Fresh-keeping noodles and preparation process thereof

Abstract

The invention belongs to the technical field of food processing, and particularly relates to fresh-keeping noodles and a preparation technology thereof.The preparation technology of the fresh-keeping noodles comprises the following preparation steps that 1, dough kneading and fermentation are conducted, and primary fermented dough is obtained; (2) yeast activation: kneading the primary fermented dough until the surface is smooth, adding activated yeast, and performing secondary fermentation to obtain secondary fermented dough; and (3) the secondary fermented dough is subjected to rolling, strip making, quantitative cutting and noodle cooking, dipping is carried out, metering and packaging are carried out, the fresh-keeping noodles are obtained, and a fresh-keeping solution adopted for dipping comprises lactic acid, alcohol and water. Alcohol plays a role in sterilization, inhibits the noodles from absorbing too much water in the soaking process to cause softening of the taste and is beneficial for keeping the noodles chewy in taste, lactic acid in the fresh-keeping liquid can adjust pH and inhibit growth of microorganisms in the noodles, secondary fermentation consumes oxygen in dough, a low-oxygen environment is formed, growth of putrefying bacteria is inhibited, and the taste of the noodles is improved. The quality stability of the cooked wheaten food in the storage process is ensured, and the shelf life of the noodles is synergistically prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to fresh-keeping noodles and a preparation process thereof. Background Art

[0002] Noodles are traditional food in my country. With the development of the times, there are more and more types of noodle products. Among them, noodles are deeply loved by consumers due to their convenience. In particular, udon noodles and cart noodles are more popular than traditional noodles because of their chewy and smooth taste. However, as consumers have higher and higher requirements for fast food products, there are more and more requirements for noodles in terms of fastness, functionality, taste, etc. How to stand out is an urgent problem that manufacturers need to solve.

[0003] In the prior art, yeast is generally added to dough for fermentation, and the carbon dioxide gas produced by the yeast is used to make the dough have a variety of small holes, thereby improving its flavor.

[0004] For example, CN11333741A discloses a brewer's yeast (Saccharomyces cerevisiae) KXMR006, whose deposit number is GDMCC No.61665. The brewer's yeast KXMR006 has strong fermentation ability, good gas production performance, fast fermentation speed, low acid production, strong environmental adaptability and fast production and reproduction speed; it also discloses a starter containing the brewer's yeast KXMR006, and the use of the brewer's yeast KXMR006 or the starter in the preparation of hollow noodles. This application uses brewer's yeast to speed up the fermentation speed and shorten the fermentation time, but does not change the taste and nutrition of the noodles.

[0005] For example, CN109169765BA discloses a high-fiber bread fermentation process, comprising the following steps: S1, by weight, 300-400 parts of wheat flour, 60-80 parts of oat flour, 30-50 parts of rye flour, 10-15 parts of white sugar, 350-435 parts of water, 80-95 parts of bread improver, 25-30 parts of apple pulp, 4.6-7 parts of dry yeast and 8-15 parts of lactic acid bacteria are mixed and stirred; S2, the prepared dough is fermented at room temperature for 1-1.5 hours, and then fermented at a fermentation temperature of 6-10°C for 12-15 hours, After squeezing the dough, let it stand for 20-30 minutes; S3, mix 180-280 of wheat flour, 20-45 of oatmeal flour, 15-25 of salt, 13-20 of white sugar, 55-60 of apple pulp and 200-255 of water, and add them to the dough in step S2 for secondary stirring; S4, ferment the dough in step S3 at a fermentation temperature of 0-4°C for 2-3 hours; S5, let the dough after secondary fermentation in step S4 rise, the rising temperature is 27-45°C, the humidity is 80-85%, and the rising time is 60min-100min. This application uses lactic acid bacteria and yeast for synergistic fermentation to make the bread have a unique flavor, but the fermentation production time of this application is too long, at least two days, and cannot be applied to industrial production.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The purpose of the invention is to provide fresh noodles and a preparation process thereof. The fresh noodles provided by the invention have unique fragrance and taste, short fermentation time and long storage time of the prepared fresh noodles.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] In a first aspect, an embodiment of the present invention provides a process for preparing fresh noodles, comprising the following preparation steps:

[0010] (1) activating selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus, mixing flour, flavor additives, and the activated selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus, and performing a primary fermentation to obtain a primary fermentation dough;

[0011] (2) activating Pichia pastoris, kneading the primary fermentation dough until the surface is smooth, adding the activated Pichia pastoris, and performing secondary fermentation to obtain secondary fermentation dough;

[0012] (3) rolling the secondary fermented dough, making strips, cutting into quantitative portions, boiling the noodles, and then soaking and packaging the noodles to obtain fresh noodles.

[0013] In a preferred embodiment, in step (1), the selenium-enriched yeast is prepared by the following method:

[0014] The brewer's yeast is inoculated into a liquid culture medium, a sodium selenite mother solution is added, and the culture is followed by washing to obtain selenium-enriched yeast.

[0015] In a preferred embodiment, the liquid culture medium is a yeast extract peptone glucose medium, and the concentration of sodium selenite in the liquid culture medium is 10-30 mg / L.

[0016] In a preferred embodiment, the culture temperature is 25-35°C, and the culture time is 18-24h.

[0017] In a preferred embodiment, in step (1), the activation temperature is 25-35° C. and the activation time is 5-15 min.

[0018] In a preferred embodiment, in step (1), the mass ratio of the flour to the flavor additive is 100:(1-4).

[0019] In a preferred embodiment, in step (1), the amount of activated selenium-enriched yeast used is 1×10 9 -2×10 11 CFU, the dosage of activated Lactobacillus helveticus is 1×10 9 -2×10 11 CFU, the amount of activated Acetobacter pasteurianus is 1×10 9 -2×10 11 CFU.

[0020] In a preferred embodiment, in step (1), the temperature of the primary fermentation is 25-30°C and the time is 15-45 min.

[0021] The present invention defines selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus so that the structure of the dough itself has a qualitative leap. The present invention first uses selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus to ferment the dough once, wherein the selenium-enriched yeast can utilize the sugar in the flour for fermentation metabolism, mainly decomposes glucose and other sugars through the glycolysis pathway, and produces carbon dioxide gas and a small amount of alcohol. Carbon dioxide gas forms many tiny bubbles inside the dough, which gradually expands the dough and lays the foundation for the formation of a loose and porous structure of pasta. During the fermentation process, although the main metabolite of Lactobacillus helveticus is not gas, it can decompose some sugars, proteins and other components in the flour to produce organic acids such as lactic acid and some small molecular peptides, amino acids and other substances. The production of these substances can adjust the pH value of the dough, making it more suitable for the growth and fermentation activity of selenium-enriched yeast, indirectly helping to maintain the stability of yeast gas production, and allowing the dough to expand continuously and stably. At the same time, the small molecular substances produced by it also help to improve the physical properties of the dough such as ductility, which is beneficial for the dough to better maintain its shape and accommodate gas during the fermentation process. Moreover, Acetobacter pasteurianus is an aerobic bacterium that can utilize alcohol (produced by fermentation of selenium-enriched yeast), sugars and other substances in the dough for oxidative metabolism to produce organic acids such as acetic acid. In this process, on the one hand, its growth and metabolic activities will also consume oxygen, creating an anaerobic environment that is relatively more conducive to yeast fermentation, and promoting selenium-enriched yeast to better play its gas production role; on the other hand, the organic acids such as acetic acid produced can work together with lactic acid produced by Lactobacillus helveticus to further adjust the pH value of the dough, so that the acid-base environment of the dough reaches a more balanced state that is more conducive to the overall fermentation process, ensuring that the dough can continue to expand fully and make the internal structure of the pasta looser.

[0022] The present invention makes the nutrition of dough have qualitative improvement by compounding these three kinds of flora, and selenium-enriched yeast itself is rich in selenium, and is integrated into pasta by fermentation, so that pasta becomes a good carrier of selenium supplementation. Selenium is a trace element essential to human body, and has many health effects such as anti-oxidation, enhancing immunity, preventing cardiovascular disease, etc., so that the pasta after fermentation can also supplement important nutrients while meeting people's dietary needs. As a kind of probiotic, Lactobacillus helveticus survives in dough during fermentation, and even after subsequent cooking processing (such as steaming, baking, etc.), some probiotics and their beneficial metabolites are still retained. After people eat these pasta, these probiotics can regulate the balance of human intestinal flora, promote intestinal health, enhance digestive function, and play a positive health care role to the digestive system of human body. The advantages of Acetobacter pasteurianum are: the acetic acid and other organic acids produced by its fermentation and some other active substances that may be involved in the metabolic process, which to a certain extent help the human body to digest and absorb the nutrients in food, such as promoting the dissolution and absorption of minerals, etc., and acetic acid itself has certain antibacterial and bactericidal effects, and can also play a certain role in pasta storage, etc., indirectly ensuring the nutritional safety of food.

[0023] The three kinds of composite flora of the present invention form the unique local flavor of dough, a small amount of alcohol produced in the selenium-enriched yeast fermentation process and some volatile substances (such as esters etc.) with special fragrance formed in its own metabolic process can give the unique fermentation fragrance of wheaten food, make wheaten food smell with strong yeast fragrance, improve its flavor quality, lactobacillus helveticus can bring light sour taste to wheaten food because it produces organic acids such as lactic acid, and this sour taste is not abrupt, but is mutually integrated with other flavor substances, so that the local flavor of wheaten food is more abundant, has a sense of hierarchy. And the small molecule peptides and amino acids etc. produced by the metabolism of lactobacillus helveticus, they themselves also have different flavor characteristics, further enrich the overall local flavor of wheaten food, such as having some similar milk fragrance, fresh taste and other sensations. The acetic acid produced by Acetobacter pasteurianus can give wheaten food obvious vinegar-flavored local flavor, and this vinegar-flavored fermentation fragrance produced by yeast in the front, the sour fragrance brought by lactobacillus etc. are interwoven and coordinated. When the three work together, they can create a complex and unique flavor combination, giving the fermented pasta a unique taste and taste experience, which is different from the simple flavor produced by fermentation of a single strain of bacteria.

[0024] Therefore, the present invention can significantly improve the properties such as the texture, flavor, and nutritional value of the dough during one fermentation.

[0025] In a preferred embodiment, in step (1), the preparation method of the flavor additive is as follows:

[0026] The yerba mate leaves are soaked in 80-100°C water for 30-60 seconds, and then dried and ground to obtain a flavor additive.

[0027] In a preferred embodiment, the particle size of the flavor additive is 100-300 μm.

[0028] The present invention adds yerba mate tea leaves as a flavor additive to the dough, so that the fermentation speed of the dough is faster and the nutritional value is higher. The yerba mate tea leaves contain certain polyphenols, which have antioxidant properties and can regulate the redox potential inside the dough to a certain extent, creating a more favorable environment for the fermentation of the above-mentioned bacteria, helping the bacteria to better perform fermentation activities, accelerating the fermentation speed of the bacteria, and making the dough ferment more fully. In addition, the crude fiber and other components in the yerba mate tea leaves can increase the toughness and ductility of the dough, making it less likely for the dough to crack during the fermentation process, and helping to maintain the shape and texture of the dough. The structural integrity of the dough makes the fermented pasta have a better appearance and taste. The polyphenols in yerba mate tea itself have a unique flavor and aroma. During the dough fermentation process, the flavor substances it contains will be integrated into the dough, adding a different flavor to the fermented pasta and making the pasta have a richer taste level. Furthermore, yerba mate is rich in nutrients such as carbohydrates, proteins, fats, vitamins, minerals and amino acids. Adding yerba mate during dough fermentation can allow these nutrients to be integrated into the pasta, thereby increasing the nutritional value of the pasta and allowing people to ingest more beneficial ingredients while eating pasta.

[0029] In a preferred embodiment, in step (2), the activation temperature is 25-35° C. and the activation time is 5-15 min.

[0030] In a preferred embodiment, in step (2), the temperature of the secondary fermentation is 15-25° C., and the fermentation time is 4-8 h.

[0031] In a preferred embodiment, in step (2), the amount of activated Pichia pastoris used is 1×10 9 -2×10 11 CFU.

[0032] On the basis of the above technical scheme, the present invention limits the temperature of secondary fermentation to 5 to 15 degrees. At this time, selenium-enriched yeast, Lactobacillus helveticus and Acetobacter pasteurianus stop fermentation due to low temperature, so no excessive lactic acid or acetic acid will be produced to cause the taste of dough to be sour, and the present invention uses Pichia pastoris for secondary fermentation. In a low temperature environment, the growth and metabolic rate of Pichia pastoris slow down. They have more time to carry out various biochemical reactions in detail, producing flavor metabolites with richer types and more suitable content, rather than fermenting quickly and relatively extensively at high temperatures, only producing more conventional and large quantities of single main metabolites, and Pichia pastoris will produce volatile compounds such as alcohols and esters when fermenting at low temperatures. These substances give the dough a unique fermentation aroma, so that the prepared pasta has a strong aroma, can stimulate people's sense of smell and taste, increase appetite, thereby further enhancing the aroma of the dough, and the aroma of alcohols, esters, etc. is further mixed with the phenolic aroma of mate tea to form a unique aroma. In addition, due to the slow fermentation speed at low temperature, mate tea leaves further increase the fermentation speed of Pichia pastoris as mentioned above.

[0033] In a preferred embodiment, in step (3), the fresh-keeping solution used for immersion comprises: by mass, 1%-2% lactic acid, 10%-20% alcohol, and the balance is water.

[0034] In a preferred embodiment, in step (3), the immersion temperature is 20-30° C., and the immersion time is 40-60 seconds.

[0035] In the present invention, the alcohol in the fresh-keeping liquid not only has a sterilizing effect, but also can inhibit the noodles from absorbing too much water during the soaking process, resulting in a softened taste, which is beneficial to maintaining the chewy taste of the noodles. In addition, the lactic acid in the fresh-keeping liquid can adjust the pH value, inhibiting the growth of microorganisms in the noodles. In addition, the secondary fermented Pichia yeast consumes oxygen in the dough at the initial stage of fermentation, forming a low-oxygen environment, which also helps to inhibit the growth of aerobic spoilage bacteria, further ensuring the quality stability of the pasta during the storage process, reducing the possibility of deterioration, and synergistically improving the shelf life of the noodles.

[0036] In a second aspect, an embodiment of the present invention provides fresh-keeping noodles obtained by the above-mentioned preparation process of fresh-keeping noodles.

[0037] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0038] 1. The present invention defines selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus to make the dough structure have a qualitative leap. The present invention first uses selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus to ferment the dough once, wherein the selenium-enriched yeast can use the sugar in the flour for fermentation metabolism, mainly decomposing glucose and other sugars through the glycolysis pathway to produce carbon dioxide gas and a small amount of alcohol. Carbon dioxide gas will form many tiny bubbles inside the dough, causing the dough to gradually expand, laying the foundation for the formation of a loose and porous structure of pasta. During the fermentation process, although the main metabolite of Lactobacillus helveticus is not gas, it can decompose some sugars, proteins and other components in the flour to produce organic acids such as lactic acid and some small molecular peptides, amino acids and other substances. The production of these substances can adjust the pH value of the dough, making it more suitable for the growth and fermentation activity of selenium-enriched yeast, indirectly helping to maintain the stability of yeast gas production, and allowing the dough to expand continuously and stably. At the same time, the small molecular substances produced by it also help to improve the physical properties of the dough such as ductility, which is beneficial for the dough to better maintain its shape and accommodate gas during the fermentation process. Moreover, Acetobacter pasteurianus is an aerobic bacterium that can utilize alcohol (produced by fermentation of selenium-enriched yeast), sugars and other substances in the dough for oxidative metabolism to produce organic acids such as acetic acid. In this process, on the one hand, its growth and metabolic activities will also consume oxygen, creating an anaerobic environment that is relatively more conducive to yeast fermentation, and promoting selenium-enriched yeast to better play its gas production role; on the other hand, the organic acids such as acetic acid produced can work together with lactic acid produced by Lactobacillus helveticus to further adjust the pH value of the dough, so that the acid-base environment of the dough reaches a more balanced state that is more conducive to the overall fermentation process, ensuring that the dough can continue to expand fully and make the internal structure of the pasta looser.

[0039] The present invention makes the nutrition of dough have qualitative improvement by compounding these three kinds of flora, and selenium-enriched yeast itself is rich in selenium, and is integrated into pasta by fermentation, so that pasta becomes a good carrier of selenium supplementation. Selenium is a trace element essential to human body, and has many health effects such as anti-oxidation, enhancing immunity, preventing cardiovascular disease, etc., so that the pasta after fermentation can also supplement important nutrients while meeting people's dietary needs. As a kind of probiotic, Lactobacillus helveticus survives in dough during fermentation, and even after subsequent cooking processing (such as steaming, baking, etc.), some probiotics and their beneficial metabolites are still retained. After people eat these pasta, these probiotics can regulate the balance of human intestinal flora, promote intestinal health, enhance digestive function, and play a positive health care role to the digestive system of human body. The advantages of Acetobacter pasteurianum are: the acetic acid and other organic acids produced by its fermentation and some other active substances that may be involved in the metabolic process, which to a certain extent help the human body to digest and absorb the nutrients in food, such as promoting the dissolution and absorption of minerals, etc., and acetic acid itself has certain antibacterial and bactericidal effects, and can also play a certain role in pasta storage, etc., indirectly ensuring the nutritional safety of food.

[0040] The three kinds of composite flora of the present invention form the unique local flavor of dough, a small amount of alcohol produced in the selenium-enriched yeast fermentation process and some volatile substances (such as esters etc.) with special fragrance formed in its own metabolic process can give the unique fermentation fragrance of wheaten food, make wheaten food smell with strong yeast fragrance, improve its flavor quality, lactobacillus helveticus can bring light sour taste to wheaten food because it produces organic acids such as lactic acid, and this sour taste is not abrupt, but is mutually integrated with other flavor substances, so that the local flavor of wheaten food is more abundant, has a sense of hierarchy. And the small molecule peptides and amino acids etc. produced by the metabolism of lactobacillus helveticus, they themselves also have different flavor characteristics, further enrich the overall local flavor of wheaten food, such as having some similar milk fragrance, fresh taste and other sensations. The acetic acid produced by Acetobacter pasteurianus can give wheaten food obvious vinegar-flavored local flavor, and this vinegar-flavored fermentation fragrance produced by yeast in the front, the sour fragrance brought by lactobacillus etc. are interwoven and coordinated. When the three work together, they can create a complex and unique flavor combination, giving the fermented pasta a unique taste and taste experience, which is different from the simple flavor produced by fermentation of a single strain of bacteria.

[0041] 2. The present invention adds yerba mate tea leaves as a flavor additive to the dough, so that the dough fermentation speed is faster and the nutritional value is higher. The yerba mate tea leaves contain certain polyphenols, which have antioxidant properties and can regulate the redox potential inside the dough to a certain extent, creating a more favorable environment for the fermentation of the above-mentioned bacteria, helping the bacteria to better ferment, accelerating the fermentation speed of the bacteria, and making the dough ferment more fully. In addition, the crude fiber and other components in the yerba mate tea leaves can increase the toughness and ductility of the dough, making the dough less likely to crack during the fermentation process, and helping to maintain the shape and Structural integrity gives the fermented pasta a better appearance and taste. The polyphenols in yerba mate tea itself have a unique flavor and aroma. During the dough fermentation process, the flavor substances it contains will be integrated into the dough, adding a different flavor to the fermented pasta and making the pasta have a richer taste level. Furthermore, yerba mate is rich in nutrients such as carbohydrates, proteins, fats, vitamins, minerals and amino acids. Adding yerba mate during dough fermentation can allow these nutrients to be integrated into the pasta, thereby increasing the nutritional value of the pasta and allowing people to ingest more beneficial ingredients while eating pasta.

[0042] 3. The present invention limits the temperature of secondary fermentation so that excessive lactic acid or acetic acid will not be produced to cause the dough to taste sour. The present invention uses Pichia for secondary fermentation. In a low temperature environment, the growth and metabolic rate of Pichia slow down. They have more time to carry out various biochemical reactions in detail, producing flavor metabolites with richer types and more suitable contents, rather than fermenting quickly and relatively extensively at high temperatures, only producing more conventional and large quantities of single main metabolites. When fermenting at low temperatures, Pichia will produce volatile compounds such as alcohols and esters, which give the dough a unique fermentation aroma, so that the prepared pasta has a strong aroma, can stimulate people's sense of smell and taste, increase appetite, and further enhance the aroma of the dough, and the aroma of alcohols, esters, etc. is further mixed with the phenolic aroma of mate tea to form a unique aroma. In addition, due to the slow fermentation speed at low temperatures, mate tea further increases the fermentation speed of Pichia as mentioned above.

[0043] 4. The alcohol in the fresh-keeping solution of the present invention not only has a sterilizing effect, but also can inhibit the noodles from absorbing too much water during the soaking process, which leads to a softening of the taste, and is beneficial to maintaining the chewy taste of the noodles. In addition, the lactic acid in the fresh-keeping solution can adjust the pH, inhibiting the growth of microorganisms in the noodles. In addition, the secondary fermented Pichia yeast itself consumes oxygen in the dough at the beginning of fermentation to form a low-oxygen environment, which also helps to inhibit the growth of aerobic spoilage bacteria, further ensuring the quality stability of pasta during storage, reducing the possibility of deterioration, and synergistically improving the shelf life of the noodles. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Unless otherwise specified, the reagents mentioned in this example are commercially available.

[0046] Saccharomyces cerevisiae, GDMCC No. 62110, purchased from Angel Yeast Co., Ltd.;

[0047] Lactobacillus helveticus, numbered GDMCC No.62536, was purchased from Shanghai Kimi Biotechnology Co., Ltd.;

[0048] Acetobacter pasteurianus, numbered GDMCC No.62536, was purchased from Shanghai Yiyan Biotechnology Co., Ltd.;

[0049] Pichia pastoris, CGMCC No. 17607, was purchased from Thermo Fisher Scientific.

[0050] Example 1

[0051] This embodiment provides a preparation process for fresh noodles, comprising the following preparation steps:

[0052] (1) inoculating brewer's yeast into a yeast extract peptone glucose medium, adding sodium selenite mother liquor so that the concentration of sodium selenite in the medium is 15 mg / L, culturing at 30° C. for 20 h, washing to obtain selenium-enriched yeast, activating selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus at a temperature of 30° C. for 10 min, mixing high-gluten flour purchased from Jinsha River, flavor additives, and activated selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus, and performing a primary fermentation at a temperature of 30° C. for 35 min to obtain a primary fermentation dough;

[0053] The mass ratio of flour to flavor additives is 100:2, and the amount of activated selenium-enriched yeast is 1.9×10 10 CFU, the amount of activated Lactobacillus helveticus is 2.3×10 10 CFU, the amount of activated Acetobacter pasteurianus is 1.2×10 9 CFU;

[0054] The preparation method of the flavor additive is as follows:

[0055] The yerba mate leaves are soaked in 95° C. water for 60 seconds, and then the yerba mate leaves are taken out, dried, ground and sieved to a particle size of less than 200 μm to obtain a flavor additive.

[0056] (2) Activate Pichia pastoris at a temperature of 30°C for 10 min. Then, knead the primary fermented dough until the surface is smooth, add the activated Pichia pastoris, and the amount of activated Pichia pastoris is 1.8×10 11 CFU, perform secondary fermentation, the temperature of the secondary fermentation is 15°C, the fermentation time is 6h, and a secondary fermentation dough is obtained;

[0057] (3) rolling, strip-making, quantitatively cutting, boiling, and soaking the secondary fermented dough and then metering and packaging to obtain fresh noodles;

[0058] The preservative liquid used for immersion includes: by weight, 1% food-grade lactic acid, 10% food-grade alcohol, and the balance is water; the immersion temperature is 25° C., and the immersion time is 50 seconds.

[0059] Example 2

[0060] This embodiment provides a preparation process for fresh noodles, comprising the following preparation steps:

[0061] (1) inoculating brewer's yeast into a yeast extract peptone glucose medium, adding sodium selenite mother liquor so that the concentration of sodium selenite in the medium is 15 mg / L, culturing at 30° C. for 20 h, and then washing to obtain selenium-enriched yeast, activating selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus at a temperature of 30° C. for 10 min, mixing high-gluten flour purchased from Jinsha River, flavor additives, and activated selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus, and performing a primary fermentation at a temperature of 30° C. for 35 min to obtain a primary fermentation dough;

[0062] The mass ratio of flour to flavor additives is 100:3, and the amount of activated selenium-enriched yeast is 1.8×10 10 CFU, the amount of activated Lactobacillus helveticus is 2.3×10 10 CFU, the amount of activated Acetobacter pasteurianus is 1.1×10 9 CFU;

[0063] The preparation method of the flavor additive is as follows:

[0064] The yerba mate leaves are soaked in 95° C. water for 60 seconds, and then the yerba mate leaves are taken out, dried, ground and sieved to a particle size of less than 200 μm to obtain a flavor additive.

[0065] (2) Activate Pichia pastoris at a temperature of 30°C for 10 min. Then, knead the primary fermented dough until the surface is smooth, add the activated Pichia pastoris, and the amount of activated Pichia pastoris is 1.9×10 11 CFU, perform secondary fermentation, the temperature of the secondary fermentation is 15°C, the fermentation time is 6h, and a secondary fermentation dough is obtained;

[0066] (3) rolling, strip-making, quantitatively cutting, boiling, and soaking the secondary fermented dough and then metering and packaging to obtain fresh noodles;

[0067] The preservative liquid used for immersion includes: by weight, 1% food-grade lactic acid, 10% food-grade alcohol, and the balance is water; the immersion temperature is 25° C., and the immersion time is 50 seconds.

[0068] Comparative Example 1

[0069] Compared with Example 1, the only difference is that, in addition to not adding selenium-enriched yeast, the amount of Lactobacillus helveticus used per 100g of flour is 3.25×10 10 CFU, the dosage of Acetobacter pasteurianus is 1.07×10 10 CFU.

[0070] Comparative Example 2

[0071] Compared with Example 1, the only difference is that, in addition to not adding Lactobacillus helveticus, the amount of selenium-enriched yeast used per 100g flour is 3.05×10 10 CFU, the dosage of Acetobacter pasteurianus is 1.27×10 10 CFU.

[0072] Comparative Example 3

[0073] Compared with Example 1, the only difference is that, in addition to not adding Acetobacter pasteurianus, the amount of selenium-enriched yeast used per 100g flour is 1.96×10 10 CFU, the dosage of Lactobacillus helveticus is 2.36×10 10 CFU.

[0074] Comparative Example 4

[0075] Compared with Example 1, the only difference is that no secondary fermentation is performed and the time of the primary fermentation is changed to 6 hours.

[0076] Comparative Example 5

[0077] Compared with Example 1, the only difference is that no flavor additive is added.

[0078] Comparative Example 6

[0079] Compared with Example 1, the only difference is that the fresh-keeping liquid in step (3) is replaced by an equal amount of water.

[0080] Performance Testing

[0081] Taking health, reliability, and concern for the test into consideration, 50 people were selected and trained on the purpose of the test and the evaluation method. The noodles made in the embodiment of the present invention and the comparative example 6 were cooked in turn, and then a sensory test was performed. The order of the tasting was to write down the evaluation of the sample after eating the first sample, then rinse the mouth with water and try the next sample for evaluation.

[0082] The sensory test here is to evaluate the five factors of overall preference, flavor, taste, chewiness and chewiness of each embodiment and comparative example using a 5-point scoring system (5 points - very good; 4 points - good; 3 points - average; 2 points - poor; 1 point - very poor). The results are shown in Table 1.

[0083] Then, the noodles prepared in Examples 1 and 2 and Comparative Examples 1 to 6 were refrigerated at 2°C. In the refrigeration test, the presence of mold represented deterioration. Each test group was tested 4 times in parallel. Then, the average deterioration time of each group was calculated, and the results are shown in Table 1.

[0084] Table 1 Performance test results

[0085]

[0086]

[0087] From the above performance test results, it can be seen that the taste, flavor, and chewiness and smoothness of Examples 1-2 are the most popular, especially the comprehensive performance of Example 2 is the most outstanding, which is mainly due to the synergistic effect between the various strains compounded in the present invention, and the primary and secondary fermentation enhances the texture and aroma of the noodles. The comparative example is significantly worse than the example in the corresponding performance test because it does not adopt the necessary technical solution, which better proves the irreplaceable nature of the specific technical solution of the present application in achieving technical effects and solving technical problems.

[0088] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A process for preparing fresh noodles, characterized in that: The method comprises the following preparation steps: (1) activating selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus, mixing flour, flavor additives, and the activated selenium-enriched yeast, Lactobacillus helveticus, and Acetobacter pasteurianus, and performing a primary fermentation to obtain a primary fermentation dough; (2) activating Pichia pastoris, kneading the primary fermentation dough until the surface is smooth, adding the activated Pichia pastoris, and performing secondary fermentation to obtain secondary fermentation dough; (3) rolling the secondary fermented dough, making strips, cutting into quantitative portions, boiling the noodles, and then soaking and packaging the noodles to obtain fresh noodles.

2. The process for preparing fresh noodles according to claim 1, characterized in that: In step (1), the selenium-enriched yeast is prepared by the following method: The brewer's yeast is inoculated into a liquid culture medium, a sodium selenite mother solution is added, and the culture is followed by washing to obtain selenium-enriched yeast.

3. The process for preparing fresh noodles according to claim 2, characterized in that: The liquid culture medium is a yeast extract peptone glucose medium, and the concentration of sodium selenite in the liquid culture medium is 10-30 mg / L; And / or, the culture temperature is 25-35°C, and the culture time is 18-24h.

4. The process for preparing fresh noodles according to claim 1, characterized in that: In step (1), in step (1), the activation temperature is 25-35° C. and the activation time is 5-15 min; and / or, in step (1), the mass ratio of the flour to the flavor additive is 100:(1-4); And / or, in step (1), the amount of activated selenium-enriched yeast used is 1×10 9 -2×10 11 CFU, the dosage of activated Lactobacillus helveticus is 1×10 9 -2×10 11 CFU, the amount of activated Acetobacter pasteurianus is 1×10 9 -2×10 11 CFU; And / or, in step (1), the temperature of the primary fermentation is 25-30°C and the time is 15-45 min.

5. The process for preparing fresh noodles according to claim 1, characterized in that: In step (1), the preparation method of the flavor additive is as follows: The yerba mate leaves are soaked in 80-100°C water for 30-60 seconds, and then dried and ground to obtain a flavor additive.

6. The process for preparing fresh noodles according to claim 5, characterized in that: The particle size of the flavor additive is 100-300 μm.

7. The process for preparing fresh noodles according to claim 1, characterized in that: In step (2), in step (2), the activation temperature is 25-35° C. and the activation time is 5-15 min; And / or, in step (2), the temperature of the secondary fermentation is 15-25° C., and the fermentation time is 4-8 h; And / or, in step (2), the amount of activated Pichia pastoris used is 1×10 9 -2×10 11 CFU.

8. The process for preparing fresh noodles according to claim 1, characterized in that: In step (3), the fresh-keeping liquid used for immersion comprises: by mass, 1%-2% lactic acid, 10%-20% alcohol, and the balance water.

9. The process for preparing fresh noodles according to claim 1, characterized in that: In step (3), the immersion temperature is 20-30° C., and the immersion time is 40-60 seconds.

10. Fresh noodles obtained by the preparation process of fresh noodles according to any one of claims 1 to 9.

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