A method for directional regulation of roasting flavor of mixed bacterial fermentation process

Abstract

The application discloses a kind of roasting flavor directional regulation methods of mixed bacteria fermentation process, it is related to food fermentation technical field, to solve the problems of existing technology flavor regulation difficulty, flavor type is limited and poor stability, the method includes the following steps: S1, from natural fermentation baked food or traditional fermented sourdough sample, by selective medium separates different potential fermentation bacteria, flavor substance composition and content in different bacterial fermentation products are analyzed using gas chromatography-mass spectrometry technique, and the fermentation bacteria that can produce target flavor substance are screened out, and are compounded according to different volume ratio, and mixed bacteria fermentation system is constructed;S2, with wheat flour, coarse cereal powder as basic raw material, add sugar, nitrogen source, inorganic salt and vitamin to prepare fermentation medium, and the concentration of each component in the medium is optimized by single factor test and response surface test.The application has the advantages of realizing the accurate design and control of flavor.

Description

Technical Field

[0001] This invention relates to the field of food fermentation technology, and more specifically, to a method for targeted regulation of baking flavor in a mixed-culture fermentation process. Background Technology

[0002] As a widely consumed food type globally, the flavor of baked goods is one of the key factors influencing consumer acceptance.

[0003] Consumers' demands for the flavor of baked goods are becoming increasingly diversified. They not only pursue the traditional wheat and milk aromas, but also expect to obtain a richer flavor experience with fruity and complex aromas.

[0004] However, in traditional baking processes, flavor formation often relies on changes in the components of the raw materials and simple fermentation with a single microbial strain. This approach suffers from difficulties in flavor control, limited flavor types, and poor stability, making it difficult to accurately meet the market's demand for diverse and personalized flavors. Therefore, we propose a method for targeted flavor control in baking using a mixed-strain fermentation process. Summary of the Invention

[0005] The purpose of this invention is to provide a method for targeted regulation of baking flavor in a mixed-culture fermentation process, aiming to solve the problems of high difficulty in flavor regulation, limited flavor types, and poor stability in existing technologies.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for directional regulation of baking flavor in a mixed-culture fermentation process, the method comprising the following steps:

[0007] S1. Different potential fermentation strains are isolated from naturally fermented baked goods or traditionally fermented sourdough samples using selective culture media. The flavor components and contents in the fermentation products of different strains are analyzed using gas chromatography-mass spectrometry. Fermentation strains that can produce target flavor substances are screened out and mixed with different volume ratios to construct a mixed fermentation system.

[0008] S2. Fermentation culture medium was prepared using wheat flour and miscellaneous grain flour as the base raw materials, with the addition of sugars, nitrogen sources, inorganic salts and vitamins. The concentration of each component in the culture medium was optimized through single-factor experiments and response surface experiments.

[0009] S3. Then, inoculate the prepared mixed bacteria into the optimized fermentation medium at an inoculum volume of 3%-5%. Control the fermentation temperature at 28-32℃, the initial pH value at 5.5-6.5, and determine the fermentation time according to the baked product and target flavor.

[0010] The optimal fermentation endpoint was determined by regularly monitoring the acidity, sugar consumption, microbial growth, and flavor substance content in the fermentation system.

[0011] S4. Then, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry is used to perform qualitative and quantitative analysis of volatile flavor substances in fermented baked products, establish a flavor substance database, compare the detection results with the target flavor characteristics, and adjust the ratio of strains in the mixed system, the composition of the fermentation medium and the fermentation conditions according to the comparison results, and carry out the next round of fermentation experiments until baked products that meet the target flavor requirements are obtained.

[0012] Preferably, in step S1 above, the target flavor substance includes substances among esters, alcohols, and aldehydes that have fruity, milky, or wheat flavor characteristics.

[0013] Preferably, in step S2 above, the ratio of wheat flour to miscellaneous grain flour is 6:4-8:2, the sugar is glucose or sucrose with a concentration of 4-6 g / L, the nitrogen source is yeast powder or peptone with a concentration of 2-4 g / L, and the inorganic salts include potassium dihydrogen phosphate with a concentration of 0.4-0.6 g / L and magnesium sulfate with a concentration of 0.1-0.3 g / L.

[0014] Preferably, in step S3 above, during the process of determining the optimal fermentation endpoint, the optimal fermentation endpoint is determined to be reached when the acidity in the fermentation system reaches 30-50°T, the remaining sugar content is less than 20% of the initial amount, the microbial growth enters a stable period, and the content of the target flavor substances no longer increases significantly.

[0015] Preferably, in step S1 above, after constructing the mixed-culture fermentation system, the compound strain is pre-cultured at the same temperature as the fermentation temperature for 2-4 hours to allow the strain activity to reach its optimal state.

[0016] Preferably, in step S2 above, the culture medium also contains a natural fragrance extract at a concentration of 5-20 g / L.

[0017] Preferably, the natural spice extract is one or more of citrus peel extract, vanilla seed extract, and cinnamon bark extract, used to enhance the natural flavor profile of baked goods.

[0018] Preferably, in step S1 above, the potential fermentation strains include acetic acid bacteria, lactic acid bacteria, and yeast.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention isolates potential fermentation strains from naturally fermented baked goods or traditionally fermented sourdough samples. By analyzing the flavor components and content in their fermentation products, strains that can produce target flavor substances such as fruity, milky, or wheat aromas are screened out. Mixed fermentation systems are constructed by compounding different strains in different volume ratios. By utilizing the synergistic effect of the metabolic characteristics of different strains, specific flavors can be produced in baked goods in a targeted manner, avoiding the limitation of a single strain having a single flavor, and achieving precise design and control of flavor.

[0021] 2. This invention uses wheat flour and mixed grain flour as base raw materials, and adds glucose or sucrose, yeast powder or peptone, as well as potassium dihydrogen phosphate, magnesium sulfate, etc. It can also add natural flavor extracts such as citrus peel extract and vanilla seed extract. The concentration of each component in the culture medium is optimized through single-factor experiments and response surface experiments to provide a suitable nutritional environment for mixed fermentation, promote the growth, reproduction and metabolic activities of microorganisms, improve sugar utilization, lay a good nutritional foundation for the generation of flavor substances, and enrich the nutritional components and taste of the product.

[0022] 3. In this invention, the prepared mixed bacteria are inoculated into the optimized fermentation medium at an inoculation rate of 3%-5% of the medium volume. The fermentation temperature and initial pH value are controlled. The fermentation time is determined according to the baked product and the target flavor. The acidity, sugar consumption, microbial growth, and flavor substance content in the fermentation system are monitored regularly. When the acidity in the fermentation system reaches 30-50°T, the remaining sugar is less than 20% of the initial amount, the microbial growth enters a stable period, and the content of the target flavor substance no longer increases significantly, the optimal fermentation endpoint is determined to have been reached. This ensures that the fermentation process is carried out under the best conditions, avoids over-fermentation or under-fermentation, stabilizes the production of flavor substances, and ensures the consistency and controllability of the flavor of the baked product. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the method of the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0025] Example 1

[0026] A method for targeted regulation of baking flavor in a mixed-culture fermentation process, comprising the following steps:

[0027] S1. Different potential fermentation strains are isolated from naturally fermented baked goods or traditionally fermented sourdough samples using selective culture media. The flavor components and contents in the fermentation products of different strains are analyzed using gas chromatography-mass spectrometry (GC-MS). Fermentation strains that can produce target flavor substances are screened out and mixed with different volume ratios to construct a mixed fermentation system. The purity of the target strains is ensured by isolating the strains using selective culture media. The flavor components are accurately analyzed using GC-MS. After the screened strains are mixed, the synergistic effect between the strains is utilized to produce richer flavor substances, laying the foundation for targeted flavor regulation.

[0028] S2. Using wheat flour and miscellaneous grain flour as the base raw materials, sugars, nitrogen sources, inorganic salts and vitamins are added to prepare a fermentation medium. The concentration of each component in the medium is optimized through single-factor experiments and response surface experiments. The composition of the medium is optimized through single-factor experiments and response surface experiments to ensure that the nutrient ratio can meet the requirements of mixed culture fermentation, promote microbial growth and flavor substance synthesis, and provide a suitable nutritional environment for the fermentation process.

[0029] S3. Then, inoculate the prepared mixed bacteria into the optimized fermentation medium at an inoculum volume of 3%-5%. Control the fermentation temperature at 28-32℃, the initial pH value at 5.5-6.5, and determine the fermentation time according to the baked product and target flavor.

[0030] By regularly testing the acidity, sugar consumption, microbial growth, and flavor substance content in the fermentation system, the optimal fermentation endpoint can be determined. This allows for precise control of the inoculum amount, temperature, and pH value to maintain optimal microbial activity. Regular testing of multiple indicators enables dynamic monitoring of the fermentation process, ensuring that fermentation is terminated when flavor substance accumulation reaches its peak, thus avoiding over-fermentation that could lead to flavor degradation.

[0031] S4. Then, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry is used to perform qualitative and quantitative analysis of volatile flavor compounds in fermented baked products, establish a flavor compound database, compare the detection results with the target flavor characteristics, and adjust the ratio of strains in the mixed culture system, the composition of the fermentation medium, and the fermentation conditions according to the comparison results, and conduct the next round of fermentation experiments until a baked product that meets the target flavor requirements is obtained. This comprehensive analysis of volatile flavor compounds and the establishment of the database provide data support for flavor regulation. Through comparison and iterative optimization, process parameters are precisely adjusted to achieve targeted regulation of baked flavor and ensure that the final product meets the target flavor requirements.

[0032] Furthermore, in step S1 above, the target flavor substances include substances among esters, alcohols, and aldehydes that have fruity, milky, or wheat flavor characteristics, in order to clarify the category and characteristics of the target flavor substances, making the strain screening and compounding more targeted, ensuring that the mixed fermentation system can directionally produce the desired flavor, and improving the flavor specificity and consistency of baked products.

[0033] Furthermore, in step S2 above, the ratio of wheat flour to mixed grain flour is 6:4-8:2, the sugar is glucose or sucrose at a concentration of 4-6 g / L, the nitrogen source is yeast powder or peptone at a concentration of 2-4 g / L, and the inorganic salts include potassium dihydrogen phosphate at a concentration of 0.4-0.6 g / L and magnesium sulfate at a concentration of 0.1-0.3 g / L, to ensure the nutritional balance of the culture medium and to increase the flavor complexity through the mixed grain flour. The concentrations of sugar and nitrogen source are set to meet the energy and nitrogen requirements for microbial growth, while the inorganic salts maintain the osmotic pressure and acid-base balance of the culture medium and promote microbial metabolism and flavor substance synthesis.

[0034] Furthermore, in step S3 above, during the process of determining the optimal fermentation endpoint, when the acidity in the fermentation system reaches 30-50°T, the remaining sugar content is less than 20% of the initial amount, the microbial growth enters a stable period, and the content of the target flavor substances no longer increases significantly, the optimal fermentation endpoint is determined. The fermentation endpoint is accurately determined by a comprehensive assessment of multiple indicators. Acidity and sugar consumption reflect the degree of microbial metabolism, while the stable period of microbial growth and the plateau period of flavor substances indicate that the fermentation system has reached the peak of flavor substance accumulation. At this point, terminating the fermentation can yield a product with better flavor.

[0035] Furthermore, in step S1 above, after constructing the mixed-culture fermentation system, the compound strains are pre-cultured at the same temperature as the fermentation temperature for 2-4 hours to allow the strains to reach their optimal activity. This pre-culture allows the strains to adapt to the fermentation environment in advance, activates their activity, shortens the lag period during fermentation, and ensures that the strains can quickly enter the logarithmic growth phase after inoculation, thereby improving fermentation efficiency and the rate of flavor substance synthesis.

[0036] Furthermore, in step S2 above, a natural spice extract with a concentration of 5-20 g / L is added to the culture medium. The natural spice extract directly provides additional flavor components to the baked product, which work synergistically with the flavor substances produced by microbial fermentation to enhance the layering and richness of the flavor, thereby improving the flavor quality and uniqueness of the product.

[0037] Furthermore, the natural flavor extracts are one or more of citrus peel extract, vanilla seed extract, and cinnamon bark extract, used to enhance the natural flavor profile of baked goods. Single or compound extracts can be selected according to the target flavor requirements to precisely control the flavor direction of baked goods and increase the naturalness and diversity of the flavor.

[0038] Furthermore, in step S1 above, the potential fermentation strains include acetic acid bacteria, lactic acid bacteria, and yeast.

[0039] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A method for targeted regulation of baking flavor in a mixed-culture fermentation process, characterized in that, The method includes the following steps: S1. Different potential fermentation strains are isolated from naturally fermented baked goods or traditionally fermented sourdough samples using selective culture media. The flavor components and contents in the fermentation products of different strains are analyzed using gas chromatography-mass spectrometry. Fermentation strains that can produce target flavor substances are screened out and mixed with different volume ratios to construct a mixed fermentation system. S2. Fermentation culture medium was prepared using wheat flour and miscellaneous grain flour as the base raw materials, with the addition of sugars, nitrogen sources, inorganic salts and vitamins. The concentration of each component in the culture medium was optimized through single-factor experiments and response surface experiments. S3. Then, the prepared mixed bacteria are inoculated into the optimized fermentation medium at an inoculation rate of 3%-5% of the culture medium volume. The fermentation temperature is controlled at 28-32℃, the initial pH value is 5.5-6.5, the fermentation time is determined according to the baking product and the target flavor, and the optimal fermentation endpoint is determined by regularly testing the acidity, sugar consumption, microbial growth and flavor substance content in the fermentation system. S4. Then, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry is used to perform qualitative and quantitative analysis of volatile flavor substances in fermented baked products, establish a flavor substance database, compare the detection results with the target flavor characteristics, and adjust the ratio of strains in the mixed system, the composition of the fermentation medium and the fermentation conditions according to the comparison results, and carry out the next round of fermentation experiments until baked products that meet the target flavor requirements are obtained.

2. The method for targeted regulation of baking flavor in a mixed-culture fermentation process according to claim 1, characterized in that, In step S1 above, the target flavor substance includes substances among esters, alcohols, and aldehydes that have fruity, milky, or wheat flavor characteristics.

3. The method for directional control of baking flavor in a mixed-culture fermentation process according to claim 1, characterized in that, In step S2 above, the ratio of wheat flour to mixed grain flour is 6:4-8:2, the sugar is glucose or sucrose with a concentration of 4-6 g / L, the nitrogen source is yeast powder or peptone with a concentration of 2-4 g / L, and the inorganic salts include potassium dihydrogen phosphate with a concentration of 0.4-0.6 g / L and magnesium sulfate with a concentration of 0.1-0.3 g / L.

4. The method for directional control of baking flavor in a mixed-culture fermentation process according to claim 1, characterized in that, In step S3 above, during the process of determining the optimal fermentation endpoint, when the acidity in the fermentation system reaches 30-50°T, the remaining sugar content is less than 20% of the initial amount, the microbial growth enters a stable period, and the content of the target flavor substances no longer increases significantly, the optimal fermentation endpoint is determined to have been reached.

5. The method for targeted regulation of baking flavor in a mixed-culture fermentation process according to claim 1, characterized in that, In step S1 above, after constructing the mixed-culture fermentation system, the compound strains are pre-cultured at the same temperature as the fermentation temperature for 2-4 hours to ensure that the strain activity reaches the optimal state.

6. The method for directional control of baking flavor in a mixed-culture fermentation process according to claim 1, characterized in that, In step S2 above, the culture medium also contains a natural fragrance extract at a concentration of 5-20 g / L.

7. The method for targeted regulation of baking flavor in a mixed-culture fermentation process according to claim 6, characterized in that, The natural spice extract is one or more of citrus peel extract, vanilla seed extract, and cinnamon bark extract, used to enhance the natural flavor profile of baked goods.

8. The method for directional control of baking flavor in a mixed-culture fermentation process according to claim 1, characterized in that, In step S1 above, the potential fermentation strains include acetic acid bacteria, lactic acid bacteria, and yeast.

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