Method for degrading total flavonoids and condensed tannins in hickory kernel seed coat based on optimal growth period of plant lactobacillus jl18

Abstract

This invention discloses a method for degrading total flavonoids and condensed tannins in pecan seed coat based on the optimal growth period of plant lactic acid bacteria JL18. This method utilizes the optimal growth time of plant lactic acid bacteria JL18, which can significantly degrade total flavonoids and condensed tannins in the inner seed coat of pecans, thereby reducing the astringency of the pecans. Reacting plant lactic acid bacteria with pecan kernels at 37°C effectively reduces the total flavonoids and condensed tannins in the inner seed coat of pecans. This invention solves the problems existing in current pecan deastringency processing techniques. Compared to traditional boiling methods, this invention retains some nutritious flavonoids and phenols while removing astringency, reducing water consumption and wastewater pollution, achieving a green and healthy processing goal.

Description

Technical Field

[0001] This invention relates to the field of pecan deastringency processing, specifically to a method for degrading total flavonoids and condensed tannins in pecan kernel seed coat based on the optimal growth period of plant lactic acid bacteria JL18. Background Technology

[0002] Pecan (Caryacathayensis), belonging to the genus Carya Nutt. of the family Juglandaceae, is an economically unique tree species in China. Its kernels are rich in nutrients and highly valued by consumers. However, the seed coat, tightly bound to the pecan embryo, is rich in various astringent substances, such as phenolic compounds, flavonoids, and tannins. Therefore, pecans must be de-astringed before consumption. High-temperature boiling and high-pressure steaming are currently the most common methods for de-astringing pecan kernels. However, during this process, some high-nutrient substances dissolve in the boiling water and are lost, while high-concentration organic wastewater is generated, causing significant environmental pollution and significantly increasing processing costs. How to improve the de-astringency process for pecans is an urgent problem to be solved. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for the degradation of total flavonoids and condensed tannins in pecan seed coat based on the optimal growth period of plant lactic acid bacteria JL18.

[0004] This invention utilizes the growth trend of plant lactic acid bacteria JL18 to obtain viable bacterial cells, which are then used to deastringe pecans, effectively reducing the total flavonoids and condensed tannins in the pecan seed coat.

[0005] Preferably, the method is as follows:

[0006] Step (1): Dissolve plant lactic acid bacteria powder in water, spread it on a solid culture medium plate to activate plant lactic acid bacteria, awaken the metabolic activity of the strain, repair cell damage, and restore its normal physiological function.

[0007] Step (2): Propagate plant lactic acid bacteria by shaking liquid culture medium;

[0008] Step (3): The propagated plant lactic acid bacteria are inoculated into a liquid culture medium to further expand their reproduction;

[0009] Step (4): After a period of time, collect the bacterial cells of plant lactic acid bacteria and remove the culture medium;

[0010] Step (5): Rehydrate the bacterial cells using physiological saline;

[0011] Step (6): Use a fermentation container to thoroughly mix the pecan kernels with the plant lactic acid bacteria from step (5), and ferment overnight.

[0012] More preferably, the activation temperature in step (1) is 37°C.

[0013] More preferably, the culture conditions in step (2) are 37°C and 200 rpm.

[0014] More preferably, in step (3), plant lactic acid bacteria are inoculated into the liquid culture medium at a bacterial count ratio of 1%.

[0015] More preferably, the incubation time in step (4) is 4 hours.

[0016] More preferably, in step (5), the amount of physiological saline used is 10% of the liquid culture medium.

[0017] More preferably, the fermentation temperature in step (6) is 37°C.

[0018] The beneficial effects of the present invention are at least as follows:

[0019] 1. Plant-based lactic acid bacteria have low production costs and can be obtained in large quantities.

[0020] The plant-based lactic acid bacteria of this invention grow rapidly and have a long activity period. They can be freeze-dried into powder for easy use and storage. They also have excellent activity after revival. The bacteria are in the logarithmic growth stage at the 4th hour of cultivation, at which point the bacteria can be used for subsequent co-fermentation and deastringency removal of pecan kernels.

[0021] 2. The product is of high quality and has a significant effect on reducing total flavonoids and condensed tannins.

[0022] The plant-based lactic acid bacteria of this invention can effectively degrade most of the condensed tannins in pecan kernels. Attached Figure Description

[0023] Figure 1 Growth curve of plant lactic acid bacteria JL18.

[0024] Figure 2 pH changes of plant lactic acid bacteria JL18. Detailed Implementation

[0025] The following embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

[0026] The following examples use plant lactic acid bacteria JL18 as the reaction object. After inoculation, fermentation was carried out for several hours to obtain the growth curve and obtain the bacterial cells in the logarithmic growth phase.

[0027] The 16SRNA sequencing sequence of the plant lactic acid bacteria JL18:

[0028]

[0029] Example 1: Revival of plant lactic acid bacteria JL18:

[0030] Step (1): Dissolve the powder in 10% sterile water, such as adding 10 μg of powder to 100 μL of water; use MRS medium for culture and propagation, and the initial pH of the medium should be maintained at 6-7.

[0031] Plant lactic acid bacteria powder is dissolved in water, spread on solid culture medium plates, and activated at 37°C to awaken the metabolic activity of the strain, repair cell damage, and restore its normal physiological function.

[0032] Step (2): Propagation of plant lactic acid bacteria using MRS liquid culture at 37℃ and 200 rpm with shaking.

[0033] Step (3): The propagated plant lactic acid bacteria are inoculated into MRS liquid culture medium at a ratio of 1% of the bacterial count to further expand their propagation; for example, 5 mL of seed culture is inoculated into 500 mL of MRS culture medium.

[0034] Step (4): After 50 hours, obtain the optimal growth curve and record the OD600 and pH value at different time points. See [link / reference]. Figure 1-2 .

[0035] Example 2

[0036] The revived plant lactic acid bacteria JL18 cells were reconstituted using physiological saline, with the amount of physiological saline being 10% of the liquid culture medium.

[0037] Use a fermentation container to thoroughly mix the pecan kernels with the plant lactic acid bacteria from step (5), and ferment overnight at 37°C.

Claims

1. A method for degrading total flavonoids and condensed tannins in pecan seed coat based on the optimal growth period of plant lactic acid bacteria JL18, characterized in that, The method utilizes the growth trend of plant lactic acid bacteria to obtain viable bacterial cells, which are then used to process pecans to remove astringency.

2. The method according to claim 1, characterized in that, The method is specifically as follows: Step (1): Dissolve plant lactic acid bacteria powder in water, spread it on a solid culture medium plate to activate plant lactic acid bacteria, awaken the metabolic activity of the strain, repair cell damage, and restore its normal physiological function. Step (2): Propagate plant lactic acid bacteria by shaking liquid culture medium; Step (3): The propagated plant lactic acid bacteria are inoculated into a liquid culture medium to further expand their reproduction; Step (4): After a period of time, collect the bacterial cells of plant lactic acid bacteria and remove the culture medium; Step (5): Rehydrate the bacterial cells using physiological saline; Step (6): Use a fermentation container to thoroughly mix the pecan kernels with the plant lactic acid bacteria from step (5), and ferment overnight.

3. The method according to claim 2, characterized in that, The activation temperature for step (1) is 37°C.

4. The method according to claim 2, characterized in that, The culture conditions for step (2) are 37℃ and 200 rpm.

5. The method according to claim 2, characterized in that, Step (3) Plant lactic acid bacteria are inoculated into liquid culture medium at a bacterial count ratio of 1%.

6. The method according to claim 2, characterized in that, Step (4) involves a 4-hour incubation period.

7. The method according to claim 2, characterized in that, Step (5) The amount of physiological saline used is 10% of the liquid culture medium.

8. The method according to claim 2, characterized in that, The fermentation temperature for step (6) is 37℃.

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