CN112450300A

CN112450300A - Fruit mulberry tea and brewing liquid thereof

Info

Publication number: CN112450300A
Application number: CN202010924065.0A
Authority: CN
Inventors: 陈莉; 杨双全; 卢红梅; 杨华连
Original assignee: Guizhou University
Current assignee: Guizhou University
Priority date: 2020-09-04
Filing date: 2020-09-04
Publication date: 2021-03-09

Abstract

The invention relates to a beverage, in particular to a mulberry tea prepared from mulberry leaves, mulberry branch bark and mulberry root bark and a brewing liquid thereof. The mulberry leaves, the mulberry branch bark and the mulberry root bark are taken as raw materials, dried, crushed and mixed respectively to obtain the mulberry tea. The mulberry tea is brewed by water to obtain the brewing liquid. The inhibition rates of the mulberry tea brewing liquid on alpha-glucosidase and alpha-amylase are 74.77% and 68.04% respectively. The prepared fruit mulberry tea product is fresh and cool in taste, clear in color and luster, high in sensory score, and has good blood sugar reducing effect and the effect of improving intestinal dysbacteriosis. The mulberry tea product prepared by the method promotes the development of mulberry functional products on one hand, improves the utilization rate of mulberry resources on the other hand, and can greatly improve the economic benefit of enterprises. The method is suitable for the mulberry processing industry.

Description

Fruit mulberry tea and brewing liquid thereof

Technical Field

The invention relates to a beverage, in particular to a mulberry tea prepared from mulberry leaves, mulberry branch bark and mulberry root bark and a brewing liquid thereof.

Background

Due to the continuous improvement of living standard of people, the changes of living style, behavior habits and eating hobbies cause a plurality of diseases, which cause serious threats to the physical and mental health of modern people, and in addition, long-term unreasonable diet, such as the ingestion of food with three high (high fever, high protein and high fat), three more (more preservatives, more flavoring agents and more hormones), the accumulation of residual pesticides and fertilizers in the body, and the pollution of air and water sources and small amount of exercise, leads the group proportion of obese patients and diabetic patients to be increased year by year.

The fruit mulberry is a plant which can be used as both medicine and food, contains rich nutrient substances and proven polysaccharide, flavone and alkaloid bioactive substances with the efficacy of reducing blood sugar in fruits, leaves, branches and roots, and has various efficacies of reducing blood sugar, regulating immunity and the like.

Although it has a certain efficacy, how to reasonably match each part to make the parts exert synergistic effect and enhance the ability of reducing blood sugar is urgently needed to be further researched. At present, mulberry resources are developed mainly aiming at mulberry fruits and mulberry leaves, the mulberry fruits are mainly used for producing fruit wine, dried mulberries and the like, the mulberry leaves are mainly used for making mulberry leaf tea, and mulberry branches and mulberry roots are mainly used for making edible fungus matrixes, so that the mulberry leaf tea is single in product structure, the utilization rate of blood sugar reducing functional components is not maximized, the waste of the mulberry resources is caused, and great loss is caused to mulberry planting enterprises. Therefore, aiming at the current situation that the incidence of diabetes is increasing year by year at present, how to obtain a tea bag which is convenient to carry and brew and has good blood sugar reducing effect by fully utilizing different parts (leaves, branches and roots) of fruit mulberry needs to be further explored.

Disclosure of Invention

The invention aims to provide a mulberry tea prepared from mulberry leaves, mulberry branch bark and mulberry root bark and a brewing liquid thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

a fruit mulberry tea is prepared from fruit mulberry leaf, mulberry twig bark and mulberry root bark through respectively baking, pulverizing and mixing.

And respectively drying the mulberry leaves, the mulberry branch barks and the mulberry root barks at the constant temperature of 50 ℃ until the water content is below 7%, and crushing for later use.

Crushing mulberry leaves to 40-60 meshes after drying, crushing mulberry twig bark to 60-80 meshes and crushing mulberry root bark to 60-80 meshes; taking mulberry leaf powder, mulberry twig bark powder and mulberry root bark powder of the different powders according to parts by weight: mulberry twig bark powder: the mulberry root bark powder is 5-90: 5-90: 5-90.

Crushing mulberry leaves to 40-60 meshes after drying, crushing mulberry twig bark to 60-80 meshes and crushing mulberry root bark to 60-80 meshes; and (2) counting the mulberry leaf powder, the mulberry branch bark powder and the mulberry root bark powder of the different powders according to the weight parts as follows: mulberry twig bark powder: the mulberry root bark powder is 62: 19: 19.

a brewing liquid of mulberry tea is prepared by mixing the mulberry tea obtained by the steps of (1: 60-1): mixing and infusing at a ratio of 100 g/ml for 10-50min to obtain the infusion solution.

The temperature of the water is 75-85 ℃.

The mulberry tea is mixed and brewed for 10-50min according to the proportion of 1:60-1:100(g/ml) to water, and the brewed liquid is obtained; wherein the temperature of water is 75-85 deg.C, and the brewing time is 1-2 times.

Use of an infusion as a modulator of the intestinal flora.

The invention has the following beneficial effects:

(1) the mulberry tea is prepared by drying mulberry leaves, mulberry branch bark and mulberry root bark at a constant temperature, crushing the mulberry leaves, the mulberry branch bark and the mulberry root bark into different particle sizes according to different raw materials, and compounding the mulberry leaves, the mulberry branch bark and the mulberry root bark.

(2) In the production process of the fruit-mulberry tea, the dried mulberry leaves, mulberry branch barks and mulberry root barks are dried and then crushed, so that the problem that meshes of a crusher are blocked due to excessive branches and barks is avoided, and the production efficiency is greatly improved.

(3) The invention solves the current situation of insufficient utilization of mulberry resources, improves the comprehensive utilization rate of the mulberry resources, promotes the development of diversified products of mulberry enterprises, and greatly improves the utilization rate of mulberry.

(4) The product of the invention is dry powder substance, has light weight and is convenient to carry and transport.

(5) The mulberry tea is brewed with water at a certain temperature according to a certain proportion, and the obtained beverage has higher alpha-glucosidase and alpha-amylase inhibition rate in vitro, and is a good auxiliary hypoglycemic product; the inhibition rates of the alpha-glucosidase and the alpha-amylase are 74.77% and 68.04% respectively.

(6) The mulberry tea drink is obtained by mixing specific components and brewing in the process, so that the components such as polysaccharide, flavone and 1-DNJ with the blood sugar reducing effect can be further improved, the utilization value of mulberry resources is further improved, and the economic benefit of an enterprise is increased.

Drawings

FIG. 1 is a graph of the effect of three components on DNJ content provided by an example of the present invention, where graph A is a 3D plot and graph B is a contour plot, where X1: a (mulberry leaf); x2: b (mulberry twig bark); x3: c (mulberry root bark).

Fig. 2 is a graph of the inhibition rate of the mulberry compound tea with different proportions on alpha-glucosidase according to the embodiment of the invention.

FIG. 3 is a graph showing the effect of tea water ratio on polysaccharide content according to the present invention.

FIG. 4 is a graph showing the effect of tea water ratio on flavone content according to the present invention.

FIG. 5 is a graph showing the effect of tea water ratio on the content of 1-DNJ according to the present invention.

FIG. 6 is a graph showing the effect of brewing temperature on polysaccharide content provided by an embodiment of the present invention.

FIG. 7 is a graph showing the effect of leaching temperature on flavone content according to the present invention.

FIG. 8 is a graph showing the effect of brewing temperature on 1-DNJ content as provided by an example of the present invention.

FIG. 9 is a graph showing the effect of brewing time on polysaccharide content provided by an embodiment of the present invention.

FIG. 10 is a graph showing the effect of brewing time on flavone content provided by an embodiment of the present invention.

FIG. 11 is a graph showing the effect of brewing time on 1-DNJ content as provided by an example of the present invention.

FIG. 12 is a graph of the effect of brewing times on polysaccharide content provided by an embodiment of the present invention; wherein lower case letters indicate significant differences among groups (P < 0.05).

FIG. 13 is a graph showing the effect of brew times on flavone content as provided by an embodiment of the present invention.

FIG. 14 is a graph of the effect of number of infusions on DNJ content as provided by an example of the present invention.

FIG. 15 is a graph showing the inhibition rate of mulberry tea infusion solution on alpha-glucosidase and alpha-amylase according to the embodiment of the present invention.

The specific implementation mode is as follows:

the following examples are presented to further illustrate embodiments of the present invention, and it should be understood that the embodiments described herein are for purposes of illustration and explanation only and are not intended to limit the invention.

The mulberry tea is prepared by drying and crushing leaves, branches and roots of mulberries (a 'Dashi' mulberry variety planted in Kaiyang county of Guizhou) at constant temperature and compounding; meanwhile, the mulberry tea is brewed under certain conditions, and the mulberry tea product prepared by the process is fresh and cool in taste, clear in color and luster, has a better blood sugar reducing effect, and can be developed into an excellent diabetes auxiliary product.

Example 1

Determining the optimal crushing mesh number of mulberry leaves, mulberry branch barks and mulberry root barks: pulverizing folium Mori, ramulus Mori and cortex Mori dried at 50 deg.C (water content below 7%) to different mesh, accurately weighing 1g of raw materials with different mesh, adding 30mL of boiling distilled water, leaching for 70min, filtering, metering to 50mL of brown volumetric flask to obtain sample extractive solution, and measuring the dissolution of polyphenol, flavone, polysaccharide and 1-DNJ (see Table 1-3).

TABLE 1 influence of the number of pulverizing meshes on the dissolution rate of functional ingredients of mulberry leaves

As shown in Table 1, when the mulberry leaves are ground to 40-60 meshes, the total polyphenol content of the mulberry leaves is 36.86 mg/g, the total flavone content is 29.08mg/g, the polysaccharide content is 5.38g/100g, and the 1-DNJ content is 0.677 mg/g. Meanwhile, when the mulberry leaves are crushed to be more than 80 meshes, tea-like powder is leached out, sensory evaluation of finished products is affected, the elution amount of functional components such as total polyphenol is lower, and the best crushing mesh number of the mulberry leaves is 40-60 meshes.

TABLE 2 influence of the number of pulverizing meshes on the dissolution rate of the functional ingredients of mulberry twig bark

As can be seen from table 2, the dissolution rate of the functional ingredients of the mulberry twig bark increases with the increase of the number of grinding meshes, but if the number of grinding meshes is too low, the functional ingredients are less dissolved, and the nutritional value is not high. When the mulberry branch bark is crushed to 60-80 meshes, polyphenol, flavone and polysaccharide in the mulberry branch bark are dissolved out to the maximum extent and are respectively 9.99mg/g, 6.50mg/g and 4.34g/100g, and the content of DNJ is 2.629 mg/g.

TABLE 3 influence of the number of pulverizing meshes on the dissolution rate of the functional ingredients of cortex Mori

As can be seen from Table 3, the dissolution rate of the functional ingredients of the mulberry root bark increases with the increase of the grinding mesh number, and when the grinding mesh number is 60-80 meshes, the contents of polyphenol, flavone, polysaccharide and DNJ of the mulberry root bark are respectively 31.81mg/g, 21.46mg/g, 5.87g/100g and 1.572 mg/g.

As can be seen from the above tables 1-3, the optimum number of the grinding meshes of the raw materials of the fruit mulberry tea is as follows: mulberry leaves (40-60 meshes), mulberry twig bark (60-80 meshes) and mulberry root bark (60-80 meshes). The crushing mesh number of the tea-like particles in the tea bag is not too large or too small, the too large is not beneficial to the dissolution of the effective components, and the too small can permeate the tea bag, so that the tea soup is turbid, and the appearance and drinking are affected.

Example 2

The fruit mulberry tea comprises the following materials in percentage by weight: the formula of the compound tea taking the mulberry leaves, the mulberry branch bark and the mulberry root bark as raw materials is optimized by utilizing the simplex lattice design in the mixed material (mix) design. The test was designed as in table 4 using Design expert (8.0) software. Accurately weighing mulberry leaf powder, mulberry branch bark powder and mulberry root bark powder according to test data in the table 4, mixing, and then mixing according to the weight ratio of 1: 30 (g: mL) is added with boiling distilled water, extracted for 70min at normal temperature, filtered to a 50mL brown volumetric flask, and the contents of flavone, polysaccharide and 1-DNJ in the extract with different proportions are respectively measured.

TABLE 4 formulation of pure lattice design of fruit mulberry tea

Accurately weighing mulberry leaf powder, mulberry branch bark powder and mulberry root bark powder according to the test data in the table 4, and weighing the mulberry leaf powder, the mulberry branch bark powder and the mulberry root bark powder according to the weight ratio of 1: 30 g (g: mL) is added with boiling distilled water, extracted for 70min, filtered to 50mL brown volumetric flasks, and the contents of flavone, polysaccharide and 1-DNJ in the extract with different proportions are respectively determined, and the results are shown in Table 5; meanwhile, Design expert (8.0.6) software is utilized to carry out quadratic polynomial regression fitting on the test results in the table 5, and three indexes (Y) are respectively established_Flavone，Y_{Polysaccharides}，Y_1-DNJ) The equation of each regression model is as follows:

Y_flavone＝20.86X1+7.82X2+12.18X3

Y_{Polysaccharides}＝3.40X1+5.82X2+10.19X3

Y_1-DNJ＝0.17X1+2.36X2+0.95X3-2.21X1*X2+2.45X1*X3-0.46X2*X3

The results of the analysis of variance analysis of the regression models for flavone, polysaccharide, 1-DNJ content are shown in tables 6-8 below and FIG. 1.

TABLE 5 compounding test results

TABLE 6 analysis of variance of regression model for flavone content

Source of variation	Sum of squares	Degree of freedom	Mean square	F value	F_0.05(2，7)	Significance of
							Model (model)	132.20	2	66.10	5.04	4.74	*
Linear mixing	132.20	2	66.10	5.04
							Residual error	91.74	7	13.11
Total variation	223.94	9

Note: r²＝0.5903，R²(adj)＝0.4733

TABLE 7 polysaccharide content regression model analysis of variance

Source of variation	Sum of squares	Degree of freedom	Mean square	F value	F_0.01(2，7)	Significance of
							Model (model)	35.52	2	17.76	15.21	9.55	**
Linear mixing	35.52	2	17.76	15.21
							Residual error	8.17	7	1.17
Total variation	43.70	9

Note: r²＝0.8129，R²(adj)＝0.7595

TABLE 81-DNJ content regression model analysis of variance

Source of variation	Sum of squares	Degree of freedom	Mean square	F value	F_0.01(5，4)	Significance of
							Model (model)	3.18	5	0.64	19.62	15.52	**
Linear mixing	2.61	2	1.31	40.34
							AB	0.25	1	0.25	7.64
AC	0.30	1	0.30	9.35
							BC	0.010	1	0.01	0.32
Residual error	0.13	4	0.032
							Total variation	3.31	9

Note: r²＝0.9608，R²(adj) ═ 0.9118; a: mulberry leaf, B: mulberry twig bark, C: cortex Mori

As can be seen from Table 6, the F value of the quadratic model was 5.04, which is larger than F_0.05(2, 7) ═ 4.74, P is stated<0.05, the obtained regression equation is remarkable when alpha is 0.05, and the determination coefficient R of the regression equation of the flavone content²The result is 0.5903, which indicates that the model has a good fit. As can be seen from Table 7, the F value of the secondary model was 15.21, which is larger than F_0.01(2, 7) ═ 9.55, P is stated<0.01, the resulting regression equation is extremely significant. Coefficient of determination R of regression equation of polysaccharide content²0.8129, the fitting degree of the model is good, and the correction coefficient of the regression equation is R²(adj) ═ 0.7595, indicating that the model can account for changes in polysaccharide content 81.29%. As can be seen from Table 8, the F value of the quadratic model was 19.62, which is larger than F_0.01(5, 4) ═ 15.52, P is stated<0.01, indicating that the regression equation of the obtained 1-DNJ content reaches the utmost significance, and the 1-DNJ contentCoefficient of determination R of the quantity regression equation²0.9608, the fitting degree of the model is good, and the correction coefficient of the regression equation is R²(adj) ═ 0.9118, indicating that the variability of 91.18% of the experimental data can be explained by the regression model, i.e., the model fits well across the regression region studied and can be used for prediction of response values.

A response surface graph and a contour graph (shown in figure 1) of mulberry leaves, mulberry branch barks and mulberry root barks to the DNJ content are obtained by a 1-DNJ model. From the response surface chart in fig. 1, it can be seen that the maximum value of the DNJ content is about 2.3594mg/g, the DNJ content of the single-component mulberry twig bark is obviously better than the DNJ content of the mulberry leaf or mulberry root bark as the single component, and the compound effect of the three components is the best.

Example 3

The optimal proportion of the fruit mulberry compound tea taking flavone as a standard is 18 percent of mulberry leaves, mulberry twig barks and mulberry root barks: 1:1 (represented by R1), wherein the content of flavone is 20.86mg/g, the content of polysaccharide is 3.40g/100g, and the content of 1-DNJ is 0.17 mg/g; the optimal proportion of the fruit mulberry compound tea taking polysaccharide as a standard is that the ratio of mulberry leaves to mulberry twig bark to mulberry root bark is 1: 1: 18 (represented by R4), wherein the polysaccharide content is 10.19g/100g, the flavone content is 12.18mg/g, and the DNJ content is 0.95 mg/g; the optimal proportion of the fruit mulberry compound tea taking 1-DNJ as the standard is that the proportion of mulberry leaves, mulberry twig barks and mulberry root barks is 1: 18: 1 (represented by R8), wherein the content of 1-DNJ is 2.36mg/g, the content of flavone is 7.82mg/g, and the content of polysaccharide is 5.82g/100 g; the proportion of the fruit mulberry compound tea with the highest comprehensive value of the contents of flavone, polysaccharide and 1-DNJ is that the proportion of mulberry leaves, mulberry branch bark and mulberry root bark is 62: 19: 19 (represented by R7), the content of flavone was 20.17mg/g, the content of polysaccharide was 5.37g/100g, and the content of 1-DNJ was 0.59 mg/g. 4 groups of compounded fruit mulberry tea are obtained to be evaluated:

alpha-glucosidase inhibition rate

Accurately weighing 1g of the 4 groups of compound fruit mulberry tea, adding 30mL of boiling distilled water for extraction for 70min, and filtering to obtain fruit mulberry compound tea infusion solutions, wherein the inhibition rates of the four compound fruit mulberry tea infusion solutions (with the concentration of 0.1mg/mL) on alpha-glucosidase are shown in figure 2; as can be seen from fig. 2, the inhibition rates of the four proportions of the mulberry compound tea on alpha-glucosidase are 63.98%, 55.04%, 68.55% and 60.79%, respectively, and the inhibition rate of the R7 group is the highest.

② sensory evaluation

Putting the 4 groups of compounded fruit mulberry tea (net content is 2g) into 150mL evaluation tea cups respectively, filling boiling water, covering and soaking for 3min, then uncovering and lifting the tea bags up and down twice (the two lifting intervals are 1min), then covering the cup covers after lifting, draining the tea soup for 5min, and evaluating the color, aroma, taste and leaf bottom of the soup in turn. And (5) evaluating the integrity of the tea bag after brewing by using the leaf bottom, and taking the average value after evaluation.

The sensory evaluation of the mulberry compound tea adopts a grammar evaluation method and a weighted percentage method, and 15 people with professional food backgrounds perform blind evaluation on the mulberry compound tea. Scoring is carried out according to the scoring weight of the tea bag in GB/T23776-: the appearance is 10%, the liquor color is 20%, the aroma is 30%, the taste is 30% and the leaf bottom is 10%, the sensory scores are shown in table 9, and the sensory scores of the fruit mulberry tea with four groups of proportions are shown in table 10.

TABLE 9 sensory evaluation of fruit and mulberry tea

TABLE 10 sensory evaluation of fruit Mulberry tea

And (4) conclusion: the inhibition rate of R7 group to alpha-glucosidase is 68.55% and the comprehensive sensory score is 88.90, so that the R7 group is the best proportion of the mulberry tea, namely the proportion of mulberry leaves, mulberry branch bark and mulberry root bark is 62: 19: 19.

example 4

Obtaining the brewing liquid after obtaining the optimal mixture ratio of the raw materials:

1) determination of optimal tea-water ratio of fruit mulberry compound tea bag

The optimal fruit mulberry tea proportion is brewed by boiling water for 30min, and under the condition of 1 brewing, the tea-water ratio is measured to be 1: 20,1: 40,1: 60,1: 80,1: 100,1: 150,1: the influence of the contents of polysaccharides, flavones and 1-DNJ in the infusion at 200 g/mL and the tea water ratio on the elution amounts of the above three components is shown in FIGS. 3, 4 and 5.

The effect of the tea water ratio on the amount of polysaccharide eluted from the fruit mulberry tea in FIG. 3 is shown in FIG. 3. As can be seen from the figure, the polysaccharide content in the mulberry tea brewing liquid tends to increase firstly and then decrease with the increase of the tea-water ratio, and the ratio of the polysaccharide content to the tea-water ratio is 1: a maximum of 28mg/100mL was reached at 80(g: mL). When the tea water is relatively small, the fruit mulberry tea powder in the tea bag is not completely contacted with the water, so that the active ingredients such as polysaccharide and the like in the tea bag are not fully dissolved in the extracting solution, and the content of the polysaccharide in the tea soup is low; and when the tea water ratio is higher than 1: 80 g/mL, the yield of the polysaccharide is rather reduced, probably because the polysaccharide is balanced by dissolution, diffusion, permeation, etc. into the tea soup at this time, and therefore, the increase of the extractant does not promote the extraction of the polysaccharide but rather lowers the concentration of the polysaccharide in the tea soup.

As shown in fig. 4, the content of flavone increases with the tea-water ratio and then decreases, and the ratio of flavone to water is 1: a maximum of 1.25mg/mL was reached at 80(g: mL). When the tea water is lower, the flavone dissolving-out amount is lower, probably because the water is not fully contacted with the fruit mulberry tea in the tea bag and the dissolving-out amount is lower; when the tea water ratio is high (more than 1: 80), effective components such as flavone and the like in the fruit mulberry tea reach diffusion balance, and the dissolution amount of the flavone cannot be increased even if the tea water ratio is increased, but the tea water ratio plays a role in dilution.

As shown in FIG. 5, the elution amount of 1-DNJ shows a tendency of increasing and then decreasing with the increase of the tea-water ratio, and is measured at a ratio of 1: a maximum of 7.89. mu.g/mL was reached at 100(g: mL), indicating that the highest dissolution limit of 1-DNJ had been reached. When the brewing water amount is low, the soaking is insufficient, 1-DNJ is not dissolved out to the maximum extent, and the ratio of the tea water to the tea water is 1: at 20(g: mL), the content of 1-DNJ in the infusion liquid is 3.53 mu g/mL, and after the tea-water ratio is respectively increased by 4 times and 5 times, the content of 1-DNJ in the infusion liquid is respectively increased to 7.21 mu g/mL and 7.89 mu g/mL, which are respectively increased by 2.04 times and 2.24 times; when the tea-water ratio is further increased, the elution amount of DNJ is rather decreased, which indicates that 1-DNJ has a tea-water ratio of 1:100 g/mL, diffusion equilibrium was reached and 1-DNJ had substantially dissolved out, and increasing the amount of water added diluted the concentration of the infusion.

The tea-water ratio refers to the ratio of the amount of tea leaves to the amount of water, and is closely related to the extraction rate and the concentration of tea soup. In conclusion, the tea-water ratio is 1: 80(g: mL), the elution of polysaccharides and flavones in the infusion reaches a maximum, while 1-DNJ is a ratio of 1: the amount eluted at 100(g: mL) was maximized, and 1-DNJ was added at a tea-to-water ratio of 1: 80(g: mL), the content of the infusion is 7.21 mu g/mL, the difference is not obvious relative to the highest value of 7.89 mu g/mL, and the contents of polysaccharide and flavone in the infusion are calculated in the ratio of tea to water of 1:100 (g: mL) in comparison with 1: the decrease was larger at 80(g: mL). Therefore, the tea-water ratio is selected to be 1: 80(g: mL) for subsequent studies, 1:60,1: 80,1: 100(g: mL) orthogonal experiments were performed.

2) Selection of optimal brewing temperature of fruit mulberry compound tea

In the ratio of tea to water of 1: 80(g: mL), brewing time is 30min, and under the condition of brewing for 1 time, the contents of polysaccharide, flavone and 1-DNJ in the brewing liquid are measured when the brewing temperature is 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃ and 95 ℃, and the influence of the brewing temperature on the extraction amount of polysaccharide, flavone and DNJ in the mulberry tea is shown in figures 6, 7 and 8.

As can be seen from FIG. 6, the polysaccharide content in the infusion increases with increasing infusion temperature as the temperature increases from 65 ℃ to 90 ℃ and then decreases with continued increase in infusion temperature. The reason for this may be that the increase of the brewing temperature accelerates the destruction of the mulberry compound tea cells, so that more polysaccharides are dissolved in the brewing liquid, the polysaccharide concentration increases, and when the brewing temperature is too high, part of the dissolved polysaccharides are combined with other components in the tea soup, so that the polysaccharide concentration in the brewing liquid is reduced.

As can be seen from FIG. 7, the flavone content tends to increase first and then decrease with the increase of the leaching temperature. When the temperature is 65-75 ℃, the flavone is increased along with the increase of the temperature and reaches a maximum value of 1.77mg/mL at 75 ℃, probably because the increase of the temperature can accelerate the permeation, diffusion and dissolution speed of the flavone, and the like, so that the flavone content is increased; when the temperature is continuously increased to 95 ℃, the flavone content shows a tendency of decreasing, probably because the structure of the flavonoid compound is damaged and the content is reduced due to the overhigh temperature.

As can be seen from FIG. 8, the 1-DNJ content of the infusion generally increased with increasing infusion temperature. When the brewing temperature is increased from 65 ℃ to 75 ℃, the 1-DNJ content in the brewing liquid is increased quickly, and when the temperature is continuously increased, the 1-DNJ content in the brewing liquid is slowly increased. It has been found that, as the temperature rises, the structure of DNJ analogues such as N-methyl-1-deoxynojirimycin or DNJ glycosides in mulberry tea is destroyed, resulting in an increase in DNJ content.

In summary, on one hand, if the brewing temperature is higher, the flavor of the brewing liquid is more prominent, the contents of polysaccharide and 1-DNJ in the brewing liquid are higher, and the content of flavone is lower; the brewing temperature is lower, the flavor of the brewing liquid is not good enough, but the content of flavone is much higher than that obtained by brewing at higher temperature, but the content of polysaccharide and 1-DNJ is not obviously different from that obtained by brewing at higher temperature. Therefore, considering the overall, 80 ℃ was chosen for the subsequent experiments, and 75 ℃, 80 ℃, 85 ℃ for the orthogonal experiments.

3) Selection of optimal brewing time of fruit mulberry compound tea

In the ratio of tea to water of 1: 80(g: mL), brewing temperature 80 ℃, and brewing for 1 time, and measuring the content of the sugar-reducing components (flavone, polysaccharide and 1-DNJ) in the brewing liquid when the brewing time is 5min, 10min, 30min, 50min and 70min, wherein the influence of the brewing time on the content of the polysaccharide, the flavone and the 1-DNJ is shown in figures 9, 10 and 11.

As can be seen from FIG. 9, the brewing time is within the range of 5min to 30min, the mass concentration of the polysaccharide in the brewing liquid increases along with the brewing time, and after the brewing time exceeds 30min, the polysaccharide concentration increases slowly. The dissolution of the polysaccharide from the tea bag takes a certain time, reaching a maximum value of 0.28mg/mL at 30min, indicating that the polysaccharide has been substantially dissolved and has reached diffusion equilibrium under this condition, and increasing the brewing time does not increase the polysaccharide content.

As shown in figure 10, when the brewing time is within the range of 5min to 30min, the flavone content in the brewing liquid is rapidly increased, because a certain time is required for dissolving the flavone out of the tea bag, the maximum value is 1.66mg/mL at 30min, and after the time exceeds 30min, the flavone content is reduced, because the flavone is oxidized or degraded to a certain extent after the brewing time is prolonged. The fact that the leaching amount of rutin and quercetin in the tartary buckwheat leaf tea bag during the brewing time is researched by the leaf sheep and the like (2019) is found, when the brewing time is 40min, the total leaching amount of the rutin and the quercetin is maximum, and then the total leaching amount is obviously reduced. And the brewing time is too long, which may cause water stuffiness and affect the quality of the tea soup. Therefore, the best brewing time is within the range of 30min to 50min to ensure that the flavone in the tea bag is fully dissolved.

As can be seen from FIG. 11, the 1-DNJ content of the infusion solution increased with the increase of the infusion time. When the brewing time is within the range of 5min to 30min, the content of 1-DNJ in the brewing liquid is rapidly increased, and after the brewing time exceeds 30min, the content of 1-DNJ is slowly increased and tends to be stable. Therefore, to obtain a high 1-DNJ content in the infusion, the optimal infusion time should be no less than 50 min.

In conclusion, polysaccharides are not sensitive to the brewing time, and flavones and 1-DNJ are sensitive to the brewing time. For flavone, the brewing time is not less than 30min, otherwise, the brewing time is too short, which can cause the concentration of flavone in the brewing liquid to be lower; if the brewing time is too long, the flavone will be oxidized and degraded to a certain extent, and the flavone content in the brewing liquid will be reduced and the tea soup quality will be poor. For 1-DNJ, the longer the infusion time, the greater the amount of dissolution in the infusion.

Example 5

Taking 2g of the mulberry tea prepared according to the formula R7 according to the brewing liquid obtained under the optimal brewing condition, wherein the brewing condition is that the brewing water temperature is 75 ℃, the brewing time is 50min, the tea water ratio is 1:100 (g: mL) and 1 time of brewing. The mulberry tea is brewed according to the brewing process, the in vitro blood sugar reduction efficacy is measured by using the brewing liquid, and the inhibition rates of alpha-glucosidase and alpha-amylase are respectively tested. The results are shown in FIG. 15.

As can be seen from fig. 15, the inhibition rates of the mulberry tea infusion solution on α -glucosidase and α -amylase were 74.77% and 68.04%, respectively.

In conclusion, the mulberry leaf tea is prepared by drying mulberry leaves, mulberry branch bark and mulberry root bark at a constant temperature, crushing the mulberry leaves, the mulberry branch bark and the mulberry root bark into different particle sizes according to different raw materials, and compounding the mulberry leaf tea with different particle sizes, and has the advantages of fresh taste, clear color and luster, simple operation conditions and easy realization of industrial production. The mulberry leaf tea is brewed by water at a certain temperature in a certain proportion, the brewing process is simple, the taste of the brewing liquid is superior to that of the traditional mulberry leaf tea, and the sugar-reducing functional components such as flavone, polysaccharide and alkaloid are higher than those of the single mulberry leaf tea.

Example 6

Taking 2g of the mulberry tea prepared according to the formula R7 according to the brewing liquid obtained under the optimal brewing condition, wherein the brewing condition is that the brewing water temperature is 75 ℃, the brewing time is 50min, the tea water ratio is 1:100 (g: mL) and 1 time of brewing. Brewing the mulberry tea according to the brewing process, then carrying out freeze-drying treatment on the brewing solution to obtain freeze-dried powder of the mulberry tea water extract, and preparing the freeze-dried powder into a tested drug of 200mg/kg by using 0.50% CMC-Na (sodium carboxymethylcellulose) solution for later use.

Test animal selection: clean grade C57BL/6J male mice, 5 weeks old, with a body weight of 20 + -2 g.

Construction of mouse model for type 2 diabetes (T2 DM): after the mice are fed into a laboratory for stable feeding for 1 week, fasting is performed for 12 hours overnight without water prohibition, the weight of the mice is measured on the next day, the fasting blood sugar of the mice is measured by a tail-cutting blood-taking method, extreme mice are removed according to the measurement result, 10 mice are randomly selected as a normal group according to the weight and fasting blood sugar level of the mice, the rest mice are fed with high-fat diet for molding, and the mice in the normal group are fed with common feed.

The model building group C57BL/6J mice are continuously fed by high-fat diet for 16 weeks, the weight of the mice has larger difference compared with the normal group, and the mice have obesity state, then Streptozotocin (STZ) induction and high-fat diet combined feeding are carried out to build a type 2 diabetes model, 35mg/kg STZ solution is injected into the abdominal cavity according to the weight of the mice, and the administration volume is 0.1 mL/10 g. After the induction of the STZ is performed by intraperitoneal injection for 1 week, the mice are fasted and are not forbidden to be water for 12 hours overnight, blood is taken out by tail cutting, the fasting blood glucose of the mice is rapidly measured by a fish jumping 580 type blood glucose meter, and the mice with the blood glucose level higher than 11.1mmoL/L are selected for subsequent experiments.

Animal grouping: after stable breeding of mice with blood glucose level higher than 11.1mmoL/L for 4 weeks, the mice were randomly divided into 3 groups of 10 mice each, each group consisting of model group, positive group and fruit mulberry tea group, plus the normal group, to give four groups, and the specific grouping and administration conditions are shown in table 11.

TABLE 11 grouping and dosing of test mice

Table 4.4Grouping and administration of test mice

Group of	Dosage form
		Normal group	0.5% CMC-Na solution
Model set	0.5% CMC-Na solution
		Positive group	100mg/kg metformin solution
Fruit mulberry tea group	200mg/kg fruit mulberry compound tea aqueous extract

Each group of mice was treated for 28 days by gavage, and then the mice were sacrificed, and feces of the mice were collected and analyzed for intestinal flora of the mice, and the results are shown in table 12.

From table 12, it can be seen that there is an obvious difference in intestinal microbial community structure between the type 2 diabetic model group mice and the normal group mice, and there is a symptom of obvious imbalance in intestinal flora in the model group mice, and 28 days after the treatment by gavage administration of the aqueous extract of morus alba tea, the abundance of beneficial flora in the intestinal flora of the group of mice is higher than that of the model group, which indicates that the morus alba tea can regulate the symptom of imbalance in intestinal flora of the diabetic mice by increasing the relative abundance of the beneficial flora in the diabetic mice, and has the effect of improving the imbalance in intestinal flora of the diabetic mice.

TABLE 11 comparison of more abundant microorganisms in various groups of mice

Claims

1. A fruit mulberry tea is characterized in that: the mulberry leaves, the mulberry branch bark and the mulberry root bark are taken as raw materials, dried, crushed and mixed respectively to obtain the mulberry tea.

2. The fruit mulberry tea according to claim 1, which is characterized in that: and respectively drying the mulberry leaves, the mulberry branch barks and the mulberry root barks at the constant temperature of 50 ℃ until the water content is below 7%, and crushing for later use.

3. The fruit mulberry tea according to claim 1 or 2, which is characterized in that: crushing mulberry leaves to 40-60 meshes after drying, crushing mulberry twig bark to 60-80 meshes and crushing mulberry root bark to 60-80 meshes; counting the mulberry leaf powder, the mulberry branch bark powder and the mulberry root bark powder of the different powders according to the parts by weight: mulberry twig bark powder: the mulberry root bark powder is 5-90: 5-90: 5-90.

4. The fruit mulberry tea of claim 3, wherein: crushing mulberry leaves to 40-60 meshes after drying, crushing mulberry twig bark to 60-80 meshes and crushing mulberry root bark to 60-80 meshes; and (2) counting the mulberry leaf powder, the mulberry branch bark powder and the mulberry root bark powder of the different powders according to the parts by weight: mulberry twig bark powder: the mulberry root bark powder is 62: 19: 19.

5. a brewing liquid of the fruit mulberry tea of claim 1, which is characterized in that: the fruit mulberry tea of claim 1, wherein the ratio of fruit mulberry tea to water is 1:60-1: mixing and infusing at a ratio of 100 g/ml for 10-50min to obtain the infusion solution.

6. The mulberry tea infusion of claim 5 wherein: the temperature of the water is 75-85 ℃.

7. The mulberry tea infusion of claim 5 wherein: the mulberry tea is mixed and brewed for 10-50min according to the proportion of 1:60-1:100(g/ml) to water, and the brewed liquid is obtained; wherein the temperature of the water is 75-85 ℃.

8. Use of an infusion according to claim 5, characterized in that: the infusion liquid is applied to being used as an intestinal flora regulator.