Black mulberry fermentation liquor as well as preparation method and application thereof

Abstract

The invention relates to black mulberry fermentation liquor as well as a preparation method and application thereof, and belongs to the technical field of plant processing. The preparation method of the black mulberry fermentation liquor comprises the following steps: inoculating zymomonas mobilis liquid into a culture medium containing black mulberry homogenate to form mixed liquor, fermenting, and carrying out solid-liquid separation on a fermented material obtained after fermentation, the inoculation volume of the zymomonas mobilis liquid is 5%-10% of the volume of the mixed liquid. According to the method, active ingredients such as flavone and anthocyanin in the black mulberries can be efficiently extracted, so that the black mulberry fermentation liquor obtained through fermentation has relatively high flavone and anthocyanin content and relatively good anti-oxidation and anti-aging effects.

Description

Technical Field

[0001] The present application relates to the field of plant processing technology, and in particular to a black mulberry fermentation liquid and a preparation method and application thereof. Background Art

[0002] Anthocyanins are a class of compounds formed by the glycosidic bond between anthocyanins and sugars. They are widely found in the cell fluid of flowers, fruits, stems, leaves and root organs of plants, making them appear in different colors from red, purple to blue. Anthocyanins are a family of compounds that can appear red in flavonoids, a class of substances based on flavonoid nuclei. Due to its unique functionality, it is used to remove free radicals in the body, proliferate lutein, fight tumors, fight cancer, fight inflammation, inhibit lipid peroxidation and platelet aggregation, prevent diabetes, lose weight, protect eyesight, etc. As a natural pigment, anthocyanins are safe, non-toxic, and have many health functions for the human body. They have been used in food, health products, cosmetics, medicine and other industries.

[0003] At present, anthocyanins are generally extracted from plants containing anthocyanins. However, the extraction rate of anthocyanins in plants is low, which is not conducive to the application of anthocyanins. Summary of the invention

[0004] In view of the deficiencies of the prior art, the purpose of the embodiments of the present application includes providing a black mulberry fermentation liquid and a preparation method and application thereof. The black mulberry fermentation liquid with high flavonoid and anthocyanin content can be prepared and can be well applied to anti-oxidation and anti-aging.

[0005] In a first aspect, an embodiment of the present application provides a method for preparing black mulberry fermentation broth, comprising: inoculating a culture medium containing black mulberry homogenate with a Zymomonas mobilis liquid to form a mixed liquid, fermenting the culture medium, and performing solid-liquid separation on the fermented material obtained after the fermentation; the inoculation volume of the Zymomonas mobilis liquid is 5%-10% of the volume of the mixed liquid.

[0006] The present application adopts an appropriate amount of Zymomonas mobilis as a fermentation strain to ferment black mulberry homogenate. The black mulberry homogenate and Zymomonas mobilis cooperate to promote the growth of Zymomonas mobilis, thereby efficiently extracting active ingredients such as flavonoids and anthocyanins in black mulberries, so that the black mulberry fermentation liquid obtained by fermentation has a higher content of flavonoids and anthocyanins, and has better antioxidant and anti-aging effects.

[0007] In some embodiments of the present application, the culture medium contains 5%-15% by mass of black mulberry homogenate.

[0008] The present application uses a suitable mass percentage of black mulberry homogenate in the culture medium and uses a suitable amount of Zymomonas mobilis for fermentation, so that active ingredients such as flavonoids and anthocyanins in black mulberries can be efficiently extracted, so that the black mulberry fermentation liquid obtained by fermentation has a higher content of flavonoids and anthocyanins, and has better antioxidant and anti-aging effects.

[0009] In some embodiments of the present application, the process includes preparing black mulberry homogenate before fermentation, and sterilizing the black mulberry homogenate. The process includes mixing and beating black mulberry dried fruits and water in a mass and volume ratio of 5%-15% to obtain black mulberry homogenate.

[0010] The present application can obtain a black mulberry homogenate with a suitable mass percentage by mixing and pulping black mulberry dried fruits of a suitable mass with a suitable volume of water. The black mulberry homogenate with a suitable mass percentage is used in conjunction with fermentation using a suitable amount of Fermentation Monosaccharides mobilis, thereby efficiently extracting active ingredients such as flavonoids and anthocyanins from black mulberries, so that the black mulberry fermentation liquid obtained by fermentation has a higher content of flavonoids and anthocyanins, and has better antioxidant and anti-aging effects.

[0011] In some embodiments of the present application, the culture medium further includes 8%-15% by mass of glucose.

[0012] The present application can assist in promoting the growth of Zymomonas mobilis by adding a suitable mass percentage of glucose into the culture medium, and effectively extract active ingredients such as flavonoids and anthocyanins from black mulberries.

[0013] In some embodiments of the present application, the pH value of the culture medium is 6.5-7.5.

[0014] The present application configures the culture medium to a suitable pH value, which can facilitate the growth of Zymomonas mobilis, promote the fermentation of black mulberry homogenate, and effectively extract active ingredients such as flavonoids and anthocyanins from black mulberries.

[0015] In some embodiments of the present application, the fermentation conditions include: fermentation at 35-38° C. for 24-36 hours.

[0016] The present application adopts a suitable temperature and a suitable fermentation time to facilitate the fermentation of black mulberry homogenate by Zymomonas mobilis, and effectively extracts active ingredients such as flavonoids and anthocyanins from black mulberries.

[0017] In some embodiments of the present application, the method further comprises activating Zymomonas mobilis before fermentation.

[0018] In some embodiments of the present application, activating Zymomonas mobilis includes: transferring the Zymomonas mobilis to a solid culture medium, incubating the culture at 37°C for activation until a single colony grows, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37°C for 10-18 hours to obtain a Zymomonas mobilis liquid.

[0019] The present application can obtain a Zymomonas mobilis liquid of suitable concentration by activating and expanding the culture of Zymomonas mobilis for a suitable time, so as to facilitate the efficient fermentation of black mulberry homogenate and effectively extract active ingredients such as flavonoids and anthocyanins in black mulberries.

[0020] In a second aspect, an embodiment of the present application provides a black mulberry fermentation broth prepared by the preparation method provided in the first aspect.

[0021] The black mulberry fermentation liquid prepared by the above-mentioned preparation method in the present application has a high content of flavonoids and anthocyanins, and has good antioxidant and anti-aging effects.

[0022] In a third aspect, an embodiment of the present application provides a use of the black mulberry fermentation liquid provided in the second aspect in the preparation of cosmetics.

[0023] The present application uses black mulberry fermentation liquid with high flavonoid and anthocyanin content and good antioxidant and anti-aging effects in the preparation of cosmetics, so that the cosmetics also have good antioxidant and anti-aging effects. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0025] The embodiment of the present application provides a method for preparing black mulberry fermentation broth, comprising: inoculating a culture medium containing black mulberry homogenate with a Zymomonas mobilis liquid to form a mixed liquid, fermenting, and performing solid-liquid separation on the fermented material obtained after the fermentation; the inoculation volume of the Zymomonas mobilis liquid is 5%-10% of the volume of the mixed liquid.

[0026] An appropriate amount of Zymomonas mobilis is used as a fermentation strain to ferment black mulberry homogenate. The black mulberry homogenate and Zymomonas mobilis cooperate to promote the growth of Zymomonas mobilis, thereby efficiently extracting active ingredients such as flavonoids and anthocyanins in black mulberries, so that the black mulberry fermentation liquid obtained by fermentation has a higher content of flavonoids and anthocyanins, and has better antioxidant and anti-aging effects.

[0027] As an example, the inoculation volume of the Zymomonas mobilis liquid can be but is not limited to 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10% of the volume of the mixed liquid.

[0028] In some embodiments of the present application, the culture medium contains 5%-15% black mulberry homogenate by mass. As an example, the culture medium may contain, but is not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15% black mulberry homogenate by mass. A suitable mass percentage of black mulberry homogenate is used in the culture medium to cooperate with an appropriate amount of mobilis Zymomonas for fermentation, so that active ingredients such as flavonoids and anthocyanins in black mulberries can be efficiently extracted, so that the black mulberry fermentation liquid obtained by fermentation has a higher content of flavonoids and anthocyanins, and has better antioxidant and anti-aging effects.

[0029] In some embodiments of the present application, before fermentation, black mulberry homogenate is further prepared and sterilized, and the preparation of black mulberry homogenate includes: mixing and beating black mulberry dried fruits and water at a mass and volume ratio of 5%-15% to obtain black mulberry homogenate. As an example, the mass and volume ratio of black mulberry dried fruits and water can be, but not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%. By mixing and beating a suitable mass of black mulberry dried fruits with a suitable volume of water, a black mulberry homogenate with a suitable mass percentage can be obtained. The black mulberry homogenate with a suitable mass percentage is used in conjunction with a suitable amount of mobilis Zymomonas for fermentation, so that active ingredients such as flavonoids and anthocyanins in the black mulberries can be efficiently extracted, and the black mulberry fermentation liquid obtained by fermentation has a higher content of flavonoids and anthocyanins, and has better antioxidant and anti-aging effects.

[0030] In some embodiments of the present application, the culture medium also includes 8%-15% glucose by mass. As an example, the culture medium may include, but is not limited to, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15% glucose by mass. Adding an appropriate mass percentage of glucose to the culture medium can assist in promoting the growth of Zymomonas mobilis and effectively extract active ingredients such as flavonoids and anthocyanins from black mulberries.

[0031] In some embodiments of the present application, the pH value of the culture medium is 6.5-7.5. As an example, the pH value of the culture medium can be, but is not limited to, 6.5, 6.8, 7.0, 7.2, 7.5. Configuring the culture medium to a suitable pH value can facilitate the growth of Zymomonas mobilis, promote the fermentation of black mulberry homogenate, and effectively extract active ingredients such as flavonoids and anthocyanins from black mulberries.

[0032] In some embodiments of the present application, the fermentation conditions include: fermentation at 35-38° C. for 24-36 hours. Fermentation at an appropriate temperature and for an appropriate time can facilitate the fermentation of black mulberry homogenate by Zymomonas mobilis and effectively extract active ingredients such as flavonoids and anthocyanins from black mulberries.

[0033] In some embodiments of the present application, the method further comprises activating Zymomonas mobilis before fermentation.

[0034] In some embodiments of the present application, activating Zymomonas mobilis includes: transferring Zymomonas mobilis to a solid culture medium, activating at 37°C until a single colony grows, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand and culture at 37°C for 10-18 hours to obtain a Zymomonas mobilis liquid. By activating and expanding Zymomonas mobilis for an appropriate time, a Zymomonas mobilis liquid of an appropriate concentration can be obtained, which is conducive to the efficient fermentation of black mulberry homogenate and the effective extraction of active ingredients such as flavonoids and anthocyanins in black mulberries.

[0035] The embodiment of the present application provides a black mulberry fermentation liquid prepared by the above-mentioned preparation method.

[0036] The black mulberry fermented liquid prepared by the preparation method has high flavonoid and anthocyanin contents and has good anti-oxidation and anti-aging effects.

[0037] The embodiment of the present application provides a use of the black mulberry fermentation liquid as described above in the preparation of cosmetics.

[0038] The black mulberry fermentation liquid with high flavonoid and anthocyanin content and good anti-oxidation and anti-aging effects is used in the preparation of cosmetics, so that the cosmetics also have good anti-oxidation and anti-aging effects.

[0039] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0040] The Zymomonas mobilis used in this application is from Guangdong Microbiological Strain Collection Center, with the number GDMCC1.133.

[0041] The liquid culture medium used in the examples of the present application is: 100 g of glucose; 5 g of yeast extract; 1 g of potassium dihydrogen phosphate; 0.5 g of magnesium sulfate; 1 g of ammonium sulfate; 1000 mL of water; and the pH is adjusted to 7.0.

[0042] Solid culture medium is: based on the liquid culture medium, add 1.5%-5% agar.

[0043] The liquid culture medium and solid culture medium may be corresponding commercially available culture media.

[0044] Example 1

[0045] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0046] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0047] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0048] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 10% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0049] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 10% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 24 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0050] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as A.

[0051] Example 2

[0052] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0053] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0054] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0055] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 10% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0056] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 5% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 36 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0057] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as B.

[0058] Example 3

[0059] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0060] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0061] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0062] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 10% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0063] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 7.5% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 30 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0064] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as C.

[0065] Example 4

[0066] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0067] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0068] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0069] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 15% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0070] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 10% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 24 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0071] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as D.

[0072] Example 5

[0073] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0074] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0075] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0076] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 15% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0077] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 5% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 36 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0078] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as E.

[0079] Example 6

[0080] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0081] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0082] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0083] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 15% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0084] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 7.5% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 30 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0085] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as F.

[0086] Example 7

[0087] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0088] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0089] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0090] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 5% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0091] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 10% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 24 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0092] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as G.

[0093] Example 8

[0094] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0095] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0096] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0097] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 5% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0098] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 5% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 36 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0099] The black mulberry fermentation liquid prepared by the preparation method provided in this example is denoted as H.

[0100] Example 9

[0101] This embodiment provides a method for preparing black mulberry fermentation liquid, comprising the following steps:

[0102] (1) adding water to black mulberry dried fruit, beating to obtain black mulberry homogenate, and sterilizing;

[0103] (2) transferring the mobilizing Zymomonas to a solid culture medium, incubating at 37° C. for activation until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37° C. for 14 h to obtain a mobilizing Zymomonas liquid;

[0104] (3) Using black mulberry homogenate as the matrix of the culture medium, the culture medium includes the following substances in percentage by weight: 5% black mulberry homogenate, 10% glucose, and a pH value of 7.0;

[0105] (4) Inoculating a culture medium containing black mulberry homogenate with a solution of Zymomonas mobilis to form a mixed solution, wherein the inoculation volume of the Zymomonas mobilis solution is 7.5% of the volume of the mixed solution, and fermenting the mixture at 37° C. for 30 h. Centrifuging the fermented material obtained after the fermentation to obtain a black mulberry fermentation solution.

[0106] The black mulberry fermentation liquid prepared by the preparation method provided in this embodiment is denoted as I.

[0107] Comparative Example 1

[0108] This comparative example provides a method for preparing grape fermentation liquid, comprising the following steps: The difference from Example 1 is that black mulberry homogenate is replaced by grape homogenate.

[0109] The grape fermentation liquid prepared by the preparation method provided in this comparative example is recorded as M1.

[0110] Comparative Example 2

[0111] This comparative example provides a method for preparing black rice fermented liquid, comprising the following steps: the difference from Example 1 is that black mulberry homogenate is replaced by black rice homogenate.

[0112] The black rice fermented liquid prepared by the preparation method provided in this comparative example is recorded as M2.

[0113] Comparative Example 3

[0114] This comparative example provides a method for preparing purple sweet potato fermentation broth, comprising the following steps: the difference from Example 1 is that black mulberry homogenate is replaced by purple sweet potato homogenate.

[0115] The purple sweet potato fermentation liquid prepared by the preparation method provided in this comparative example is recorded as M3.

[0116] Comparative Example 4

[0117] This comparative example provides a method for preparing blueberry fermented liquid, comprising the following steps: The difference from Example 1 is that black mulberry homogenate is replaced by blueberry homogenate.

[0118] The blueberry fermented liquid prepared by the preparation method provided in this comparative example is recorded as M4.

[0119] Comparative Example 5

[0120] This comparative example provides a method for preparing black wolfberry fermentation broth, comprising the following steps: the difference from Example 1 is that black mulberry homogenate is replaced with black wolfberry homogenate.

[0121] The black wolfberry fermentation liquid prepared by the preparation method provided in this comparative example is recorded as M5.

[0122] The preparation methods of the fermentation broths provided in Examples 1-9 and Comparative Examples 1-5 are shown in Table 1.

[0123] Table 1 Preparation method of fermentation broth

[0124]

[0125] Test Example 1

[0126] In this test example, the total flavonoid content of the black mulberry fermentation broth AI prepared in Examples 1-9 and the fermentation broth M1-M5 prepared in Comparative Examples 1-5 was determined by spectrophotometry. The specific method is as follows:

[0127] Pipette 2.4 mL of the rutin standard stock solution of a series of concentrations, water (for blank control) and each fermentation broth into a stoppered test tube, add 0.4 mL of 5% sodium nitrite solution to each test tube, shake well, react for 6 minutes; add 0.4 mL of 10% aluminum nitrate solution, shake well, react for 6 minutes; add 1.0 mL of 4% sodium hydroxide solution and 0.7 mL of water, shake well, react for 15 minutes; use a 10 mm cuvette and a spectrophotometer to measure the absorbance at a wavelength of 510 nm. Draw a standard curve y=0.0016x+0.0422, R 2 =0.9987, and the flavonoid content was calculated from the absorbance value of each fermentation broth in the standard curve. The results are shown in Table 2.

[0128] Table 2 Flavonoid content of fermentation broth

[0129] Fermentation broth samples Flavonoid content (mg / mL) A 1.152 B 1.014 C 0.969 D 1.079 E 0.973 F 0.957 G 0.881 H 0.978 I 0.775 M1 0.043 M2 0.063 M3 0.218 M4 0.103 M5 0.561

[0130] From the results in Table 2, it can be seen that the black mulberry fermentation broth prepared in Example 1-9 and the fermentation broth prepared in Comparative Example 1-5 have flavonoid contents greater than 0.7 mg / mL, while the flavonoid contents in the fermentation broth prepared in Comparative Example 1-5 are less than 0.6 mg / mL, and the flavonoid content in the fermentation broth prepared in Comparative Example 1-2 is even less than 0.1 mg / mL. This indicates that the present application uses an appropriate amount of Zymomonas mobilis as a fermentation strain, and ferments an appropriate amount of black mulberry homogenate. The black mulberry homogenate cooperates with Zymomonas mobilis to promote the growth of Zymomonas mobilis, thereby efficiently extracting flavonoids from black mulberries, so that the black mulberry fermentation broth obtained by fermentation has a higher flavonoid content.

[0131] Test Example 2

[0132] In this test example, the black mulberry fermentation broth AI prepared in Examples 1-9 and the fermentation broth M1-M5 prepared in Comparative Examples 1-5 were used to determine the anthocyanin content by pH differential method. When pH = 1.0, anthocyanin has a characteristic absorption peak at 530nm. When pH = 4.5, anthocyanin is converted into a colorless chalcone form with no absorption peak at 530nm. This characteristic is used to measure the absorbance values ​​at 530nm and 700nm under different pH conditions, respectively, to quantitatively detect the content of plant anthocyanin. The specific determination method and data processing are carried out according to the instructions of the BOXBIO Anthocyanin Detection Kit (Beijing Box Biotechnology Co., Ltd.). The results are shown in Table 3.

[0133] Table 3 Anthocyanin content of fermentation broth

[0134] Fermentation broth samples Anthocyanin content (μmol / mL) A 0.5680 B 0.4755 C 0.5415 D 0.4562 E 0.5038 F 0.5172 G 0.4934 H 0.3684 I 0.4031 M1 0.0100 M2 0.0159 M3 0.0589 M4 0.0004 M5 0.0000

[0135] From the results in Table 3, it can be seen that the black mulberry fermentation broth prepared in Example 1-9 and the fermentation broth prepared in Comparative Example 1-5 have anthocyanin contents greater than 0.3 μmol / mL, while the anthocyanin contents in the fermentation broth prepared in Comparative Example 1-5 are less than 0.05 μmol / mL, and the anthocyanin content in the fermentation broth prepared in Comparative Example 4-5 is even almost 0. This indicates that the present application uses an appropriate amount of Zymomonas mobilis as a fermentation strain, and ferments an appropriate amount of black mulberry homogenate. The black mulberry homogenate and Zymomonas mobilis cooperate to promote the growth of Zymomonas mobilis, thereby efficiently extracting anthocyanins from black mulberries on the basis of efficiently extracting flavonoids from black mulberries, so that the black mulberry fermentation broth obtained by fermentation has a higher content of flavonoids and anthocyanins.

[0136] Test Example 3

[0137] This test example measures the scavenging rate of DPPH free radicals of the black mulberry fermentation broth AI prepared in Examples 1-9. The specific method is as follows:

[0138] Pipette 2.0mL of black mulberry fermentation broth sample (or anhydrous ethanol) and 2.0mL of DPPH solution into a stoppered test tube and mix well; react in the dark for 30 minutes and measure the absorbance at a wavelength of 517nm. The DPPH free radical scavenging rate is calculated as follows:

[0139]

[0140] Where:

[0141] A 0 : 2 mL of anhydrous ethanol + 2 mL of DPPH;

[0142] A 1 :Sample 2mL+DPPH 2mL;

[0143] A 2 : 2mL of anhydrous ethanol + 2mL of sample.

[0144] The results are shown in Table 4.

[0145] Table 4 Scavenging rate of DPPH free radicals by black mulberry fermentation liquid

[0146]

[0147]

[0148] As shown in Table 4, the scavenging rate of the black mulberry fermentation broth prepared in Examples 1-9 on DPPH free radicals reached more than 55%. This indicates that the present application uses an appropriate amount of Zymomonas mobilis as a fermentation strain and ferments an appropriate amount of black mulberry homogenate, which can efficiently extract flavonoids and anthocyanins from black mulberries, so that the black mulberry fermentation broth obtained by fermentation has a higher content of flavonoids and anthocyanins, thereby having a better scavenging ability for DPPH free radicals. It can be used as an antioxidant in cosmetics.

[0149] Test Example 4

[0150] This test example measures the scavenging rate of ABTS+ free radicals of the black mulberry fermentation broth AI prepared in Examples 1-9. The specific method is as follows:

[0151] (1) Take 7 mmol / L ABTS solution and dilute it 60 times with 10 mmol / L PBS (pH = 7.4) to obtain ABTS working solution;

[0152] (2) Pipette 190 μL of ABTS working solution (or PBS), add 10 μL of black mulberry fermentation solution sample (or PBS), shake for 10 seconds, let stand for 6 minutes at 30°C, and measure the absorbance at 734 nm. The scavenging rate of ABTS+ free radicals is calculated as follows:

[0153]

[0154] Where:

[0155] A 0 : PBS 10 μL + ABTS 190 μL;

[0156] A 1 :Sample 10μL+ABTS 190μL;

[0157] A 2 : PBS 190μL + sample 10μL.

[0158] The results are shown in Table 5.

[0159] Table 5 Scavenging rate of ABTS+ free radicals by black mulberry fermentation broth

[0160] Black mulberry fermentation broth sample ABTS+ free radical scavenging rate (%) A 99.74 B 82.50 C 50.92 D 82.28 E 30.26 F 73.62 G 36.33 H 81.58 I 48.99

[0161] From the results in Table 5, it can be seen that the black mulberry fermentation broth prepared in Examples 1-9 has a scavenging rate of more than 30% for the fermentation product against ABTS+ free radicals. This indicates that the present application uses an appropriate amount of Zymomonas mobilis as a fermentation strain and ferments an appropriate amount of black mulberry homogenate, which can efficiently extract flavonoids and anthocyanins from black mulberries, so that the black mulberry fermentation broth obtained by fermentation has a higher content of flavonoids and anthocyanins, thereby having a better scavenging ability against ABTS+ free radicals. It can be used as an antioxidant in cosmetics.

[0162] Test Example 5

[0163] This test example measures the scavenging rate of hydroxyl radicals of the black mulberry fermentation broth AI prepared in Examples 1-9. The specific method is as follows:

[0164] 20 μL of black mulberry fermentation broth sample (or pure water) and 180 μL of hydroxyl radical reaction color solution (or hydroxyl radical blank solution) were added to a 96-well plate and mixed; incubated at 37°C for 15 minutes, and the absorbance at a wavelength of 510 nm was measured. The hydroxyl radical scavenging rate was calculated as follows:

[0165] Hydroxyl radical scavenging rate (%) = 100% (A0-(AX-AXO)) / A0

[0166] Where:

[0167] A0 :Pure water 20μL+reaction color development solution 180μL;

[0168] A X :Sample 20μL+reaction color development solution 180μL;

[0169] A xo : Sample 20μL+blank solution 180μL.

[0170] The results are shown in Table 6.

[0171] Table 6 Scavenging rate of hydroxyl radicals by black mulberry fermentation broth

[0172] Black mulberry fermentation broth sample Hydroxyl free radical scavenging rate (%) A 84.73 B 70.56 C 71.64 D 84.09 E 79.92 F 69.66 G 58.96 H 58.65 I 59.77

[0173] As shown in Table 6, the scavenging rate of the black mulberry fermentation broth prepared in Examples 1-9 for hydroxyl radicals reached more than 55%. This indicates that the present application uses an appropriate amount of Zymomonas mobilis as a fermentation strain and ferments an appropriate amount of black mulberry homogenate, which can efficiently extract flavonoids and anthocyanins from black mulberries, so that the black mulberry fermentation broth obtained by fermentation has a high content of flavonoids and anthocyanins, thereby having a good scavenging ability for hydroxyl radicals. It can be used as an antioxidant in cosmetics.

[0174] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

Claims

1. A method for preparing black mulberry fermentation liquid, characterized in that: The preparation method comprises: inoculating Zymomonas mobilis liquid into a culture medium containing black mulberry homogenate to form a mixed liquid, fermenting, and performing solid-liquid separation on the fermented material obtained after the fermentation; the inoculation volume of the Zymomonas mobilis liquid is 5%-10% of the volume of the mixed liquid.

2. The preparation method according to claim 1, characterized in that: The culture medium contains 5%-15% by mass of black mulberry homogenate.

3. The preparation method according to claim 1 or 2, characterized in that: The method also includes preparing the black mulberry homogenate before fermentation and sterilizing the black mulberry homogenate. The method includes mixing and beating black mulberry dried fruits and water in a mass and volume ratio of 5% to 15% to obtain the black mulberry homogenate.

4. The preparation method according to claim 1 or 2, characterized in that: The culture medium also includes 8%-15% glucose by mass.

5. The preparation method according to claim 1 or 2, characterized in that: The pH value of the culture medium is 6.5-7.

5.

6. The preparation method according to claim 1, characterized in that: The fermentation conditions include: fermentation at 35-38° C. for 24-36 hours.

7. The preparation method according to claim 1, characterized in that: The method further comprises activating Zymomonas mobilis before fermentation.

8. The preparation method according to claim 7, characterized in that: Activating the mobilizing Zymomonas includes: transferring the mobilizing Zymomonas to a solid culture medium, activating the culture at 37°C until a single colony grows out, transferring the single colony grown on the solid culture medium to a liquid culture medium, and continuing to expand the culture at 37°C for 10-18 hours to obtain a mobilizing Zymomonas liquid.

9. A black mulberry fermentation liquid prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the black mulberry fermentation liquid according to claim 9 in preparing cosmetics.

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