Osmanthus powder with whitening and antioxidant effects, and preparation method and application thereof

Abstract

The application discloses osmanthus pollen with whitening and antioxidant effects and a preparation method and application thereof. The preparation method of the osmanthus pollen with whitening and antioxidant effects comprises the following steps: 1) osmanthus and protease are subjected to enzymolysis, enzyme inactivation, and solid-liquid separation, so that filter residue and first filtrate are obtained; 2) the filter residue is subjected to hot water extraction and solid-liquid separation, so that second filtrate is obtained; 3) the first filtrate and the second filtrate are mixed to form an extraction liquid, the extraction liquid is subjected to ceramic membrane filtration, and first permeate is obtained; 4) the first permeate is subjected to ultrafiltration membrane filtration, and second permeate is obtained; and 5) the second permeate is subjected to concentration and drying, and the osmanthus pollen with whitening and antioxidant effects is obtained. The osmanthus pollen with whitening and antioxidant effects obtained by the preparation method has high polyphenol content and polypeptide content, can effectively promote skin whitening and antioxidant effects, and can comprehensively protect skin and resist aging.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a whitening and antioxidant osmanthus powder, its preparation method, and its application. Background Technology

[0002] Skin whitening is a complex physiological process that reduces skin pigmentation by intervening in melanin metabolism. Its core lies in inhibiting melanin production, blocking its transfer to the skin surface, and accelerating the metabolism and shedding of existing melanin. Specifically, when the skin is stimulated by ultraviolet rays, it activates tyrosinase, which catalyzes the conversion of tyrosine into melanin. Whitening ingredients (such as vitamin C and polyphenols) can inhibit the activity of tyrosinase, reducing melanin production at its source and thus lightening skin tone. In addition, poor dietary habits, irregular lifestyles, and prolonged exposure to computer screens can all lead to the production of free radicals in the skin, causing aging of the stratum corneum and resulting in a dull, yellowish complexion.

[0003] Osmanthus, a unique germplasm resource in my country, is rich in polyphenolic active substances, thus possessing potential application value in the field of skin whitening. However, traditional extraction processes (such as hot water extraction) suffer from technical bottlenecks such as low retention rate of active ingredients and high impurity content, severely limiting its industrial application. CN118059156A discloses an anti-fatigue standard active ingredient PHEG50 from osmanthus, its preparation method, and its application. This method involves extracting osmanthus under acidic conditions, followed by treatment with ceramic membranes, ultrafiltration membranes, nanofiltration membranes, and RO membranes to obtain the standard active ingredient PHEG50. However, this patent requires a large amount of acidic water for extraction, resulting in a large volume of extract. This not only increases the difficulty of subsequent concentration but also introduces water-soluble impurities, affecting the purity of the final product.

[0004] Therefore, it is of great technical necessity and industrial application value to find a way to provide osmanthus powder that can efficiently retain the active ingredients of osmanthus polyphenols and has both whitening and antioxidant effects. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide osmanthus powder with whitening and antioxidant effects, its preparation method and application, in order to solve the problems in the prior art.

[0006] To achieve the above and other related objectives, the present invention is obtained through the following technical solution.

[0007] The first aspect of the present invention provides a method for preparing osmanthus powder with whitening and antioxidant effects, comprising the following steps:

[0008] 1) Osmanthus flowers are hydrolyzed with protease, enzyme is inactivated, and solid-liquid separation is performed to obtain filter residue and first filtrate;

[0009] 2) The filter residue is extracted with hot water and the solid and liquid are separated to obtain a second filtrate;

[0010] 3) The first filtrate and the second filtrate are mixed to form an extract, and the extract is filtered through a ceramic membrane to obtain a first permeate;

[0011] 4) The first permeate is filtered through an ultrafiltration membrane to obtain the second permeate;

[0012] 5) The second permeate is concentrated and dried to obtain osmanthus powder with whitening and antioxidant effects.

[0013] A second aspect of the present invention provides osmanthus powder with whitening and antioxidant effects obtained by the preparation method described above.

[0014] A third aspect of the present invention provides the use of osmanthus powder, which has whitening and antioxidant effects as described above, in the preparation of food, pharmaceuticals or cosmetics with antioxidant effects.

[0015] A fourth aspect of the present invention provides a food, medicine or cosmetic with antioxidant properties, comprising osmanthus powder with whitening and antioxidant properties as described above.

[0016] As described above, the osmanthus powder with whitening and antioxidant effects of the present invention, its preparation method, and its application have the following beneficial effects:

[0017] 1) The preparation method of the present invention involves enzymatic hydrolysis with protease, hot water extraction, treatment with ceramic membrane and ultrafiltration membrane, followed by concentration and drying to obtain osmanthus powder with whitening and antioxidant effects, with a yield of over 25%. Furthermore, the preparation method of the present invention does not use any organic solvents or toxic or harmful compounds, is simple to operate, safe, environmentally friendly, and suitable for large-scale production.

[0018] 2) The preparation method of the present invention, through the synergistic treatment steps of protease hydrolysis, hot water extraction, ceramic membrane and ultrafiltration membrane treatment, can extract high content of polyphenols and polypeptides. The total polyphenol content in the obtained osmanthus powder is 25-35 wt%, the total sugar content is 40-55 wt%, and the polypeptide content is 10-15 wt%. The high content of polyphenols and polypeptides provides multi-dimensional support for the whitening and antioxidant effects of osmanthus powder.

[0019] 3) When the osmanthus powder of the present invention, which has whitening and antioxidant effects, was used to evaluate the melanin inhibition effect in zebrafish, it could significantly reduce the melanin signal intensity, which was reduced by 82.3% compared with the blank control group, indicating that it has the effect of promoting skin whitening.

[0020] 4) When the osmanthus powder of the present invention, which has whitening and antioxidant effects, was subjected to an in vitro DPPH free radical scavenging experiment, it was found that the osmanthus powder showed a scavenging rate of more than 20% for DPPH free radicals at an extremely low concentration (0.01 mg / mL), and achieved a highly efficient scavenging effect of more than 70% at a concentration of 0.1 mg / mL, indicating that it can effectively improve the dull yellow skin caused by skin oxidation and other factors. Attached Figure Description

[0021] Figure 1 Typical images showing the inhibitory effect of osmanthus powder on melanin in the head of zebrafish obtained in Example 1 and Comparative Examples 1-11.

[0022] Figure 2 The effect of Osmanthus powder obtained in Example 1 and Comparative Examples 1-11 on the melanin signal intensity in the head of zebrafish is shown in the figure (compared with the blank control group, ****p<0.0001, **p<0.01, ns represents no significant difference). Detailed Implementation

[0023] The first aspect of the present invention provides a method for preparing osmanthus powder with whitening and antioxidant effects, comprising the following steps:

[0024] 1) Osmanthus flowers are hydrolyzed with protease, enzyme is inactivated, and solid-liquid separation is performed to obtain filter residue and first filtrate;

[0025] 2) The filter residue is extracted with hot water and the solid and liquid are separated to obtain a second filtrate;

[0026] 3) The first filtrate and the second filtrate are mixed to form an extract, and the extract is filtered through a ceramic membrane to obtain a first permeate;

[0027] 4) The first permeate is filtered through an ultrafiltration membrane to obtain the second permeate;

[0028] 5) The second permeate is concentrated and dried to obtain osmanthus powder with whitening and antioxidant effects.

[0029] Unless otherwise specified in this invention, osmanthus powder refers to the flower of Osmanthus fragrans Lour., a plant of the Oleaceae family and the Osmanthus genus. It is rich in aromatic substances, such as α-lactone, α-ionone, 3-ionone, trans-linalool oxide, cis-linalool oxide, linalool, aldehydes, as well as β-phellandrene, nerol, geraniol, and dihydro-β-ionone.

[0030] In some embodiments, in step 1), the osmanthus flowers are pretreated before use, and the pretreatment includes washing and drying.

[0031] In some embodiments, the pretreatment involves soaking osmanthus flowers in water at 20-35°C, followed by solid-liquid separation. This invention, by soaking dried osmanthus flowers in water, facilitates subsequent enzymatic hydrolysis and extraction. Soaking time that is too long or too short is detrimental; too short a soaking time hinders subsequent enzymatic hydrolysis and extraction, while too long a soaking time causes the osmanthus flowers to become mushy.

[0032] In some embodiments, the osmanthus flowers are dried osmanthus flowers.

[0033] In some embodiments, the mass ratio of osmanthus flowers to water is 1:(15-20), or it can be 1:(15-18), or it can be 1:(16-20), or it can be 1:15, 1:16, 1:17, 1:18, 1:19, or 1:20.

[0034] In some embodiments, the soaking temperature is 20-35°C, or it can be 20-31°C, or it can be 30-35°C, or it can be 20°C, 25°C, 28°C, 30°C, 32°C, 33°C, or 35°C.

[0035] In some embodiments, the soaking time is 1 to 2 hours, or it can be 1 hour, 1.2 hours, 1.5 hours, 1.8 hours, or 2 hours.

[0036] In some embodiments, in step 1), the mass ratio of osmanthus and protease is 100:(0.1-0.5), or it can be 100:(0.1-0.3), or it can be 100:(0.25-0.5), or it can be 100:0.1, 100:0.2, 100:0.3, 100:0.4, or 100:0.5.

[0037] In some embodiments, the protease is selected from one or more of neutral protease, papain, fig protease, and bromelain. For example, the protease is a combination of three enzymes, such as a combination of neutral protease, papain, and fig protease; a combination of neutral protease, papain, and bromelain; a combination of neutral protease, fig protease, and bromelain; or a combination of papain, fig protease, and bromelain. It can also be a combination of four enzymes.

[0038] In some specific embodiments, the protease is selected from a mixture of neutral protease, papain, fig protease, and bromelain. The inventors have also used any three of these four enzymes to form a complex enzyme for enzymatic hydrolysis of osmanthus. The results showed that the osmanthus powder obtained from the combination of the three proteases had a total sugar content >55 wt%, but the yield was only 17-23 wt%, the total polyphenol content was 20-27 wt%, and the polypeptide content was 5.4-8.3 wt%. Furthermore, when monk fruit protease was used to replace any one of the neutral protease, papain, fig protease, and bromelain, the yield improved somewhat, but remained below 23%, and the polypeptide content was below 10%. However, the osmanthus powder obtained by enzymatic hydrolysis using a complex protease composed of neutral protease, papain, fig protease, and bromelain had a yield of over 25%, a total polyphenol content of 25-35 wt%, a total sugar content of 40-55 wt%, and a polypeptide content of 10-15 wt%. This indicates that the combination of these four enzymes exhibits high enzymatic specificity and synergistic effect on osmanthus, effectively increasing the total polyphenol content and polypeptide content, and enabling the high-value utilization of osmanthus resources.

[0039] In some more specific embodiments, the mass ratio of the neutral protease, papain, fig protease and bromelain is (1-2):(1-2):(0.5-1):(0.5-1), or it can be 1:2:0.5:0.5, 4:4:2:1, or 1:1:0.5:1.

[0040] In some embodiments, in step 1), the temperature of the enzymatic hydrolysis is 45-55°C, or it can be 45-51°C, or it can be 47-55°C, or it can be 45°C, 47°C, 49°C, 50°C, 52°C, 53°C, 54°C, or 55°C.

[0041] In some embodiments, in step 1), the enzymatic hydrolysis time is 2-6 hours, or it can be 2-4.5 hours, or it can be 4-6 hours, or it can be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, or 6 hours.

[0042] In some embodiments, in step 1), the pH value of the enzymatic hydrolysis is 7 to 8, or it can be 7, 7.2, 7.4, 7.5, 7.6, 7.8, 7.9, or 8.

[0043] In some embodiments, in step 1), the method for inactivating the enzyme is to heat the enzymatically hydrolyzed slurry to 90-100°C for 5-10 minutes. The enzyme inactivation temperature can also be 90°C, 92°C, 94°C, 96°C, 98°C, or 100°C, and the enzyme inactivation time can also be 5 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes.

[0044] In some embodiments, in step 1), the solid-liquid separation is performed by sieving. Specifically, sieving is done through a 100-200 mesh sieve.

[0045] In some embodiments, in step 2), the hot water extraction temperature is 80–100°C, or it can be 80°C, 85°C, 90°C, 95°C, or 100°C. Preferably, it is 85–95°C. This invention has also attempted hot water extraction at 60°C, and the results showed a significant increase in polypeptide content, but a substantial decrease in yield, percentage, and total polyphenol content. This indicates that hot water extraction is beneficial for breaking down plant cell walls and dissolving polyphenolic substances.

[0046] In some embodiments, in step 2), the hot water extraction time is 1 to 3 hours, or it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours. Preferably, it is 1 to 2 hours.

[0047] In some embodiments, in step 2), the mass ratio of the filter residue to water is 1:(15-30), or it can be 1:15, 1:18, 1:20, 1:22, 1:25, 1:28, or 1:30. Preferably, it is 1:(18-25).

[0048] In some implementations, in step 2), the hot water extraction is performed at least once, such as once, twice, three times, four times, or five times. Preferably, for cost reasons, it is performed twice.

[0049] In some embodiments, in step 3), the pore size of the ceramic membrane is 200–800 nm, or it can be 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, or 800 nm. Preferably, it is 300–500 nm. This invention removes large molecules such as proteins and water-insoluble impurities from the first permeate using a ceramic membrane. This invention has also attempted filtration without a ceramic membrane, and the results showed a decrease in total polyphenols and total sugars, while a significant increase in polypeptide content, indicating that direct ultrafiltration without a ceramic membrane leads to ultrafiltration membrane fouling or a decrease in retention efficiency.

[0050] In some embodiments, in step 4), the molecular weight cutoff of the ultrafiltration membrane is 5-50 kDa, or it can be 5 kDa, 10 kDa, 15 kDa, 20 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, or 50 kDa. Preferably, it is 10-20 kDa. This invention removes water-soluble macromolecules such as proteins and crude polysaccharides (total sugars) from the second permeate using an ultrafiltration membrane. This invention has also attempted filtration without an ultrafiltration membrane, and found that the total polyphenol and polypeptide content was significantly reduced. Without the fine separation of the ultrafiltration membrane, although the solids yield was higher, the concentration of effective active ingredients (polyphenols and polypeptides) was actually lost. Only through the combination of a ceramic membrane and an ultrafiltration membrane can polyphenols, total sugars, and polypeptides be enriched.

[0051] In some embodiments, in step 5), the concentration temperature is 40–75°C, and the concentration is carried out to a solid content mass fraction of 20–40%. The concentration temperature can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, or 75°C; the concentration to a solid content mass fraction can be 20%, 25%, 30%, 35%, or 40%. The solid content in this application cannot be too low or too high. If it is too low, the subsequent powder spraying time will be too long, and the powder will be too fluffy and have poor flowability; if it is too high, the viscosity of the concentrate will be too high, and the subsequent powder spraying will easily clog the nozzle.

[0052] In some embodiments, the concentration temperature is 50-70°C, and the concentration is carried out to a solid content of 25-35% by mass.

[0053] In some implementations, the drying in step 5) is spray drying.

[0054] In some embodiments, the inlet temperature of the spray dryer is 160–220°C, or it can be 160–190°C, or 180–200°C, or it can be 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 200°C, 210°C, or 220°C.

[0055] A second aspect of the present invention provides osmanthus powder with whitening and antioxidant effects obtained by the preparation method described above.

[0056] In some embodiments, the osmanthus powder with whitening and antioxidant effects contains 25-35 wt% polyphenols, 40-55 wt% total sugars, and 10-15 wt% polypeptides.

[0057] In some implementations, the total polyphenol and polypeptide content is higher than 38.5 wt%.

[0058] The method for detecting total polyphenols in this invention is based on the determination method in GB / T8313-2018. The method for detecting total sugars is based on the "Phenol-Sulfuric Acid Spectrophotometric Determination of Crude Polysaccharides" in "Detection Methods for Efficacy Components of Health Foods" edited by Bai Hong, published in May 2011. The relative molecular weight of polypeptides is ≤5000. The method for detecting polypeptides is based on the "Determination Method of Peptide Content" in Appendix B of GB / T22492 "Soybean Peptide Powder". The peptide content is obtained by subtracting the free amino acid content from the acid-soluble protein content.

[0059] Osmanthus powder contains polyphenolic active ingredients, especially verbascoside, rhodioloside, and privetin. Among them, verbascoside can effectively inhibit tyrosinase activity and melanin synthesis in melanoma cells; phenylethyl glycosides can competitively inhibit tyrosinase and scavenge free radicals, thereby reducing melanin production signals induced by ultraviolet radiation or oxygen free radicals. However, existing osmanthus extracts have low total polyphenol and polypeptide content, resulting in poor whitening effects. High total sugar content increases the viscosity of the extract, affecting the penetration and absorption efficiency of active ingredients (such as polyphenols).

[0060] This invention utilizes protease to hydrolyze osmanthus flowers to release a large amount of active substances, followed by hot water extraction at 80°C and filtration through ultrafiltration and ceramic membranes. This significantly increases the total polyphenol and polypeptide content in the osmanthus extract while reducing the total sugar content.

[0061] A third aspect of the present invention provides the use of osmanthus powder, which has whitening and antioxidant effects as described above, in the preparation of food, pharmaceuticals or cosmetics with antioxidant effects.

[0062] A fourth aspect of the present invention provides a food, medicine or cosmetic with antioxidant properties, comprising osmanthus powder with whitening and antioxidant properties as described above.

[0063] In some embodiments, the dosage form of the medicine is any one of tablets, capsules, powders, granules, or oral liquids.

[0064] In some embodiments, the pharmaceutical product further includes pharmaceutically acceptable excipients.

[0065] In some specific embodiments, the pharmaceutically acceptable excipients are excipients, glidants, sweeteners, diluents, preservatives, dyes / colorants, flavor enhancers, surfactants, wetting agents, dispersants, suspending agents, stabilizers, isotonic agents, solvents, or emulsifiers.

[0066] In some embodiments, the food and health food also include nutritionally acceptable excipients.

[0067] In some embodiments, the health food is selected from one or more of solid beverages, liquid beverages, dairy products, flavoring powders, nutritional products, and oral health care products, preferably solid beverages.

[0068] In some embodiments, the nutritionally acceptable excipient is selected from one or more of sweeteners, acid regulators, fillers, flavoring agents, colorants, antioxidants, thickeners, stabilizers, emulsifiers, anti-caking agents, flow aids, and lubricants.

[0069] The preparation method of this invention involves a series of steps including enzymatic hydrolysis with protease, hot water extraction, and synergistic treatment with ceramic membranes and ultrafiltration membranes. In particular, the enzymatic hydrolysis method using a specific protease yields osmanthus powder with whitening and antioxidant effects. The yield is higher than 25%, and the content of active ingredients is also high, with total polyphenols at 25-35 wt%, total sugars at 40-55 wt%, and polypeptides at 10-15 wt%. In vivo zebrafish experiments using the osmanthus powder of this invention showed an 82.3% reduction in melanin signal intensity compared to the blank control group, indicating its skin-whitening effect. Furthermore, in vitro DPPH free radical scavenging experiments revealed that osmanthus powder exhibited a DPPH scavenging rate exceeding 20% ​​at extremely low concentrations (0.01 mg / mL), and achieved a highly efficient scavenging effect of over 70% at a concentration of 0.1 mg / mL, demonstrating its ability to effectively improve dull skin caused by skin oxidation and other factors. Furthermore, the preparation method of this invention does not use any organic solvents or toxic and harmful compounds. It is simple to operate, safe, and environmentally friendly, making it suitable for large-scale production. Therefore, it has broad industrialization and application prospects.

[0070] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0071] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0072] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0073] Unless otherwise specified, the raw materials used in the following embodiments and comparative examples of this application are all commercially available raw materials.

[0074] The neutral protease was purchased from Shanxi Zhongnuo Biotechnology Co., Ltd., food grade, with an enzyme activity of 100,000 U / g.

[0075] Papain was purchased from Chongqing Tianrun Biological Products Co., Ltd., food grade, enzyme activity 100,000 U / g;

[0076] The fig protease was purchased from Jiangsu Duoyang Bioengineering Technology Co., Ltd., food grade, with an enzyme activity of 800,000 U / g.

[0077] Bromelain was purchased from Nanning Pangbo Biotechnology Co., Ltd. in Guangxi Zhuang Autonomous Region. It was food grade and had an enzyme activity of 50,000 U / g.

[0078] The monk fruit protease was purchased from Guilin Jifusi Monk Fruit Biotechnology Co., Ltd. in Guangxi Zhuang Autonomous Region. It is food grade and has an enzyme activity of 50,000 U / g.

[0079] Example 1

[0080] This embodiment 1 provides an osmanthus powder with whitening and antioxidant effects, specifically through the following steps:

[0081] 1) Osmanthus flowers and water were mixed at a mass ratio of 1:15 and soaked at 25℃ for 1 hour. Solid-liquid separation was performed, and the mixture was dried to obtain pretreated dried osmanthus flowers. 100 kg of dried osmanthus flowers and 100 g of protease were weighed and enzymatically hydrolyzed in water at 50℃ and pH 7 for 4 hours. Then, the temperature was raised to 95℃ for 8 minutes to inactivate the enzyme. The mixture was passed through a 100-mesh sieve to obtain filter residue and the first filtrate. The protease consisted of neutral protease, papain, fig protease, and bromelain, with a mass ratio of 1:2:0.5:0.5.

[0082] 2) Add 20 times the weight of purified water to the filter residue and heat to 95℃ for 2 hours. Repeat the extraction twice and pass the residue through a 100-mesh sieve to obtain the second filtrate.

[0083] 3) Separation and purification: Combine the first filtrate and the second filtrate to obtain the extract. Filter the extract through a 300nm ceramic membrane, discard the retentate, and collect the filtrate to obtain the first permeate.

[0084] 4) Filter the first permeate using a 5 kDa ultrafiltration membrane to remove the retentate and retain the filtrate to obtain the second permeate;

[0085] 5) Concentration and drying: The second permeate is concentrated at 60°C to a solid content of 30%, and then spray-dried at an outlet temperature of 195°C to obtain osmanthus powder with whitening and antioxidant effects.

[0086] The yield and output are shown in Table 2.

[0087] Example 2

[0088] This embodiment 2 provides an osmanthus powder with whitening and antioxidant effects, specifically through the following steps:

[0089] 1) Osmanthus flowers and water were mixed at a mass ratio of 1:17 and soaked at 20℃ for 1.5 hours. Solid-liquid separation was performed, and the mixture was dried to obtain pretreated dried osmanthus flowers. 100 kg of dried osmanthus flowers and 200 g of protease were weighed and enzymatically hydrolyzed in water at 45℃ for 6 hours. Then, the temperature was raised to 100℃ for 5 minutes to inactivate the enzyme. The mixture was passed through a 100-mesh sieve to obtain filter residue and the first filtrate. The protease consisted of neutral protease, papain, fig protease, and bromelain, with a ratio of 2:4:1:1.

[0090] 2) Add 15 times the weight of purified water to the filter residue and heat to 80℃ for 3 hours. Repeat the extraction twice and pass through a 100-mesh sieve to obtain the second filtrate.

[0091] 3) Separation and purification: Combine the first filtrate and the second filtrate to obtain the extract. Filter the extract through a 200nm ceramic membrane, discard the retentate, and collect the filtrate to obtain the first permeate.

[0092] 4) Filter the first permeate using a 25kDa ultrafiltration membrane to remove the retentate and retain the filtrate to obtain the second permeate;

[0093] 5) Concentration and drying: The second permeate is concentrated at 75°C to a solid content of 20%, and then spray-dried at an outlet temperature of 200°C to obtain osmanthus powder with whitening and antioxidant effects.

[0094] The yield and output are shown in Table 2.

[0095] Example 3

[0096] This embodiment 3 provides an osmanthus powder with whitening and antioxidant effects, specifically through the following steps:

[0097] 1) Osmanthus flowers and water were mixed at a mass ratio of 1:20 and soaked at 20℃ for 2 hours. Solid-liquid separation was performed, and the mixture was dried to obtain pretreated dried osmanthus flowers. 100 kg of dried osmanthus flowers and 300 g of protease were weighed and hydrolyzed in water at 55℃ for 2 hours. Then, the temperature was raised to 90℃ for 10 minutes to inactivate the enzyme. The mixture was passed through a 100-mesh sieve to obtain filter residue and the first filtrate. The protease consisted of neutral protease, papain, fig protease, and bromelain, with a ratio of 2:4:1:1.

[0098] 2) Add 30 times the weight of purified water to the filter residue and heat to 100℃ for 1 hour. Repeat the extraction twice and pass through a 100-mesh sieve to obtain the second filtrate.

[0099] 3) Separation and purification: Combine the first filtrate and the second filtrate to obtain the extract. Filter the extract through an 800nm ​​ceramic membrane, discard the retentate, and collect the filtrate to obtain the first permeate.

[0100] 4) Filter the first permeate using a 50 kDa ultrafiltration membrane to remove the retentate and retain the filtrate to obtain the second permeate;

[0101] 5) Concentration and drying: The second permeate is concentrated at 45°C to a solid content of 40%, and then spray-dried at an outlet temperature of 160°C to obtain osmanthus powder with whitening and antioxidant effects.

[0102] The yield and output are shown in Table 2.

[0103] Example 4

[0104] The difference between Example 4 and Example 1 is that the ratio of neutral protease, papain, fig protease, and bromelain is 4:4:2:1. All other aspects are the same as in Example 1.

[0105] Its yield was 26.3%, the total polyphenol content was 31.9 wt%, the total sugar content was 52.5 wt%, and the polypeptide content was 11.6 wt%.

[0106] Example 5

[0107] The difference between Example 5 and Example 1 is that the ratio of neutral protease, papain, fig protease, and bromelain is 1:1:0.5:1. All other aspects are the same as in Example 1.

[0108] Its yield was 26.8 wt%, the total polyphenol content was 31.4 wt%, the total sugar content was 51.9 wt%, and the polypeptide content was 11.8 wt%.

[0109] Comparative Example 1

[0110] The only difference from Example 1 is that 60°C hot water extraction is used; otherwise, they are the same as in Example 1.

[0111] The yield and output are shown in Table 2.

[0112] Comparative Example 2

[0113] The only difference from Example 1 is that only an ultrafiltration membrane is used, and ceramic membrane filtration is not used; otherwise, they are the same as in Example 1.

[0114] The yield and output are shown in Table 2.

[0115] Comparative Example 3

[0116] The difference from Example 1 is that only ceramic membrane filtration is used, and ultrafiltration membrane is not used; otherwise, they are the same as in Example 1.

[0117] The yield and output are shown in Table 2.

[0118] Comparative Example 4

[0119] The difference from Example 1 is that neutral protease, papain, and fig protease were used, but bromelain was not used; otherwise, they are the same as in Example 1.

[0120] The yield and output are shown in Table 2.

[0121] Comparative Example 5

[0122] The difference from Example 1 is that neutral protease, papain, and bromelain were used, but fig protease was not used; otherwise, they are the same as in Example 1.

[0123] The yield and output are shown in Table 2.

[0124] Comparative Example 6

[0125] The difference from Example 1 is that neutral protease, fig protease, and bromelain were used, but papain was not used; otherwise, they are the same as in Example 1.

[0126] The yield and output are shown in Table 2.

[0127] Comparative Example 7

[0128] The difference from Example 1 is that papain, fig protease and bromelain were used, and neutral protease was not used. Otherwise, they are the same as in Example 1.

[0129] The yield and output are shown in Table 2.

[0130] Comparative Example 8

[0131] The difference from Example 1 is that neutral protease, papain, bromelain, and monk fruit protease are used, while the rest are the same as in Example 1.

[0132] The yield and output are shown in Table 2.

[0133] Comparative Example 9

[0134] The difference from Example 1 is that neutral protease, fig protease, bromelain, and monk fruit protease are used, while the rest are the same as in Example 1.

[0135] The yield and output are shown in Table 2.

[0136] Comparative Example 10

[0137] The difference from Example 1 is that papain, fig protease, bromelain, and monk fruit protease are used, while the rest are the same as in Example 1.

[0138] The yield and output are shown in Table 2.

[0139] Comparative Example 11

[0140] The difference from Example 1 is that neutral protease, fig protease, papain, bromelain, and monk fruit protease are used, while the rest are the same as in Example 1.

[0141] The yield and output are shown in Table 2.

[0142] The amounts of osmanthus and protease added in Examples 1-3 and Comparative Examples 1-11 are shown in Table 1 below.

[0143] Table 1

[0144]

[0145] Total polyphenols, total sugars and polypeptide content

[0146] The yield and productivity of osmanthus powder in Examples 1-3 and Comparative Examples 1-11, as well as the content of total polyphenols, total sugars and polypeptides in osmanthus powder, are shown in Table 2.

[0147] The determination method for total polyphenols is based on the method specified in GB / T8313-2018 "Determination of the content of tea polyphenols and catechins in tea", which is the determination method for the content of tea polyphenols.

[0148] The total sugar was determined according to the "Phenol-Sulfuric Acid Spectrophotometric Determination of Crude Polysaccharides" in "Detection Methods for Efficacy Components of Health Foods" edited by Bai Hong and published in May 2011.

[0149] The determination method for peptides is as described in Appendix B of GB / T22492 "Soybean Peptide Powder," which specifies the determination of peptide content. The peptide content is calculated by subtracting the free amino acid content from the acid-soluble protein content. The relative molecular weight of peptides should be ≤5000.

[0150] Table 2

[0151] Example 1 25.5 25.5 32.5 52.1 10.8 Example 2 27.9 27.9 29.7 51.8 12.5 Example 3 30.1 30.1 27.3 53.6 13.6 Comparative Example 1 15.3 15.3 19.5 43.7 22.7 Comparative Example 2 18.6 18.6 24.6 47.3 24.9 Comparative Example 3 29.6 29.6 27.4 59.3 7.4 Comparative Example 4 21.3 21.3 27.1 58.6 8.3 Comparative Example 5 20.7 20.7 26.4 59.7 7.9 Comparative Example 6 18.1 18.1 21.4 66.5 5.4 Comparative Example 7 17.6 17.6 20.3 65.4 7.6 Comparative Example 8 19.9 19.9 28.0 58.8 8.6 Comparative Example 9 18.3 18.3 22.3 64.6 6.1 Comparative Example 10 18.0 18.0 19.8 65.3 5.9 Comparative Example 11 22.3 22.3 28.6 56.9 9.1

[0152] As shown in Table 2, compared with Example 1, Comparative Example 1, which did not use hot water extraction above 80°C, had a very low yield and rate of osmanthus powder, decreasing by 40%. Furthermore, the total polyphenol content decreased by 40%, and the total sugar content decreased by 16.1%, but the polypeptide content increased by 110.2%. This indicates that extraction without hot water above 80°C leads to incomplete extraction, resulting in relatively lower total polyphenol and total sugar content, leading to a lower final yield and a relatively higher polypeptide content. Therefore, the use of hot water extraction above 80°C in this invention is beneficial for breaking down plant cell walls and dissolving total polyphenols and total polysaccharides.

[0153] As shown in Table 2, compared with Example 1, Comparative Example 2, which was filtered through an ultrafiltration membrane but not through a ceramic membrane, had a lower yield and efficiency of osmanthus powder, decreasing by 27.1%. Furthermore, the total polyphenol content decreased by 24.3%, the total sugar content decreased by 9.2%, but the peptide content increased by 130.6%. This indicates that without a ceramic membrane, direct ultrafiltration allows large particles to clog the ultrafiltration membrane, further leading to membrane fouling or decreased retention efficiency.

[0154] As shown in Table 2, compared with Example 1, Comparative Example 3, which only used ceramic membrane filtration without ultrafiltration, showed a slight increase in the yield and output of osmanthus powder, increasing by 16.1%. Furthermore, the total polyphenol content decreased by 15.7%, the total sugar content increased by 13.8%, but the polypeptide content decreased by 31.5%. This indicates that using only ceramic membrane filtration without ultrafiltration removed a small amount of large particulate matter. Although the yield and output were higher, the concentration of effective active ingredients (polyphenols and polypeptides) was actually lower.

[0155] As shown in Table 2, compared with Example 1, Comparative Example 4 used neutral protease, papain and fig protease but not bromelain. The results showed that the yield and efficiency of osmanthus powder were reduced by 16.5%. In addition, the total polyphenol content decreased by 16.6%, the total sugar content increased by 12.5%, but the polypeptide content decreased by 23.1%.

[0156] As shown in Table 2, compared with Example 1, Comparative Example 5 used neutral protease, papain and bromelain instead of fig protease. The results showed that the yield and efficiency of osmanthus pollen were reduced by 18.8%. In addition, the total polyphenol content was reduced by 18.8%, the total sugar content was increased by 14.6%, but the polypeptide content was reduced by 26.9%.

[0157] As shown in Table 2, compared with Example 1, Comparative Example 6 used neutral protease, fig protease and bromelain but not papain. The results showed that the yield and efficiency of osmanthus pollen were reduced by 29.0%. In addition, the total polyphenol content decreased by 34.2%, the total sugar content increased by 27.6%, but the polypeptide content decreased by 50%.

[0158] As shown in Table 2, compared with Example 1, Comparative Example 7 used papain, fig protease and bromelain instead of neutral protease. The results showed that the yield and efficiency of osmanthus pollen were reduced by 31%. In addition, the total polyphenol content decreased by 37.5%, the total sugar content increased by 25.5%, but the polypeptide content decreased by 29.6%.

[0159] Comparative analysis of the experimental results of Example 1 and Comparative Examples 4-7 shows that although the combination of three proteases improved the extraction rate of total sugar to a certain extent, the overall quality indicators of the product declined significantly, specifically in terms of yield, output, total polyphenol content and polypeptide content.

[0160] As shown in Table 2, compared with Example 1, Comparative Example 8 used neutral protease, papain, bromelain and monk fruit protease. The results showed that the yield and efficiency of osmanthus powder were reduced by 22%. In addition, the total polyphenol content decreased by 13.8%, the total sugar content increased by 12.9%, but the polypeptide content decreased by 20.4%.

[0161] As shown in Table 2, compared with Example 1, Comparative Example 9 used neutral protease, fig protease, bromelain and monk fruit protease. The results showed that the yield and efficiency of osmanthus powder were reduced by 28.2%. In addition, the total polyphenol content was reduced by 31.4%, the total sugar content was increased by 24%, but the polypeptide content was reduced by 43.5%.

[0162] As shown in Table 2, compared with Example 1, Comparative Example 10 used cucurbitacin, fig protease, bromelain and monk fruit protease. The results showed that the yield and efficiency of osmanthus powder were reduced by 29.4%. In addition, the total polyphenol content decreased by 39.1%, the total sugar increased by 25.3%, but the polypeptide content decreased by 45.4%.

[0163] As shown in Table 2, compared with Example 1, Comparative Example 11 used neutral protease, papain, bromelain and monk fruit protease. The results showed that the yield and efficiency of osmanthus powder were reduced by 12.5%. In addition, the total polyphenol content was reduced by 12.0%, the total sugar content was increased by 9.2%, but the polypeptide content was reduced by 15.7%.

[0164] Enzyme substitution experiments in ratios 8-11 revealed that when any one of the neutral protease, papain, fig protease, and bromelain was replaced with monk fruit protease, although the total sugar content increased, other key indicators (yield, yield, total polyphenols, and polypeptides) also deteriorated. This demonstrates the irreplaceable nature of the four enzymes in the combination; any omission or substitution will disrupt the synergistic effect of the enzyme system.

[0165] In summary: 1) Comparative Examples 1-3 demonstrate that the three steps of hot water extraction, ceramic membrane filtration, and ultrafiltration in the process of this invention constitute a functionally synergistic whole. The absence of any one step would prevent the achievement of high yield, high polyphenol content, and high polypeptide content of osmanthus pollen, and would instead lead to an imbalance in the indicators.

[0166] 2) Comparative Examples 4-11 demonstrate that a specific complex protease system composed of neutral protease, papain, fig protease, and bromelain exhibits high enzymatic specificity and synergistic effect on osmanthus. This combination not only significantly improves the extraction yield and efficiency of osmanthus powder, but also simultaneously enriches total polyphenols and polypeptides, realizing the high-value utilization of osmanthus resources.

[0167] Application Example 1

[0168] Taking Example 1 as an example, the applicant conducted experiments to determine the whitening and antioxidant effects of the osmanthus powder obtained in Example 1 and Comparative Examples 1 to 11.

[0169] 1.1 Whitening effect

[0170] 1.1.1 Experimental Materials

[0171] The wild-type AB strain zebrafish broodstock used in this experiment were purchased from Huante Biotechnology Co., Ltd., and the juveniles were bred by our company using broodstock.

[0172] The instruments and equipment used included a biochemical incubator (HT-250H-T, Huante Biotechnology, China), an electronic balance (0.1 g, METTLER, Switzerland), a six-well culture plate (corning, USA), a stereomicroscope (MZ62, Mshot, China), and a microscope imaging system (BX53, OLYMPUS Japan).

[0173] 1.1.2 Determination of maximum tolerated concentration

[0174] Wild-type AB strain zebrafish embryos with normal development at 24 hpf were randomly selected and placed into six-well culture plates, 30 embryos per well. The standard dilution water of the six-well plate was removed without harming the embryos. 3 mL of osmanthus pollen dilution prepared in Example 1 and Comparative Examples 1-11 with concentrations of 4 mg / mL, 2 mg / mL, 1 mg / mL, 0.5 mg / mL, and 0.25 mg / mL were added to each well (the dilution was obtained by dissolving the final product of osmanthus pollen in water from each example and comparative example).

[0175] Cover the culture plate with the panel and wrap it with aluminum foil. Incubate in a biochemical incubator at (28.5±1)℃ in the dark for 24 hours. After 24 hours, count the number of zebrafish that died in each concentration group and determine the maximum tolerance concentration of the sample to zebrafish. The concentration at which no zebrafish died was the maximum tolerance concentration of zebrafish to the sample.

[0176] 1.1.3 Evaluation of melanin inhibition effect

[0177] 1) The experimental groups were set as a blank control group and experimental groups (Example 1 group and Comparative Examples 1-11 groups). The blank control group was purified water, and the experimental groups were diluted osmanthus pollen solutions prepared in Example 1 and Comparative Examples 1-11. The volume of each well was 3 mL. According to the above maximum tolerated concentration determination, the survival rate of zebrafish treated with 1 mg / mL osmanthus pollen reached 100%. Therefore, the effective concentration of osmanthus pollen in subsequent experiments was set at 1 mg / mL.

[0178] 2) After incubating in a (28.5±1)℃ biochemical incubator in the dark for 24 hours, at least 10 zebrafish were randomly selected from each experimental group, fixed with 3% methylcellulose, observed and photographed under a bright-field microscope, and the melanin patches on the heads of the zebrafish were photographed and collected. The results are as follows: Figure 1 As shown.

[0179] 3) The intensity of melanin signal in the zebrafish head was quantitatively analyzed using ImageJ advanced image processing software. The statistical analysis results of this index were used to evaluate the ability of the samples to inhibit melanin production. Statistical results are expressed as mean ± SD. Graphpad Prism 8.0 software was used for plotting and statistical analysis. P < 0.05 indicated that the difference was statistically significant.

[0180] 4) Result Interpretation: Using the melanin signal intensity in the zebrafish head as an indicator, a one-way ANOVA was performed with the results compared to the blank control group. A P-value < 0.05 was considered indicative of the test sample's ability to inhibit melanin production in zebrafish. The test results are shown in Table 3. Figure 1 and Figure 2As shown.

[0181] Table 3

[0182] Blank control group 32014.65±1898.86 / Example 1 5659.29±1031.81 <0.0001 Comparative Example 1 31034.85±2146.65 0.9996 Comparative Example 2 21011.12±658.84 <0.01 Comparative Example 3 22011.12±2857.85 ＜0.05 Comparative Example 4 22791.54±2238.44 ＜0.05 Comparative Example 5 23418.79±3855.75 ＜0.05 Comparative Example 6 28375.63±1942.09 0.8295 Comparative Example 7 28839.21±1804.88 0.9156 Comparative Example 8 14457.06±787.73 ＜0.0001 Comparative Example 9 28040.06±1732.44 0.7512 Comparative Example 10 29993.30±2438.75 0.9957 Comparative Example 11 14501.02±968.19 ＜0.0001

[0183] As shown in Table 3 and Figure 2 As shown, compared with the blank control group, the melanin signal intensity in the heads of zebrafish in Example 1 and Comparative Examples 1-11 was reduced by 82.3%, 3.1%, 34.4%, 31.2%, 28.8%, 26.8%, 11.4%, 9.9%, 54.8%, 12.4%, 6.3%, and 54.7%, respectively. Among them, the melanin signal intensity in Example 1 was significantly reduced (P<0.0001), indicating that the osmanthus powder prepared by the method of the present invention can effectively inhibit the production of melanin in zebrafish and has the strongest whitening effect.

[0184] Compared with the blank control group, the melanin signal intensity of Comparative Example 1 was almost not reduced, with no significant difference (P=0.9996). The reason may be that Comparative Example 1 did not use hot water to extract osmanthus, resulting in the total polyphenol content in osmanthus powder being less than 25wt%, which in turn led to a weaker ability to inhibit melanin.

[0185] Compared with the blank control group, the melanin signal intensity of Comparative Example 2 was significantly reduced (P<0.01). The reason may be that only ultrafiltration membrane was used instead of ceramic membrane filtration, resulting in a higher permeability of small molecule peptides, which led to an increase in peptide content and thus better melanin inhibition ability.

[0186] Compared with the blank control group, there was no significant difference in the reduction of melanin signal intensity in Comparative Example 3 (P < 0.05). The reason may be that only ceramic membrane filtration was used instead of ultrafiltration membrane filtration, which could only remove a small amount of large particles, resulting in a decrease in the proportion of total polyphenols and total sugars. Although it has the ability to inhibit melanin, the effect is not significant.

[0187] Compared with the blank control group, the osmanthus powder obtained by enzymatic hydrolysis using a complex protease formed by any three of the enzymes selected from papain, fig protease, bromelain, and neutral protease in Comparative Examples 4-7 showed a decrease in melanin signal intensity between 9.9% and 28.8%. This indicates that the osmanthus powder obtained by enzymatic hydrolysis using a complex protease formed by any three enzymes has almost no whitening effect because the total polyphenol content is less than 29%, the polypeptide content is less than 9.5%, and the sum of the total polyphenol and polypeptide content is less than 38.5%.

[0188] Compared with the blank control group, comparative examples 8-11, which used monk fruit protease to replace any one of the neutral protease, papain, fig protease and bromelain respectively, reduced the melanin signal intensity by 6.3-54.8%; especially comparative examples 9 and 10, the total polyphenol content was less than 25%, the polypeptide content was less than 6.5%, and the sum of the total polyphenol and polypeptide content was less than 31.5%, resulting in almost no whitening effect (P>0.05).

[0189] In summary, the osmanthus powder prepared by the method of the present invention has the effect of inhibiting the production of melanin in zebrafish, thereby having a whitening effect.

[0190] 1.2 Determination of antioxidant properties

[0191] DPPH radical (1,1-diphenyl-2-trinitrophenylhydrazine) is a very stable free radical, often used to evaluate the in vitro antioxidant properties of active substances. A higher free radical scavenging rate indicates stronger antioxidant capacity. Improving the skin's antioxidant capacity can effectively reduce oxidative stress and improve dull skin.

[0192] 1.2.1 Solution Preparation

[0193] Weigh 20 mg of DPPH, dissolve it in 95% ethanol, and bring the volume to 250 mL to prepare a 0.2 mmol / L DPPH solution for later use; prepare osmanthus pollen dilutions of 0.01 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.5 mg / mL, and 1 mg / mL concentrations as in Example 1 and Comparative Examples 1-11, as well as solutions of Vc (water-soluble antioxidant) and BHT (lipid-soluble synthetic antioxidant) with the same concentration gradient.

[0194] 1.2.2 DPPH Reaction System

[0195] The reaction was performed using a 96-well plate, with 200 μL of the test system added to each sample well. The groups were set as follows:

[0196] Experimental group: Equal volumes of Osmanthus pollen dilution from Example 1 and Comparative Examples 1-11 and 0.2 mmol / L DPPH solution were mixed in the sample wells;

[0197] Sample background control group: equal amounts of Osmanthus powder dilution from Example 1 and Comparative Examples 1-11 and 75% ethanol aqueous solution were mixed in the sample wells;

[0198] Blank group: Equal volumes of 75% ethanol aqueous solution and 0.2 mmol / L DPPH solution were mixed in the sample wells;

[0199] Positive control group: Equal volumes of vitamin C and 0.2 mmol / L DPPH solution were mixed in the sample wells; equal volumes of BHT solution and 0.2 mmol / L DPPH solution were mixed in the sample wells.

[0200] After mixing the test system in the above sample wells evenly, react at room temperature (25℃) in the dark for 45 min, and then use a spectrophotometer to measure the absorbance value at 517 nm.

[0201] 1.2.3 Calculation of free radical scavenging rate

[0202] Free radical scavenging rate = [1-(A1-A2) / A0]×100%, where A1 is the absorbance value of the experimental group, A2 is the absorbance value of the sample background control group, and A0 is the absorbance value of the blank group.

[0203] Scavenging rate is a direct indicator of antioxidant capacity. The higher the scavenging rate, the stronger the antioxidant capacity.

[0204] The specific test results are shown in Table 4.

[0205] Table 4

[0206] Example 1 20.88 45.19 73.28 98.26 99.34 Comparative Example 1 8.30 17.91 25.52 91.35 95.58 Comparative Example 2 10.15 25.33 33.05 95.33 96.43 Comparative Example 3 13.03 29.45 39.91 95.76 95.99 Comparative Example 4 12.76 29.07 39.22 95.48 96.42 Comparative Example 5 12.49 28.19 38.17 95.76 95.86 Comparative Example 6 9.85 21.83 28.93 91.77 95.08 Comparative Example 7 8.70 20.82 27.42 91.46 95.65 Comparative Example 8 13.54 30.30 41.21 95.83 96.72 Comparative Example 9 11.30 20.49 30.62 91.79 95.16 Comparative Example 10 8.54 19.05 26.39 91.35 95.31 Comparative Example 11 14.03 30.66 42.51 96.01 96.61

[0207] As shown in Table 4, the scavenging rate of Example 1 consistently exceeded the preset high thresholds (20%, 40%, and 70%) at low (0.01 mg / mL), medium (0.05 mg / mL, 0.1 mg / mL), and high (0.5 mg / mL, 1 mg / mL) test concentrations. This indicates that the osmanthus powder obtained by the preparation method of the present invention exhibits a scavenging rate exceeding 20% ​​at extremely low concentrations (0.01 mg / mL) and achieves a highly efficient scavenging effect of over 70% at a concentration of 0.1 mg / mL.

[0208] As can be seen from the scavenging rate data corresponding to the test concentrations (0.05 mg / mL, 0.1 mg / mL) in Table 4, the scavenging rate of DPPH free radicals by the osmanthus powder of Comparative Examples 1 to 11 is much lower than that of the osmanthus powder of Example 1.

[0209] In summary, the osmanthus powder provided by this application has a good effect on inhibiting melanin and scavenging DPPH free radicals, thus having good whitening and antioxidant functions.

[0210] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing osmanthus powder with whitening and antioxidant effects, characterized in that, Includes the following steps: 1) Osmanthus flowers are hydrolyzed with protease, enzyme is inactivated, and solid-liquid separation is performed to obtain filter residue and first filtrate; 2) The filter residue is extracted with hot water and the solid and liquid are separated to obtain a second filtrate; 3) The first filtrate and the second filtrate are mixed to form an extract, and the extract is filtered through a ceramic membrane to obtain a first permeate; 4) The first permeate is filtered through an ultrafiltration membrane to obtain the second permeate; 5) The second permeate is concentrated and dried to obtain osmanthus powder with whitening and antioxidant effects; The temperature of the hot water extraction is 80–100°C; The protease is a mixture of neutral protease, papain, fig protease and bromelain, wherein the mass ratio of the neutral protease, papain, fig protease and bromelain is (1-2):(1-2):(0.5-1):(0.5-1).

2. The preparation method according to claim 1, characterized in that, In step 1), the mass ratio of the osmanthus flower to the protease is 100:(0.1-0.5).

3. The preparation method according to claim 1, characterized in that, The enzymatic hydrolysis temperature is 45–55°C; And / or, the enzymatic hydrolysis time is 2–6 hours; And / or, the pH value of the enzymatic hydrolysis is 7-8.

4. The preparation method according to claim 1, characterized in that, In step 2), the hot water extraction time is 1 to 3 hours; And / or, in step 2), the mass ratio of the filter residue to water is 1:(15-30); And / or, in step 3), the pore size of the ceramic membrane is 200–800 nm; And / or, in step 4), the molecular weight cutoff of the ultrafiltration membrane is 5 to 50 kDa; And / or, in step 5), the concentration temperature is 40–75°C, and the concentration is carried out until the mass fraction of solid content is 20–40%.

5. The preparation method according to claim 1, characterized in that, The osmanthus flowers are pretreated before use, and the pretreatment includes washing and drying.

6. Osmanthus powder with whitening and antioxidant effects obtained by the preparation method according to any one of claims 1 to 5.

7. The osmanthus powder with whitening and antioxidant effects as described in claim 6, characterized in that, The osmanthus powder with whitening and antioxidant effects contains 25-35 wt% polyphenols, 40-55 wt% total sugars, and 10-15 wt% polypeptides.

8. The use of osmanthus powder with whitening and antioxidant effects as described in claim 6 or 7 in the preparation of food, medicine or cosmetic with antioxidant effects.

9. A food, medicine, or cosmetic with antioxidant properties, characterized in that, It contains osmanthus powder with whitening and antioxidant effects as described in claim 6 or 7.

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