Solid beverage containing raspberry ketone and method for preparing solid beverage from raspberry ketone leaves

Abstract

The invention discloses a solid beverage containing raspberry ketone and a method for preparing the solid beverage by using raspberry ketone leaves, and the preparation method comprises the following steps: step 1, treating raspberry leaves by using a steam explosion method to obtain raspberry leaf powder; step 2, extracting the raspberry leaf powder by using purified water, and concentrating an extracting solution to obtain a concentrated solution with the soluble solid content of 10%-20%; step 3, uniformly mixing the concentrated solution, xylitol, maltodextrin and citric acid to obtain a mixed solution; and step 4, drying the mixed solution to obtain the solid beverage. The extraction efficiency of raspberry ketone is improved through a method of combining steam explosion and low-temperature superfine grinding, and after the raspberry ketone is prepared into the solid beverage, the effects of promoting brown adipose tissue to produce heat and enhancing metabolism are achieved after the solid beverage is drunk.

Description

Technical Field

[0001] The present application relates to the technical field of raspberry ketone extraction, and in particular to a solid beverage containing raspberry ketone and a method for preparing the solid beverage using raspberry ketone leaves. Background Art

[0002] Raspberry, also known as raspberry, is widely cultivated and planted in temperate and cold regions. The fruit contains a variety of functional factors, such as flavonoids, phenolic acids and other polyphenolic compounds, among which raspberry ketone is the main functional factor. Studies have shown that raspberry ketone has antioxidant, anti-inflammatory, anti-cancer, and skin elasticity-enhancing effects. It can also reduce the body weight of obese rats through the combined effects of regulating sugar and lipid metabolism, improving leptin resistance, and insulin resistance, and can prevent obesity and relieve hyperlipidemia caused by obesity.

[0003] Studies have found that the total raspberry ketone content (TPC) of raspberry leaves is much greater than that of raspberry fruits. Raspberry leaves can be processed into tea to achieve the multiple benefits of raspberry ketones. However, compared with organic solvent extraction, the reduced release of raspberry ketones in the aqueous phase limits the application of raspberry leaves. Currently, research on raspberry ketones is mainly focused on synthesis and its functionality, and there are few reports on the extraction of raspberry ketones from raspberry leaves. Summary of the invention

[0004] Based on this, the present application provides a method for preparing a solid beverage using raspberry leaves. The amount of raspberry ketone extracted from the raspberry leaves is relatively high, and drinking it can effectively promote thermogenesis of brown fat.

[0005] The present application provides a method for preparing a solid beverage using raspberry leaves, comprising:

[0006] Step 1, treating raspberry leaves by steam explosion to obtain raspberry leaf powder;

[0007] Step 2, extracting the raspberry leaf powder with purified water, and concentrating the extract to a concentrated solution having a soluble solid content of 10% to 20%;

[0008] Step 3, uniformly mixing the concentrate, xylitol, maltodextrin and citric acid to obtain a mixed solution;

[0009] Step 4, drying the mixed solution to obtain a solid beverage.

[0010] In the present application, steam explosion is used to process raspberry leaves so that raspberry ketones in the raspberry leaves are fully released. After the solid beverage is prepared with water (20g of solid beverage uses 200mL of 60°C water), the raspberry ketone content is relatively high. After drinking, brown fat heat production can be effectively promoted, thereby enhancing metabolism.

[0011] Steam explosion can strongly change the physical and chemical structure of plant-based materials, thereby changing the release behavior of bioactive substances such as phenolic compounds. The steam explosion treatment method has the advantages of low cost, low energy consumption, environmental friendliness, easy operation and industrialization.

[0012] The principle of steam explosion is to carry out steam hydrolysis at high temperature and then release steam molecules instantly. These steam molecules have penetrated the plant tissue and are used to physically tear the hydrolyzed material. During the steam explosion process, the biomass matrix is ​​destroyed and the pore space in the cell wall increases, resulting in a large amount of rapid release of raspberry ketones from the cells. Raspberry leaf powder is obtained after steam explosion.

[0013] In the present application, raspberry leaves are placed in a high temperature and high pressure environment for steam explosion. The generated steam will penetrate into the interior of the raspberry leaves, filling the tissue gaps with steam. The high pressure generated by the saturated steam is released instantly, causing the steam in the tissue gaps to expand and further explode, resulting in the formation of micropores on the cell walls, making it easier for small molecules (such as raspberry ketones) to be released from the cells, thereby promoting the extraction of raspberry ketones.

[0014] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution, but are merely further supplements or preferences. Under the premise that there are no technical or logical contradictions, each optional method can be combined with the above-mentioned overall solution separately, and multiple optional methods can also be combined.

[0015] Optionally, the steam explosion step comprises the following steps performed in sequence:

[0016] Step a, blasting for 25 to 35 seconds at a pressure of 0.9 to 1.2 MPa and a temperature of 115 to 125°C;

[0017] Step b, blasting for 25 to 35 seconds at a pressure of 1.4 to 1.8 MPa and a temperature of 95 to 105°C.

[0018] In the present application, steam explosion is divided into two steps, firstly, explosion is carried out at a lower pressure and a higher temperature, and then explosion is carried out at a higher pressure and a lower temperature, so that raspberry ketones can be fully released without destroying the structure of raspberry ketones.

[0019] Optionally, the steam-exploded raspberry leaf powder is pulverized using an ultrafine pulverizer for 12 to 18 minutes.

[0020] Ultrafine grinding technology uses mechanical or fluid dynamic methods to make materials collide, extrude, shear, rub and disperse inside the grinder, thereby crushing the material particle size to micron level, giving the powder a larger surface area and porosity, and ultimately making the particles have higher interfacial activity. Ultrafine grinding technology improves material utilization, improves product performance, makes product quality better, and is more conducive to the development and preparation of high-quality products.

[0021] At present, the application of ultrafine grinding technology in the domestic food industry is mostly concentrated in the preparation of food additives and the production of high-fiber foods. Ultrafine grinding technology can more evenly refine raspberry leaf powder into micron-sized particles, thereby increasing the release of raspberry ketones.

[0022] Optionally, when the raspberry leaf powder is crushed by an ultrafine grinder, the temperature is 8 to 12°C.

[0023] The combination of steam explosion and low-temperature ultrafine pulverizer can further promote the release of raspberry ketones in raspberry leaves. When the raspberry leaf powder is extracted with pure water, the release amount of raspberry ketones can reach 6.1μg / g.

[0024] Optionally, the raspberry leaf powder may be freeze dried before being placed in the micronizer.

[0025] Optionally, when the raspberry leaf powder is extracted with purified water, the solid-liquid ratio of the raspberry leaf powder to purified water is 1 g: 35-45 mL.

[0026] Optionally, when the raspberry leaf powder is extracted with purified water, the extraction is performed at 85 to 95° C. for 20 to 40 minutes.

[0027] Optionally, the mixing in step 3 is performed in a water bath at 65-75°C.

[0028] Optionally, in step 4, the mixed solution is dried by spray drying, and the conditions for spray drying are: an inlet air temperature of 110 to 130° C., a peristaltic pump speed of 10 to 20 r / min, and a fan frequency of 40 to 60 Hz.

[0029] The present application also provides a solid beverage containing raspberry ketone, which is prepared by the preparation method.

[0030] The present application improves the extraction efficiency of raspberry ketone (RK) by combining steam explosion with low-temperature ultrafine grinding. After being prepared into a solid beverage, drinking it has the effect of promoting thermogenesis of brown adipose tissue and enhancing metabolism. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a graph showing the dissolution rate of raspberry ketone under different steam explosion conditions in Example 1 and Comparative Example 1;

[0032] Figure 2 This is the dissolution rate of raspberry ketone at different extraction temperatures;

[0033] Figure 3 This is the dissolution rate of raspberry ketone at different crushing times;

[0034] Figure 4 This is a graph of glucose tolerance test results;

[0035] Figure 5 This is a graph of insulin tolerance test results;

[0036] Figure 6 This is a diagram of rectal temperature in the acute cold tolerance experiment;

[0037] Figure 7 This is a graph of scapular temperature in the acute cold tolerance experiment;

[0038] Figure 8 Sensory scores were given for different xylitol addition levels;

[0039] Fig. 9 Sensory scores for different maltodextrin addition levels;

[0040] Fig.10 Sensory scores for different citric acid addition levels. DETAILED DESCRIPTION

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] Example 1

[0043] A method for preparing a solid beverage using raspberry leaves, comprising:

[0044] (1) Raspberry leaves are placed in a material barrel, and then placed in a blasting chamber of a steam explosion device for treatment, first blasting at a pressure of 1.0 MPa and a temperature of 120° C. for 30 seconds, and then the pressure is increased to 1.5 MPa and the temperature is 100° C. for 30 seconds. After the steam explosion treatment, raspberry leaf powder is obtained, and the raspberry leaf powder is first frozen and then freeze-dried.

[0045] (2) After freeze-drying, 500 g of raspberry leaf powder was weighed and placed in the feed barrel of a WZJ-6BI low-temperature ultrafine pulverizer at a temperature of 10°C and a pulverization time of 15 min. The prepared raspberry leaf powder was placed in a 4°C refrigerator for storage.

[0046] (3) Raspberry leaf powder and purified water were mixed at a solid-liquid ratio of 1 g:40 mL, and extracted at 90° C. for 30 min. The raspberry leaf tea obtained after filtration was concentrated under reduced pressure to a soluble solid content of about 15%.

[0047] (4) Add 3% xylitol, 14% maltodextrin, and 0.7% citric acid in sequence in a 70°C water bath and mix well.

[0048] (5) The prepared solution is spray dried, and the parameters are set as follows: inlet air temperature 120° C., peristaltic pump speed 15 r / min, and fan frequency 50 Hz. After drying, a solid beverage containing raspberry ketone can be obtained.

[0049] Comparative Example 1

[0050] In this comparative example, the steam explosion conditions are temperature 120° C., time 15 min, and pressure 0.5 MPa. Except for the different steam explosion conditions, the other conditions are the same as those in Example 1.

[0051] Comparative Example 2

[0052] In this comparative example, raspberry leaf powder and purified water were mixed at a solid-liquid ratio of 1 g:40 mL, and extracted with water at 80°C for 30 min. The raspberry leaf tea obtained after filtration was subjected to a vacuum concentration operation. Except for the different extraction water temperature, the other conditions were the same as in Example 1.

[0053] Comparative Example 3

[0054] In this comparative example, xylitol, maltodextrin and citric acid of different concentrations were added in sequence under a 70° C. water bath condition and mixed evenly. Other conditions were the same as those in Example 1.

[0055] Comparative Example 4

[0056] In this comparative example, the prepared solution was subjected to vacuum freeze drying. Other conditions were the same as those in Example 1.

[0057] Performance Characterization

[0058] (1) Quantitative analysis of raspberry ketone dissolved under different steam explosion conditions

[0059] The raspberry ketone content was analyzed by taking the dissolution amount of raspberry ketone as an indicator. The instruments used for the analysis of raspberry ketone content include: Agilent UHPLC-QQQ-MS / MS (1290-6470) coupling instrument (Agilent, USA); XS105DU electronic balance (Mettler, Switzerland); DL-360D intelligent ultrasonic cleaner (Shanghai Zhixin Instrument Co., Ltd.); Milli-QAdvantage A10 ultrapure water system (Merck Millipore, Germany).

[0060] Chromatographic conditions: Agilent RRHD Eclipse Plus C18 (2.1 mm × 50 mm, 1.8 μm) column; mobile phase was methanol (A), 0.1% formic acid aqueous solution (B), gradient elution program was 0-5 min, 5% → 15% A, 5-10 min, 15% → 25% A, 10-15 min, 25% → 45% A, 15-18 min, 45% → 90% A, flow rate 0.3 mL min-1; column temperature 35 ° C; injection volume 0.5 μL.

[0061] Mass spectrometry conditions: electrospray ionization (ESI) source; sheath gas temperature 250 °C, sheath gas flow rate 11 L min -1 ; Drying gas is N2, temperature is 300℃, flow rate is 5L·min -1 ; Positive and negative ion modes, capillary voltage 3500V; quantitative analysis using multiple reaction monitoring mode.

[0062] Accurately weigh the reference substance and add chromatographic methanol to make the concentration about 500 μg mL -1 Prepare the reference substance stock solution, then accurately measure an appropriate amount of each reference substance stock solution and dilute them with methanol to prepare a mixed reference substance solution.

[0063] Take 0.3 g of the raspberry leaf powder obtained in Example 1, Comparative Example 1 and Comparative Example 2, each divided into 3 groups as parallel experiments, accurately weighed, placed in a stoppered conical flask, accurately added with 25 mL of ultrapure water, vortexed and ultrasonically treated for 30 minutes, cooled to room temperature, centrifuged at 16000 rpm for 10 minutes, took the supernatant, filtered with a 0.22 μm microporous filter membrane, and took the filtrate to obtain the sample.

[0064] Accurately measure an appropriate amount of the mixed reference solution, dilute it with methanol to prepare a series of concentration reference solutions, inject them separately for measurement, and use the peak area (Y) to the mass concentration (X, ng·mL -1 ) is used for linear regression, and finally the release amount of raspberry ketone in the sample can be obtained by calculation.

[0065] See also Figure 1 As shown, from Figure 1 It can be seen that under the steam explosion conditions of Example 1, the dissolution rate of raspberry ketone is higher, significantly greater than the dissolution rate of raspberry ketone under the steam explosion treatment conditions in Comparative Example 1, and the average raspberry ketone dissolution amount of Example 1 is 3.5 μg / g.

[0066] See also Figure 2 As shown, under the extraction water temperature conditions of Example 1, the dissolution rate of raspberry ketone is higher, significantly greater than the dissolution rate of raspberry ketone in Comparative Example 2.

[0067] (2) Effect of ultrafine grinding on the extraction rate of raspberry ketone

[0068] The raspberry leaf powder obtained after steam explosion in Example 1 was subjected to ultrafine grinding. Specifically, vacuum freeze drying was first used for drying. The raspberry leaf powder after steam explosion was directly pre-frozen at -40°C for 3h, and the vacuum drying time was 24h. After drying, the moisture content of the raw material was controlled at 5±1%. The dried powder was then crushed in a WZJ-6BI low-temperature ultrafine grinder. The temperature of the crushing chamber was maintained at 10-13°C in real time by the equipment. The crushing times were 3min, 9min, 15min, and 21min, respectively, to obtain ultrafine crushed raspberry powder.

[0069] See also Figure 3 As shown in the figure, when the crushing time is 15min and 21min, the dissolution amount of raspberry ketone is above 6μg / g on average, but there is no significant difference in the dissolution amount of raspberry ketone between 15min and 21min, that is, the crushing time of 15min is the best time.

[0070] (3) Orthogonal optimization of solid beverage ratio

[0071] A single factor experiment was conducted, with xylitol added at 0.5%, 1%, 3%, 5%, and 10%, maltodextrin added at 5%, 10%, 12%, 14%, and 16%, and citric acid added at 0.1%, 0.5%, 0.7%, 0.9%, and 1.2%. Sensory evaluation was performed, and the indicators, standards, and scores of sensory evaluation are shown in Table 1. The sensory evaluation scores are shown in Table 1. Figure 8 , Fig. 9 , Fig.10 shown.

[0072] Table 1

[0073]

[0074] from Figure 8 It can be seen that the sensory score of raspberry ketone solid beverage first increases and then decreases with the addition of xylitol. The same rule is true for maltodextrin and citric acid. It can be seen that when the sensory score reaches the highest, the addition amounts of xylitol, maltodextrin and citric acid are 3%, 14% and 0.7% respectively.

[0075] On the basis of the single factor experiment, the optimal experimental range of each factor of xylitol, maltodextrin and citric acid addition was selected, that is, xylitol at about 3%, maltodextrin at about 14%, and citric acid at about 0.7%, and an orthogonal optimization experiment was carried out. The addition amounts of xylitol, maltodextrin and citric acid are shown in Table 2. Sensory evaluation was carried out to optimize the sample ratio.

[0076] Table 2

[0077]

[0078] The results of the orthogonal optimization experiment are shown in Table 3.

[0079] Table 3

[0080]

[0081] As shown in Table 3, when 3% xylitol, 14% maltodextrin, and 0.7% citric acid were added, the sensory evaluation score was the highest, which means that it was the best ratio.

[0082] (4) Spray drying (SD) sample preparation: The beverage concentrate was sucked into a spray dryer for drying. The air inlet temperature was set at 120 °C, the peristaltic pump speed was 15 r / min, and the fan frequency was 50 Hz. The sample was sieved through an 80-mesh sieve.

[0083] Vacuum freeze drying (VFD) sample preparation: The thickness of the culture dish extract was controlled at about 5 mm, pre-frozen in the refrigerator for 48 hours and then transferred to the vacuum freeze dryer. During the drying process, it was kept below 20 Pa until the end of drying. After drying for 48 hours, it was taken out and crushed through an 80-mesh sieve to obtain the sample.

[0084] From the results in Table 4, it can be seen that the samples using spray drying have good solubility and shorter dissolution time, and the spray drying operation is simpler and easy to mass produce. Therefore, spray drying is more suitable for the production of raspberry solid beverages.

[0085] Table 4

[0086]

[0087] (5) Animal experiments

[0088] Twenty 8-week-old C57BL / 6 mice were divided into two groups. One group was given normal drinking water plus high-fat feed to induce obesity, namely the CON group, and the other group was given drinking water replaced with water mixed with solid beverages, namely the RK group. The mice consumed raspberry ketones in an amount equivalent to 800 mg per day for a 50-kg human. The following experiment was conducted 12 weeks after induction.

[0089] 5-1. Glucose tolerance test

[0090] Intraperitoneal glucose tolerance test (ipGTT), performed after 6 hours of fasting, uses intraperitoneal injection of 50% weight / volume hypertonic glucose at a dose of 2 g / kg body weight. Peripheral blood samples were obtained through a small incision at the distal end of the mouse tail at 0 minutes, 15 minutes, 30 minutes, 60 minutes and 120 minutes after injection, with an estimated volume of 5-10 μL each time for measuring glucose levels.

[0091] See also Figure 4As shown, the RK group had better glucose tolerance, that is, they recovered faster after glucose injection.

[0092] 5-2. Insulin tolerance test

[0093] Intraperitoneal insulin sensitivity test (ipITT): Mice received a dose of 0.75 UI / Kg of insulin 100 UI / mL, and blood glucose levels were measured at 0, 15, 30, 60, and 120 minutes after injection.

[0094] See also Figure 5 As shown, after insulin injection, the blood glucose of RK group mice recovered faster and more smoothly.

[0095] 5-3. Acute cold resistance test

[0096] The mice were placed individually in cages and exposed to 4°C for 6 hours, during which the shoulder and rectal temperatures of the mice were measured every hour.

[0097] See also Figure 6 , Figure 7 As shown, mice in the RK group had a higher body temperature under cold exposure, especially the scapula temperature in the RK group was significantly higher than that in the CON control group, which indicates that solid beverages can promote thermogenesis in brown fat at the scapula, and this effect depends on peroxisome proliferator-activated receptor α (PPARα) and fibroblast growth factor 21 (FGF21).

[0098] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for preparing a solid beverage using raspberry leaves, characterized in that: include: Step 1, treating raspberry leaves by steam explosion to obtain raspberry leaf powder; Step 2, extracting the raspberry leaf powder with purified water, and concentrating the extract to a concentrated solution having a soluble solid content of 10% to 20%; Step 3, uniformly mixing the concentrate, xylitol, maltodextrin and citric acid to obtain a mixed solution; Step 4, drying the mixed solution to obtain a solid beverage.

2. The method for preparing a solid beverage using raspberry leaves according to claim 1, characterized in that: The steps of steam explosion include: Step a, blasting for 25 to 35 seconds at a pressure of 0.9 to 1.2 MPa and a temperature of 115 to 125°C; Step b, blasting for 25 to 35 seconds at a pressure of 1.4 to 1.8 MPa and a temperature of 95 to 105°C.

3. The method for preparing a solid beverage using raspberry leaves according to claim 1, characterized in that: Also includes: The steam-exploded raspberry leaf powder was pulverized using an ultrafine pulverizer for 12 to 18 minutes.

4. The method for preparing a solid beverage using raspberry leaves according to claim 3, characterized in that: When the raspberry leaf powder is pulverized by an ultrafine pulverizer, the temperature is 8 to 12°C.

5. The method for preparing a solid beverage using raspberry leaves according to claim 4, characterized in that: The raspberry leaf powder was freeze-dried before being put into the micronizer.

6. The method for preparing a solid beverage using raspberry leaves according to claim 1, characterized in that: When the raspberry leaf powder is extracted with purified water, the solid-liquid ratio of the raspberry leaf powder to the purified water is 1 g: 35-45 mL.

7. The method for preparing a solid beverage using raspberry leaves according to claim 6, characterized in that: When the raspberry leaf powder is extracted with purified water, the extraction is performed at 85 to 95° C. for 20 to 40 minutes.

8. The method for preparing a solid beverage using raspberry leaves according to claim 1, characterized in that: The mixing in step 3 is carried out in a water bath at 65-75°C.

9. The method for preparing a solid beverage using raspberry leaves according to claim 1, characterized in that: In step 4, the mixed solution is dried by spray drying, and the conditions for spray drying are as follows: an inlet air temperature of 110 to 130° C., a peristaltic pump speed of 10 to 20 r / min, and a fan frequency of 40 to 60 Hz.

10. A solid beverage containing raspberry ketone, characterized in that: The preparation is obtained by the preparation method according to any one of claims 1 to 9.

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