7) Primary fermentation: standing the whole wheat dough in a proofing box with the relative temperature of 78% at 37 ℃ for 40min, fermenting, taking out, placing in a stirrer, stirring at a medium speed, adding 12g of sugar and 4g of salt into the whole wheat dough under stirring, adding 40mL of drinking water, and stirring at the medium speed for 8min until the dough is uniformly mixed.

(8) And (3) secondary fermentation: and placing the formed uniform dough into a square mold, standing and fermenting for 40min in a fermenting box with the temperature of 37 ℃ and the relative temperature of 78% for the second time, and finally fermenting and maturing the dough (the volume is 2-3 times as large as the original volume, and the dough is pressed by fingers to be sunken without rebounding and collapsing).

(9) Baking the whole wheat bread: baking the fermented and mature whole wheat dough at 140 ℃ for 15min, then adjusting the temperature to 210 ℃ for baking for 10min, demolding and cooling to room temperature to obtain the whole wheat bread (YNB) prepared by the yeast-Aspergillus niger mixed solid fermentation wheat bran addition method.

COMPARATIVE EXAMPLE 2 Trichoderma koningii-Haematococcus Mixed solid-state fermented wheat bran Whole wheat bread (KEB)

(1) Activation of trichoderma koningii (aerobic): activating and culturing Aspergillus oryzae lyophilized powder in MEB culture medium without agar, shaking and activating and culturing at 28 deg.C for 18h in a constant temperature incubator, centrifuging at 3000r/min for 5min, and washing with 0.8% sterile physiological saline for 3 times to obtain Trichoderma koningii mud.

(2) Activation of aerocyst (aerobic) ready-to-eat bacteria: respectively performing activation culture on the freeze-dried powder of the good vein-eating bacillus in an agar-free MRS culture medium, performing vibration activation culture for 18h in a constant temperature incubator at the constant temperature of 28 ℃, then centrifuging for 5min at 3000r/min, and washing for 3 times by using 0.8% sterile physiological saline to respectively obtain bacterial sludge of the good vein-eating bacillus.

(3) Preparing mixed bacterium suspension: mixing Trichoderma koningii and good vein-eating bacillus in the mass ratio of 3 to 1, and adding 10mL of sterile water into each 0.1g of mixed bacteria mud to respectively prepare mixed bacteria suspension for later use.

(4) Wheat bran pretreatment and solid state fermentation treatment as in example 1, wheat bran powder solid state fermented by Trichoderma koningii-Haematococcus was labeled KE; wheat bran powder obtained by solid state fermentation of Trichoderma koningii-Haematococcus mixture is labeled KEB.

(5) Preparing whole wheat bread dough: taking 300g of wheat flour; 75g of mixed-strain solid-state fermented wheat bran powder; 19.50g of gluten; 7.50g of hydroxypropyl methyl cellulose; TG enzyme 1.85 g; 0.30g of glucose oxidase; 0.75g of glutathione; 0.80g of vitamin is added with 200mL of water, the mixture is slowly stirred for 5min, then 15g of butter is added, the mixture is slowly stirred for 4min, the dough is made to be cohesive and smooth and not stick to a pot, and the mixture is stirred at a medium speed for 5min, so that the whole wheat bread dough is obtained preliminarily.

(6) Primary fermentation: standing the whole wheat dough in a proofing box with the relative temperature of 78% at 37 ℃ for 40min, fermenting, taking out, placing in a stirrer, stirring at a medium speed, adding 12g of sugar and 4g of salt into the whole wheat dough under stirring, adding 40mL of drinking water, and stirring at the medium speed for 8min until the dough is uniformly mixed.

(7) And (3) secondary fermentation: and placing the formed uniform dough into a square mold, standing and fermenting for 40min in a fermenting box with the temperature of 37 ℃ and the relative temperature of 78% for the second time, and finally fermenting and maturing the dough (the volume is 2-3 times as large as the original volume, and the dough is pressed by fingers to be sunken without rebounding and collapsing).

(8) Baking the whole wheat bread: baking the fermented and mature whole wheat dough at 140 ℃ for 15min, then adjusting the temperature to 210 ℃ for baking for 10min, demolding and cooling to room temperature to obtain the whole wheat bread prepared by the trichoderma koningii-good-vein-bacillus mixed solid-state fermented wheat bran addition method, and marking the whole wheat bread as KEB.

COMPARATIVE EXAMPLE 3 Aspergillus awamori-Trichoderma reesei mixed solid state fermentation wheat bran made wholewheat bread (PTB)

(1) Activation of aspergillus awamori (aerobic): activating and culturing the aspergillus awamori freeze-dried powder in an agar-free MEB culture medium, carrying out constant-temperature shaking and activating culture for 18h in a constant-temperature incubator at the constant temperature of 28 ℃, then centrifuging for 5min at 3000r/min, and washing for 3 times by using 0.8% sterile physiological saline to obtain the aspergillus awamori bacterial mud.

(2) Activation of trichoderma reesei (aerobic): the trichoderma reesei freeze-dried powder is respectively subjected to activation culture in agar-free PDA culture medium, is subjected to constant temperature oscillation activation culture for 18h in a constant temperature incubator at the constant temperature of 30 ℃, is then centrifuged for 5min at 3000r/min, and is washed for 3 times by 0.8% sterile physiological saline to respectively obtain bacterial sludge of good vein-eating bacteria.

(3) Preparing mixed bacterium suspension: mixing the aspergillus awamori and trichoderma reesei in a mass ratio of 1:1, and adding 10mL of sterile water into each 0.1g of mixed bacteria mud to respectively prepare mixed bacteria suspension for later use.

(4) Wheat bran pretreatment and solid state fermentation treatment wheat bran flour from solid state fermentation of Aspergillus awamori-Trichoderma reesei, labeled PT, was used as in example 1.

(5) Preparing whole wheat bread dough: taking 300g of wheat flour; 75g of mixed-strain solid-state fermented wheat bran powder; 19.50g of gluten; 7.50g of hydroxypropyl methyl cellulose; TG enzyme 1.85 g; 0.30g of glucose oxidase; 0.75g of glutathione; 0.80g of vitamin is added with 200mL of water, the mixture is slowly stirred for 5min, then 15g of butter is added, the mixture is slowly stirred for 4min, the dough is made to be cohesive and smooth and not stick to a pot, and the mixture is stirred at a medium speed for 5min, so that the whole wheat bread dough is obtained preliminarily.

(6) Primary fermentation: standing the whole wheat dough in a proofing box with the relative temperature of 78% at 37 ℃ for 40min, fermenting, taking out, placing in a stirrer, stirring at a medium speed, adding 12g of sugar and 4g of salt into the whole wheat dough under stirring, adding 40mL of drinking water, and stirring at the medium speed for 8min until the dough is uniformly mixed.

(7) And (3) secondary fermentation: and placing the formed uniform dough into a square mold, standing and fermenting for 40min in a fermenting box with the temperature of 37 ℃ and the relative temperature of 78% for the second time, and finally fermenting and maturing the dough (the volume is 2-3 times as large as the original volume, and the dough is pressed by fingers to be sunken without rebounding and collapsing).

(8) Baking the whole wheat bread: baking the fermented and mature whole wheat dough at 140 ℃ for 15min, then adjusting the temperature to 210 ℃ for baking for 10min, demolding and cooling to room temperature to obtain the whole wheat bread prepared by the aspergillus awamori-trichoderma reesei mixed bacteria solid state fermentation wheat bran addition method, and marking the whole wheat bread as PTB.

Test example 1

The test method comprises the following steps: (1) Folin-Ciocalteu method for determining content of polyphenol substances

Accurately weighing 2.00g wheat bran sample, placing into 50mL plastic centrifugal test tube, adding 40mL methanol, ultrasonic extracting (40 deg.C, 100% power, ultrasonic 30min), centrifuging (3500r/min centrifuging for 10min), collecting supernatant, repeating the operation for 1 time, mixing the supernatants, rotary evaporating at 40 deg.C, and diluting to 2mL with methanol. Mixing 250 μ L of sample diluent with 500 μ L of distilled water and 250 μ L of Folin phenol reagent, reacting for 6min, adding 2.5mL of 7g/100mL Na2CO3 solution and 2mL of distilled water, reacting at room temperature in a dark place for 90min, and measuring absorbance at 765nm wavelength. A standard curve is established by taking gallic acid as a standard sample, and the polyphenol content of the sample is expressed by the milligrams of gallic acid contained in 100g of dry basis (abbreviated as mg/100 g).

(2) Phytic acid content

The determination of the phytic acid content is carried out by using a phytic acid (total phosphorus) detection kit (Megzyme, Wilklow Ireland), and the specific experimental steps refer to the kit specification.

(3) Soluble dietary fiber content

The soluble dietary fiber content is determined by reference to the method of AOAC.

(4) Specific volume of bread

The bread specific volume was measured by rapeseed displacement method. The specific volume is calculated as the ratio of the bread volume to the bread mass.

(5) Density of pores

The bread was sliced into 2.5 cm thick slices, each of which was photographed with a digital camera (EOS M50; canon, tokyo, japan). The bread images were then analyzed using Image J software (version 1.8.0.112). And selecting a center image of the bread slice and determining the area of the bread slice. To obtain a black and white threshold, the image is converted to 8 bits and binary segmented. The void density (%) value, i.e., the percentage of void area in the total area of the selected region of the slice, was recorded.

(6) Hardness of

And analyzing the hardness of the bread by using a texture analyzer.

And (4) comparing the results:

the whole wheat bread prepared by adding different mixed bacteria solid state fermented wheat bran powder back to wheat flour is shown in figure 1. Among the seven kinds of whole wheat bread, the wheat bran powder which is solid-state fermented by saccharomycetes-lactobacillus-bacillus and saccharomycetes-lactobacillus-mould is added back to the whole wheat bread (YPLB, YPSB, YPAB and YPRB) made of wheat flour, the volume of the bread is larger than that of the whole wheat bread (CK) made of wheat bran without solid fermentation and is also obviously larger than that of the whole wheat bread (KEB, PTB and YNB) made of wheat bran by solid fermentation of other three strains.

The contents of polyphenols, phytic acid and soluble dietary fibers in the different mixed-strain solid-state fermented wheat bran powder are shown in table 1, and compared with wheat bran without solid-state fermentation treatment, the contents of polyphenols and soluble dietary fibers in the solid-state fermented wheat bran are obviously increased, and the phytic acid content is obviously reduced. In the wheat bran adopting the solid state fermentation strain, the content of polyphenol substances is changed to be more than 5.56 times of that of the wheat bran without fermentation treatment, the phytic acid content is at least reduced to 21.99 percent of the original content, the content of soluble dietary fibers is improved to be more than 15.87 percent, and compared with wheat bran samples subjected to other three (YNB, KEB and PTB) solid state fermentation, the wheat bran with the solid state fermentation strain has higher contents of polyphenol substances and soluble dietary fibers and lower content of phytic acid.

TABLE 1 comparison of the contents of polyphenols, phytic acid and soluble dietary fiber in the solid-state fermented wheat bran powder of different mixed strains

Note: CK is a wheat bran sample without fermentation treatment; YPL is solid-state fermented wheat bran of yeast-lactobacillus-Bacillus licheniformis; YPS is yeast-lactobacillus-bacillus subtilis solid-state fermented wheat bran; YPA is solid fermented testa Tritici of yeast-lactobacillus-Aspergillus oryzae; YPR yeast-lactobacillus-Rhizopus oryzae solid state fermentation wheat bran; YN is yeast-Aspergillus niger solid state fermentation wheat bran; KE is wheat bran obtained by solid state fermentation of Trichoderma koningii and Neurospora eutropha; PT is Aspergillus awamori-Trichoderma reesei solid state fermentation wheat bran.

The specific volume, pore density and hardness of whole wheat bread made by adding different mixed-strain solid-state fermented wheat bran powder back to wheat flour are shown in Table 2. In the invention, the whole wheat dough can be directly proofed by utilizing the existing strains in the solid-state fermented wheat bran without adding additional active dry yeast, the specific volume of the whole wheat bread finally prepared by utilizing the solid-state fermented wheat bran of the invention mixed strain is more than 3.50mL/g, the pore density is more than 30 percent, the hardness is less than 600 and is obviously higher than that of the whole wheat bread prepared by wheat bran without fermentation treatment, and the whole wheat bread (KEB, PTB and YNB) prepared by other three kinds of non-patent mixed fermented wheat bran.

TABLE 2 comparison of specific volume, pore density and hardness of whole wheat bread made by adding different mixed-bacteria solid-state fermented wheat bran flour back to wheat flour

Note: CK is bread made of wheat bran samples without fermentation treatment; YPLB is bread made by solid-state fermentation of wheat bran with yeast-lactobacillus-Bacillus licheniformis; YPSB is bread prepared by solid-state fermentation of testa Tritici with yeast, lactobacillus and Bacillus subtilis; YPAB is bread prepared by fermenting testa Tritici with yeast, lactobacillus, and Aspergillus oryzae; bread prepared by fermenting wheat bran with YPRB yeast-lactobacillus-Rhizopus oryzae in solid state; YNB is bread made from wheat bran by yeast-Aspergillus niger solid state fermentation; KEB is bread made by solid-state fermentation of wheat bran by Trichoderma koningii and Neurospora amurensis; PTB is bread made by solid state fermentation of wheat bran with Aspergillus awamori and Trichoderma reesei.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. Not all embodiments are exhaustive. All obvious changes and modifications which are obvious to the technical scheme of the invention are covered by the protection scope of the invention.