Preparation method of cranberry extract
Technical Field
The invention relates to an extraction and separation process of active ingredients in cranberry plants, in particular to a preparation method of a cranberry extract.
Background
Cranberries, also known as cranberries, are a plant of the evergreen shrub dwarf cranberry of the genus Vaccinium macrocarpon of the family Ericaceae. The red berries of cranberries can be eaten as fruits and have the advantages of high moisture, low calorie, and rich vitamins, minerals, dietary fibers, etc. Modern researches have shown that cranberry fruits contain various active substances, such as procyanidins, anthocyanins (anthocyanins), flavonols, phenolic acids, resveratrol, ursolic acid, and the like. The corresponding application effects comprise: antibacterial, antioxidant, antitumor activity, etc. Because of its health care efficacy and medical value, it is well-received by the market of developed countries, and has a large market sales volume in france, usa, japan, germany, switzerland and other countries.
Anthocyanins (anthocyanidins) are one of the most important active ingredients in cranberry fruits, and have a positive protective effect on human health. Research shows that anthocyanin has multiple physiological activity functions of resisting oxidation, promoting resynthesis of rhodopsin, resisting inflammation, improving immunity, resisting cardiovascular diseases, resisting aging, resisting cancer and the like. But its properties are very unstable and easily changed by external factors such as light, oxygen, temperature, pH, metal ions, etc. during food processing and storage. Therefore, the stability of anthocyanins is a problem that has received much attention from researchers. At present, methods for improving anthocyanin stability mainly comprise: color-assisting effect, structure modification, microcapsule technology and the like. Wherein the acylated anthocyanin shows strong stability to pH change, heat treatment, illumination and the like.
Procyanidin is the main active ingredient of cranberry fruit, and is divided into oligomeric procyanidin (polymerization degree of 2-5) and polymeric procyanidin (polymerization degree of more than 5). Research shows that the procyanidine has strong oxidation resistance, and also has various physiological activities of inhibiting bacteria, promoting blood circulation, protecting eyesight and the like. The high polymeric proanthocyanidins have oxidation resistance far inferior to that of oligomers, are difficult to be absorbed and utilized by human bodies, and reduce the resource utilization value to a certain extent. Therefore, if a certain process is adopted to effectively degrade the high polymeric proanthocyanidins into the oligomeric proanthocyanidins, the biological activity and the resource utilization efficiency of the product can be greatly improved, thereby creating social and economic values.
Many techniques for extracting and preparing anthocyanin and procyanidine at home and abroad are reported. For example, chinese patent 201010503367.7 discloses a method for extracting anthocyanin and procyanidin from cranberry fruits, which comprises the steps of performing enzymolysis on cranberry fruits with a biological enzyme, extracting with an acid solution and an alcohol solution, combining the extracts, concentrating, and adsorbing with macroporous adsorbent resin to obtain a mixture containing anthocyanin and procyanidin. The method can promote the extraction of anthocyanin and procyanidine by adding biological enzymes (cellulase, pectinase, amylase, etc.), and the stability of anthocyanin is protected by adopting an acidic environment in the technical process, but the stability problem of anthocyanin in the product application process cannot be solved; in addition, the procyanidin and the anthocyanin components cannot be effectively separated, and the selective application of the product is greatly limited. Chinese patent application 201610817839.3 discloses a method for extracting and purifying anthocyanidin from cowberry fruit, and discloses inoculating microorganism to degrade cowberry fruit, and performing molecular modification-acylation reaction on anthocyanin molecules through acetic acid which is a main product of cellulose bacteria metabolism to improve the stability of anthocyanin products; meanwhile, the anthocyanin content in the product is improved through flocculation precipitation and macroporous adsorption resin separation and purification. Although the method intentionally adopts a structure modification method to improve the stability of anthocyanin products, acylation reaction conditions are not controlled, and a single organic acid is involved in the acylation reaction, so that the acylation effect is possibly poor. Chinese patent application 201810984976.5 discloses a high-quality oligomeric proanthocyanidin and its preparation method, which discloses that a polymerization reduction promoter (ozone) is added to carry out polymerization reduction treatment on the high-quality oligomeric proanthocyanidin under an alkaline condition (pH value is 8-9). Ozone is a strong oxidizing substance, and procyanidin itself is a component with very strong oxidation resistance, which may cause the destruction of its antioxidant bioactivity in an ozone environment. In addition, international environmental air quality standards suggest that a human may accept ozone at a maximum concentration of 260 μ g/m3 within one hour. When the patient moves for 1 hour in the environment of 320 mu g/m3 ozone, the patient can have cough, dyspnea and lung function reduction, and therefore, the use of ozone in the process has certain potential safety hazard.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects of the prior art and provide a preparation method of the cranberry extract, which has the advantages of high raw material utilization rate, simple process and easy realization of industrial production, and the obtained product has higher stability and bioactivity.
The technical scheme adopted for solving the technical problems is that the preparation method of the cranberry extract comprises the following steps:
A. extracting and concentrating: adding crushed fresh cranberry fruits into an extraction tank, adding an acidic ethanol solution I which is 8-12 times of the volume of the raw materials of the fresh cranberry fruits, performing reflux extraction for more than 2 times (preferably 3 times) (the extraction frequency is too low, effective components cannot be fully extracted, the extraction frequency is too high, the extraction rate is increased to a limited extent, the solvent and the operation cost are increased), performing reflux extraction for 0.5-1 hour each time, concentrating the obtained extracting solution under reduced pressure, and recovering ethanol to obtain a concentrated solution;
B. centrifuging: centrifuging and separating the concentrated solution obtained in the step A to obtain centrifugal supernatant and centrifugal slag;
C. ion exchange resin separation: b, passing the centrifugal supernatant obtained in the step B through weak acid cation exchange resin, and eluting by using pure water and an acidic ethanol solution II in sequence; mixing the effluent and pure water eluate, and concentrating under reduced pressure to obtain mixed concentrated solution. Concentrating the acidic ethanol solution II eluent under reduced pressure, adding excipient, and drying to obtain cranberry anthocyanin product;
when the centrifugal supernatant passes through the weak acid cation exchange resin, part of liquid flows out to call a sample-loading effluent liquid;
the excipient is preferably maltodextrin.
D. Separating by macroporous adsorption resin: c, passing the combined concentrated solution obtained in the step C through macroporous adsorption resin, and eluting by using pure water, an ethanol solution III (eluting to remove impurities and basically not containing anthocyanin) and an ethanol solution IV in sequence; and concentrating the ethanol solution IV eluent under reduced pressure, adding an excipient, and drying to obtain the cranberry procyanidin product.
The excipient is preferably maltodextrin.
Further, in the step A, the volume concentration of ethanol in the acidic ethanol solution I is 65-85%. Wherein the acid is mixed organic acid. The mixed organic acid is 3-6 of citric acid, malic acid, quinic acid, acetic acid, benzoic acid, and cinnamic acid, and more preferably mixture of citric acid, malic acid, and quinic acid. In the acidic ethanol solution I, the total molar concentration of the mixed organic acid is 0.01-0.02 mol/L. The extraction temperature is 85-95 ℃.
Different organic acids and anthocyanin have different reaction mechanisms, and the acylation reaction has different strengths and can play a complementary role. Compared with single organic acid, the acylation effect of the reaction of various organic acids and anthocyanin is better. The reaction effect of the citric acid, the malic acid and the quinic acid is optimal, and impurities influencing the purity of the product are not introduced.
Further, in the step B, the centrifugal mode is tubular centrifugation, disc centrifugation or horizontal screw centrifugation.
Further, in step C, the weak acid cation exchange resin used is one of the common types of D113, D131, D152, etc. The volume concentration of the ethanol in the acidic ethanol solution II is 50-70%. The acid in the acidic ethanol solution II is an organic acid, preferably one or more of citric acid, malic acid and quinic acid. The total mass concentration of the organic acid in the acidic ethanol solution II is 0.2-0.5%. The drying method is freeze drying or spray drying.
Furthermore, in the step D, the macroporous adsorption resin is one of common models such as AB-8, D101, NKA-9 and the like. The volume concentration of ethanol in the ethanol solution III is 25-35%. The volume concentration of ethanol in the ethanol solution IV is 50-60%. The drying method is vacuum drying or spray drying.
The method can fully extract and purify the active ingredients of the cranberry, improve the stability and the bioactivity of the product and meet the market application requirements better.
Compared with the prior art, the invention has the following advantages:
1. the cranberry raw material is fully utilized: anthocyanin products and procyanidin products can be obtained simultaneously;
2. the anthocyanin product has good stability: adding mixed organic acid, reflux extracting at 85-95 deg.c to create acid environment and protect anthocyanin from being damaged, and acylating reaction of anthocyanin and organic acid at relatively high temperature to regulate molecular stability structurally; the ion exchange resin is eluted by acidic ethanol solution, so that organic acid can be used as a color auxiliary agent to be remained in anthocyanin products, the stability of the products is improved, and meanwhile, the organic acid introduced in the process is the organic acid contained in the cranberry raw materials, and no external component is introduced.
3. The proanthocyanidin product has high biological activity: adding mixed organic acid, reflux extracting at 85-95 deg.C, and catalytically decomposing high polymeric procyanidin into oligomeric procyanidin under controlled conditions (pH value range, temperature, time), reducing average polymerization degree of procyanidin, and improving bioactivity and material availability;
4. the content of active ingredients is high: the anthocyanin content of the cranberry anthocyanin product is greater than or equal to 30 wt%, and the procyanidin content of the cranberry procyanidin product is greater than or equal to 50 wt%.
The preparation method provided by the invention has the advantages of high utilization rate of raw materials, simple process and easy realization of industrial production. The product prepared by the method has the characteristics of high active ingredient content, stable color, strong biological activity and the like, and has good market prospect in the fields of nutrition and health care, food and beverage, daily chemical industry and the like.
Detailed Description
The present invention will be further described with reference to the following specific examples, but the present invention is not limited to the following examples. Those skilled in the art can modify the process parameters appropriately to achieve the desired results with reference to the disclosure herein. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.
In the present specification, the percentages are percentages by mass, unless otherwise specified.
Example 1
The preparation method of the cranberry extract of the present example comprises the following steps:
A. extracting and concentrating: 50.5kg of crushed fresh cranberry fruit (water content 76.34 wt%) is placed in an extraction tank, and an acidic ethanol solution I (the volume concentration of ethanol in the acidic ethanol solution I is 85%) which is 10 times of the volume of the raw material of the fresh cranberry fruit is added. Wherein the acid is mixed organic acid. The mixed organic acid is a mixed acid of citric acid, malic acid and quinic acid (the molar ratio is 1:1: 2). In the acidic ethanol solution I, the total molar concentration of the mixed organic acid is 0.01mol/L, reflux extraction is carried out for 3 times at 85 ℃, each reflux extraction is carried out for 0.5 hour, the obtained extracting solution is subjected to reduced pressure concentration at 70 ℃, and alcohol is recovered, so as to obtain concentrated solution;
B. centrifuging: c, centrifuging the concentrated solution obtained in the step A in a tubular manner, and separating to obtain centrifugal supernatant and centrifugal slag;
C. ion exchange resin separation: and D113 passing the centrifugal supernatant obtained in the step B through weak acid cation exchange resin, and then sequentially eluting by using 3BV of pure water and 2BV of acidic ethanol solution II (the volume concentration of ethanol in the acidic ethanol solution II is 50 percent, the acid is citric acid, and the mass concentration of the acid in the acidic ethanol solution II is 0.2 percent). Mixing the effluent of the D113 resin sample with the pure water eluate, and concentrating at 70 deg.C under reduced pressure until Brix is 12.3 to obtain a mixed concentrated solution. Concentrating the acidic ethanol solution II eluate at 70 deg.C under reduced pressure, recovering ethanol, measuring the content of the concentrated solution, adding 0.10kg maltodextrin as excipient, and spray drying (air inlet temperature of 170 deg.C, air outlet temperature of 90 deg.C) to obtain 0.43kg anthocyanin product (with anthocyanin content of 30.89 wt%). The mass of the concentrated solution plus the mass of maltodextrin equals the mass of the anthocyanin product.
D. Separating by macroporous adsorption resin: and D, passing the combined concentrated solution obtained in the step C through AB-8 macroporous adsorption resin, eluting with 2BV of pure water, 2BV of 30% (volume concentration) ethanol solution and 3BV of 60% (volume concentration) ethanol solution in sequence, collecting the eluent of the 60% ethanol solution, concentrating under reduced pressure at 70 ℃, and recovering the alcohol. After the content of the concentrated solution is measured, 0.35kg of maltodextrin is added as excipient, and spray drying is carried out (the air inlet temperature is 180 ℃, the air outlet temperature is 90 ℃) to obtain 1.33kg of procyanidine products (wherein the content of procyanidine is 51.23 wt%).
Example 2
The preparation method of the cranberry extract of the present example comprises the following steps:
A. extracting and concentrating: 51.4kg (water content: 77.52%) of the crushed fresh cranberry fruit is put into an extraction tank, and an acidic ethanol solution I (75% of ethanol volume concentration in the acidic ethanol solution I) is added into the extraction tank, wherein the acidic ethanol solution I is 12, 10 and 8 times of the volume of the raw material of the fresh cranberry fruit, and the acid is mixed organic acid. The mixed organic acid is citric acid, malic acid, acetic acid and benzoic acid, and the molar ratio is 1:1: 2: 2, the total molar concentration of the mixed organic acid in the acidic ethanol solution is 0.015mol/L, and the reflux extraction is carried out for 3 times at 90 ℃, wherein the extraction time is 1.0 hour, 0.5 hour and 0.5 hour respectively. Concentrating the obtained extractive solution at 70 deg.C under reduced pressure, and recovering ethanol to obtain concentrated solution;
B. centrifuging: centrifuging the concentrated solution obtained in the step A through a horizontal screw, and separating to obtain centrifugal supernatant and centrifugal slag;
C. ion exchange resin separation: b, enabling the centrifugal supernatant obtained in the step B to pass through D131 weak-acid cation exchange resin, and then eluting with 3BV of pure water and 2BV of acidic ethanol solution II (the volume concentration of ethanol in the acidic ethanol solution II is 60%, the acid is citric acid and quinic acid (the molar ratio is 1:1), and the total mass concentration of the citric acid and the quinic acid in the acidic ethanol solution is 0.3 percent); mixing the effluent and pure water eluate, and concentrating at 70 deg.C under reduced pressure to Brix13.5 to obtain mixed concentrated solution. Concentrating the acidic ethanol solution eluate at 70 deg.C under reduced pressure, recovering ethanol, measuring the content of the concentrated solution, adding 0.12kg maltodextrin as excipient, and spray drying (air inlet temperature of 170 deg.C, air outlet temperature of 90 deg.C) to obtain 0.42kg anthocyanin product (anthocyanin content of 30.55 wt%).
D. Separating by macroporous adsorption resin: c, passing the combined concentrated solution obtained in the step C through D101 macroporous adsorption resin, and then eluting with 2BV of pure water, 2BV of ethanol solution with the volume concentration of 30% (eluting to remove impurities, and basically no anthocyanin) and 3BV of ethanol solution with the volume concentration of 50%; collecting 50% ethanol solution eluate, concentrating at 70 deg.C under reduced pressure, and recovering ethanol. After the content of the concentrated solution is measured, 0.28kg of maltodextrin is added as excipient, and spray drying is carried out (the air inlet temperature is 180 ℃, the air outlet temperature is 90 ℃) to obtain 1.24kg of procyanidine product (the procyanidine content is 50.69%).
Example 3
The preparation method of the cranberry extract of the present example comprises the following steps:
A. extracting and concentrating: 49.8kg of crushed fresh cranberry fruit (water content: 80.06%) is placed in an extraction tank, and acidic ethanol solution I (65% by volume of ethanol in acidic ethanol solution I) is added into the extraction tank, wherein the volume of acidic ethanol solution I is 10, 10 and 8 times of the volume of the raw material of the fresh cranberry fruit. Wherein the acid is mixed organic acid. The mixed organic acid is citric acid, malic acid, quinic acid, acetic acid and benzoic acid, and the molar ratio is 1: 2: 2: 1:1, in the acidic ethanol solution, the total molar concentration of the mixed organic acid is 0.02mol/L, and the reflux extraction is carried out for 3 times at 95 ℃, wherein the extraction time is 1.0 hour/time each time. Concentrating the obtained extractive solution at 70 deg.C under reduced pressure, and recovering ethanol to obtain concentrated solution;
B. centrifuging: c, centrifuging the concentrated solution obtained in the step A in a tubular manner, and separating to obtain centrifugal supernatant and centrifugal slag;
C. ion exchange resin separation: b, passing the centrifugal supernatant obtained in the step B through D152 weakly acidic cation exchange resin, and then eluting by using 3BV of pure water and 2BV of acidic ethanol solution II (the volume concentration of ethanol in the acidic ethanol solution II is 70%, the acid is citric acid, malic acid and quinic acid (the molar ratio is 1:1:1), and the total mass concentration of organic acid in the acidic ethanol solution is 0.4%); mixing the effluent and pure water eluate, and concentrating at 70 deg.C under reduced pressure to Brix11.9 to obtain mixed concentrated solution. Concentrating the acidic ethanol solution eluate at 70 deg.C under reduced pressure, recovering ethanol, measuring the content of the concentrated solution, adding 0.08kg maltodextrin as excipient, and spray drying (air inlet temperature of 170 deg.C, air outlet temperature of 90 deg.C) to obtain 0.34kg anthocyanin product (anthocyanin content of 31.92 wt%).
D. Separating by macroporous adsorption resin: c, enabling the combined concentrated solution obtained in the step C to pass through NKA-9 macroporous adsorption resin, and then sequentially eluting with 2BV of pure water, 2BV of ethanol solution with the volume concentration of 30% (eluting to remove impurities, and basically no anthocyanin) and 3BV of ethanol solution with the volume concentration of 50%; collecting 50% ethanol solution eluate, concentrating at 70 deg.C under reduced pressure, and recovering ethanol. After the content of the concentrated solution was measured, 0.15kg of maltodextrin was added as an excipient, and spray-dried (air inlet temperature 180 ℃ C., air outlet temperature 90 ℃ C.) to obtain 1.04kg of procyanidin product (procyanidin content 50.85 wt%).
Example 4
The preparation method of the cranberry extract of the present example comprises the following steps:
A. extracting and concentrating: 50.6kg (water content: 76.98%) of the crushed fresh cranberry fruit is put into an extraction tank, and acidic ethanol solution I (70% volume concentration of ethanol in acidic ethanol solution I) is added into the extraction tank, wherein the volume of the acidic ethanol solution I is 12, 8 and 8 times of that of the raw material of the fresh cranberry fruit, and the acid is mixed organic acid. The mixed organic acid is citric acid, malic acid, quinic acid, acetic acid, benzoic acid and cinnamic acid, and the molar ratio of the mixed organic acid to the cinnamic acid is 1:1: 1:1: 1: 1; in the acidic ethanol solution, the total molar concentration of the mixed organic acid is 0.01mol/L, and the reflux extraction is carried out for 3 times at the temperature of 95 ℃, wherein the extraction time is 1.0 hour, 1.0 hour and 0.5 hour respectively; concentrating the obtained extractive solution at 70 deg.C under reduced pressure, and recovering ethanol to obtain concentrated solution;
B. centrifuging: b, performing butterfly centrifugation on the concentrated solution obtained in the step A, and separating to obtain centrifugal supernatant and centrifugal slag;
C. ion exchange resin separation: b, passing the centrifugal supernatant obtained in the step B through D131 weak-acid cation exchange resin, and then sequentially eluting by using 3BV of pure water and 2BV of acidic ethanol solution II (the volume concentration of ethanol in the acidic ethanol solution II is 60%, the acid is malic acid and quinic acid (the molar ratio is 1:1), and the total mass concentration of organic acid in the acidic ethanol solution is 0.5%); mixing the effluent and pure water eluate, and concentrating at 70 deg.C under reduced pressure to Brix14.2 to obtain mixed concentrated solution. Concentrating the acidic ethanol solution eluate at 70 deg.C under reduced pressure, recovering ethanol, measuring the content of the concentrated solution, adding 0.10kg maltodextrin as excipient, and spray drying (air inlet temperature of 170 deg.C, air outlet temperature of 90 deg.C) to obtain 0.41kg anthocyanin product (anthocyanin content of 30.27 wt%).
D. Separating by macroporous adsorption resin: c, passing the combined concentrated solution obtained in the step C through AB-8 macroporous adsorption resin, and then sequentially eluting with 2BV of pure water, 2BV of ethanol solution with the volume concentration of 30% (eluting to remove impurities, and basically no anthocyanin) and 3BV of ethanol solution with the volume concentration of 50%; collecting 50% ethanol solution eluate, concentrating at 70 deg.C under reduced pressure, and recovering ethanol. After the content of the concentrated solution is measured, 0.20kg of maltodextrin is added as excipient, and spray drying is carried out (the air inlet temperature is 180 ℃, the air outlet temperature is 90 ℃) to obtain 1.25kg of procyanidine product (the procyanidine content is 50.15 wt%).
Control group
The preparation process of the cranberry extract comprises the following steps:
50.1kg (water content: 78.14%) of crushed fresh cranberry fruit is put into an extraction tank, 12, 10 and 8 times of 75% ethanol in volume is added respectively, and reflux extraction is carried out for three times at 90 ℃, wherein the extraction time is respectively 1.0 hour, 0.5 hour and 0.5 hour. Concentrating the extractive solution at 70 deg.C under reduced pressure, and recovering ethanol to obtain concentrated solution; after the content of the concentrated solution is measured, 0.44kg of maltodextrin is added as excipient, and the mixture is sprayed and dried (the air inlet temperature is 180 ℃, the air outlet temperature is 90 ℃) to obtain 3.54kg of products (the anthocyanin content is 2.17%, and the procyanidine content is 9.39%).
According to two indexes of procyanidine extraction transfer rate and average polymerization degree, the effect of hydrolyzing high polymeric procyanidine into oligomeric procyanidine is judged, and the specific formula is shown in the following tables 1 and 2:
TABLE 1 procyanidin extraction transfer Rate data
Name of article
|
Weight (kg)
|
Content of procyanidin
|
Transfer rate
|
Raw materials
|
/
|
0.48%
|
|
Control procyanidin product
|
3.54
|
9.39%
|
138.23%
|
Example 1 procyanidin product
|
1.33
|
51.23%
|
281.09%
|
Example 2 procyanidin product
|
1.24
|
50.69%
|
254.76%
|
Example 3 procyanidin product
|
1.04
|
50.85%
|
221.23%
|
Example 4 procyanidin product
|
1.25
|
50.15%
|
258.10% |
① raw material contains procyanidin, calculated as wet product.
② percent transfer rate ═ procyanidin product weight · procyanidin content/raw material weight/raw material content%.
③ the cranberry material contains organic acids (citric acid, malic acid, quinic acid) at a certain content, and under the condition of high temperature extraction, the high polymeric procyanidin in the cranberry material is partially hydrolyzed into oligomeric procyanidin, so that the procyanidin transfer rate in the control group is more than 100% (138.23%).
TABLE 2 measurement of average degree of polymerization of procyanidins
Name of article
|
Weight (kg)
|
Average degree of polymerization of procyanidin
|
Control procyanidin product
|
3.54
|
6.35
|
Example 1 procyanidin product
|
1.33
|
2.43
|
Example 2 procyanidin product
|
1.24
|
2.52
|
Example 3 procyanidin product
|
1.04
|
2.78
|
Example 4 procyanidin product
|
1.25
|
2.53 |
Note: ① method for measuring average degree of polymerization of procyanidin, reference (Weiguanhong. high polymeric procyanidin hydrolysis process [ D ]. Zhejiang: Zhejiang university, 2006.)
② the higher the average degree of polymerization of procyanidins, the higher the proportion of polymeric procyanidins (degree of polymerization greater than 5) is, the example procyanidins have an average degree of polymerization between 2.43 and 2.78, which is much lower than the control group 6.35, and the example procyanidins have an extremely low proportion even close to 0.
③ since the antioxidant property of high polymeric proanthocyanidins is far inferior to that of oligomers and is difficult to be absorbed by human body, the lower the ratio of high polymeric proanthocyanidins is, the stronger the biological activity of proanthocyanidins.
Reference literature, "xuyuan gold, duoqi zhen, anthocyanin separation and identification method and biological activity [ J ]. food and fermentation process, 2006,32(3): 67-72", judge the anthocyanin acylation effect according to the absorption peak of anthocyanin in the range of 300-330nm, and concretely show in the following table 3:
table 3 measurement results of absorbance peak of anthocyanin at 300 to 330nm (anthocyanin concentration 10mg/mL)
Name of article
|
Maximum absorption wavelength λ
|
Absorbance value A
|
Control procyanidin product
|
330
|
0.15
|
Example 1 procyanidin product
|
325
|
0.45
|
Example 2 procyanidin product
|
323
|
0.48
|
Example 3 procyanidin product
|
323
|
0.54
|
Example 4 procyanidin product
|
320
|
0.50 |
Note: under the same conditions of anthocyanin concentration, the higher the absorbance value of the absorption peak value between 300-330nm, the better the anthocyanin acylation effect is. Therefore, the anthocyanin acylation effect of the technical example of the invention is better and is obviously better than that of the control group.