Preparation and detection method for promoting dissolution of burdock active substances and improving burdock flavor

Abstract

The invention relates to a preparation and detection method for promoting the dissolution of burdock active substances and improving the flavor of burdock, comprising the following steps: taking fresh burdock, removing both ends, washing and peeling; and subjecting the obtained burdock to ultrahigh pressure pretreatment. The treated burdock is cut into burdock pieces of uniform size, added into ultrapure water, and then added into a pulping machine for pulping to obtain a burdock homogenate. Cellulase is added into the obtained burdock homogenate, fully stirred to make the mixture uniform, the pH value is adjusted to 6-7 with a sodium hydroxide solution, and then ultrasonic enzymolysis is performed, and the supernatant is taken after centrifugation to obtain a burdock enzymolysis solution. The ultrahigh pressure pretreatment of burdock can expose glycosidic bonds, improve enzymolysis efficiency, and reduce enzymolysis time. Ultrasonic waves and enzymes are used to destroy the cell wall structure, so as to maximize the content, and the enzyme treatment can change the precursor substances involved in the formation of volatile substances, affect the content of some flavor amino acids, and change the flavor of burdock.

Description

Technical Field

[0001] The invention relates to a preparation and detection method for promoting the dissolution of burdock active substances and improving the flavor of burdock, belonging to the technical field of food processing. Background Art

[0002] Burdock is a large herbaceous plant of the Asteraceae family. Its seeds, leaves and roots are not only rich in pharmacological activity, but also edible. It is a valuable medicinal and edible plant. Burdock is rich in nutrients such as inulin, cellulose, protein, calcium, amino acids, and active ingredients such as arctiin and arctigenin. In Japan, burdock is even known as "Oriental ginseng" and "white ginseng", which is enough to show that burdock has extremely high nutritional and medicinal value.

[0003] Burdock is rich in polysaccharides, inulin, flavonoids, chlorogenic acid, dietary fiber and other active ingredients. Studies have found that they have biological activity and other functions, and also have certain pharmacological value. For example, inulin can improve the intestinal flora environment, increase the amount of beneficial bacteria such as bifidobacteria, and promote intestinal health; polysaccharides have antioxidant, hypoglycemic and intestinal flora regulating effects; flavonoids have a certain preventive effect on hyperuricemia and protect the kidneys; chlorogenic acid has the function of regulating sugar and lipid metabolism, improving insulin resistance, and reducing the risk of type 2 diabetes and cardiovascular disease; dietary fiber can improve chronic non-communicable diseases such as cardiovascular disease, hypertension, and diabetes. Moreover, the carotene content in burdock is 150 times higher than that in carrots, and the protein and calcium content is the highest among rhizomes.

[0004] At present, most of the research on burdock is in the medical field. As a plant with both medicinal and edible properties, there are not many studies on burdock in food, and the research is relatively simple. With the improvement of living standards and the demand for nutrition, health products with certain functions have begun to be sought after by people, and the nutritional value and edible value of burdock have gradually been valued by people. However, the scale of burdock food processing is small and single at present. Single burdock products such as burdock silk, burdock sauce, burdock tea and other products have certain disadvantages, such as poor storage resistance, bad taste, and difficulty in dissolving active ingredients. Although burdock mixed with other products can cover the smell of burdock to a certain extent, it can only slow down the smell of burdock to a certain extent, and there is no fundamental solution to the problem of burdock. Therefore, the active substances are difficult to dissolve and play a role, and the flavor of burdock itself is not good. These factors limit the development of burdock health food industry and affect its popularity among consumers.

[0005] At present, there are no reports on the preparation methods for promoting the dissolution of active substances in burdock and improving the flavor of burdock food. The methods for promoting the dissolution of active substances in burdock include water extraction, ultrasonic extraction, pressurized solvent extraction, and ultrasonic-enzyme method. The ultrasonic-enzyme method uses ultrasound and enzymes to destroy the cell wall structure to maximize the content, and the enzyme treatment can change the precursor substances involved in the formation of volatile substances, and affect the content of some flavor amino acids, so that the flavor of burdock changes. However, during the enzymatic treatment process, because the tissue structure of burdock is tight, it is not easy for the enzyme to enter the cell to react with the glycosidic bond. Ultrahigh pressure treatment of burdock can expose or even break the glycosidic bond, synergistically improving the efficiency of enzymatic hydrolysis. At present, there are no reports on the application of ultrahigh pressure-ultrasonic-enzyme method to promote the dissolution of burdock active substances and improve the flavor of burdock. Summary of the invention

[0006] Purpose of the invention: In view of the above-mentioned existing problems and deficiencies, the purpose of the present invention is to provide a preparation and detection method for promoting the dissolution of burdock active substances and improving the flavor of burdock. Ultrahigh pressure pretreatment of burdock can expose glycosidic bonds, improve enzymatic hydrolysis efficiency, and reduce enzymatic hydrolysis time. The ultrasonic-enzymatic method uses ultrasound and enzymes to destroy the cell wall structure, maximize the dissolution of active substances, and after enzyme treatment, the precursor substances involved in the formation of volatile substances can be changed, affecting the content of some flavor amino acids, so that the flavor of burdock changes. After the burdock is enzymatically hydrolyzed, the burdock is micro-fermented to increase the content of active substances related to blood sugar reduction, and the blood sugar reduction function is improved. At the same time, the effect of removing the earthy smell is achieved, and the product has a fresh flavor.

[0007] Technical solution: To achieve the above-mentioned invention object, the present invention adopts the following technical solution:

[0008] A preparation method for promoting the dissolution of burdock active substances and improving the flavor of burdock comprises the following steps:

[0009] Step 1: Take fresh burdock, remove both ends, wash and peel;

[0010] Step 2: Keep the burdock obtained in step 1 under ultra-high pressure for 10 to 30 minutes; ultra-high pressure pretreatment can expose or even break the glycosidic bonds, improve the efficiency of enzymatic hydrolysis, and reduce the enzymatic hydrolysis time. Generally, the pretreatment effect is best within a period of 10 to 30 minutes. If it is too short, the treatment will be incomplete, and if it is too long, the structural properties of the burdock will be affected.

[0011] Step 3: Cut the burdock obtained in step 2 into burdock pieces of uniform size, add them into ultrapure water, and then add them into a pulping machine for pulping to obtain a burdock homogenate;

[0012] Step 4: Add cellulase to the burdock homogenate obtained in step 3, stir thoroughly to make the mixture uniform, adjust the pH to 6-7 with sodium hydroxide solution, perform ultrasonic enzymolysis, and collect the supernatant after centrifugation to obtain burdock enzymolysis solution.

[0013] Furthermore, lactic acid bacteria are inoculated into the burdock enzymatic hydrolysate obtained in step 4, and the burdock fermentation liquid is obtained by filtering after standing and fermenting.

[0014] Furthermore, the lactic acid bacteria are Weissella and Leuconostoc mesenteroides.

[0015] Furthermore, the ratio of Weissella to Leuconostoc mesenteroides is 1:2 to 6. The combination of the two bacteria in this range can achieve the best fermentation effect.

[0016] Furthermore, the temperature during the fermentation is 30-40° C., and the fermentation time is 35-50 hours. The obtained fermentation liquid and enzymolysis liquid are both finished products. The finished product has no earthy smell of burdock itself and has good flavor.

[0017] Furthermore, the ultrahigh pressure in step 2 is 300-400 MPa.

[0018] Furthermore, the cellulase added in step 4 is 3-5% of the mass of the burdock block, the enzymolysis temperature is 50-60° C., and the enzymolysis time is 1-3 h.

[0019] Furthermore, the ultrasonic power in step 4 is 200-300w.

[0020] Furthermore, the centrifugation in step 4 is performed at 3500-5000 r / min for 15-20 min.

[0021] The invention discloses a detection method for promoting the dissolution of burdock active substances and improving burdock flavor, and the specific steps are as follows: burdock enzymatic hydrolysate or burdock fermentation liquid is subjected to total phenol and flavonoid determination, namely, gas chromatography-mass spectrometry and electronic tongue treatment are respectively performed, and the volatile substance content of the supernatant before enzymatic hydrolysis and the change of burdock flavor are determined.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0023] 1. Burdock is a plant with both medicinal and edible properties, with extremely high nutritional and medicinal value. In addition, my country's burdock production is relatively high, which provides a basis for industrialization. Ultra-high pressure pretreatment can expose or even break the glycosidic bonds, change the fiber structure, and synergistically promote the efficiency of the next enzymatic hydrolysis. Improve enzymatic hydrolysis efficiency and reduce enzymatic hydrolysis time. Inhibit the activity of browning-related enzymes such as polyphenol oxidase, improve product quality; reduce harmful microorganisms in burdock from the source, and extend the shelf life of the product; convert part of the insoluble dietary fiber in burdock into soluble dietary fiber, which has physiological activities such as lowering blood sugar and blood lipids.

[0024] 2. The present invention adopts ultrasound-assisted enzymolysis to dissolve the active substances to the maximum extent under the condition of avoiding the dissolution of the active substances, and does not affect the activity and structure of the active substances, so that the enzymolysis solution has certain physiological activity. This treatment method is green and safe, destroys the cell wall, further promotes the release of volatile substances, and produces some new volatile substances, which alleviates the original earthy smell of burdock and improves the flavor of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic block diagram of a method flow of an embodiment of the present invention;

[0026] Figure 2 is the effect of different treatment methods on the polysaccharide content in the embodiments of the present invention;

[0027] Figure 3 is the GC-MS spectrum of Example 1 of the present invention;

[0028] Figure 4 It is the GC-MS spectrum of Example 5 of the present invention;

[0029] Figure 5 is an electronic tongue radar diagram of an embodiment of the present invention;

[0030] Figure 6 It is the front part of the fingerprint spectrum of volatile components of burdock of the embodiment of the present invention;

[0031] Figure 7 It is the middle section of the fingerprint spectrum of the volatile components of burdock of the embodiment of the present invention;

[0032] Figure 8 This is the latter part of the fingerprint spectrum of the volatile components of burdock of the embodiment of the present invention;

[0033] Fig. 9 This is a top-down GC-IMS spectrum of burdock according to an example of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0035] like Figure 1 As shown, a preparation and detection method for promoting the dissolution of burdock active substances and improving the flavor of burdock. The steps are:

[0036] (1) Select fresh burdocks with uniform thickness and good growth condition, remove the top and tail parts of the burdocks, select the middle part of the burdock as the processing raw material, wash the burdock roots and peel them;

[0037] (2) The washed and peeled burdock is subjected to ultrahigh pressure pretreatment at a pressure of 300 MPa for 10 to 15 minutes. After the treatment, the burdock is cut into blocks of uniform size. 10 to 20 parts of ultrapure water are added to the cut blocks of burdock, and the blocks are beaten in a beater for 5 to 10 minutes to prepare a burdock homogenate;

[0038] (3) Add 3% to 5% of the mass of burdock to the burdock homogenate obtained in step (2), stir well to mix the two, adjust the pH to 6 to 7 with sodium hydroxide solution, and perform enzymolysis in 50°C to 60°C water for 1 to 3 hours. During the enzymolysis process, ultrasonic treatment is used with an ultrasonic power of 200 to 300 W. After the ultrasonic-assisted enzymolysis is completed, centrifuge at 3500 to 5000 r / min for 15 to 20 minutes, and take the supernatant after completion;

[0039] (4) inoculating lactic acid bacteria into the burdock hydrolysate obtained in step (3), fermenting it statically for 36 to 48 hours, and filtering it after the fermentation is completed;

[0040] (5) The burdock enzymatic hydrolysate obtained in step (3) is subjected to GC-MS and electronic tongue treatment to measure the changes in the content of volatile substances in the supernatant before enzymatic hydrolysis and the changes in the taste of the burdock.

[0041] (6) The fermentation broth obtained in step (4) is subjected to total phenol and flavonoid determination.

[0042] Example 1.

[0043] A preparation method for promoting the dissolution of burdock active substances and improving the flavor of burdock, comprising the following steps:

[0044] (1) Select fresh burdocks with uniform thickness and good growth condition, remove the top and tail parts of the burdock, select the middle part of the burdock as the processing raw material, wash the burdock roots and peel them;

[0045] (2) The washed and peeled burdock is subjected to ultrahigh pressure pretreatment, and the burdock is cut into blocks of uniform size. 15 parts of ultrapure water are added to the cut burdock blocks, and the blocks are beaten in a beater for 5 minutes to prepare a burdock homogenate.

[0046] Example 2.

[0047] A preparation method for promoting the dissolution of burdock active substances and improving the flavor of burdock, comprising the following steps:

[0048] (1) Select fresh burdocks with uniform thickness and good growth condition, remove the top and tail parts of the burdocks, select the middle part of the burdocks as the processing raw material, wash the burdock roots and peel them;

[0049] (2) subjecting the washed and peeled burdock to ultrahigh pressure pretreatment, cutting the burdock into blocks of uniform size, adding 15 parts of ultrapure water to the blocks, and beating them in a pulper for 5 minutes to prepare a burdock homogenate;

[0050] (3) The burdock homogenate prepared in step (2) was heated in a water bath at 55° C., and 200 W of ultrasound was applied during the water bath heating process. After ultrasonication in the water bath for 1.5 h, the mixture was centrifuged at 4500 r / min for 15 min, and the supernatant was collected.

[0051] Example 3

[0052] A preparation method for promoting the dissolution of burdock active substances and improving the flavor of burdock, comprising the following steps:

[0053] (1) Select fresh burdocks with uniform thickness and good growth condition, remove the top and tail parts of the burdocks, select the middle part of the burdocks as the processing raw material, wash the burdock roots and peel them;

[0054] (2) subjecting the washed and peeled burdock to ultrahigh pressure pretreatment, cutting the burdock into blocks of uniform size, adding 15 parts of ultrapure water to the blocks, and beating them in a pulper for 5 minutes to prepare a burdock homogenate;

[0055] (3) Add about 4% of the mass of burdock to the burdock homogenate prepared in step (2) of cellulase, stir well to make the burdock homogenate and cellulase fully mixed, adjust the pH to 6, and perform enzymolysis in 55°C water for 1.5 h. After the enzymolysis is completed, centrifuge at 4500 r / min for 15 min, and collect the supernatant after the centrifugation is completed.

[0056] Example 4

[0057] (1) Select fresh burdocks with uniform thickness and good growth condition, remove the top and tail parts of the burdocks, select the middle part of the burdocks as the processing raw material, wash the burdock roots and peel them;

[0058] (2) subjecting the washed and peeled burdock to ultrahigh pressure pretreatment, cutting the burdock into blocks of uniform size, adding 15 parts of ultrapure water to the blocks, and beating them in a pulper for 5 minutes to prepare a burdock homogenate;

[0059] (3) The burdock homogenate obtained in step (2) is inoculated with lactic acid bacteria, and statically fermented for 46 hours. After the fermentation is completed, the mixture is filtered.

[0060] Example 5

[0061] (1) Select fresh burdocks with uniform thickness and good growth condition, remove the top and tail parts of the burdocks, select the middle part of the burdocks as the processing raw material, wash the burdock roots and peel them;

[0062] (2) The washed and peeled burdock is subjected to ultrahigh pressure pretreatment, and the burdock is cut into blocks of uniform size after the treatment. The cut burdock is added with 15 parts of ultrapure water, and the blocks are beaten in a beater for 5 minutes to prepare a burdock homogenate;

[0063] (3) Add 4% cellulase by weight of burdock to the burdock homogenate obtained in step (2), stir thoroughly to mix the burdock homogenate and the cellulase, adjust the pH to 6 with sodium hydroxide solution, and perform enzymolysis in 55°C water for 1.5 hours. During the enzymolysis process, ultrasonic treatment is applied at an ultrasonic power of 200W. After ultrasonic-assisted enzymolysis, centrifuge at 4500r / min for 15 minutes, and collect the supernatant after centrifugation;

[0064] (4) inoculating lactic acid bacteria with the burdock hydrolysate obtained in step (3) at an inoculation amount of 3%, performing static fermentation for 46 hours, and filtering after the fermentation ends when the pH reaches 4;

[0065] (5) The burdock enzymatic hydrolysate obtained in step (3) is subjected to GC-MS and electronic tongue treatment to measure the changes in the content of volatile substances in the supernatant before enzymatic hydrolysis and the changes in the taste of the burdock.

[0066] (6) The fermentation broth obtained in step (4) is subjected to total phenol and flavonoid determination.

[0067] Effects of different treatment methods on polysaccharide content and soluble dietary fiber content in burdock supernatant

[0068] The effects of different treatment methods on the polysaccharide content and soluble dietary fiber content in burdock supernatant were determined. The steps and results are as follows:

[0069] Take 1 mL of the supernatant in Example 1, Example 2, Example 3 and Example 5 respectively, dilute them to a certain concentration, add 1 mL of 6% phenol solution, and then add 6 mL of concentrated sulfuric acid. After standing for 0.5 h, measure the absorbance value and calculate the polysaccharide content in the supernatant in mg / mL. The calculation results are shown in Figure 2 , take the supernatant, then take the supernatant of Example 1 and Example 5 to adjust the pH, concentrate and precipitate with alcohol, remove ethanol by rotary evaporation, and vacuum freeze-dry to obtain soluble dietary fiber, and calculate the soluble dietary fiber content, see Table 1.

[0070] surface Difference in soluble dietary fiber content between Example 1 and Example 5

[0071]

[0072] from Figure 2 It can be seen that the polysaccharide content in the supernatant can be significantly increased by both ultrasound and enzymatic hydrolysis treatment, but the polysaccharide content increased the most after ultra-high pressure-ultrasound-assisted enzymatic hydrolysis treatment, and the effect was the best; ultra-high pressure treatment can increase the content of soluble dietary fiber in burdock, and soluble dietary fiber can regulate blood sugar and inhibit glucose absorption, thereby improving the blood sugar-lowering ability of the enzymatic hydrolyzate.

[0073] Gas chromatography-mass spectrometry analysis of volatile substances

[0074] Example 1 and Example 5 were placed in headspace bottles, respectively, and extracted in a water bath at 60°C for 1 hour. After the extraction was completed, they were inserted into a gas chromatography-mass spectrometer for thermal desorption for 3 minutes, and then subjected to gas chromatography-mass spectrometry analysis to conduct qualitative and quantitative analysis of the volatile substances. The results are shown in Tables 2 and Figure 3~4 .

[0075] Table 2 Comparison of volatile matter content

[0076]

[0077] Ultrasonic-assisted hydrolysis of fresh burdock under the optimal conditions of cellulase can change the volatile components of burdock. Before treatment, the main volatile components in fresh burdock are aldehydes, alcohols and olefins. After ultrasonic-assisted hydrolysis, the main volatile components are esters, ketones and aldehydes. Among them, the olefins with the highest content of volatile substances before hydrolysis are 51.41%, and the content of olefins is reduced to 25.32% after ultrasonic-assisted hydrolysis. For example, the leathery curcumin is reduced from 10.9% to 2.649%. Most terpene compounds have bitter taste. After treatment, the terpene substances in burdock are greatly reduced, for example, B-serene is reduced from 11.59% to 6.279%, which improves the flavor of burdock. After treatment, the content of volatile substances is more dispersed and the aroma is richer.

[0078] Electronic tongue detection

[0079] The electronic tongue test was performed on Example 1 and Example 5 respectively. The results are shown in Figure 5 .

[0080] Enzymatic treatment can also affect the taste of burdock, which can be divided into sour, sweet, bitter, astringent and salty. The radar chart shows that the taste richness and tannin of burdock after enzymatic hydrolysis have increased slightly, while the saltiness and sweetness have decreased slightly. Cellulase treatment can destroy the cell wall structure and release some flavor amino acids and soluble sugars in the cells, improving the taste of burdock. After enzymatic hydrolysis of burdock, the free amino acid content in the hydrolyzate increases, and these free amino acids may contain flavor amino acids that change the taste.

[0081] Spectral analysis of volatile substances

[0082] 1 g of each of Example 1, Example 2, Example 3 and Example 5 were weighed, placed in a 20 mL headspace bottle, incubated at 80° C. for 10 min, and then sampled to analyze the differences in volatile substances.

[0083] The difference in the content of volatile substances can be seen intuitively from the fingerprint. The detection results of GC-IMS are presented in the form of a three-dimensional map, showing information such as retention time, migration time and signal intensity. The GC-IMS spectrum can be used to make an intuitive comparison and preliminary judgment on the volatile substance composition between different samples, especially in the two-dimensional top view, the types and concentrations of volatile substances in different samples are more intuitive, such as Fig. 9 As shown, the X-axis represents the normalized migration time, the Y-axis represents the retention time, and the ion signal intensity is represented by different colors, the darker the color, the higher the content, and vice versa. Samples 1, 2, 3, and 4 are Examples 1, 2, 3, and 5, respectively. Figures 6-8 It can be seen that the volatile substance contents of the four samples are quite different. The types of volatile substance contents of Comparative Examples 1, 2, and 3 do not vary much, while Example 5 produces more new volatile substances compared with the first three, and the contents of some volatile substances are significantly reduced in Example 5. For example, the concentrations of phenylacetaldehyde with floral aroma and 2-ethylfuran with caramel aroma are significantly increased, while the concentrations of (E)-2-heptenal with grassy and irritating odors and 1-octen-3-ol with rice bran oil odor are reduced. It can be seen that ultrahigh pressure-ultrasound-assisted enzymatic hydrolysis can improve the odor of burdock and increase the content of burdock aroma compound components.

[0084] Differences in the analysis of active substance content by Folin-phenol method and aluminum nitrate method

[0085] A certain volume of Example 4 and Example 5 was taken respectively, and the total phenol content was determined by the Folin phenol method, and the flavonoid content was determined by the aluminum nitrate method. The results are shown in Table 3.

[0086] Table 3 Differences in active substance content between Example 4 and Example 51

[0087]

[0088] As can be seen from the table, fermentation treatment followed by enzymatic hydrolysis can increase the content of active substances total phenols and flavonoids in the fermentation broth.

Claims

1. A preparation method for promoting the dissolution of burdock active substances and improving the flavor of burdock, characterized in that: The steps include: Step 1: Take fresh burdock, remove both ends, wash and peel; Step 2: Keep the burdock obtained in step 1 under ultra-high pressure for 10 to 30 minutes; Step 3: Cut the burdock obtained in step 2 into burdock pieces of uniform size, add them into ultrapure water, and then add them into a pulping machine for pulping to obtain a burdock homogenate; Step 4: adding cellulase to the burdock homogenate obtained in step 3, stirring thoroughly to make the mixture uniform, adjusting the pH to 6-7 with a sodium hydroxide solution, performing ultrasonic enzymolysis, and collecting the supernatant after centrifugation to obtain a burdock enzymolysis solution; Inoculating lactic acid bacteria into the obtained burdock enzymatic hydrolysate, allowing it to ferment and then filtering it to obtain burdock fermented liquid; The ultra-high pressure in step 2 is 300-400 MPa; The ultrasonic power in step 4 is 200-300w; Step 5, subjecting the burdock enzymatic hydrolysate obtained in step 4 to GC-MS and electronic tongue treatment, respectively, to measure the change in the content of volatile substances in the supernatant before and after enzymatic hydrolysis, and the change in the taste of the burdock; Step 6, determining the total phenols and flavonoids in the fermentation broth obtained in step 4.

2. The method for promoting the dissolution of burdock active substances and improving the flavor of burdock according to claim 1, characterized in that: The lactic acid bacteria are Weissella and Leuconostoc mesenteroides.

3. The method for promoting the dissolution of burdock active substances and improving the flavor of burdock according to claim 2, characterized in that: The ratio of Weissella to Leuconostoc mesenteroides is 1:2-6.

4. The method for promoting the dissolution of burdock active substances and improving the flavor of burdock according to claim 1, characterized in that: The temperature during the fermentation is 30-40° C., and the fermentation time is 35-50 hours.

5. The method for promoting the dissolution of burdock active substances and improving the flavor of burdock according to claim 1, characterized in that: The cellulase added in step 4 is 3-5% of the mass of the burdock block, the enzymolysis temperature is 50-60° C., and the enzymolysis time is 1-3 hours.

6. The method for promoting the dissolution of burdock active substances and improving the flavor of burdock according to claim 1, characterized in that: The centrifugation in step 4 is performed at 3500-5000 r / min for 15-20 min.

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