Liquid-state fermented gastrodia elata product and preparation method thereof

Abstract

The invention discloses a liquid-state fermented gastrodia elata product and a preparation method thereof, and relates to the technical field of food microbial ferment.The preparation method of the liquid-state fermented gastrodia elata product is characterized by comprising the following steps of S1, gastrodia elata pretreatment and alcohol deodorization, specifically, fresh gastrodia elata is sliced, the surface area is increased, and deodorization is conducted through alcohol in two stages, then washing with distilled water, and then draining and sterilizing; s2, preparing a complex microbial inoculant: preparing an alcohol-resistant saccharomycetes inoculant and an eurotium cristatum inoculant; s3, optimized inoculation of a liquid culture medium: preparing the culture medium, and inoculating with an alcohol-resistant saccharomycetes agent and an eurotium cristatum agent in sequence; s4, dynamic fermentation control: controlling the temperature and dissolved oxygen in two stages, subsequently supplementing ethanol for regulation and control, and monitoring the fermentation process; according to the preparation method of the liquid-state fermented gastrodia elata product, a two-stage alcohol deodorization process is adopted, and sulfides and volatile peculiar smell substances in gastrodia elata can be more accurately removed.

Description

Technical Field

[0001] The invention relates to the technical field of food microbial fermentation, in particular to a liquid fermented gastrodia elata product and a preparation method thereof. Background Art

[0002] Gastrodia elata (Gastrodia elata Blume) is a traditional and precious Chinese medicinal herb. Its main active ingredients, including gastrodin, polysaccharides, and phenolic compounds, have sedative, anticonvulsant, and brain-improving effects. However, Gastrodia elata itself possesses a distinctive odor, often described as "earthy" or "musty." This odor may originate from its growing environment and the production of volatile compounds during the drying process. The rhizome of Gastrodia elata is particularly endowed with this unique odor, which is part of its natural properties. While this odor may be unpleasant to some, it does not affect its medicinal value. During processing, the odor of Gastrodia elata is reduced after washing and drying, but it is still unacceptable to most people. Traditional methods use a single bacterial community to ferment Gastrodia elata to dilute its distinctive odor, but this process is time-consuming and the removal of foreign matter is still insufficient for most people. Therefore, a method for preparing a liquid fermented Gastrodia elata product with significantly improved odor is provided. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the present invention provides a liquid fermented Gastrodia elata product and a preparation method thereof, which solves the problems raised in the above-mentioned background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for preparing a liquid fermented Gastrodia elata product, characterized in that it comprises the following steps: S1. Gastrodia elata pretreatment and alcohol deodorization: Fresh Gastrodia elata was sliced to increase the surface area and deodorized with alcohol in two stages. The slices were then rinsed with distilled water and then drained and sterilized. S2. Preparation of composite microbial agents: Preparation of alcohol-resistant yeast agents and Eurotium cristatum agents; S3. Optimized inoculation of liquid culture medium: Prepare the culture medium and inoculate it with the alcohol-resistant yeast inoculant first and then the Eurotium cristatum inoculant; S4. Dynamic fermentation control: Control temperature and dissolved oxygen in two stages, and then add ethanol for regulation, and then monitor the fermentation process; S5, dealcoholization: after the fermentation is completed, dealcoholization treatment is performed; S6. Fragrance enhancement: Add β-glucosidase and hydrolyze to release bound phenols.

[0005] According to the above technical solution, in S1, the first deodorization stage uses 30% ethanol (v / v) to soak for 2 hours (solid-liquid ratio 1:5) to dissolve sulfides and volatile acids, and the second deodorization stage uses 10% ethanol (v / v) to soak for 1 hour to further remove residual odor, followed by rinsing with distilled water 3 times, draining and sterilizing at 121°C for 20 minutes.

[0006] According to the above technical solution, in S2, the alcohol-resistant yeast is Saccharomyces cerevisiaeEC1118 (preservation number: CICC 33077), with an alcohol tolerance of 18% (v / v), and the Eurotium cristatum is Eurotium cristatum YAZC (preservation number: CCTCC NO: M 20231875), which is derived from the symbiotic bacteria of dark tea and has a strong aroma-producing ability.

[0007] According to the above technical solution, in S2, the alcohol-resistant yeast inoculum was cultured in YPD liquid medium (containing 2% ethanol) at 30°C for 24 hours (OD600 ≥ 2.0), and the Eurotium cristatum inoculum was cultured in PDA medium at 28°C for 5 days. The spore concentration was adjusted to 1×10 6 pieces / mL.

[0008] According to the above technical solution, in S3, the culture medium contains 10% (w / v) pretreated Gastrodia elata, 3% maltose, 1.2% yeast extract powder, 0.1% KH2PO4, and an initial ethanol concentration of 2% (v / v), the yeast inoculation amount is 8% (v / v), and the spore liquid of Eurotium cristatum is 5% (v / v).

[0009] According to the above technical solution, in S4, the temperature and dissolved oxygen in the first stage are 0-24h: 30°C, 200r / min, and high dissolved oxygen promotes yeast growth. The temperature and dissolved oxygen in the second stage are 24-72h: 28°C, 120r / min, and low dissolved oxygen induces the metabolism of Aspergillus niger. 1% ethanol (total amount ≤3%) is added in 24h, and 0.5% ethanol (total amount ≤3.5%) is added in 48h.

[0010] According to the above technical solution, in S4, sampling is performed every 12 hours, and sulfide is detected by HS-SPME-GC (target: reduction ≥90%), sampling is performed every 24 hours, and total polyphenols / flavonoids are detected by HPLC (target: polyphenols ≥5 mg / g, flavonoids ≥2.7 mg / g), and an offline alcohol meter is used for detection at the same time, and the control is ≤3.5%.

[0011] According to the above technical solution, in S5, ethanol is removed by vacuum rotary evaporation at 40°C (pressure 0.1 bar).

[0012] According to the above technical solution, in S6, 0.02% β-glucosidase is added and a hydrolysis reaction is performed (40° C., 1 h) to release bound phenols.

[0013] The present invention provides a liquid fermented Gastrodia elata product and a preparation method thereof, which has the following beneficial effects:

[0014] (1) Compared with the traditional method, this invention adopts a two-stage alcohol deodorization process, which can more accurately remove the sulfide and volatile odor substances in Gastrodia elata. At the same time, the synergistic effect of alcohol-resistant yeast and Aspergillus niger can further generate phenols and esters through metabolism to cover up the residual odor.

[0015] (2) This invention can synergistically improve the efficiency of ingredient conversion through staged temperature control and dissolved oxygen design. The precursor substances generated by yeast through glycolysis provide substrates for polyphenol oxidase and flavonoid synthase of Aspergillus niger. In addition, the addition of ethanol can maintain microbial activity, avoid the inhibitory effect of alcohol, and improve the stability of the overall fermentation process.

[0016] (3) This invention subsequently adds β-glucosidase to release bound phenols and glycosylated aroma precursors in Gastrodia elata through enzymatic hydrolysis, forming a synergistic effect with the aroma production of the composite fungus agent, thereby increasing the content of flavor substances such as the fungus flower aroma and mint aroma in the fermented Gastrodia elata, further enhancing the flavor dimension and better meeting the flavor requirements of modern functional foods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Prepare a flow chart for the present invention; Figure 2 This is a data table showing the effect of the double-stage alcohol deodorization of the present invention; Figure 3 A data table for accumulating the functional components of the composite bacterial agent fermentation of the present invention; Figure 4 This is a table of fermentation process parameters and monitoring data for the present invention in different stages. DETAILED DESCRIPTION

[0018] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0019] See also Figure 1-Figure 4 One embodiment of the present invention is: a method for preparing a liquid fermented Gastrodia elata product, characterized in that it comprises the following steps: S1. Gastrodia elata pretreatment and alcohol deodorization: Fresh Gastrodia elata was sliced to increase the surface area and deodorized with alcohol in two stages. The slices were then rinsed with distilled water and then drained and sterilized. S2. Preparation of composite microbial agents: Preparation of alcohol-resistant yeast agents and Eurotium cristatum agents; S3. Optimized inoculation of liquid culture medium: Prepare the culture medium and inoculate it with the alcohol-resistant yeast inoculant first and then the Eurotium cristatum inoculant; S4. Dynamic fermentation control: Control temperature and dissolved oxygen in two stages, and then add ethanol for regulation, and then monitor the fermentation process; S5, dealcoholization: after the fermentation is completed, dealcoholization treatment is performed; S6. Fragrance enhancement: Add β-glucosidase and hydrolyze to release bound phenols.

[0020] In S1, the first stage of deodorization uses 30% ethanol (v / v) to soak for 2 hours (solid-liquid ratio 1:5) to dissolve sulfides and volatile acids. The second stage of deodorization uses 10% ethanol (v / v) to soak for 1 hour to further remove residual odor. It is then rinsed with distilled water 3 times, drained and sterilized at 121°C for 20 minutes. High-concentration ethanol quickly dissolves volatile sulfides and organic acids, significantly reducing the "horse urine smell". Low-concentration ethanol removes residual odor, reduces the subsequent dealcoholization pressure, and avoids excessive ethanol from inhibiting bacterial activity.

[0021] In S2, the alcohol-resistant yeast is Saccharomyces cerevisiae EC1118 (Deposit Number: CICC 33077), with an alcohol tolerance of 18% (v / v). The Eurotium cristatum is Eurotium cristatum YAZC (Deposit Number: CCTCC NO: M 20231875), which is derived from the symbiotic bacteria of dark tea and has a strong aroma-producing ability. The alcohol-resistant yeast is taken and the yeast is induced to metabolize to produce esters, which imparts fruity and floral aromas. The total polyphenol / flavonoid content is increased by secreting polyphenol oxidase through the Eurotium cristatum.

[0022] In S2, the alcohol-resistant yeast inoculum was cultured in YPD liquid medium (containing 2% ethanol) at 30°C for 24 hours (OD600 ≥ 2.0), and the Eurotium cristatum inoculum was cultured in PDA medium at 28°C for 5 days. The spore concentration was adjusted to 1×10 6 pieces / mL.

[0023] In the S3, the culture medium contains 10% (w / v) pretreated Gastrodia elata, 3% maltose, 1.2% yeast extract powder, and 0.1% KH2PO4, with an initial ethanol concentration of 2% (v / v), an 8% (v / v) yeast inoculation amount, and 5% (v / v) spore liquid of Eurotium cristatum. The Gastrodia elata residue is directly used as a carbon and nitrogen source to reduce raw material costs. At the same time, the initial ethanol concentration of 2% (v / v) can balance the deodorization residue and the tolerance of the strain, avoiding inhibition in the early stage of fermentation.

[0024] In S4, the temperature and dissolved oxygen in the first stage are 0-24h: 30°C, 200r / min, and high dissolved oxygen promotes yeast growth. The temperature and dissolved oxygen in the second stage are 24-72h: 28°C, 120r / min, and low dissolved oxygen induces the metabolism of Aspergillus niger. 1% ethanol (total amount ≤3%) is added for 24h, and 0.5% ethanol (total amount ≤3.5%) is added for 48h. In the first stage, high dissolved oxygen promotes rapid yeast proliferation and accumulation of ester precursors. In the second stage, low dissolved oxygen induces Aspergillus niger to secrete secondary metabolic enzymes. The two bacteria are inoculated in stages, and the metabolic needs of the two bacteria are matched at the same time to avoid competitive inhibition and improve the fermentation effect. 1% ethanol is added for 24h and 0.5% ethanol is added for 48h to maintain the carbon source balance of the fermentation system and directionally regulate the synthesis of aroma substances.

[0025] In the S4, samples were taken every 12 hours, and sulfides were detected by HS-SPME-GC (target: reduction ≥90%), samples were taken every 24 hours, and total polyphenols / flavonoids were detected by HPLC (target: polyphenols ≥5 mg / g, flavonoids ≥2.7 mg / g), and an offline alcohol meter was used for detection, controlling ≤3.5%. The sulfide removal rate was accurately monitored to ensure that the odor met the standard. At the same time, polyphenols (≥5 mg / g) and flavonoids (≥2.7 mg / g) were quantified to ensure the content of active ingredients. If the polyphenol content was insufficient during this process, 0.05% ferulic acid was added.

[0026] In the S5, vacuum rotary evaporation at 40°C (pressure 0.1 bar) is used to remove ethanol and retain heat-sensitive components (such as polyphenols and flavonoids) to avoid high-temperature degradation.

[0027] In the S6, 0.02% β-glucosidase is added and a hydrolysis reaction is performed (40°C, 1h) to release bound phenols (such as vanillin and ferulic acid), thereby increasing the free phenol content by 20%-30%.

[0028] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a liquid fermented Gastrodia elata product, characterized in that: The following steps are involved: S1. Gastrodia elata pretreatment and alcohol deodorization: Fresh Gastrodia elata was sliced to increase the surface area and deodorized with alcohol in two stages. The slices were then rinsed with distilled water and then drained and sterilized. S2. Preparation of composite microbial agents: Preparation of alcohol-resistant yeast agents and Eurotium cristatum agents; S3. Optimized inoculation of liquid culture medium: Prepare the culture medium and inoculate it with the alcohol-resistant yeast inoculant first and then the Eurotium cristatum inoculant; S4. Dynamic fermentation control: Control temperature and dissolved oxygen in two stages, and then add ethanol for regulation, and then monitor the fermentation process; S5, dealcoholization: after the fermentation is completed, dealcoholization treatment is performed; S6. Fragrance enhancement: Add β-glucosidase and hydrolyze to release bound phenols.

2. The method for preparing a liquid fermented Gastrodia elata product according to claim 1, characterized in that: In S1, the first deodorization stage uses 30% ethanol (v / v) to soak for 2 hours (solid-to-liquid ratio 1:5) to dissolve sulfides and volatile acids. The second deodorization stage uses 10% ethanol (v / v) to soak for 1 hour to further remove residual odor, and then rinse with distilled water 3 times, drain and sterilize at 121°C for 20 minutes.

3. The method for preparing a liquid fermented Gastrodia elata product according to claim 2, characterized in that: In S2, the alcohol-resistant yeast is Saccharomyces cerevisiae EC1118 (preservation number: CICC 33077), with an alcohol tolerance of 18% (v / v), and the Eurotium cristatum is Eurotium cristatum YAZC (preservation number: CCTCC NO: M20231875), which is derived from the symbiotic bacteria of dark tea and has a strong aroma-producing ability.

4. The method for preparing a liquid fermented Gastrodia elata product according to claim 3, characterized in that: In S2, the alcohol-resistant yeast inoculum was cultured in YPD liquid medium (containing 2% ethanol) at 30°C for 24 hours (OD600 ≥ 2.0), and the Eurotium cristatum inoculum was cultured in PDA medium at 28°C for 5 days. The spore concentration was adjusted to 1×10 6 pieces / mL.

5. The method for preparing a liquid fermented Gastrodia elata product according to claim 4, characterized in that: In the S3, the culture medium contains 10% (w / v) pretreated Gastrodia elata, 3% maltose, 1.2% yeast extract powder, 0.1% KH2PO4, and an initial ethanol concentration of 2% (v / v), the yeast inoculation amount is 8% (v / v), and the spore solution of Eurotium cristatum is 5% (v / v).

6. The method for preparing a liquid fermented Gastrodia elata product according to claim 5, characterized in that: In the S4, the temperature and dissolved oxygen in the first stage are 0-24h: 30°C, 200r / min, and high dissolved oxygen promotes yeast growth. The temperature and dissolved oxygen in the second stage are 24-72h: 28°C, 120r / min, and low dissolved oxygen induces the metabolism of Aspergillus niger. 1% ethanol (total amount ≤3%) is added for 24h, and 0.5% ethanol (total amount ≤3.5%) is added for 48h.

7. The method for preparing a liquid fermented Gastrodia elata product according to claim 6, characterized in that: In the S4, samples were taken every 12 h and sulfide was detected by HS-SPME-GC (target: reduction ≥90%), and samples were taken every 24 h and total polyphenols / flavonoids were detected by HPLC (target: polyphenols ≥5 mg / g, flavonoids ≥2.7 mg / g), and an offline alcohol analyzer was used for detection, with a control level of ≤3.5%.

8. The method for preparing a liquid fermented Gastrodia elata product according to claim 7, characterized in that: In the S5, ethanol was removed by vacuum rotary evaporation at 40°C (pressure 0.1 bar).

9. The method for preparing a liquid fermented Gastrodia elata product according to claim 8, characterized in that: In the S6, 0.02% β-glucosidase was added and a hydrolysis reaction was performed (40° C., 1 h) to release bound phenols.

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