CN113528360B - Preparation method of natural yeast - Google Patents
Preparation method of natural yeast Download PDFInfo
- Publication number
- CN113528360B CN113528360B CN202110769726.1A CN202110769726A CN113528360B CN 113528360 B CN113528360 B CN 113528360B CN 202110769726 A CN202110769726 A CN 202110769726A CN 113528360 B CN113528360 B CN 113528360B
- Authority
- CN
- China
- Prior art keywords
- generation
- natural yeast
- seed
- prepared
- yeast
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
- C12N1/14—Fungi; Culture media therefor
- C12N1/16—Yeasts; Culture media therefor
Abstract
The application relates to the field of microbial fermentation, and particularly discloses a preparation method of natural yeast, which comprises the following steps: s1, respectively weighing a rye powder natural yeast seed, a grape natural yeast seed, medium gluten powder and water according to a weight ratio of 15-20 to 30-35; s2, weighing the mixed seeds for 1 generation, medium gluten powder and water respectively according to the weight ratio of 0.8-1.2 to 0.8-1.2, mixing, and fermenting for 4-6h at 25-32 ℃ to obtain the mixed seeds for 2 generation; s3, carrying out subculture on the mixed seed 2 generation according to the method in the S2, wherein the number of passages is less than or equal to 28, the passage interval time is 2-7d, then carrying out cold storage at the temperature of 1-4 ℃, and taking the mixed seed 2 generation or any generation in the passages as a finished natural yeast; has the advantage of being suitable for industrial production.
Description
Technical Field
The application relates to the field of microbial fermentation, in particular to a preparation method of natural yeast.
Background
The yeast is divided into common yeast and natural yeast, and the common yeast is prepared by taking sugarcane as a raw material and adding chemical substances in the manufacturing process; the natural yeast is mainly prepared by taking yeast attached to fruits, grains, flowers, leaves and the like of plants as raw materials and naturally propagating; the natural yeast has better flavor than common yeast because the natural yeast can make flour fully absorb water and the ripening time is long, and on the other hand, the natural yeast contains a plurality of bacteria, and each bacteria can emit different fragrance when baking, so that the flavor of the bread is more diversified.
In the related art, application publication No. CN106939287 discloses a preparation method of a pure natural yeast liquid, which comprises three stages, wherein a first premix is prepared in the first stage, a second premix is prepared in the second stage, and a finished natural yeast liquid is prepared in the third stage; wherein the first premix is used for culturing yeast flora and lactobacillus flora for 10-20 days; the second premix is cultured by nutrient raw materials for 20-60 days; the finished natural yeast liquid is prepared by mixing a first premix and a second premix, and culturing for 2-5 days.
The natural yeast bread is prepared by taking natural yeast liquid as a raw material, if the pure natural yeast liquid in the related technology is used up, the pure natural yeast liquid needs to be prepared again, the required culture time is longer no matter which stage of the three stages is used for preparation, and in the process of industrially producing the natural yeast bread, the longer culture time not only increases the production cost of an enterprise, but also influences the production efficiency of the enterprise.
Therefore, it is urgently needed to provide a natural yeast suitable for industrial production, and the production efficiency of producing natural yeast bread by enterprises can be improved.
Disclosure of Invention
In order to provide natural yeast suitable for industrial production and improve the production efficiency of enterprises for producing natural yeast bread, the application provides a preparation method of the natural yeast.
The preparation method of the natural yeast adopts the following technical scheme:
a preparation method of natural yeast comprises the following steps:
s1, respectively weighing naked wheat powder natural yeast seeds, grape natural yeast seeds, medium gluten flour and water according to a weight ratio of 15-20 to 30-35, mixing, and fermenting for 22-26h at 27-32 ℃ to obtain a mixed seed for 1 generation;
s2, weighing the mixed seeds for 1 generation, medium gluten powder and water respectively according to the weight ratio of 0.8-1.2 to 0.8-1.2, mixing, and fermenting for 4-6h at 25-32 ℃ to obtain the mixed seeds for 2 generation;
and S3, carrying out subculture on the mixed seed 2 generation according to the method in the S2, wherein the number of subcultures is less than or equal to 28 generations, the interval time of the subcultures is 2-7d, then carrying out cold storage at the temperature of 1-4 ℃, and using the mixed seed 2 generation or any generation in the subcultures as a finished natural yeast.
By adopting the technical scheme, the rye powder natural yeast strain and the grape natural yeast are matched and fermented to prepare the mixed strain, so that the mixed strain contains high-content saccharomycetes and lactic acid bacteria, the activity and stability of the saccharomycetes and the lactic acid bacteria in the mixed strain are high, the subsequent subculture is facilitated, and the saccharomycetes and the lactic acid bacteria subjected to multiple subculture are ensured to have high fertility and activity.
In the industrialized bread production process, the mixed seed 2 generation can be directly used as a finished product natural yeast, when the mixed seed 2 generation is nearly used up, the mixed seed 2 generation is directly used as a raw material and is mixed with medium gluten flour and water to prepare the mixed seed 3 generation, the culture time is only 4-6h, the culture time is obviously shortened by 26-32h compared with the culture time for culturing the mixed seed 1 generation and culturing the mixed seed 2 generation, the quantity of thalli contained in the newly prepared mixed seed 3 generation is basically the same as that of the thalli of the mixed seed 2 generation, and the pH of the mixed seed 3 generation and the pH of the mixed seed 2 generation are both about 4.0; the newly prepared mixed seed 3 generations can be directly used as the finished product of the natural yeast for preparing the bread, and the physicochemical property and the sensory evaluation of the finished product of the natural yeast bread are basically the same as those of the natural yeast bread prepared by the mixed seed 2 generations, so that the production efficiency of an enterprise is improved on the premise of ensuring the property of the natural yeast bread.
After the mixed strain 3 is substituted, directly using the mixed strain 3 as a raw material to prepare a mixed strain 4 generations, sequentially carrying out passage, wherein the passage can be carried out to 28 generations at most, and when any generation within 28 generations is used as a natural yeast to prepare the natural yeast bread, the number of detected saccharomycetes and lactobacillus thalli in the natural yeast is very close to the number of thalli in the natural yeast prepared by the mixed strain 2 generations, and the pH value is about 4.0; the bread can be prepared by using any one of the generation 2 to the generation 28 of the mixed seeds as the finished product of the natural yeast, so that the natural yeast bread with good physicochemical property and sensory evaluation can be obtained, and the production efficiency of an enterprise is improved in the process of industrially producing the natural yeast bread.
Preferably, the rye powder natural yeast strain in the S1 is prepared by the following method:
weighing rye flour, water and malt extract according to the weight ratio of 40-48 to 50-58;
II, respectively weighing the first generation of breeder seeds, rye flour, water and malt extract according to the weight ratio of 30-35;
III, respectively weighing a second generation original seed, medium gluten flour, malt extract and water according to the weight ratio of 30-35;
and IV, subculturing the third generation of stock seeds according to the method in the step III to sequentially prepare a fourth generation of stock seeds and a fifth generation of stock seeds, wherein the fifth generation of stock seeds are the rye powder natural yeast seeds.
By adopting the technical scheme, the rye powder, the water and the malt extract are used as raw materials, the rye contains a large amount of ash, the growth and the propagation of lactic acid bacteria are facilitated, a large amount of wild yeasts are attached to the surface of the rye powder, and the lactic acid bacteria flora and the yeasts flora are enabled to grow and propagate rapidly through fermentation; mixing the obtained flora as stock with rye powder, water and malt extract, and performing amplification culture on lactobacillus and yeast to obtain second generation stock; then taking the second generation of original seeds as raw materials, matching with the raw materials such as medium gluten flour, malt extract, water and the like, fermenting to obtain flour seeds containing a large amount of lactobacillus thalli and saccharomycete thalli, and obtaining a third generation of original seeds; then taking the third generation protospecies as a raw material, adopting the raw material proportion of the third generation protospecies, fermenting to prepare a fourth generation protospecies, and continuously enlarging the thallus quantity and reducing the pH value in the culture process; and finally, taking the fourth generation of original seeds as raw materials, and fermenting according to the raw material proportion of the third generation of original seeds to obtain fifth generation of original seeds, wherein the fifth generation of original seeds are the rye powder natural yeast seeds.
The prepared rye powder natural yeast seed not only contains higher thallus quantity, but also has the pH of about 4.0-4.1, and lactobacillus and saccharomycetes can grow and reproduce under the condition of lower pH, and the growth of harmful bacteria is inhibited, so that the quantity of the harmful bacteria in the rye powder natural yeast seed is gradually reduced, the saccharomycetes and lactobacillus thallus in the rye powder natural yeast seed are stable and have strong activity, the finished product natural yeast is ensured to still have higher thallus quantity and pH stability after multiple subcultures, the physical and chemical properties and sensory evaluation are better when the natural yeast bread is prepared, and the production efficiency of enterprises is improved.
Preferably, the fermentation temperature is 27-32 ℃ and the fermentation time is 22-26h.
By adopting the technical scheme, the fermentation temperature and the fermentation time are limited, so that the mass growth and reproduction of the lactobacillus and the saccharomycete are promoted, and the fermentation efficiency is improved.
Preferably, the step III and the step IV are stirred at the rotating speed of 150-250r/min every 10-20s within 1-2h and 5min after fermentation, the mixture is kept stand for 28-34min after the stirring is finished, and the stirring and standing operations are repeated until the fermentation is carried out for 18-21h.
Through adopting above-mentioned technical scheme, in the stirring process, the yeast of being convenient for contacts with oxygen, and the yeast fermentation speed is very fast under the oxygen condition to promote the growth reproduction of yeast, and the in-process of stewing, under the anaerobic condition, the growth reproduction that can restrain other harmful bacteria of lactic acid bacteria, a large amount of growth reproduction of yeast, through intermittent type nature stirring operation, under the prerequisite of guaranteeing yeast, lactic acid bacteria growth reproduction, restrain harmful bacteria's growth reproduction, and improve fermentation efficiency.
Preferably, the grape natural yeast species in the S1 is prepared by the following method:
(1) weighing raisin, water and sugar in a weight ratio of 22-28;
(2) weighing first-generation grape seed solution, medium gluten meal and sugar in sequence according to the weight ratio of 55-65 to 25-35, mixing, fermenting for 22-26h at 25-35 ℃, and filtering to obtain second-generation grape seed solution;
(3) weighing the second generation grape seed liquid, the medium gluten powder and the sugar in sequence according to the weight ratio of 55-65 to 25-35.
By adopting the technical scheme, raisins, water and sugar are mixed and fermented, a large amount of wild saccharomycetes are attached to the surfaces of the raisins, and under the coordination of sugar, a large amount of saccharomycetes on the surfaces of the raisins grow and propagate to prepare a first-generation grape seed solution; then adopting the first generation grape seed solution, medium gluten powder and sugar to mix and ferment, carrying out enlarged culture on the yeast, thereby continuously reducing the pH value of the small seeds and preparing the second generation grape seed solution; and finally, using the second-generation grape seed solution as a raw material, matching with medium gluten powder and sugar, continuously carrying out amplification culture on the yeast, and fermenting to ensure that the pH of the finished grape natural yeast strain is about 4.0-4.1, so that the thalli in the grape natural yeast strain are stable, the activity is strong, the number of harmful bacteria is low, the finished grape natural yeast strain still has higher thalli number and pH stability after multiple subculture, and the production efficiency of an enterprise is improved on the premise of ensuring the physicochemical property and sensory evaluation of the natural yeast bread.
Preferably, the sugar consists of honey and white granulated sugar in a weight ratio of 1.3-0.8.
By adopting the technical scheme, the fermentation efficiency of the grape natural yeast strain is improved by matching honey and white granulated sugar, the prepared grape natural yeast strain thallus has higher stability and activity, and the natural yeast after multi-generation culture still has higher thallus quantity and more stable pH.
Preferably, the raw materials in the step (1) further comprise coated microspheres, the weight ratio of raisins to the coated microspheres is 25-3, the coated microspheres are knocked 10-20 after fermentation is carried out for 18-26h, and filtration is carried out after fermentation, wherein filtrate is first-generation grape seed solution;
the coated microsphere is prepared by the following method:
placing the diatomite particles in a citric acid solution with the mass fraction of 5-12%, stirring for 5-10min, and taking out the diatomite particles to prepare load diatomite particles; and (3) spraying a gellan gum solution on the surfaces of the loaded diatomite particles, wherein the weight ratio of the loaded diatomite particles to the gellan gum solution is 1.2-0.6, and drying to obtain the coated microspheres.
By adopting the technical scheme, the diatomite particles are placed in the citric acid solution and stirred, the citric acid solution is absorbed by the diatomite by utilizing the water absorption effect of the diatomite, then the diatomite particles are taken out, the gellan gum solution is sprayed on the surface of the diatomite and dried, then the gellan gum solution is solidified into a gellan gum film, and the citric acid solution is wrapped inside the diatomite particles by the gellan gum film, so that the coated microspheres are prepared.
The coating microspheres are added in the fermentation process of grape seeds, the gellan gum solution gradually swells under the soaking condition of fermentation liquor along with the fermentation of the grape seeds, the gellan gum film is gradually damaged by means of vibration, so that the citric acid solution loaded in diatomite pores is gradually contacted with the fermentation liquor, the citric acid solution is gradually released along with the increase of the growth and reproduction quantity of yeast and lactic acid bacteria, the acidity of the fermentation liquor is gradually improved, the growth and reproduction of harmful bacteria can be inhibited under the condition of gradually reducing the pH value of the fermentation liquor, the growth and reproduction of the yeast and lactic acid bacteria are ensured, the quantity of the yeast and lactic acid bacteria in the first generation grape seed solution is improved, meanwhile, the prepared grape natural yeast has good stability and activity, the prepared grape natural yeast is adopted to culture the natural yeast, and the natural yeast obtained after multiple passages still has high thallus quantity and stable pH value.
Preferably, the gellan gum solution is prepared by the following method:
preparing a gellan gum solution with the mass fraction of 1-3%, weighing 1-3 parts of a sodium citrate solution with the mass fraction of 2-5%, adding into 95-100 parts of the gellan gum solution, and stirring and mixing to obtain the gellan gum solution.
By adopting the technical scheme, the gellan gum solution and the sodium citrate solution are matched, and a gellan gum film formed by the gellan gum solution has higher strength under the matching action of sodium ions and acid radical ions; the frozen glue film is convenient to break in the vibrating process, and the broken frozen glue film gradually breaks away from the surface of the diatomite under the continuous swelling action of the fermentation liquor, so that the citric acid solution in the diatomite is gradually released into the fermentation liquor, the pH value of the fermentation liquor is reduced, the growth and the propagation of the yeast and the lactic acid bacteria are guaranteed, and the growth and the propagation of harmful bacteria are inhibited, so that the growth and the propagation of the yeast and the lactic acid bacteria are indirectly promoted.
Preferably, the gellan gum is low acyl gellan gum.
By adopting the technical scheme, the low-acyl gellan gum is matched with sodium ions and acid radical ions, so that the gellan gum film has higher strength, and the coated microspheres are knocked, so that the gellan gum film on the surfaces of the coated microspheres is broken conveniently.
Preferably, in the fermentation process of the 3 rd to 4 th days in the step (1), the cover is opened every 20 to 40min and the mixture is stirred for 2 to 8min.
By adopting the technical scheme, under the condition of ensuring the growth and the propagation of the saccharomycetes, the growth and the propagation of harmful flora are inhibited from the initial state, and large-area saccharomycetes flora are gradually established; and then aerobic fermentation is carried out, the citric acid solution in the coated microspheres is gradually released into the fermentation liquor, and the pH value of the fermentation liquor is reduced, so that the growth and the propagation of harmful bacteria in the grape seed solution generation are further inhibited, the propagation speed of saccharomycetes is accelerated under aerobic conditions, the number of the saccharomycetes in the grape seed solution generation is further increased, and the growth and the propagation of the harmful bacteria are indirectly inhibited.
The fermentation conditions of the first generation grape seed liquid are limited in the fermentation process of the first generation grape seed liquid, so that the growth and the propagation of harmful bacteria are inhibited while the propagation quantity of yeast in the first generation grape seed liquid is high, the prepared natural grape yeast has good stability and activity, and the natural yeast obtained after multiple passages is still high in thallus quantity and stable in pH value by culturing the natural grape yeast.
In summary, the present application has the following beneficial effects:
1. any generation from the generation 2 to the generation 28 of the mixed seeds can be used as a finished product of the natural yeast for preparing the bread, the natural yeast bread with good physicochemical property and sensory evaluation can be obtained, and the production efficiency of an enterprise is improved in the process of industrially producing the natural yeast bread.
2. The rye flour is cultured for five generations, so that thalli of microzyme and lactobacillus in a rye flour natural yeast strain are stable and strong in activity, the finished product natural yeast is ensured to have higher thallus quantity and pH stability after multiple subcultures, the prepared natural yeast bread has better physicochemical property and sensory evaluation, and the production efficiency of enterprises is improved.
3. The acidic substances released gradually from the coated microspheres ensure that the pH of the fermentation liquor is gradually reduced along with the bacterial reproduction quantity, and the growth and reproduction of the saccharomycetes and the lactic acid bacteria are ensured on the premise of reducing the growth and reproduction of harmful bacteria.
4. The gellan gum solution and the sodium citrate solution are matched, so that the strength of the gellan gum film is improved, the gellan gum film is broken in the knocking and vibrating process, the citric acid solution in the diatomite is gradually released into the fermentation liquor, the pH value of the fermentation liquor is reduced, the growth and the propagation of the yeast and the lactic acid bacteria are guaranteed, and the growth and the propagation of harmful bacteria are inhibited, so that the growth and the propagation of the yeast and the lactic acid bacteria are indirectly promoted.
Detailed Description
The present application will be described in further detail with reference to examples.
Preparation example of rye powder Natural Yeast species
The rye flour in the following raw materials is purchased from triticale whole wheat flour produced by Shanxi Yucao Biotech limited; other raw materials and equipment are all sold in the market.
Preparation example 1: the rye powder natural yeast seed is prepared by the following method:
weighing 250g of rye flour, 300g of warm water at 40 ℃ and 10g of malt extract, mixing, stirring at the rotating speed of 110r/min for 3min, fermenting at 30 ℃ for 24h, and preparing a first generation protospecies after fermentation; the rye flour is whole triticale flour;
II, weighing 560g of the first generation original seed, 560g of rye powder, 560g of warm water at 40 ℃ and 20g of malt extract, mixing, stirring at the rotating speed of 110r/min for 5min, fermenting at 30 ℃ for 24h, and fermenting to obtain a second generation original seed;
III, weighing 1680g of second generation original seed, 1680g of middle gluten flour, 60g of malt extract and 1680g of warm water at 40 ℃, mixing, placing in a sterilized yeast making machine, fermenting at 30 ℃ for 24h, stirring every 15s within 5min at a rotating speed of 150r/min after fermenting for 1h, standing for 30min after stirring, repeating stirring and standing operations until fermentation is carried out for 20h, and standing for 3h to obtain a third generation original seed;
IV, weighing 1680g of third generation protospecies, 1680g of medium gluten meal, 60g of malt extract and 1680g of warm water at 40 ℃, mixing, placing in a sterilized yeast making machine, fermenting for 24 hours at 30 ℃, stirring every 15s within 5 minutes at a rotating speed of 150r/min after fermenting for 1 hour, standing for 30 minutes after stirring is finished, repeating stirring and standing operations until fermentation is carried out for 20 hours, and standing for 3 hours to prepare a fourth generation protospecies;
v, weighing 1680g of fourth generation original seed, 1680g of middle gluten meal, 60g of malt extract and 1680g of warm water at 40 ℃, mixing, placing in a sterilized yeast making machine, fermenting at 30 ℃ for 24h, stirring every 15s within 5min at a rotating speed of 150r/min after fermenting for 1h, standing for 30min after stirring, repeating stirring and standing operations until fermentation is carried out for 20h, and standing for 3h to prepare a fifth generation original seed; the fifth generation of original strain is rye powder natural yeast strain, the pH of the prepared rye powder natural yeast strain is 4.0, and the final product rye powder natural yeast strain is stored at 2-3 deg.C.
Preparation example 2: the rye powder natural yeast seed is prepared by the following method:
weighing 200g of rye flour, 290g of warm water at 40 ℃ and 10g of malt extract, mixing, stirring at a rotating speed of 110r/min for 3min, fermenting at 27 ℃ for 26h, and fermenting to obtain a first generation of original seeds; the rye flour is whole triticale flour;
II, weighing 600g of the first generation original seed, 600g of rye powder, 600g of warm water at 40 ℃ and 20g of malt extract, mixing, stirring at the rotating speed of 110r/min for 5min, fermenting at 27 ℃ for 26h, and fermenting to obtain a second generation original seed;
III, weighing 1800g of second generation original seed, 1800g of medium gluten flour, 60g of malt extract and 1800g of warm water at 40 ℃, mixing, placing in a sterilized yeast making machine, fermenting at 27 ℃ for 26h, stirring at a rotating speed of 250r/min every 10s within 5min after fermenting for 1.5h, standing for 28min after stirring, repeating stirring and standing operations until fermentation lasts for 21h, and standing for 2.5h to obtain a third generation original seed;
IV, weighing 1800g of third generation protospecies, 1800g of medium gluten flour, 60g of malt extract and 1800g of warm water at 40 ℃, mixing, placing in a sterilized yeast maker, fermenting at 27 ℃ for 26h, stirring every 10s within 5min at a rotating speed of 250r/min after fermenting for 1.5h, standing for 28min after stirring, repeating stirring and standing operations until fermentation lasts for 21h, and standing for 2.5h to obtain fourth generation protospecies;
weighing 1800g of fourth generation original seed, 1800g of medium gluten flour, 60g of malt extract and 1800g of warm water at 40 ℃, mixing, placing in a sterilized yeast making machine, fermenting at 27 ℃ for 26h, stirring every 10s within 5min at a rotating speed of 250r/min after fermenting for 1.5h, standing for 28min after stirring, repeating the operations of stirring and standing until the fermentation lasts for 21h, and standing for 2.5h to obtain a fifth generation original seed; the fifth generation of original strain is naked wheat powder natural yeast strain, the pH of the prepared naked wheat powder natural yeast strain is 3.9, and the finished naked wheat powder natural yeast strain is stored at the temperature of 2-3 ℃.
Preparation example 3: the rye powder natural yeast seed is prepared by the following method:
weighing 240g of rye flour, 250g of warm water at 40 ℃ and 10g of malt extract, mixing, stirring at the rotating speed of 110r/min for 3min, fermenting at 32 ℃ for 22h, and preparing a first generation protospecies after fermentation; the rye flour is whole triticale flour;
II, weighing 600g of the first generation protospecies, 700g of rye flour, 700g of warm water at 40 ℃ and 20g of malt extract, mixing, stirring at the rotating speed of 110r/min for 5min, fermenting at 32 ℃ for 22h, and preparing a second generation protospecies after fermentation;
III, weighing 1800g of second generation original seed, 2100g of medium gluten flour, 60g of malt extract and 2100g of warm water at 40 ℃, mixing, placing in a sterilized yeast making machine, fermenting at 32 ℃ for 22h, stirring every 20s within 5min at a rotating speed of 150r/min after fermenting for 2h, standing for 34min after stirring, repeating stirring and standing operations until fermentation lasts for 18h, and standing for 4h to obtain a third generation original seed;
IV, weighing 1800g of third generation original seed, 2100g of medium gluten flour, 60g of malt extract and 2100g of warm water at 40 ℃, mixing, placing in a sterilized yeast making machine, fermenting at 32 ℃ for 22h, stirring every 20s within 5min at a rotating speed of 150r/min after fermenting for 2h, standing for 34min after stirring, repeating stirring and standing operations until fermentation lasts for 18h, and standing for 4h to obtain a fourth generation original seed;
weighing 1800g of fourth generation protospecies, 2100g of medium gluten flour, 60g of malt extract and 2100g of warm water at 40 ℃, mixing, placing in a sterilized yeast maker, fermenting at 32 ℃ for 22h, stirring every 20s within 5min at a rotating speed of 150r/min after fermenting for 2h, standing for 34min after stirring is finished, repeating stirring and standing operations until fermentation lasts for 18h, and standing for 4h to obtain fifth generation protospecies; the fifth generation of original strain is naked wheat powder natural yeast strain, the pH of the prepared naked wheat powder natural yeast strain is 4.2, and the finished naked wheat powder natural yeast strain is stored at the temperature of 2-3 ℃.
Preparation example of gellan gum solution
The low-acyl gellan gum in the following raw materials is purchased from low-acyl gellan gum produced by Shaanxi morning-Ming Biotechnology Limited; other raw materials and equipment are all sold in the market.
Preparation example 4: the gellan gum solution is prepared by the following method:
weighing low acyl gellan gum, dissolving in water to obtain a gellan gum solution with a mass fraction of 2%, weighing sodium citrate, dissolving in water to obtain a sodium citrate solution with a mass fraction of 3.5%, weighing 0.2kg sodium citrate solution, adding into 10kg gellan gum solution, and stirring at 500r/min for 5min to obtain the gellan gum solution.
Preparation example 5: the gellan gum solution is prepared by the following method:
weighing low acyl gellan gum, dissolving in water to obtain a gellan gum solution with a mass fraction of 1%, weighing sodium citrate, dissolving in water to obtain a sodium citrate solution with a mass fraction of 2%, weighing 0.1kg sodium citrate solution, adding into 9.5kg gellan gum solution, and stirring at 500r/min for 5min to obtain the gellan gum solution.
Preparation example 6: the gellan gum solution is prepared by the following method:
weighing low acyl gellan gum, dissolving in water to obtain a gellan gum solution with a mass fraction of 3%, weighing sodium citrate, dissolving in water to obtain a sodium citrate solution with a mass fraction of 5%, weighing 0.3kg sodium citrate solution, adding into 10.5kg gellan gum solution, and stirring at 500r/min for 5min to obtain the gellan gum solution.
Preparation example of coated microspheres
The diatomite particles in the following raw materials are purchased from shinyleaf mine product processing Limited company in Lingshu county, and have the particle size of 0.5-1cm; other raw materials and equipment are all sold in the market.
Preparation example 7: the coated microsphere is prepared by the following method:
placing the diatomite particles in a citric acid solution with the mass fraction of 10%, stirring for 8min, and filtering out the diatomite particles to obtain loaded diatomite particles; uniformly spraying the gellan gum solution prepared in preparation example 4 on the surfaces of the loaded diatomite particles, wherein the weight ratio of the loaded diatomite particles to the gellan gum solution is 1.
Preparation example 8: the coated microsphere is prepared by the following method:
placing the diatomite particles in a citric acid solution with the mass fraction of 5%, stirring for 5min, and filtering out the diatomite particles to obtain loaded diatomite particles; uniformly spraying the gellan gum solution prepared in preparation example 4 on the surfaces of the loaded diatomite particles, wherein the weight ratio of the loaded diatomite particles to the gellan gum solution is 1.
Preparation example 9: the coated microsphere is prepared by the following method:
placing the diatomite particles in a citric acid solution with the mass fraction of 15%, stirring for 10min, and filtering the diatomite particles to obtain loaded diatomite particles; and (3) uniformly spraying the gellan gum solution prepared in the preparation example 4 on the surface of the loaded diatomite particles, wherein the weight ratio of the loaded diatomite particles to the gellan gum solution is 1.
Preparation example 10: the difference between this preparation and preparation 7 is that:
the gellan gum solution prepared in preparation example 5 was used.
Preparation example 11: the difference between the preparation example and the preparation example 7 is that:
the gellan gum solution prepared in preparation example 6 was used.
Preparation example of grape Natural Yeast species
Raisins in the following raw materials are purchased from flame raisers produced by Shanghai Fengnian food Co., ltd; other raw materials and equipment are all sold in the market.
Preparation example 12: the grape natural yeast seed is prepared by the following method:
(1) weighing 400g of raisin, 1000g of warm water at 40 ℃ and 200g of sugar, mixing, fermenting for 7d at 27 ℃, uncovering to deflate every morning and evening, shaking for 10s, and sieving with a 100-mesh sieve after fermentation is finished to obtain a first-generation grape seed solution; the sugar consists of honey and white granulated sugar with the weight ratio of 1;
(2) weighing 400g of first-generation grape seed solution, 200g of medium gluten flour and 70g of sugar, mixing, and fermenting at 27 ℃ for 24h to obtain second-generation grape seed solution;
(3) weighing 400g of second generation grape seed liquid, 200g of medium gluten powder and 70g of sugar, mixing, fermenting at 27 ℃ for 24h to obtain grape natural yeast strain, wherein the pH of the grape natural yeast strain is 4.0, and storing the finished product grape natural yeast strain at 2-3 ℃.
Preparation example 13: the grape natural yeast seed is prepared by the following method:
(1) weighing 440g of raisin, 1320g of warm water at 40 ℃ and 260g of sugar, mixing, fermenting for 5d at 27 ℃, uncovering to deflate every morning and evening, shaking for 10s, and sieving with a 100-mesh sieve after fermentation is finished to obtain a first-generation grape seed solution; the sugar consists of honey and white granulated sugar with the weight ratio of 1;
(2) weighing 550g of first generation grape seed solution, 350g of medium gluten powder and 100g of sugar, mixing, and fermenting at 27 ℃ for 24h to obtain second generation grape seed solution;
(3) weighing 550g of second-generation grape seed liquid, 350g of medium gluten meal and 100g of sugar, mixing, fermenting at 27 ℃ for 24h to obtain grape natural yeast seeds, wherein the pH of the grape natural yeast seeds is 4.2, and storing the finished grape natural yeast seeds at 2-3 ℃.
Preparation example 14: the grape natural yeast seed is prepared by the following method:
(1) weighing 560g of raisin, 1200g of warm water at 40 ℃ and 260g of sugar, mixing, fermenting for 8 days at 27 ℃, uncovering to deflate every morning and evening, shaking for 10s, and sieving with a 100-mesh sieve after fermentation is finished to obtain a first-generation grape seed solution; the sugar consists of honey and white granulated sugar with the weight ratio of 1;
(2) weighing 650g of first-generation grape seed solution, 250g of medium gluten powder and 100g of sugar, mixing, and fermenting at 27 ℃ for 24 hours to obtain second-generation grape seed solution;
(3) weighing 650g of second-generation grape seed liquid, 250g of medium gluten powder and 100g of sugar, mixing, fermenting at 27 ℃ for 24h to obtain grape natural yeast strain with pH of 3.9, and storing the finished product grape natural yeast strain at 2-3 ℃.
Preparation example 15: the difference between this preparation and preparation 12 is that:
(1) weighing 400g of raisin, 1000g of warm water at 40 ℃, 200g of sugar and 32g of the coated microspheres prepared in preparation example 7, mixing, fermenting for 7d at 27 ℃, wherein the cover is opened to release gas every morning and evening every day for 1-2 days, shaking is carried out for 10s, the cover is opened every 30min every 3-4 days, stirring is carried out for 5min, the cover is opened to release gas every morning and evening every day for 5-7 days, shaking is carried out for 10s, after fermenting for 22h, all the coated microspheres are uniformly knocked by a wood stick under 15 meshes, and after fermenting, sieving by a 100-mesh sieve to obtain first-generation grape seed liquid.
Preparation example 16: the difference between this preparation and preparation 12 is that:
(1) weighing 400g of raisin, 1000g of warm water at 40 ℃, 200g of sugar and 16g of coated microspheres prepared in preparation example 7, mixing, fermenting for 7d at 27 ℃, wherein the cover is opened for deflation every morning and evening every day 1-2 days, shaking is carried out for 10s, the cover is opened for stirring for 2min every 20min every 3-4 days, the cover is opened for deflation every morning and evening every day 5-7 days, shaking is carried out for 10s, uniformly knocking all the coated microspheres below 10 by a wood stick after fermenting for 18h, and sieving by a 100-mesh sieve after fermenting to prepare first-generation grape seed solution.
Preparation example 17: the difference between this preparation and preparation 12 is that:
(1) weighing 400g of raisin, 1000g of warm water at 40 ℃, 200g of sugar and 48g of the coated microspheres prepared in preparation example 7, mixing, fermenting for 7d at 27 ℃, wherein the cover is opened to release gas every morning and evening every day for 1-2 days, shaking is carried out for 10s, the cover is opened every 40min every 3-4 days, stirring is carried out for 8min, the cover is opened to release gas every morning and evening every day for 5-7 days, shaking is carried out for 10s, after fermenting for 26h, all the coated microspheres are uniformly knocked by a wood stick under 20 meshes, and after fermenting, sieving by a 100-mesh sieve to obtain first-generation grape seed liquid.
Preparation example 18: the difference between the present preparation example and preparation example 15 is that:
the coated microspheres prepared in preparation example 8 were used.
Preparation example 19: the difference between the preparation example and the preparation example 15 is that:
the coated microspheres prepared in preparation example 9 were used.
Preparation example 20: the difference between the present preparation example and preparation example 15 is that:
the coated microspheres prepared in preparation example 10 were used.
Preparation example 21: the difference between the present preparation example and preparation example 15 is that:
the coated microspheres prepared in preparation example 11 were used.
Examples
The following raw materials are all commercially available.
Example 1: a preparation method of natural yeast comprises the following steps:
s1, weighing 100g of rye powder natural yeast seed prepared in the preparation example 1, 100g of grape natural yeast seed prepared in the preparation example 12, 200g of medium gluten flour and 200g of warm water at 40 ℃, mixing and stirring, and fermenting at 30 ℃ for 24 hours to obtain a mixed seed for 1 generation, wherein the pH is 4.0;
s2, weighing 300g of mixed seeds 1 generation prepared by the S1, 300g of medium gluten meal and 300g of water, mixing and stirring, fermenting for 5 hours at the temperature of 27 ℃ to prepare mixed seeds 2 generation, wherein the pH value is 4.0;
and S3, subculturing the mixed seed 2 generation according to the method in the S2, namely mixing 300g of the mixed seed 2 generation, 300g of the medium gluten meal and 300g of water as raw materials for the mixed seed 3 generation, fermenting for 5 hours at the temperature of 27 ℃, wherein the number of passages is less than or equal to 28, the interval time of passages is 5d, refrigerating and storing the mixed seed 2 generation and the mixed seed prepared after passages at the temperature of 2 ℃, and directly taking the mixed seed 2 generation or any generation in the passages as the finished natural yeast.
Example 2: a preparation method of natural yeast comprises the following steps:
s1, weighing 150g of rye powder natural yeast seed prepared in the preparation example 1, 150g of grape natural yeast seed prepared in the preparation example 12, 350g of medium gluten flour and 350g of warm water at 40 ℃, mixing and stirring, and fermenting at 27 ℃ for 26 hours to prepare a mixed seed for 1 generation;
s2, weighing 240g of the mixed seeds 1 generation prepared by the S1, 360g of medium gluten meal and 300g of water, mixing and stirring, and fermenting for 6 hours at 25 ℃ to prepare mixed seeds 2 generation;
and S3, subculturing the mixed seed 2 generation according to the method in the S2, namely mixing 240g of the mixed seed 2 generation, 360g of the medium gluten meal and 300g of water as raw materials for the mixed seed 3 generation, fermenting for 6 hours at 25 ℃, wherein the number of passages is less than or equal to 28, the interval time of passages is 2d, refrigerating and storing the mixed seed 2 generation and the mixed seed prepared after passages at 4 ℃, and directly taking the mixed seed 2 generation or any generation of passages as a finished product natural yeast.
Example 3: a preparation method of natural yeast comprises the following steps:
s1, weighing 100g of rye powder natural yeast seed prepared in the preparation example 1, 100g of grape natural yeast seed prepared in the preparation example 12, 150g of medium gluten flour and 150g of warm water at 40 ℃, mixing and stirring, and fermenting for 22 hours at 32 ℃ to prepare a mixed seed 1 generation;
s2, weighing 360g of mixed seed 1 generation prepared by the S1, 240g of medium gluten meal and 300g of water, mixing and stirring, and fermenting for 4 hours at the temperature of 32 ℃ to prepare mixed seed 2 generation;
and S3, subculturing the mixed seed 2 generation according to the method in the S2, namely mixing 360g of the mixed seed 2 generation, 240g of the medium gluten meal and 300g of water as raw materials for the mixed seed 3 generation, fermenting for 4 hours at 32 ℃, wherein the number of passages is less than or equal to 28, the interval time of passages is 7d, refrigerating and storing the mixed seed 2 generation and the mixed seed prepared after transmission at 1 ℃, and directly taking the mixed seed 2 generation or any generation of passages as a finished product natural yeast.
Example 4: the present embodiment is different from embodiment 1 in that:
the rye powder natural yeast is selected from the rye powder natural yeast prepared in the preparation example 2.
Example 5: the present embodiment is different from embodiment 1 in that:
the rye flour natural yeast seed prepared in preparation example 3 is selected.
Example 6: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 13 was selected as the grape natural yeast strain.
Example 7: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 14 was selected.
Example 8: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 15 was selected.
Example 9: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 16 was selected as the grape natural yeast strain.
Example 10: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 17 was selected as the grape natural yeast strain.
Example 11: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 18 was selected as the grape natural yeast strain.
Example 12: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 19 was selected as the grape natural yeast strain.
Example 13: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 20 was selected.
Example 14: the present embodiment is different from embodiment 1 in that:
the grape natural yeast strain prepared in preparation example 21 was selected.
Example 15: the present embodiment is different from embodiment 8 in that:
(1) weighing 400g of raisin, 1000g of warm water at 40 ℃, 200g of sugar and 32g of coated microspheres prepared in preparation example 7, mixing, fermenting for 7d at 27 ℃, wherein the cover is opened to deflate every morning and evening every day on the 1-2 days, shaking is carried out for 10s, the cover is opened to stir every 30min for 5min on the 3-4 days, the cover is opened to deflate every morning and evening every day on the 5-7 days, shaking is carried out for 10s, and sieving with a 100-mesh sieve after fermentation to prepare a generation of grape seed solution.
Example 16: the present embodiment is different from embodiment 8 in that:
in the preparation process of the coated microsphere, the diatomite particles are placed in a citric acid solution with the mass fraction of 10% to be stirred for 8min, then the diatomite particles are filtered to prepare the loaded diatomite particles, and the moisture on the surface of the loaded diatomite particles is drained to prepare the coated microsphere.
Example 17: the present embodiment is different from embodiment 8 in that:
weighing low-acyl gellan gum, and dissolving in water to obtain a gellan gum solution with a mass fraction of 2%.
Example 18: the present embodiment is different from embodiment 8 in that:
the gellan gum is high acyl gellan gum.
Example 19: the present embodiment is different from embodiment 1 in that:
in the process of preparing the naked wheat powder natural yeast, the fourth generation of original seeds are the finished product naked wheat powder natural yeast.
Example 20: the present embodiment is different from embodiment 1 in that:
and after fermenting for 1h in the steps III, IV and V, stirring at the rotating speed of 150r/min every 10min within 1h.
Comparative example
Comparative example 1: this comparative example differs from example 1 in that:
the natural yeast of the grape is replaced by the natural yeast of the rye flour with the same mass in the raw materials.
Comparative example 2: this comparative example differs from example 1 in that:
the time interval for passage was 8d.
Performance test
1. Detection of dough thallus quantity
The preparation methods of the embodiments 1-20 and the comparative examples 1-2 are respectively adopted to prepare natural yeast, GB/T4789.15-2010 food microbiology is adopted to check mould and yeast count, GB/T4789.35-2016 food microbiology is adopted to check lactobacillus check, the number of yeasts and the number of lactobacillus of natural yeast species are respectively detected, 2 nd generation, 8 th generation, 15 th generation, 22 th generation and 28 th generation recorded data are taken, the change degree of the number of bacteria within 28 generations is indirectly represented through the 5 generations, if the change of the number of bacteria of the 8 th generation and the 15 th generation is small, the number of bacteria of each generation in the 8 th generation and the 15 th generation is in a relatively stable state, the bacteria still have good fertility and activity after being cultured by multiple times of passage, other generations are identical, and the organoleptic properties of the prepared finished product natural yeast bread have small differences with those of the second generation natural yeast, so that the production efficiency of enterprises is improved on the premise of ensuring the bread properties of the natural yeast.
TABLE 1 Yeast number assay
TABLE 2 detection of lactic acid bacteria
3. Dough pH detection
The natural yeasts are prepared by the methods of examples 1-20 and comparative examples 1-2, respectively, 5g of the prepared natural yeast is weighed and placed in 100mL of distilled water to be stirred and dissolved, the pH value of the natural yeast is measured by a pH meter, and data are recorded according to the 2 nd generation, the 8 th generation, the 15 th generation, the 22 th generation and the 28 th generation.
TABLE 3 dough pH Performance test Table
By combining the embodiment 1 and the embodiments 2-3 with the table 1, the table 2 and the table 3, it can be seen that the natural yeast of rye powder and the natural yeast of grape are matched, and the prepared natural yeast has higher thallus quantity and more stable pH after multiple subcultures; the natural yeast is cultured by adopting a subculture method, and then the yeast bread is prepared by using the natural yeast, so that the production efficiency of producing the natural yeast bread by enterprises can be improved.
It can be seen from the combination of examples 1 and 4-5 and tables 1, 2 and 3 that the preparation process of the rye flour natural yeast in examples 4-5 is different, and the rye flour natural yeast strain is cultured by adopting a proper weight ratio of raw materials, so that the yeast and lactobacillus in the prepared rye flour natural yeast strain are stable and strong in activity, the finished natural yeast has high cell number and pH stability after multiple subculture, the physical and chemical properties and sensory evaluation are good when the natural yeast bread is prepared, and the production efficiency of enterprises is improved.
Combining the example 1 and the examples 6-7 with tables 1, 2 and 3, it can be seen that the raw material ratio of the grape natural yeast strains in the examples 6-7 is different from that in the example 1, the grape natural yeast strains with the proper raw material ratio can stabilize the thalli of the finished product natural yeast and have strong activity, and the finished product natural yeast still has higher thallus number and pH stability after multiple subculture, so that the production efficiency of enterprises is improved on the premise that the natural yeast bread has better physicochemical properties and sensory evaluation.
When the examples 1 and 8 to 10 are combined and tables 1, 2 and 3 are combined, it can be seen that the natural yeasts prepared in examples 8 to 10 have higher yeast and lactic acid bacteria cell numbers than those of the natural yeasts prepared in example 1 and the natural yeasts prepared in examples 8 to 10 have lower pH than that of the natural yeasts prepared in example 1 when the coated microspheres are added to the raw materials of examples 8 to 10; the release of the citric acid solution in the coated microspheres is shown, so that the acidity of the fermentation liquor is improved, the growth and the propagation of the saccharomycetes and the lactic acid bacteria are guaranteed and the growth and the propagation of harmful bacteria are inhibited at the same time under the acidic condition of the fermentation liquor, so that the growth and the propagation of the saccharomycetes and the lactic acid bacteria are indirectly promoted, the prepared grape natural yeast has good stability and activity, and the natural yeast cultured by the prepared grape natural yeast still has high thallus number and stable pH value after multiple passages.
Combining example 8 and examples 11-12 with tables 1, 2 and 3, it can be seen that the preparation processes of the coated microspheres of examples 11-12 are different, which shows that the coating effect of the coated microspheres has an influence on the activity and stability of the strains of natural grape yeast, and thus on the number and pH stability of the strains of natural yeast after multiple subcultures.
It can be seen from the combination of example 8 and examples 13 to 14 and tables 1, 2 and 3 that the different preparation processes of gellan gum in examples 13 to 14 show that different gellan gum solutions have different coating effects, and thus the cell number and pH stability of natural yeast after multiple subcultures are easily affected.
When the example 8 and the examples 15 to 18 are combined and the table 1, the table 2 and the table 3 are combined, the coated microspheres are not knocked in the process of preparing the grape seed solution for one generation of the example 15, compared with the example 8, the natural yeast and the lactobacillus prepared in the example 15 have the bacteria number smaller than that of the example 8 regardless of the passage, the difference of the bacteria number between the generations is larger than that of the example 8, and the pH of the natural yeast prepared in the example 15 is larger than that of the example 8 regardless of the passage; the method indicates that the citric acid solution in the coated microspheres can be released into the fermentation liquor by knocking the coated microspheres, the pH value of the fermentation liquor is properly reduced to promote the growth of lactic acid bacteria, the growth of yeast is ensured, the growth of harmful bacteria is inhibited, and the natural yeast still has higher thallus quantity and more stable pH value after multiple subcultures.
Example 16 in the process of preparing the coated microspheres, no gellan gum treatment was performed, and compared to example 8, the number of yeast and lactic acid bacteria of the natural yeast prepared in example 16 was less than that of example 8, and the pH of the natural yeast of generation 2 was also lower than that of example 8; the explanation shows that the uncoated diatomite particles are not beneficial to the culture of natural yeast because the citric acid solution in the coated microspheres can be quickly transferred into the fermentation liquor after the coated microspheres are placed in the fermentation liquor, the pH value of the fermentation liquor is quickly reduced, and the growth of the thalli is easily inhibited by lower pH value.
Example 17 in the preparation process of gellan gum solution, low acyl gellan gum is directly dissolved in water, high acyl gellan gum is used in example 18, compared to example 8, the natural yeasts prepared in examples 17 and 18 have yeast and lactobacillus bacteria numbers smaller than the corresponding generation number in example 8 regardless of passage number, and the difference in bacteria number between the generations is larger, and meanwhile, the natural yeasts prepared in examples 17 and 18 have pH larger than the corresponding generation number in example 8 regardless of passage number; the method is characterized in that the gellan gum solution is matched with the sodium citrate solution, so that the gellan gum film has higher strength, the gellan gum film is convenient to break in the knocking process, the citric acid solution in the diatomite is convenient to gradually release into the fermentation liquor, the pH value of the fermentation liquor is reduced, the growth and the propagation of the yeast and the lactic acid bacteria are inhibited, the growth and the propagation of the yeast and the lactic acid bacteria are indirectly promoted, and the natural yeast still has better thallus content and more stable pH value after multiple subculture.
In the process of preparing the natural yeast strain of rye flour in example 19, the fourth generation of the natural yeast strain is the finished natural yeast strain of rye flour, as can be seen by combining example 1 with examples 19-20 and tables 1, 2 and 3, the pH of the natural yeast strain prepared in example 19 is significantly higher than that of the natural yeast strain prepared in example 1 compared with example 1; the fourth generation of the protospecies has higher pH, and the physical and chemical indexes of the natural yeast are easily influenced through multiple subcultures, so that the quality of the yeast bread is influenced.
Example 20 after fermenting steps III, IV and V for 1 hour, stirring at a rotation speed of 150r/min every 10min within 1 hour, compared with example 1, the number of cells of each generation of the natural yeast prepared in example 20 is smaller than that of the generation corresponding to the natural yeast prepared in example 1, and the pH of each generation of the natural yeast prepared in example 20 is larger than that of the generation corresponding to the natural yeast prepared in example 1; the method proves that multiple stirring within a short time can promote the contact of oxygen and the microzyme, and the propagation speed of the microzyme is accelerated under the aerobic condition, so that the growth and propagation of the microzyme are further promoted, and the prepared natural yeast has high thallus quantity, high thallus activity and high stability.
Combining example 1 and comparative examples 1-2 with tables 1, 2 and 3, it can be seen that, in the raw material of comparative example 1, replacing the natural yeast strain of grape with the natural yeast strain of rye flour of the same quality, the number of the cells of each generation of the natural yeast prepared in comparative example 1 is smaller than that of the corresponding generation of the natural yeast prepared in example 1, and the pH of each generation of the natural yeast prepared in comparative example 1 is larger than that of the corresponding generation of the natural yeast prepared in example 1, compared with example 1; the natural yeast prepared by mixing the rye powder natural yeast and the grape natural yeast is proved to have higher thallus quantity and more stable pH after being subjected to multiple passages.
Comparative example 2 the passage interval was 8d, and in comparison with example 1, the number of cells in each generation of the natural yeast prepared in comparative example 2 was smaller than that in the corresponding generation of the natural yeast prepared in example 1, and the pH in each generation of the natural yeast prepared in comparative example 2 was greater than that in the corresponding generation of the natural yeast prepared in example 1; the method shows that the time interval of the passage is longer, the activity of thalli is easily influenced, so that the activity of the natural yeast is easily influenced, the number of thalli of the natural yeast after multiple passages is reduced, the pH value is higher, the physicochemical property of the natural yeast is poorer, and the quality of yeast bread is easily influenced.
4. Staphylococcus aureus detection
Finished natural yeasts are prepared by the methods of examples 1-3, examples 8-10 and examples 15-18 respectively, the content of staphylococcus aureus of natural yeast strains prepared by the methods of examples 1-3, examples 8-10 and examples 15-18 is decomposed and detected by a method of food microbiology inspection staphylococcus aureus inspection of GB4789.10-2010, and the data is recorded at the 28 th generation.
The results show that no staphylococcus aureus can be detected in the above examples, and the natural yeast prepared by the method has the advantage of inhibiting the growth and reproduction of harmful bacteria.
5. Bread shelf life detection
Respectively adopting the methods of the embodiment 1, the embodiment 8 and the embodiments 15-18 to prepare finished natural yeast, weighing 2100g of high gluten flour, 5g of salt, 250g of milk powder, 800g of natural yeast, 500g of whole egg liquid, 400g of water at 10 ℃ and 350g of white granulated sugar, mixing and then placing in a dough mixer, stirring at low speed for 3min, then stirring at high speed for 9min, then adding 350g of butter, stirring at low speed for 3min, stirring at high speed for 3min, beating gluten until the gluten is slightly too high, preparing dough, loosening the dough for 20min, then dividing into small blocks of 80g, loosening and loosening the small blocks after rounding for 15min, then fermenting for 60min under the conditions of the temperature of 38 ℃ and the relative humidity of 85%, baking for 12min under the conditions of the temperature of 200 ℃ and the temperature of 150 ℃ after fermentation, and then cooling, filling nitrogen and packaging to prepare finished yeast bread; and (4) storing the finished yeast bread at room temperature, and recording the time for primary mold growth.
The shelf life of the yeast bread prepared in example 1 is 30 days, and the shelf life of the yeast bread prepared in example 8 is 45 days, which shows that the pH value of the natural yeast is reduced under the action of the coated microspheres, and the shelf life of the finished yeast bread is prolonged.
The shelf life of the yeast bread prepared in example 15 is 36d, the shelf life of the yeast bread prepared in example 16 is 38d, the shelf life of the yeast bread prepared in example 17 is 40d, and the shelf life of the yeast bread prepared in example 18 is 35d, compared with example 8, the shelf lives of examples 15, 16, 17 and 18 are all lower than that of example 8, which shows that the pH of natural yeast can be adjusted by matching diatomite and citric acid solution with gellan gum solution, so that the shelf life of finished yeast bread is prolonged.
The specific embodiments are only for explaining the present application and are not limiting to the present application, and those skilled in the art can make modifications to the embodiments without inventive contribution as required after reading the present specification, but all the embodiments are protected by patent law within the scope of the claims of the present application.
Claims (6)
1. A preparation method of natural yeast is characterized by comprising the following steps:
s1, respectively weighing naked wheat powder natural yeast seeds, grape natural yeast seeds, medium gluten flour and water according to a weight ratio of 15-20 to 30-35, mixing, and fermenting for 22-26h at 27-32 ℃ to obtain a mixed seed for 1 generation;
s2, weighing the mixed seeds 1 generation, medium gluten powder and water respectively according to the weight ratio of 0.8-1.2;
s3, subculturing the mixed seed 2 generation according to the method in the S2, wherein the number of passages is less than or equal to 28, the passage interval time is 2-7d, then refrigerating and storing at the temperature of 1-4 ℃, and taking the mixed seed 2 generation or any generation in the passages as a finished product natural yeast;
the grape natural yeast seed is prepared by the following method:
(1) weighing raisins, water, sugar and coated microspheres, mixing, wherein the weight ratio of the raisins to the water to the sugar is (22-28) and (1-3) fermenting for 5-7d at 25-35 ℃, knocking the coated microspheres for 10-20 hours after fermenting for 18-26 hours, uncovering the cover in the morning and evening every day, deflating, and filtering after fermenting, wherein the filtrate is first-generation grape liquid;
(2) weighing first-generation grape seed liquid, medium gluten powder and sugar in a weight ratio of 55-65 to 25-35 in turn, mixing, fermenting for 22-26h at 25-35 ℃, and filtering to obtain second-generation grape seed liquid;
(3) weighing the second-generation grape seed liquid, the medium gluten powder and the sugar in sequence according to the weight ratio of 55-65 to 25-35, mixing, fermenting for 22-26h at the temperature of 25-35 ℃, and filtering to obtain a grape natural yeast seed;
the coated microsphere is prepared by the following method:
placing the diatomite particles in a citric acid solution with the mass fraction of 5-12%, stirring for 5-10min, and taking out the diatomite particles to prepare load diatomite particles; spraying a gellan gum solution on the surface of the loaded diatomite particles, wherein the weight ratio of the loaded diatomite particles to the gellan gum solution is 1.2-0.6, and drying to obtain the coated microspheres;
the gellan gum solution is prepared by the following method:
preparing low acyl gellan gum with mass fraction of 1-3%, weighing 1-3 parts of sodium citrate solution with mass fraction of 2-5%, adding into 95-100 parts of low acyl gellan gum, and stirring and mixing to obtain gellan gum solution.
2. The method for producing a natural yeast according to claim 1, wherein: the rye powder natural yeast strain in the S1 is prepared by the following method:
weighing rye flour, water and malt extract respectively according to a weight ratio of 40-48;
II, respectively weighing a first generation original seed, rye powder, water and malt extract according to the weight ratio of 30-35;
III, respectively weighing a second generation original seed, medium gluten flour, malt extract and water according to the weight ratio of 30-35;
and IV, subculturing the third generation of stock seeds according to the method in the step III to sequentially prepare a fourth generation of stock seeds and a fifth generation of stock seeds, wherein the fifth generation of stock seeds are the rye powder natural yeast seeds.
3. The method for preparing natural yeast according to claim 2, wherein the fermentation temperature is 27-32 ℃ and the fermentation time is 22-26h.
4. The method for preparing natural yeast according to claim 3, wherein the step III and the step IV are stirred at the rotation speed of 150-250r/min every 10-20s within 1-2h, 5min after fermentation, the mixture is kept stand for 28-34min after the stirring is finished, and the stirring and standing operations are repeated until the fermentation is carried out for 18-21h.
5. The method for preparing natural yeast according to claim 1, wherein the sugar comprises honey and white granulated sugar in a weight ratio of 1.
6. The method for preparing natural yeast according to claim 1, wherein in the fermentation process of the 3 rd to 4 th days in the step (1), the mixture is stirred for 2 to 8 minutes every 20 to 40 minutes after being uncapped.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110769726.1A CN113528360B (en) | 2021-07-07 | 2021-07-07 | Preparation method of natural yeast |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110769726.1A CN113528360B (en) | 2021-07-07 | 2021-07-07 | Preparation method of natural yeast |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113528360A CN113528360A (en) | 2021-10-22 |
| CN113528360B true CN113528360B (en) | 2023-02-10 |
Family
ID=78127022
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110769726.1A Active CN113528360B (en) | 2021-07-07 | 2021-07-07 | Preparation method of natural yeast |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113528360B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102613265A (en) * | 2012-03-31 | 2012-08-01 | 福建省麦都食品发展有限公司 | Natural yeast powder and preparation method therefore |
| CN107012112A (en) * | 2017-04-28 | 2017-08-04 | 苏州花园饼屋有限公司 | A kind of preparation method of unartificial yeast |
| CN111057655A (en) * | 2019-08-12 | 2020-04-24 | 山东环丰食品股份有限公司 | Preparation method of natural yeast, natural yeast and application of natural yeast |
| CN112400951A (en) * | 2020-11-26 | 2021-02-26 | 浙江一鸣食品股份有限公司 | Fruit and vegetable natural yeast acid flour and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014054838A1 (en) * | 2012-10-04 | 2014-04-10 | Paris Croissant Co., Ltd. | Methods of making natural sourdough starter for baking bread and methods of making bread using the same |
-
2021
- 2021-07-07 CN CN202110769726.1A patent/CN113528360B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102613265A (en) * | 2012-03-31 | 2012-08-01 | 福建省麦都食品发展有限公司 | Natural yeast powder and preparation method therefore |
| CN107012112A (en) * | 2017-04-28 | 2017-08-04 | 苏州花园饼屋有限公司 | A kind of preparation method of unartificial yeast |
| CN111057655A (en) * | 2019-08-12 | 2020-04-24 | 山东环丰食品股份有限公司 | Preparation method of natural yeast, natural yeast and application of natural yeast |
| CN112400951A (en) * | 2020-11-26 | 2021-02-26 | 浙江一鸣食品股份有限公司 | Fruit and vegetable natural yeast acid flour and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113528360A (en) | 2021-10-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111269770B (en) | Tartary buckwheat white spirit and brewing process thereof | |
| KR20140043989A (en) | Methods of manufacturing bread using a natural sourdough starter | |
| CN110973204A (en) | Original flavor toast added with fructo-oligosaccharide and preparation method thereof | |
| CN103834522A (en) | Six-grain highly-flavored white spirit and preparation method thereof | |
| CN112400950A (en) | Making method for improving quality of whole-wheat bread | |
| CN110999937A (en) | Original flavor toast added with galactooligosaccharide and preparation method thereof | |
| CN104010514A (en) | Methods of making natural sourdough starter for baking bread and methods of making bread using the same | |
| KR20140043988A (en) | Methods of manufacturing a natural sourdough starter for baking | |
| CN113519592B (en) | Toast bread and preparation method thereof | |
| CN105581236A (en) | Jiaozi sour dough wheat flour and production method thereof | |
| CN113528360B (en) | Preparation method of natural yeast | |
| CN108703287A (en) | A kind of whitening enzyme beverage and preparation method thereof containing small-molecular peptides Yu a variety of enzymes | |
| CN106819352B (en) | Preparation method of pearl plum flavor fruitcake | |
| RU2422008C1 (en) | "kaizer" cooked bread production method | |
| CN111418768A (en) | Method for making instant steamed rice cake and product thereof | |
| CN116114846A (en) | Method for producing low-sugar fermented crisp jujube by using whole red jujube | |
| CN104876669A (en) | Special fertilizer for wheat | |
| KR20090129277A (en) | Laver containing green tea and manufacturing method thereof | |
| CN1559274A (en) | No-pollution and preserved thin pancake made of millet flour, and its processing method | |
| CN113678993A (en) | Method for making organic purple glutinous rice cake | |
| CN112931047A (en) | Method for manufacturing mushroom sticks of bag-cultivated mushrooms | |
| CN112971018A (en) | Fresh wet rice flour and fermentation method applied to same | |
| CN112868699A (en) | Acidity regulator for bread preservation | |
| KR20120043527A (en) | Method of preparing seaweed makgeolli | |
| RU2492654C1 (en) | Method for production of bakery product for dietary alimentation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |