Mesona jelly and application thereof in preparation of beverage

Abstract

The invention relates to the technical field of food biology. In particular to a preparation method of mesona jelly and application of the mesona jelly in preparation of drinks. By optimizing the enzyme composition, when the mesona chinensis jelly is prepared, the extraction efficiency of mesona chinensis polysaccharide is obviously improved, and the extracted mesona chinensis polysaccharide has very good oxidation resistance. The mesona chinensis jelly with high mesona chinensis polysaccharide content has better health efficacy when being used for preparing food. The method is low in energy consumption, simple to operate and suitable for large-scale production and preparation in food factories.

Description

Technical Field

[0001] The present invention relates to the field of food biotechnology, and in particular to a method for preparing grass jelly and a use thereof in preparing beverages. Background Art

[0002] Mesona chinensis Benth, also known as fairy grass and jelly grass, has a scientific name of Mesona chinensis Benth and an English name of Mesona Blume. According to the Dictionary of Chinese Medicine, Mesona chinensis is astringent, sweet and cold in nature, and has the effects of clearing away heat and relieving thirst, cooling blood and relieving heat, and diuresis; it is commonly used in traditional Chinese medicine to treat heatstroke, thirst, colds, jaundice, hypertension, kidney disease, diabetes, and joint and muscle pain; modern medical analysis and determination show that Mesona chinensis has sedative, cooling, blood sugar lowering, and anti-oxidation effects, so it has a very high medicinal value.

[0003] Although the herb is not suitable for direct consumption, it is a medicinal and edible plant rich in herb polysaccharides (herb gelatin) and flavonoids. It is suitable for extracting various effective ingredients such as herb polysaccharides and is an edible raw material with great development prospects. Mesona chi nens is polysaccharides (MCP) are mostly extracted from herb hay by alkali extraction and alcohol precipitation. They have good gel properties and are also called herb gelatin. Studies have shown that MCP has biological activities such as anti-oxidation, hypoglycemic, and immunomodulatory. At present, the application of herb products mainly includes herb jelly, herb milk tea, solidified herb yogurt, health-care herb honey, herb fermented wine beverage, herb compound health-care beverage, herb black fungus jelly powder, etc. The formation mechanism of herb jelly is that herb polysaccharides and amylose can form a special network gel structure. The gel formed has a tender, refreshing, and elastic taste. It is a new type of gelling agent that can be used to make foods containing herb jelly.

[0004] Different extraction methods will affect the extraction rate of grass jelly polysaccharide. At present, the extraction methods of grass jelly polysaccharide mainly include alkaline extraction, microwave or ultrasound assisted extraction, enzymatic extraction, etc. How to improve the extraction efficiency of grass jelly polysaccharide is the research focus and difficulty in the prior art. The biological enzymatic hydrolysis method has the advantages of mild reaction conditions, high efficiency and specificity, environmental protection, and easy operation. For example, CN102919833A records a method for extracting grass jelly polysaccharide with low energy consumption and retaining the natural flavor of grass jelly, which includes the following steps: crushing, sterilization, adjusting pH, adding enzymes, enzymatic hydrolysis, filtering, and making grass jelly. This method does not require high-temperature boiling throughout the process, is energy-saving and efficient, and retains the original flavor of grass jelly juice.

[0005] The technical problem to be solved by the present invention is to improve the enzymatic hydrolysis effect by optimizing the enzyme composition, so that the grass jelly obtained after the raw material processing contains more grass jelly polysaccharides, thereby improving its edible value. Summary of the invention

[0006] In order to further improve the yield of Herba Imperatae polysaccharides on the basis of the existing technology, the object of the present invention is to provide a simple and high-yield method for extracting Herba Imperatae polysaccharides.

[0007] In order to achieve the above object, the present invention adopts the following specific technical scheme: a method for preparing grass jelly, comprising the following steps:

[0008] Grinding: Grind the selected dried grass jelly into 130-180 mesh;

[0009] Sterilization: Add the crushed grass jelly into the extraction tank, add deionized water at a material-water ratio of 1:15 to 1:25, heat to 100℃ and let stand for 5 minutes, then use circulating cooling water to reduce the material liquid temperature to 45℃-55℃ and adjust the pH;

[0010] Enzymatic hydrolysis: add 0.3%-0.5% cellulase, 0.2%-0.4% hemicellulase, 0.1%-0.2% β-glucosidase and 0.3%-0.5% pectinase to the pH-adjusted liquid; perform enzymatic hydrolysis at 45°C-55°C for 2-4 hours, and then raise the temperature to inactivate the enzymes;

[0011] Filtration: Drain the enzymatically hydrolyzed liquid, filter it 2-3 times with 200-mesh gauze, and then centrifuge to obtain the supernatant;

[0012] Making grass jelly jelly: add 3%-4% starch to the filtered liquid, heat until fully gelatinized, and cool to make grass jelly jelly.

[0013] Preferably, after extracting the polysaccharide from the herb, the polysaccharide content is determined by the pH-phenol-sulfuric acid method, the principle of which is to use the polysaccharide to first hydrolyze into monosaccharides under the action of sulfuric acid, and then quickly dehydrate to generate aldehyde derivatives, and then generate orange-yellow compounds with phenol, and then determine by colorimetry. The specific operation steps are: add phenol to the sample to be tested, shake well, quickly add concentrated sulfuric acid and mix well, heat in a water bath, and quickly cool and measure the absorbance at 490nm. Then use glucose as a standard to calculate the content of polysaccharides in the extract and the extraction rate.

[0014] Preferably, the starch used in the present invention is corn starch, potato starch or tapioca starch.

[0015] Preferably, the present invention uses a DPPH free radical scavenging activity test to evaluate the antioxidant capacity of the sample. DPPH refers to 1,1-diphenyl-2-trinitrophenylhydrazine. As a stable free radical, DPPH can stably exist in an organic solvent. Its alcohol solution is purple and needs to be stored at low temperature and away from light. It has a single electron, so it can accept an electron or hydrogen ion and has maximum absorption at a wavelength of 517nm. In the presence of a free radical scavenger, the single electron of DPPH is captured to make its color lighter, and the absorbance value at the wavelength of maximum light absorption decreases, and the degree of decrease is linear. The decrease in the absorbance level indicates an increase in antioxidant activity, thereby evaluating the antioxidant capacity of the test sample. The greater the scavenging rate, the stronger the antioxidant activity.

[0016] Another object of the present invention is to provide the use of the aforementioned grass jelly in preparing food. Preferably, the food is a beverage. More preferably, the beverage is milk tea, yogurt or health drink containing grass jelly.

[0017] Another object of the present invention is to provide a food comprising the aforementioned grass jelly.

[0018] Compared with the existing technology, the present invention has the following outstanding advantages and effects:

[0019] 1) The present invention optimizes the enzyme composition, so that the extraction efficiency of grass jelly polysaccharide is significantly improved when preparing grass jelly.

[0020] 2) The present invention further proves through the DPPH free radical scavenging activity test that the DPPH free radical scavenging rate is positively correlated with the yield of jelly grass polysaccharide, that is, after extraction, the yield of jelly grass polysaccharide increases, and the DPPH free radical scavenging rate also increases. It also proves that the extraction method of the present invention can well retain the scavenging ability of jelly grass polysaccharide on DPPH free radicals.

[0021] 3) The grass jelly with a high content of grass jelly polysaccharide obtained by the present invention is used to prepare food, which has better health effects, such as anti-oxidation, hypoglycemic, immune regulation and other biological activities. In addition, the method based on the present invention has low energy consumption and simple operation, and is suitable for large-scale production of grass jelly in food factories. DETAILED DESCRIPTION

[0022] The following will be combined with specific embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The experimental techniques and methods used in this example are all conventional technical methods unless otherwise specified. The materials, reagents and biological materials used in this example can be obtained through regular commercial channels unless otherwise specified.

[0024] Source of reagents:

[0025] Cellulase: purchased from Shanghai MacLean Biochemical Technology Co., Ltd., specification: 10000U / g;

[0026] Pectinase: purchased from Shanghai MacLean Biochemical Technology Co., Ltd., specification is 30000U / g;

[0027] Hemicellulase: purchased from Shanghai MacLean Biochemical Technology Co., Ltd., specification: 200 un it / mg;

[0028] Glucosidase was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with a specification of 30,000 U / g.

[0029] Drawing of glucose standard curve:

[0030] Weigh 100 mg of dried glucose accurately and prepare a glucose standard solution with a concentration of 1 mg / mL. Dilute the prepared standard solution to 0, 10, 20, 30, 40, and 50 μg / mL, accurately transfer 1 mL of the standard solution of different concentrations into each test tube, add 6% phenol solution and 5 mL of concentrated sulfuric acid in turn, shake well, heat in a water bath for 15 minutes, cool quickly, and measure the absorbance at 490 nm. Draw a glucose standard curve and get the regression equation: Y = 0.0102X + 0.0286, R 2 =0.9975.

[0031] Example 1

[0032] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added according to the material-water ratio of 1:20, and then the temperature is raised to 100°C and allowed to stand for 5 minutes, and then the temperature is reduced to 50°C; the pH is adjusted to 5.5, and 0.4% cellulase, 0.1% β-glucosidase, 0.3% hemicellulase and 0.4% pectinase are added to the liquid, and the enzyme is hydrolyzed at 50°C for 3 hours, and the liquid is heated to 100°C again to kill the enzyme for 15 minutes. After cooling, filter it with 200 mesh gauze for 3 times, and then centrifuge it at 4500rpm for 10 minutes to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95°C; pour it into a film and cool it to form grass jelly.

[0033] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0034] Example 2

[0035] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added according to the material-water ratio of 1:20, and then the temperature is raised to 100℃ and allowed to stand for 5min, and then the temperature is reduced to 50℃; the pH is adjusted to 5.5, and 0.5% cellulase, 0.1% β-glucosidase, 0.4% hemicellulase, and 0.5% pectinase are added to the liquid, and enzymolysis is carried out at 50℃ for 3 hours, and the liquid is heated to 100℃ again to kill the enzyme for 15min. After cooling, filter it with 200 mesh gauze for 3 times, and then centrifuge it at 4500rpm for 10min to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95℃; pour it into a film and cool it to form grass jelly.

[0036] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0037] Example 3

[0038] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added according to the material-water ratio of 1:20, and then the temperature is raised to 100°C and allowed to stand for 5 minutes, and then the temperature is reduced to 50°C; the pH is adjusted to 5.5, and 0.3% cellulase, 0.1% β-glucosidase, 0.2% hemicellulase, and 0.3% pectinase are added to the liquid, and enzymolysis is carried out at 50°C for 3 hours, and the liquid is heated to 100°C again to kill the enzyme for 15 minutes. After cooling, filter it with 200 mesh gauze for 3 times, and then centrifuge it with a centrifuge at 4500rpm for 10 minutes to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95°C; pour it into a film and cool it to form grass jelly.

[0039] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0040] Example 4

[0041] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added according to the material-water ratio of 1:20, and then the temperature is raised to 100°C and allowed to stand for 5 minutes, and then the temperature is reduced to 55°C; the pH is adjusted to 5.5, and 0.4% cellulase, 0.1% β-glucosidase, 0.3% hemicellulase, and 0.4% pectinase are added to the liquid, and enzymolysis is carried out at 55°C for 3 hours, and the liquid is heated to 100°C again to kill the enzyme for 15 minutes. After cooling, filter it with 200 mesh gauze for 3 times, and then centrifuge it with a centrifuge at 4500rpm for 10 minutes to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95°C; pour it into a film and cool it to form grass jelly.

[0042] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0043] Example 5

[0044] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added according to the material-water ratio of 1:20, and then the temperature is raised to 100°C and allowed to stand for 5 minutes, and then the temperature is reduced to 45°C; the pH is adjusted to 5.5, and 0.4% cellulase, 0.1% β-glucosidase, 0.3% hemicellulase, and 0.4% pectinase are added to the liquid, and enzymolysis is carried out at 45°C for 3 hours, and the liquid is heated to 100°C again to kill the enzyme for 15 minutes. After cooling, filter it three times with 200 mesh gauze, and then centrifuge it at 4500rpm for 10 minutes to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95°C; pour it into a film and cool it to form grass jelly.

[0045] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0046] Comparative Example 1

[0047] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added according to the material-water ratio of 1:20, and then the temperature is raised to 100℃ and allowed to stand for 5min, and then the temperature is reduced to 50℃; the pH is adjusted to 5.5, and 0.4% cellulase, 0.3% hemicellulase and 0.4% pectinase are added to the liquid, and enzymolysis is carried out at 50℃ for 3 hours, and the liquid is heated to 100℃ again to kill the enzyme for 15min. After cooling, filter it with 200 mesh gauze for 3 times, and then centrifuge it with a centrifuge at 4500rpm for 10min to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95℃; pour it into a film and cool it to form grass jelly.

[0048] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0049] Comparative Example 2

[0050] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added at a material-water ratio of 1:20, and then the temperature is raised to 100°C and allowed to stand for 5 minutes, and then the temperature is reduced to 50°C; the pH is adjusted to 5.5, and 0.4% cellulase, 0.1% β-glucosidase and 0.4% pectinase are added to the liquid, and enzymolysis is carried out at 50°C for 3 hours, and the liquid is heated to 100°C again to kill the enzyme for 15 minutes. After cooling, filter it three times with 200 mesh gauze, and then centrifuge it at 4500rpm for 10 minutes to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95°C; pour it into a film and cool it to form grass jelly.

[0051] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0052] Comparative Example 3

[0053] The selected dried grass jelly is crushed to 150 mesh, and then the processed grass jelly powder is added to the extraction tank, and deionized water is added according to the material-water ratio of 1:20, and then the temperature is raised to 100°C and allowed to stand for 5 minutes, and then the temperature is reduced to 50°C; the pH is adjusted to 5.5, and 0.4% cellulase, 0.1% β-glucosidase and 0.3% hemicellulase are added to the liquid, and enzymolysis is carried out at 50°C for 3 hours, and the liquid is heated to 100°C again to kill the enzyme for 15 minutes. After cooling, filter it with 200 mesh gauze for 3 times, and then centrifuge it with a centrifuge at 4500rpm for 10 minutes to obtain the supernatant. Add 4% corn starch to the supernatant, stir and heat it to 95°C; pour it into a film and cool it to form grass jelly.

[0054] Among them, 10 ml of the supernatant obtained after centrifugation was taken and subjected to alcohol precipitation, concentration, and dialysis steps, and the content of the herb polysaccharide was determined by the pH-phenol-sulfuric acid method, and the herb polysaccharide yield was further calculated according to the amount of the raw materials.

[0055] The results of the yields of the polysaccharides extracted from the above different embodiments and comparative examples are shown in Table 1:

[0056] Table 1 Results of the yield of celery polysaccharides extracted from different treatment groups

[0057] Group Yield of Herba Immortalis Polysaccharides Example 1 15.83％ Example 2 13.22％ Example 3 11.96％ Example 4 14.31％ Example 5 13.65％ Comparative Example 1 8.75％ Comparative Example 2 7.97％ Comparative Example 3 5.25％

[0058] As can be seen from Table 1, the present invention uses a composite enzyme to extract the celery polysaccharide in the celery, and explores and optimizes the key factors affecting the extraction efficiency, such as enzyme type, enzyme action temperature and enzyme dosage. Through experiments (only some comparative experiments are shown), the best method suitable for the extraction of celery polysaccharide is obtained, that is, the enzyme composition including cellulase, β-glucosidase, hemicellulase and pectinase has a good enzymolysis effect on the extraction of celery polysaccharide, and the enzyme composition of 0.4% cellulase, 0.1% β-glucosidase, 0.3% hemicellulase and 0.4% pectinase has the best enzymolysis effect, and the optimal enzymolysis temperature is 50°C. The extraction method in the present invention has mild conditions, energy saving and no alkali is added, and can effectively preserve the effective ingredients of polysaccharides while ensuring the taste.

[0059] Example 6 DPPH free radical scavenging activity test

[0060] Prepare 0.2mmol DPPH, take 2mL DPPH solution and 2mL polysaccharide obtained in different embodiments or comparative examples as sample group, shake well and place in dark conditions for half an hour, measure the absorbance of the sample at 517nm with a spectrophotometer, and repeat the measurement twice for each sample to take the average value. Among them, anhydrous ethanol is used as a blank control, pure water is used as a negative control, and Vc solution is used as a positive control.

[0061]

[0062] Where: A i is the absorbance of polysaccharide solution and DPPH solution; A j is the absorbance of polysaccharide solution and anhydrous ethanol; A0 is the absorbance of pure water and DPPH solution in the control group.

[0063] The DPPH free radical scavenging rate of different celery polysaccharide samples was determined according to the above method, and the relative scavenging rate was calculated with Vc solution as the positive control. The results are shown in Table 2:

[0064] Table 2 Results of relative scavenging rate of DPPH free radicals in different treatment groups

[0065] Group Relative DPPH free radical scavenging rate Example 1 85.54％ Example 2 81.18％ Example 3 72.59％ Example 4 82.26％ Example 5 81.55％ Comparative Example 1 68.51％ Comparative Example 2 66.72％ Comparative Example 3 53.21％ VC solution 100％

[0066] As can be seen from Table 2, the DPPH radical scavenging rate of different treatment groups is positively correlated with the yield of jelly grass polysaccharide presented in Table 1. As the yield of jelly grass polysaccharide increases after extraction, the DPPH radical scavenging rate also increases. In addition, the above results further illustrate that the extraction method can retain the scavenging ability of jelly grass polysaccharide on DPPH radicals.

[0067] 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 method for preparing grass jelly, comprising the following steps: a. Grinding: Grind the selected dried grass jelly into 130-180 mesh; b. Sterilization: Add the crushed grass jelly into the extraction tank, add deionized water at a material-water ratio of 1:15 to 1:25, heat to 100°C and let stand for 5 minutes, then use circulating cooling water to reduce the liquid temperature to 45°C-55°C and adjust the pH; c. Enzymatic hydrolysis: add 0.3%-0.5% cellulase, 0.2%-0.4% hemicellulase, 0.1%-0.2% β-glucosidase and 0.3%-0.5% pectinase to the PH adjusted liquid; enzymatic hydrolysis at 45℃-55℃ for 2-4 hours, and heat to inactivate the enzyme; d. Solid-liquid separation: discharge the enzymatically hydrolyzed liquid, filter it 2-3 times with 200-mesh gauze, and then centrifuge to obtain the supernatant; e. Making grass jelly: Add 3%-4% starch to the filtered liquid, heat until fully gelatinized, and cool to make grass jelly.

2. The method for preparing the grass jelly according to claim 1, characterized in that: In step c, 0.4% of cellulase, 0.1% of β-glucosidase, 0.3% of hemicellulase and 0.4% of pectinase were added.

3. The method for preparing the grass jelly according to claim 1 or 2, characterized in that: Step c is enzymatic hydrolysis at 50°C for 3 hours.

4. The method for preparing the grass jelly according to claim 3, characterized in that: The starch is corn starch, potato starch or tapioca starch.

5. Use of the grass jelly prepared by the preparation method according to claim 4 in preparing food.

6. The use of the grass jelly in preparing food according to claim 5, characterized in that: The food is a drink.

7. The use of the grass jelly in preparing food according to claim 6, characterized in that: The beverage is milk tea, yogurt or a health drink.

8. A food, characterized in that The invention comprises the grass jelly prepared by the preparation method according to claim 4.

9. The food according to claim 8, characterized in that The food is a drink.

10. The food according to claim 9, characterized in that The beverage is milk tea, yogurt or a health drink.

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