Old yeast head preparation method of traditional fermented sour dough

Abstract

The invention belongs to the field of deep processing of foods, and particularly relates to a preparation method of an aged fermentation head of traditional fermented sour dough. The culture medium is prepared from the following components in parts by mass: 0.8-1.2 parts of original yeast, 18-22 parts of culture medium and 18-22 parts of water. Wherein the original fermentation head is an old fermentation head used for locally fermenting steamed buns or annual steamed buns. The culture medium is prepared from the following raw materials in percentage: 10% of barley flour, 15% of corn flour, 55% of wheat flour, 15% of soybean flour and 5% of yeast for making hard liquor. The preparation method comprises the following steps: firstly, carrying out enlarged culture on an old fermentation head, and carrying out the following steps: firstly, crushing and sieving the culture components according to ingredient requirements, then, weighing according to the ingredient requirements, then, adding required water (cooled after boiling), carrying out full stirring, then, adding the original fermentation head into the mixed components under an aseptic condition, and carrying out uniform stirring. Culturing at 37 DEG C under the condition that the relative humidity is 85-90, terminating the culture after 24 hours, and then drying the fermented fermentation head under the condition of constant temperature.

Description

Technical Field

[0001] The invention belongs to the field of food deep processing, and in particular relates to a method for preparing an old starter for traditional fermented sourdough. Background Art

[0002] Steamed bread has a history of thousands of years in my country and is one of the traditional fermented staple foods in my country. At present, the starter for making steamed bread in my country is mainly commercially available high-activity yeast and traditional old dough starter. Among them, the traditional old dough starter is a natural starter formed by natural fermentation, continuous passage, enrichment, optimization of beneficial microorganisms in the ecosystem and expansion of cultivation. Therefore, the composition of the microbial flora in the old dough is diverse and complex, making the old dough steamed bread made with it richer and more special in flavor and taste than the steamed bread made with commercial yeast.

[0003] Old dough contains a variety of microbial communities, and the bacterial community structure is more complex than that of dough fermented with highly active yeast. During the storage and repeated use, the types and relative abundance of microorganisms in the dough are constantly changing. Due to the interaction between microorganisms, saccharification, protein decomposition, esterification and gas production reactions will occur in the dough. There are many types of yeast in old dough, among which Saccharomyces cerevisiae has a higher abundance, followed by Pichia anomala, Wickerhamomyces anomalus, Issatchenkia orientalis, Saccharomycopsis fibuligera, etc. Yeast can undergo esterification reactions through metabolism during dough fermentation, giving steamed bread a unique flavor and taste. In addition, the gas production ability of yeast during the fermentation process is crucial to the final quality of steamed bread, because the CO produced by yeast 2 and other metabolites will affect the rheological properties of the dough and the texture, volume and taste of steamed bread.

[0004] However, old dough is formed by natural fermentation, and the raw materials and processes are not fixed, resulting in complex and unstable microbial species, including many microorganisms and substances that have negative effects on flavor and quality, such as phytic acid, moldy or sour smells, etc. Therefore, the complex microbial species also reduce the safety of old dough steamed bread, making it difficult to control the safety, flavor and quality stability of steamed bread made by traditional old dough fermentation process.

[0005] Commercial yeast on the market has the characteristics of short fermentation time and stable fermentation quality, but due to its single strain, its flavor and mouthfeel are not as good as old-style steamed bread. Many studies have also pointed out that steamed bread fermented with old-style dough has better taste and flavor. A large number of studies have shown that yeast and lactic acid bacteria synergistically ferment dough, which helps to improve the rheological properties of dough and the texture and flavor of baked products. The nutrients that lactic acid bacteria and yeast can utilize are very similar, which can promote their growth and reproduction. The organic acids, extracellular polysaccharides, antibacterial substances and rich enzyme systems produced by the co-fermentation of the two promote biochemical changes in the gluten network and affect the granular structure of starch, thereby improving its nutritional properties and rheological properties, improving the ductility of the dough and generating metabolites related to flavor substances, giving the product a special aroma. The starter used in traditional old-style fermentation has a small output and unstable quality, making it difficult to form a scale advantage. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a traditional sourdough starter. The present invention utilizes the activity and culture characteristics of microorganisms to prepare the starter, which can not only ensure the fermentation activity but also improve the quality of the fermented dough and steamed bread.

[0007] The present invention provides a method for preparing a traditional fermented sourdough starter, which uses the following components in the following mass ratios:

[0008] 0.8-1.2 parts of original starter, 18-22 parts of culture medium, 18-22 parts of water.

[0009] The unit of this portion can be: gram, kilogram or other standard mass units.

[0010] The original starter mentioned is the old starter used for fermenting steamed buns or New Year's steamed buns locally.

[0011] The culture medium is prepared from the following raw materials in the following mass proportions: 10% barley flour, 15% corn flour, 55% wheat flour, 15% soybean flour and 5% Daqu.

[0012] First, the old starter is expanded and cultured, and the preparation steps are as follows: the culture components are first crushed and sieved according to the ingredient requirements, and then weighed according to the ingredient requirements, and then the required water (boiled and cooled) is added and fully stirred, and then the original starter is added to the above mixed ingredients under sterile conditions and stirred evenly.

[0013] The culture was carried out at 37°C and relative humidity of 85-90°C, and the number of viable bacteria and morphology were observed regularly.

[0014] The culture was terminated after 24 hours, and the fermented starter was then dried under constant temperature conditions.

[0015] The present invention also provides a method for preparing the above-mentioned old starter of traditional fermented sourdough, comprising the following steps:

[0016] (1) crushing and sieving the required components of each culture medium;

[0017] (2) Weigh and mix the various ingredients, then add water and stir into a paste;

[0018] (3) Adding the original old starter under relatively sterile conditions;

[0019] (4) Cultivate under constant temperature and humidity conditions and dry in the shade after cultivation.

[0020] In the above-mentioned preparation method, in step (1), the culture medium components are crushed and need to pass through an 80-mesh sieve.

[0021] In the above preparation method, the culture temperature may be 37° C., and the culture time may be 24 hours.

[0022] In the above preparation method, the temperature of the shade-dried starter can be 25-30°C, specifically 25°C, and the drying time can be 36-48h, specifically 36h or 48h.

[0023] The microbial composition of fermented old starter includes Saccharomyces kudriavirensis, Saccharomyces membranaceus, Pichia kluyveri, Leuconostoc mesenteroides, Pediococcus pentosaceus, Lactobacillus helveticus, and Enterococcus italicum, and the richness of microorganisms is higher than that of Angel Yeast (single yeast). The number and relative content of steamed bread flavors after fermentation are higher than those of Angel Yeast.

[0024] The present invention has the following advantages:

[0025] The present invention utilizes the original complex microbial community in the starter, combines the growth characteristics of yeast and lactic acid bacteria, expands and re-cultivates the starter, and can provide a starter with uniform and stable performance for the fermentation of traditional sourdough. At the same time, the present technology determines the basic culture medium composition and culture conditions, which can ensure the relative stability and consistency of the starter during the expansion and cultivation process, and can maximize the quality of the fermented dough and the final steamed bun.

[0026] Instruction Manual

[0027] Figure 1 The effect of different barley flour addition amounts on the number of viable bacteria and pH after starter fermentation;

[0028] Figure 2 The effect of different cornmeal addition amounts on the number of live bacteria and pH after starter fermentation;

[0029] Figure 3The effect of different amounts of Daqu added on the number of live bacteria and pH after starter fermentation;

[0030] Figure 4 The effect of different soybean powder addition amounts on the number of viable bacteria and pH after starter fermentation;

[0031] Figure 5 The interactive effect of cornmeal and barley flour addition on pH;

[0032] Figure 6 The interactive effect of cornmeal and soybean flour addition on pH;

[0033] Figure 7 The interactive effect of the amount of barley flour and soybean flour added on pH;

[0034] Figure 8 The interactive effect of corn flour and soybean flour addition on the viable bacterial count;

[0035] Fig. 9 The interactive effect of the amount of barley flour and soybean flour added on the number of viable bacteria;

[0036] Fig.10 The interactive effect of corn flour and barley flour addition on viable bacterial count;

[0037] Fig.11 The effect of different fermentation time on the number of live bacteria and pH in the starter;

[0038] Fig.12 For the actual molding and drying process of the starter preparation;

[0039] Fig.13 Analyze the microbial composition of the old starter microbial metagenomics;

[0040] Fig.14 To predict the functional genes of microorganisms in starter;

[0041] Fig.15 Comparison of volatile flavor compounds between steamed buns fermented with old yeast and steamed buns fermented with Angel yeast. DETAILED DESCRIPTION

[0042] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0043] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0044] In the following embodiments, the old starter comes from the starter used in the traditional production of New Year's steamed buns in Huozhou, and is mainly composed of yeast and lactic acid bacteria, and the bacteria are in a dormant state.

[0045] Example 1: A method for preparing a traditional sourdough starter

[0046] The old starter for preparing traditional fermented sourdough includes the following components by weight:

[0047] Original starter: 2.44g; culture medium 48.8g, water 48.8g.

[0048] The culture medium is prepared from the following raw materials in proportion by mass: 10% barley flour, 15% corn flour, 55% wheat flour, 15% soybean flour and 5% Daqu.

[0049] The method for preparing the traditional sourdough starter comprises the following steps:

[0050] (1) Grind and sieve each culture medium:

[0051] Crush the barley, soybeans, corn and wheat separately and then pass through 80 mesh.

[0052] (2) Weigh and mix the various ingredients, then add water and stir into a paste:

[0053] Weigh and mix 10% barley flour, 15% cornmeal, 55% wheat flour, 15% soybean flour and 5% Daqu to obtain 48.8 g of culture medium, measure 48.8 parts of sterilized water, and then mix and stir thoroughly until it becomes a uniform paste.

[0054] (3) Add the original old starter under relatively sterile conditions:

[0055] Grind 2.44 portions of old starter under sterile conditions, then add to the above culture medium and stir evenly.

[0056] (4) Cultivate and dry at appropriate temperature and humidity

[0057] The culture was carried out at 37°C and RH85-90 until the fermentation was completed, and then the culture was dried in the shade at 25°C for 36 hours.

[0058] Example 2: A method for preparing a traditional sourdough starter

[0059] The old starter for preparing traditional fermented sourdough includes the following components by weight:

[0060] Original starter: 0.8g; culture medium 22g (10% barley flour, 15% cornmeal, 55% wheat flour, 15% soybean flour, 5% Daqu), water 22g.

[0061] The method for preparing the traditional sourdough starter comprises the following steps:

[0062] (1) Grind and sieve each culture medium:

[0063] Crush the barley, soybeans, corn and wheat separately and then pass through 80 mesh.

[0064] (2) Weigh and mix the various ingredients, then add water and stir into a paste:

[0065] Weigh 22 portions of barley flour 10%, cornmeal 15%, wheat flour 55%, soybean flour 15%, and Daqu 5%, measure 22 g of sterilized water, and then mix and stir thoroughly until it becomes a uniform paste.

[0066] (3) Add the original old starter under relatively sterile conditions:

[0067] Grind 0.8% of the old starter under sterile conditions, then add it to the above culture medium and stir evenly.

[0068] (4) Cultivate and dry at appropriate temperature and humidity

[0069] The culture was carried out at 37°C and RH85-90 until the fermentation was completed, and then the mixture was shade-dried at 25°C for 48 hours.

[0070] Example 3: A method for preparing a traditional sourdough starter

[0071] The old starter for preparing traditional fermented sourdough includes the following components by weight:

[0072] Original starter: 1.2g; culture medium 18g (10% barley flour, 15% cornmeal, 55% wheat flour, 15% soybean flour, 5% Daqu), water 18g.

[0073] The method for preparing the traditional sourdough starter comprises the following steps:

[0074] (1) Grind and sieve each culture medium:

[0075] Crush the barley, soybeans, corn and wheat separately and then pass through 80 mesh.

[0076] (2) Weigh and mix the various ingredients, then add water and stir into a paste:

[0077] Weigh 18 portions of barley flour 10%, cornmeal 15%, wheat flour 55%, soybean flour 15%, and Daqu 5%, measure 18 g of sterilized water, and then mix and stir thoroughly until it becomes a uniform paste.

[0078] (3) Add the original old starter under relatively sterile conditions:

[0079] Grind 1.2 portions of old starter under sterile conditions, then add to the above culture medium and stir evenly.

[0080] (4) Cultivate and dry at appropriate temperature and humidity

[0081] The culture was carried out at 37°C and RH85-90 until the fermentation was completed, and then the mixture was shade-dried at 25°C for 40 hours.

[0082] From the above results, it can be seen that the method for preparing the old starter of traditional fermented sourdough of the present invention can produce the old starter

[0083] The number of live bacteria is high and the microbial composition is rich, so the fermented dough has stable performance. The fermented New Year's steamed bun has a strong aroma and good texture. Compared with the New Year's steamed bun fermented by Angel yeast, it has better wheat flavor and chewiness.

[0084] The present invention may also be derived into many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding adjustments based on the present invention, but these corresponding adjustments should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a traditional sourdough starter, using the following components in the following mass ratios: 0.8-1.2 parts of original starter, 18-22 parts of culture medium, 18-22 parts of water, The original leaven mentioned here is the old leaven used for fermenting local steamed bread or New Year's bread. The culture medium is made of the following raw materials: 10% barley flour, 15% corn flour, 55% wheat flour, 15% soybean flour, 5% Daqu, The water is sterile water that is boiled and then cooled. First, the old starter is expanded and cultured. The preparation steps are as follows: first, the culture components are crushed and sieved according to the ingredient requirements, then weighed according to the ingredient requirements, and then the required water is added and fully stirred, and then the original starter is added to the above mixed components under sterile conditions and stirred evenly. The culture is carried out at 37°C and RH 85-90, and the culture is terminated after 24-30 hours. The fermented starter is then dried under constant temperature conditions.

2. The method for preparing the old starter of the traditional fermented sourdough according to claim 1, characterized in that The following mass proportions of components were used: 1 part original starter, 20 parts culture medium, 20 parts water, The original leaven mentioned here is the old leaven used for fermenting local steamed bread or New Year's bread. The culture medium is made of the following raw materials: 10% barley flour, 15% corn flour, 55% wheat flour, 15% soybean flour, 5% Daqu, The water is sterile water that is boiled and then cooled. First, the old starter is expanded and cultured. The preparation steps are as follows: first, the culture components are crushed and sieved according to the ingredient requirements, then weighed according to the ingredient requirements, and then the required water is added and fully stirred, and then the original starter is added to the above mixed components under sterile conditions and stirred evenly. The culture is carried out at 37°C and RH 85-90, and the culture is terminated after 24 hours. The fermented starter is then dried at a constant temperature of 25-30°C for 36-48 hours.

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