Composition and application thereof in maintaining healthy level of blood sugar

Abstract

The invention relates to the technical field of health food, in particular to a composition and application thereof in maintaining the healthy level of blood sugar. The composition comprises rutin, quercetin, kaempferol and pectin. Experiments show that the composition obviously reduces the activity of alpha-glucosidase and obviously delays the digestibility of starch, so that the postprandial blood sugar level of mice is reduced, and the effect of the composition is obviously superior to that of other flavonoid and pectin compositions. It is shown that after the rutin, the quercetin, the kaempferol and the pectin are compounded according to a certain proportion, an obvious synergistic effect is generated. Besides, according to the composition prepared by the invention, the dosage of quercetin is reduced, the utilization rate of pectin is increased, the production cost is reduced, the raw materials are pure natural, safe and non-toxic, the functionality is strong, the cost is low, and the composition has a wide application prospect in the aspect of deep processing of starch-based healthy foods.

Description

Technical Field

[0001] The present invention relates to the technical field of health food, in particular to a composition and application thereof in maintaining healthy blood sugar level. Background Art

[0002] α-Glucosidase is one of the starch digestive enzymes that has received much attention in research. When starch is consumed, it is first hydrolyzed by amylase into molecules such as disaccharides and oligosaccharides; then, the non-reducing ends of these molecules are cleaved by α-glucosidases on intestinal epithelial cells, releasing glucose into the blood circulation, which is then absorbed and utilized by the human body. Therefore, by inhibiting the activity of α-glucosidase, the production of glucose in the intestine can be delayed or inhibited, and the blood sugar level in the body can be controlled. At present, α-glucosidase inhibitors are mainly some chemically synthesized drugs, such as acarbose, metformin and miglitol. In clinical practice, they are used as adjuvants in the treatment of diabetes, but long-term use can easily cause side effects such as hypoglycemia, gastrointestinal dysfunction and weight gain. Therefore, it is very necessary to find new natural α-glucosidase inhibitors with stronger inhibitory activity and fewer side effects.

[0003] It has been reported that flavonoids can block the digestion and absorption of carbohydrates by inhibiting the activity of α-glucosidase, thereby achieving the purpose of controlling postprandial hyperglycemia, but the effect is still not ideal. It is of great significance to develop a composition with better hypoglycemic effect for preparing health products or foods. Pectin is a soluble dietary fiber naturally present in fruits and vegetables, is one of the components of plant cell walls, and has been widely used in food processing. At present, there is no report on the combination of pectin and flavonoids for maintaining blood sugar. Summary of the invention

[0004] In view of this, the present invention provides a composition and use thereof in maintaining healthy blood sugar levels.

[0005] A composition comprising rutin, quercetin, kaempferol and pectin.

[0006] In the present invention, the mass ratio of rutin, quercetin, kaempferol and pectin is (0.0019-0.0074): (0.0008-0.0032): (0.0011-0.0044): (10-15). In some specific embodiments, the mass ratio of rutin, quercetin, kaempferol and pectin is 0.0019:0.0008:0.0011:2.5, 0.0019:0.0008:0.0011:3.75, 0.0037:0.0016:0.0022:2.5, 0.0037:0.0016:0.0022:3.75, 0.0074:0.0032:0.0044:2.5, 0.0074:0.0032:0.0044:3.75, or any ratio between the above two ratio ranges.

[0007] The present invention investigates the activity of α-glucosidase and hypoglycemic effect after other flavonoids (such as rutin, quercetin, kaempferol in pairs) and pectin are used together. The results show that the composition of rutin, quercetin, kaempferol and pectin in the present invention can effectively inhibit the activity of α-glucosidase, solve the problem of limited anti-starch digestion and hypoglycemic effect of single active ingredients in the prior art, and significantly improve the inhibitory activity and hypoglycemic effect of α-glucosidase compared with other compositions, with a CI of less than 0.9. It shows that in the composition of the present invention, the four components of rutin, quercetin, kaempferol and pectin are reasonably matched, resulting in a synergistic effect.

[0008] In the present invention, "composition" is not limited to the physical mixture of active ingredients in the composition, but also includes the combination of active ingredients in any order at a certain time interval. Specifically, in the present invention, the composition is a combination of flavonoids and pectin in the prevention and treatment of diabetes or maintenance of healthy blood sugar levels, and the two can exist in a mixed form or separately.

[0009] In the present invention, the composition further comprises a buffer. In some embodiments, the buffer comprises a sodium phosphate buffer, a potassium phosphate buffer, a potassium phosphate buffer, a sodium acetate buffer or a potassium acetate buffer. In some specific embodiments, the buffer is a phosphate buffer. In some embodiments, the concentration of the buffer is 0.1M to 0.3M, specifically 0.1M, 0.2M, 0.3M. In some embodiments, the pH of the buffer is 6.0 to 8.0, specifically 6.0, 6.5, 7.0, 7.5, 8.0.

[0010] The present invention also provides a method for preparing the composition, comprising: dissolving the rutin, quercetin, kaempferol and pectin in a phosphate buffer. In some embodiments, the preparation method comprises: dissolving the rutin, quercetin and kaempferol in a phosphate buffer, dissolving pectin in a phosphate buffer, and then mixing. In other embodiments, the preparation method comprises: dissolving the rutin, quercetin, kaempferol and pectin in a phosphate buffer at the same time.

[0011] The present invention also provides application of the composition in preparing products that are helpful in maintaining healthy blood sugar levels.

[0012] In the application of the present invention, maintaining a healthy blood sugar level includes: inhibiting α-glucosidase, delaying starch digestion, reducing RDS content, increasing RS content and / or increasing SDS content.

[0013] In the present invention, when the composition of the present invention is used to inhibit α-glucosidase or to maintain a healthy blood sugar level, flavonoids (rutin, quercetin and kaempferol) and pectin can be used simultaneously or in any order. When the two are used simultaneously, there are two situations: the flavonoids and pectin exist in a mixed form, or the flavonoids and pectin exist independently and then used simultaneously. Experiments show that whether the two are used simultaneously or in different orders, they have a significant inhibitory effect on the activity of α-glucosidase.

[0014] The invention also provides application of the composition in preparing α-glucosidase inhibitor.

[0015] The present invention also provides a product for maintaining healthy blood sugar levels, which includes the composition and excipients of the present invention. In the present invention, the product includes health food or food. Further, the health food and food include but are not limited to starch-based health food, starch-based health care food, etc. In the present invention, the dosage form of the product includes but is not limited to oral liquid, syrup, granules, pills, capsules, pills, tablets.

[0016] The present invention has no special restrictions on the types of auxiliary materials, and any common auxiliary materials in the art can be used. Conventional selection and adjustment can be made in combination with the product type. For example, when the product is a health food, the auxiliary materials of the health food include but are not limited to fillers, sweeteners, disintegrants, lubricants, adhesives, etc. When the product is a food, the food auxiliary materials include but are not limited to sweeteners, thickeners, acidulants, emulsifiers, preservatives, etc. There is no special restriction on the specific types of the above auxiliary materials, and any commonly used auxiliary materials in the art can be used.

[0017] The present invention also provides a method for maintaining healthy blood sugar levels, comprising: administering the composition or product of the present invention.

[0018] The present invention provides a composition and its application in maintaining healthy blood sugar levels. The composition includes rutin, quercetin, kaempferol and pectin. Experimental results show that the composition of the present invention significantly reduces the activity of α-glucosidase, significantly delays starch digestibility, and thus reduces the postprandial blood sugar level of mice, and its effect is significantly better than other flavonoid and pectin compositions. It is explained that the present invention produces a significant synergistic effect after compounding rutin, quercetin, kaempferol and pectin in a certain proportion. In addition, the composition prepared by the present invention reduces the amount of quercetin, increases the utilization rate of pectin, reduces the production cost, and the raw materials are pure and natural, safe and non-toxic, highly functional, and low in cost, and has broad application prospects in the deep processing of starch-based health foods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the inhibition rate of flavonoid monomers on α-glucosidase activity;

[0020] Figure 2 is the CI value of different combinations of flavonoids inhibiting α-glucosidase activity;

[0021] Figure 3 is the inhibition rate of different flavonoid compositions on α-glucosidase activity in the presence of pectin;

[0022] Table 1 shows the CI values ​​of the pectin-flavonoid composition for inhibiting α-glucosidase;

[0023] Figure 4 Inhibition rate of α-glucosidase activity by pectin-rutin-quercetin-kaempferol mixture under different addition orders;

[0024] Figure 5 is the digestion and hydrolysis curve of starch in the presence and absence of pectin and rutin-quercetin-kaempferol mixture;

[0025] Figure 6 is the digestible fragment content of starch in the presence or absence of pectin and rutin-quercetin-kaempferol mixture;

[0026] Figure 7 The changes in postprandial blood glucose levels in mice in the presence or absence of pectin and rutin-quercetin-kaempferol mixture. DETAILED DESCRIPTION

[0027] The present invention discloses a composition for regulating starch digestion and blood glucose levels by inhibiting the activity of α-glucosidase. Those skilled in the art can draw on the content herein and appropriately improve the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in the present invention. The composition for regulating starch digestion and blood glucose levels by inhibiting the activity of α-glucosidase described in the present invention has been described through preferred embodiments. Relevant personnel can obviously make changes or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0028] The method for measuring the inhibitory activity of α-glucosidase involved in the embodiments of the present invention:

[0029] Mix 50 μL of the sample, 50 μL of α-glucosidase (0.33 U / mL), and 50 μL of phosphate buffer (0.2 M) thoroughly and react at 37 °C for 10 min. Then, add 100 μL of p-nitrophenyl-β-D-glucopyranoside (3 mM) and react at 37 °C for 20 min. After the reaction is completed, immediately add 750 μL of 0.2 M sodium carbonate solution to terminate the reaction. Use PBS as the blank control. Finally, use a microplate reader to measure the absorbance of the sample at 405 nm. The calculation formula (1) for the inhibition rate of α-glucosidase is as follows:

[0030]

[0031] Among them, A, B, C, and D represent the absorbance values of the sample, sample blank, control, and control blank, respectively.

[0032] The method for measuring the combined inhibitory effect of α-glucosidase involved in the embodiments of the present invention:

[0033] Using phosphate buffer (0.2 mol / L, pH 6.9) as the solvent, prepare a series of sample solutions with different ratios. Fix the concentration ratio of the samples in the reaction system as IC 50 ratio. The combined dose-effect relationship of flavonoids on α-glucosidase was established. The dose is the concentration of the flavonoid compound combination, and Fa (0 < Fa < 1) is the effect, that is, the inhibition rate. The combined inhibitory effect of flavonoid compounds on α-glucosidase was evaluated using the Fa-combination index (CI) curve. CI < 0.9, CI = 0.9 - 1.1, and CI > 1.1 represent synergistic effect, additive effect, and antagonistic effect, respectively.

[0034] The method for measuring the hydrolysis rate and the content of digestion fragments of in vitro starch digestion involved in the embodiments of the present invention:

[0035] Dissolve 10 mg / mL of cassava starch in sodium acetate buffer solution (0.2 mol / L), gelatinize at 90°C for 20 min, and store at 37°C for later use. Thoroughly mix 0.75 mL of sample solution of different concentrations and 1.25 mL of mixed enzyme solution (290 U / mL α-amylase and 60 U / mL α-glucosidase) and incubate at 37°C for 20 min. Sodium acetate buffer solution was used as a control. Add 1.8 mL of gelatinized starch to the above reaction solution and oscillate in a constant temperature water bath at 37°C at a speed of 150 r / min. Take 150 μL of the reaction solution at 0, 20, 40, 60, 90, 120 and 180 min and add it to a 1.5 mL test tube containing 300 μL of 0.3M Na2CO3 to stop the reaction. Then, centrifuge the reaction solution at 7300 rpm for 5 min, and the supernatant and precipitate are both for later use. Then, 100 μL of the supernatant was added with 3 mL of GOPOD reagent and placed in a water bath at 50°C for 20 min. The absorbance of each sample was measured at 510 nm. 100 μL of 1 mg / mL glucose solution was used as the standard sample. The calculation formulas (2)-(5) for the hydrolysis rate and digestion fragment content of starch are as follows:

[0036]

[0037] RS(%)=(1-RDS-SDS)×100% (Formula 5)

[0038] Among them, G t represents the glucose content in the sample at time t; RDS represents the rapidly digestible starch content, %; SDS represents the slowly digestible starch content, %; RS represents the resistant starch content, %; G0 represents the amount of free glucose before enzymatic hydrolysis, mg; G 20 Indicates the amount of glucose produced after 20 minutes of enzymatic hydrolysis, mg; G 120 It represents the amount of glucose produced after hydrolysis for 120 min, mg; S represents the total starch content in the sample, mg.

[0039] The method for determining the postprandial blood sugar response involved in the embodiments of the present invention is as follows:

[0040] Four-week-old male golden hamsters (initial body weight: 75-85g) were purchased and raised in an SPF animal room (temperature: 24±2°C; relative humidity: 55±5% humidity; 12h light / dark cycle), 6 per cage, fed with ordinary feed, and allowed to eat and drink freely. After one week of adaptive feeding, the mice were divided into 4 groups (n=5) according to their body weight, and each group of mice was fasted for 18h. Then, the fasted mice were given physiological saline (100mL / kg body weight (BW)), flavonoid mixture samples (100mg / kg BW) and flavonoid mixture-pectin samples (100mg / kg BW~200mg / kg BW, 100mg / kg BW~300mg / kg BW) separately by feeding. After about 30min of feeding, each mouse was given a cassava starch sample (2g / kg BW) by gavage. Blood samples were collected from the lateral tail vein at 0, 30, 60 and 120 min after gavage. Blood glucose levels were measured by a glucometer.

[0041] To further illustrate the present invention, a composition for regulating starch digestion and blood sugar level by inhibiting α-glucosidase activity provided by the present invention is described in detail below in conjunction with examples.

[0042] The test materials used in the present invention are all common commercial products and can be purchased in the market.

[0043] The present invention will be further described below in conjunction with embodiments:

[0044] Comparative Example 1

[0045] Rutin was dissolved in phosphate buffer (0.3M, pH 6.5). 50 μL of rutin solution with different concentrations (100, 200, 300, 400, 500 μg / mL) was mixed with 50 μL of α-glucosidase (0.33 U / mL) and 50 μL of phosphate buffer, and incubated at 37°C for 25 min to measure its inhibitory ability on α-glucosidase activity.

[0046] Comparative Example 2

[0047] Quercetin was dissolved in phosphate buffer (0.2M, pH 6.9). 50 μL of quercetin solution of different concentrations (50, 100, 150, 200, 250 μg / mL) was mixed with 50 μL of α-glucosidase (0.33 U / mL) and 50 μL of phosphate buffer, incubated at 37°C for 20 min, and its inhibitory ability on α-glucosidase activity was measured.

[0048] Comparative Example 3

[0049] Kaempferol was dissolved in phosphate buffer (0.2M, pH 7.5). 50 μL of kaempferol solution of different concentrations (100, 200, 300, 400, 500 μg / mL) was mixed with 50 μL of α-glucosidase (0.33 U / mL) and 50 μL of phosphate buffer, and incubated at 37°C for 15 min to measure its inhibitory ability on α-glucosidase activity.

[0050] Comparative Example 4

[0051] Rutin and quercetin were dissolved in phosphate buffer (0.2 M, pH 6.9) and mixed in different proportions. The concentration gradient of rutin and quercetin was set at IC 50 The value is based on 1 / 8IC 50 、1 / 4IC 50 、1 / 2IC 50 、IC 50 and 2IC 50 . The concentration ratios of rutin and quercetin are 74.44:31.78, 148.89:63.57, 297.78:127.13, 595.55:254.26, and 1191.11:508.52, respectively. The concentration unit of each component is μg / mL. 50 μL of rutin-quercetin mixture was mixed with 50 μL of α-glucosidase and 50 μL of phosphate buffer, and incubated at 37°C for 15 min. The inhibitory ability of α-glucosidase activity was measured and the CI value was calculated.

[0052] Comparative Example 5

[0053] Rutin and kaempferol were dissolved in phosphate buffer (0.3 M, pH 6.5) and mixed in different proportions. The concentration gradient of rutin and kaempferol was set at IC 50 The value is based on 1 / 8IC 50 、1 / 4IC 50 、1 / 2IC 50 、IC 50 and 2IC 50 The concentration ratios of rutin and kaempferol were 74.44:43.79, 148.89:87.59, 297.78:175.17, 595.55:350.35, and 1191.11:700.69, respectively. The concentration of each component is in μg / mL. 50 μL of rutin-kaempferol mixture was mixed with 50 μL of α-glucosidase and 50 μL of phosphate buffer, and incubated at 37°C for 25 min. The inhibitory ability of α-glucosidase activity was measured and the CI value was calculated.

[0054] Comparative Example 6

[0055] Quercetin and kaempferol were dissolved in phosphate buffer (0.3 M, pH [7.5]) and mixed in different proportions. The concentration gradient of quercetin and kaempferol was set at IC 50 The value is based on 1 / 8IC 50 、1 / 4IC 50 、1 / 2IC 50 、IC 50 and 2IC 50 The concentration ratios of quercetin and kaempferol were 31.78:43.79, 63.57:87.59, 127.13:175.17, 254.26:350.35, and 508.52:700.69, respectively. The concentration of each component is in μg / mL. 50 μL of quercetin-kaempferol mixture was mixed with 50 μL of α-glucosidase and 50 μL of phosphate buffer, and incubated at 37°C for 20 min. The inhibitory ability of α-glucosidase activity was measured and the CI value was calculated.

[0056] Example 1

[0057] Rutin, quercetin and kaempferol were dissolved in phosphate buffer (0.2 M, pH 6.9) and mixed in different proportions. The concentration gradient of rutin, quercetin and kaempferol was set at IC 50 The value is based on 1 / 8IC 50 、1 / 4IC 50 、1 / 2IC 50 、IC 50 and 2IC 50 The concentration ratios of rutin, quercetin and kaempferol are 74.44:31.78:43.79, 148.89:63.57:87.59, 297.78:127.13:175.17, 595.55:254.26:350.35, 1191.11:508.52:700.69. The concentration of each component is in μg / mL. 50 μL of rutin-quercetin-kaempferol mixture was mixed with 50 μL of α-glucosidase and 50 μL of phosphate buffer, incubated at 37°C for 20 min, and its inhibitory ability on α-glucosidase activity was measured, and the CI value was calculated.

[0058] The experimental results obtained in Example 1 and Comparative Examples 1 to 6 are as follows Figure 1 and Figure 2 As shown. Figure 1 It can be seen that the concentrations of rutin, quercetin and kaempferol are positively correlated with the ability to inhibit α-glucosidase. Quercetin has the strongest ability to inhibit α-glucosidase, followed by kaempferol, and rutin is the weakest. Among them, when the concentration of quercetin is 250μg / mL, its inhibition rate on α-glucosidase activity can reach 52.71±1.71%. Figure 2 It can be seen that compared with the two-way combination of flavonoids, the CI value of rutin, quercetin and kaempferol combined is the lowest. Among them, when the concentration ratio of rutin-quercetin-kaempferol mixture is 74.44:31.78:43.79, 148.89:63.57:87.59, 297.78:127.13:175.17, 595.55:254.26:350.35, 1191.11:508.52:700.69, the CI values ​​are all less than 0.9 (CI values ​​are between 0.891±0.009 and 0.307±0.010). This shows that the combination of rutin, quercetin and kaempferol has the strongest synergistic effect on the inhibition of α-glucosidase.

[0059] Comparative Example 7

[0060] Rutin and quercetin were dissolved in phosphate buffer (0.2M, pH 6.9) at concentration ratios of 37.22:15.89, 74.44:31.78 and 148.89:63.57 to obtain different rutin-quercetin solutions, wherein the concentration of each component is in μg / mL. A mixture of 250 μL pectin (10 mg / mL to 15 mg / mL) dissolved in 0.2 M pH 6.5 phosphate buffer and 50 μL rutin-quercetin was incubated at 37°C for 15 min. The mass ratios of rutin-quercetin and pectin were 0.0027:2.5, 0.0027:3.75, 0.0053:2.5, 0.0053:3.75, 0.0106:2.5, and 0.0106:3.75. Then, 50 μL of α-glucosidase solution and 50 μL phosphate buffer were added, and the mixture was incubated at 37°C for 15 min before measuring the inhibitory ability on α-glucosidase activity.

[0061] Comparative Example 8

[0062] Rutin and kaempferol were dissolved in phosphate buffer (0.3M, pH 6.9) at a concentration ratio of 37.22:21.90, 74.44:43.79 and 148.89:87.59 to obtain different rutin-kaempferol solutions. The concentration of each component is in μg / mL. 250 μL of pectin (10 mg / mL to 15 mg / mL) dissolved in 0.2M pH 6.5 phosphate buffer was mixed with 50 μL of a mixture of rutin-quercetin-kaempferol at 37°C and incubated for 20 minutes. The mass ratios of rutin-kaempferol and pectin were 0.0030:2.5, 0.0030:3.75, 0.0059:2.5, 0.0059:3.75, 0.0118:2.5, and 0.0118:3.75. Then, 50 μL of α-glucosidase solution and 50 μL of phosphate buffer were added, and the mixture was incubated at 37° C. for 25 min before measuring the inhibitory ability of the mixture on the activity of α-glucosidase.

[0063] Comparative Example 9

[0064] Quercetin and kaempferol were dissolved in phosphate buffer (0.2M, pH 7.5) at a concentration ratio of 15.89:21.90, 31.78:43.79 and 63.57:87.59 to obtain different quercetin-kaempferol solutions. The concentration of each component is in μg / mL. 250 μL of pectin (10 mg / mL-15 mg / mL) dissolved in 0.2M pH 6.5 phosphate buffer was mixed with 50 μL of quercetin-kaempferol mixture and incubated at 37°C for 10 min. The mass ratios of quercetin-kaempferol and pectin were 0.0019:2.5, 0.0019:3.75, 0.0038:2.5, 0.0038:3.75, 0.0076:2.5, 0.0076:3.75. Then, 50 μL of α-glucosidase solution and 50 μL of phosphate buffer were added, and the mixture was incubated at 37° C. for 20 min before measuring the inhibitory ability of the mixture on the activity of α-glucosidase.

[0065] Example 2

[0066] Rutin, quercetin and kaempferol were dissolved in phosphate buffer (0.2M, pH 6.9) at concentration ratios of 37.22:15.89:21.90, 74.44:31.78:43.79 and 148.89:63.57:87.59 to obtain different rutin quercetin-kaempferol solutions (i.e. flavonoid solutions). The concentration of each component is in μg / mL. 250 μL of pectin solution (pectin concentration of 10 mg / mL to 15 mg / mL) dissolved in 0.2M pH 6.5 phosphate buffer was mixed with 50 μL of flavonoid solution and incubated at 37°C for 10 min. Among them, the mass ratios of rutin-quercetin-kaempferol and pectin were 0.0038:2.5, 0.0038:3.75, 0.075:2.5, 0.0075:3.75, 0.0150:2.5, and 0.0150:3.75. Then, 50 μL of α-glucosidase solution and 50 μL of phosphate buffer were added, and the mixture was incubated at 37°C for 20 min before measuring its ability to inhibit α-glucosidase activity.

[0067] Example 3

[0068] Rutin, quercetin and kaempferol were dissolved in phosphate buffer (0.2M, pH 6.9) at concentration ratios of 37.22:15.89:21.90, 74.44:31.78:43.79 and 148.89:63.57:87.59 to obtain different rutin-quercetin-kaempferol solutions. The concentration of each component is in μg / ml. 50 μL of the mixture of rutin-quercetin-kaempferol was incubated with 50 μL of α-glucosidase solution and 50 μL of phosphate buffer at 37°C for 20 min. Then, 250 μL of pectin solution (10 mg / mL to 15 mg / mL, dissolved in 0.2M pH 7.5 phosphate buffer) was added. The mass ratios of rutin-quercetin-kaempferol and pectin were 0.0038:2.5, 0.0038:3.75, 0.075:2.5, 0.0075:3.75, 0.0150:2.5, and 0.0150:3.75. Then, the mixture was incubated at 37°C for 10 min to measure its ability to inhibit α-glucosidase activity.

[0069] The experimental results obtained in Examples 2 to 3 and Comparative Examples 7 to 9 are as follows Figure 3 and Figure 4 As shown. Figure 3It can be seen that the addition of pectin enhances the inhibition of α-glucosidase by different flavonoid combinations. At the same concentration, the pectin-rutin-quercetin-kaempferol combination has the strongest synergistic effect on the inhibition of α-glucosidase (Table 1). Among them, when the pectin concentration is 10-15 mg / mL, the inhibition rate of 0.075 mg / mL rutin-quercetin-kaempferol mixture on α-glucosidase increases from 26.69±0.74% to 37.38±1.50%~42.57±1.17%. In addition, Figure 4 It can be seen that compared with mixing the rutin-quercetin-kaempferol mixture and pectin before adding α-glucosidase (sequence 1), the effect of adding sequence 2 (mixing the rutin-quercetin-kaempferol mixture and α-glucosidase before adding pectin) on the inhibition of α-glucosidase by the rutin-quercetin-kaempferol mixture is consistent with the effect trend produced by sequence 1, that is, pectin and the rutin-quercetin-kaempferol mixture synergistically inhibit α-glucosidase. Among them, under sequence 2, when the pectin concentration is 10-15 mg / mL and the concentration of the rutin-quercetin-kaempferol mixture is 0.15 mg / mL, the inhibition rate of α-glucosidase is 68.27±0.67%~77.68±1.36%. The inhibition rate of sequence 1 at the same concentration is 58.33±1.02%~48.86±0.97%. It can be seen that the protective effect of sequence 1 on α-glucosidase is stronger than that of sequence 2.

[0070] Table 1 shows the CI values ​​of pectin-flavonoid compositions for inhibiting α-glucosidase

[0071]

[0072] Note: R, Q and K stand for rutin, quercetin and kaempferol respectively, and P stands for pectin.

[0073] Comparative Example 10

[0074] 1.95 mL of sodium acetate buffer solution (0.2 mol / L, pH 5.4) and 1.25 mL of mixed enzyme solution were thoroughly mixed. The hydrolysis rate and digestion fragment content of the samples at different time periods were measured.

[0075] Comparative Example 11

[0076] The mixture of rutin, quercetin and kaempferol was dissolved in sodium acetate buffer (0.3 mol / L, pH 5.4) at a concentration ratio of 595.55:254.26:350.35. 1.20 mL of sodium acetate buffer solution (0.2 mol / L, pH 5.4) and 0.75 mL of the mixture of rutin-quercetin-kaempferol were incubated at 37°C for 20 min. The hydrolysis rate and digestion fragment content of the samples at different time periods were determined.

[0077] Example 4

[0078] The mixture of rutin, quercetin and kaempferol was dissolved in sodium acetate buffer (0.2 mol / L, pH 5.2) at a concentration ratio of 595.55:254.26:350.35. 1.20 mL of pectin solution (2.5 mg / mL, dissolved in 0.2 M pH 5.2 phosphate buffer) and 0.75 mL of the mixture of rutin-quercetin-kaempferol were incubated at 37°C for 10 min. The hydrolysis rate and digestion fragment content of the samples at different time periods were determined.

[0079] Example 5

[0080] The mixture of rutin, quercetin and kaempferol was dissolved in sodium acetate buffer (0.3 mol / L, pH 5.4) at a concentration ratio of 595.55:254.26:350.35. 1.20 mL of pectin solution (5 mg / mL, dissolved in 0.3 M pH 5.4 phosphate buffer) and 0.75 mL of the mixture of rutin-quercetin-kaempferol were incubated at 37°C for 15 min. The hydrolysis rate and digestion fragment content of the samples at different time periods were determined.

[0081] Example 6

[0082] The mixture of rutin, quercetin and kaempferol was dissolved in sodium acetate buffer (0.2 mol / L, pH 5.6) at a concentration ratio of 595.55:254.26:350.35. 1.20 mL of pectin solution (10 mg / mL, dissolved in 0.2 M pH 5.6 phosphate buffer) and 0.75 mL of the mixture of rutin-quercetin-kaempferol were incubated at 37°C for 20 min. The hydrolysis rate and digestion fragment content of the samples at different time periods were determined.

[0083] The effects of Examples 4 to 6 and Comparative Examples 10 to 11 on starch hydrolysis rate and digestion fragment content are shown in FIG. Figure 5 and Figure 6 As shown. Figure 5 It can be seen that the hydrolysis rate of starch increased rapidly within 0-20 minutes, slowed down within 20-60 minutes, and leveled off from 60-180 minutes. After adding the rutin-quercetin-kaempferol mixture, the hydrolysis rate of starch at 180 minutes decreased from 59.18% to 30.93%. After adding different concentrations of pectin, the hydrolysis rate of starch at 180 minutes further decreased to 28.17%-24.26%, indicating that the combination of pectin and flavonoids enhances the ability of flavonoids to inhibit starch hydrolysis. Figure 6It can be seen that after the addition of rutin-quercetin-kaempferol mixture, the RDS content of starch decreased from 49.27% ​​to 16.92%, and the SDS and RS contents increased from 8.56% and 42.17% to 14.23% and 68.85%, respectively. When different concentrations of pectin were used in combination with rutin-quercetin-kaempferol mixture, the RDS content further decreased with the increase of pectin concentration, and the SDS and RS contents showed an opposite trend. This indicates that pectin helps to enhance the conversion of RDS in starch to SDS and RS by rutin-quercetin-kaempferol mixture.

[0084] Comparative Example 12

[0085] Each mouse was given a sample of cassava starch (2 g / kg BW) by gavage. Blood samples were collected from the lateral tail vein at 0, 30, 60 and 120 minutes after gavage to measure blood glucose levels.

[0086] Comparative Example 13

[0087] Mice were fed a mixture of rutin-quercetin-kaempferol (100 mg / kg BW, concentration ratio of IC 50 After about 30 minutes, each mouse was given a cassava starch sample (2 g / kg BW) by gavage. Blood was collected from the lateral tail vein at 0, 30, 60 and 120 minutes after gavage to measure blood glucose levels.

[0088] Example 7

[0089] Mice were fed with a mixture of rutin-quercetin-kaempferol and pectin samples (100 mg / kg BW to 200 mg / kg BW), and about 30 minutes later, each mouse was given a cassava starch sample (2 g / kg BW) by gavage. Blood was collected from the lateral tail vein at 0, 30, 60 and 120 minutes after gavage to measure blood glucose levels.

[0090] Example 8

[0091] Mice were fed with a mixture of rutin-quercetin-kaempferol and pectin samples (100 mg / kg BW to 300 mg / kg BW), and about 30 minutes later, each mouse was given a cassava starch sample (2 g / kg BW) by gavage. Blood was collected from the lateral tail vein at 0, 30, 60 and 120 minutes after gavage to measure blood glucose levels.

[0092] The experimental results obtained in Examples 7 to 8 and Comparative Examples 12 to 13 are as follows Figure 6 shown.

[0093] Among them, the blank control group was given the cassava starch sample of Comparative Example 12.

[0094] RQK group: given to the sample of Comparative Example 13.

[0095] RQ-K+200 mg / kg BW P group: given the sample of Example 7.

[0096] RQ-K+300 mg / kg BW P group: given the sample of Example 8.

[0097] The results show that the postprandial blood glucose level of mice after starch feeding first increases and then decreases, and is the highest at 30min. After feeding with a mixture of rutin-quercetin-kaempferol, the postprandial blood glucose level of mice at 30min decreased from 288.7mg / dL to 231.1mg / dL. The combined feeding of rutin-quercetin-kaempferol mixture and pectin further delayed the starch digestion of mice and reduced the postprandial blood glucose level (see RQ-K+200mg / kg BW P group, RQ-K+300mg / kg BW P group). Among them, the postprandial blood glucose level of mice in the RQ-K+300mg / kg BW P group at 30min and 60min was 198.8mg / dL and 144.2mg / dL, and the hypoglycemic effect was the best. The above results show that the pectin-rutin-quercetin-kaempferol composition of the present invention has great advantages in hypoglycemic.

[0098] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composition, characterized in that These include rutin, quercetin, kaempferol, and pectin.

2. The composition according to claim 1, characterized in that In the composition, the mass ratio of rutin, quercetin, kaempferol and pectin is (0.0019-0.0074): (0.0019-0.0074): (0.0008-0.0032): (0.0011-0.0044): (10-15).

3. The composition according to claim 3, characterized in that The mass ratios of rutin, quercetin, kaempferol and pectin are 0.0019:0.0008:0.0011:2.5, 0.0019:0.0008:0.0011:3.75, 0.0037:0.0016:0.0022:2.5, 0.0037:0.0016:0.0022:3.75, 0.0074:0.0032:0.0044:2.5, and 0.0074:0.0032:0.0044:3.

75.

4. The composition according to any one of claims 1 to 3, characterized in that It also includes a buffer; the buffer includes at least one of a sodium phosphate buffer, a potassium phosphate buffer, a potassium phosphate buffer, a sodium acetate buffer or a potassium acetate buffer.

5. The composition according to claim 4, characterized in that The concentration of the buffer solution is 0.10-0.30 M, and the pH value is 6.00-8.

0.

6. A method for preparing the composition according to any one of claims 1 to 5, characterized in that: The rutin, quercetin, kaempferol and pectin were dissolved in phosphate buffer.

7. Use of the composition according to any one of claims 1 to 5 or the composition prepared by the preparation method according to claim 6 in the preparation of a product that helps maintain a healthy blood sugar level.

8. The use according to claim 7, characterized in that: The method of maintaining healthy blood sugar level includes: inhibiting α-glucosidase activity, delaying starch digestion, reducing RDS content, increasing RS content and / or increasing SDS content.

9. Use of the composition according to any one of claims 1 to 5 or the composition prepared by the preparation method according to claim 6 in the preparation of an α-glucosidase inhibitor.

10. A product, characterized in that Comprising the composition according to any one of claims 1 to 5 and auxiliary materials; Preferably, the product comprises a health food or a food, and its dosage form comprises an oral liquid, a syrup, a granule, a drop pill, a capsule, a pill, and a tablet.

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