Quinoa saponin with umami taste and preparation method and application thereof

Abstract

The invention provides quinoa saponin with umami taste and a preparation method and application thereof. Quinoa bran is used as a raw material, and quinoa saponin with umami taste is prepared through ultrasonic extraction, macroporous resin elution and reverse C18 chromatographic column elution. The quinoa saponin is used as a food additive in yogurt, which has the effect of improving the umami taste of the yogurt and can significantly improve the taste of the yogurt. The quinoa saponin with umami taste prepared by the invention is a natural umami agent, has a high degree of safety, is in line with the current social health care and healthy diet concepts, and still has good biological activity at high temperature, thereby expanding the application scope of the umami agent. In addition, the invention provides a theoretical basis for the application of saponin in food additives, promotes the development of food additives, and belongs to the technical field of food additives.

Description

Technical Field

[0001] The invention relates to the technical field of food additives, and in particular to quinoa saponin with umami taste and a preparation method and application thereof. Background Art

[0002] Food additives refer to chemically synthesized or natural substances added to food to improve food quality and color, aroma and taste, as well as for preservation and processing needs. Food additives include flavor enhancers, defoamers, leavening agents, colorants, preservatives, etc. Among them, flavor enhancers refer to substances that supplement, enhance and improve the original taste or flavor in food, also known as flavor enhancers or taste enhancers. The commonly used flavor enhancers in modern food are mainly monosodium glutamate, which is commonly known as monosodium glutamate. It has a strong meat flavor and is a nutrient for the human body. Although it is not an essential amino acid for the human body, it can synthesize other amino acids after metabolism in the body and amino acid transfer with ketoacids. 96% of it can be absorbed by the human body after consumption. However, excessive intake of monosodium glutamate can cause symptoms such as dizziness, numbness in the back, palpitations, weakness, and mandibular tremors, and monosodium glutamate will be converted into pyroglutamate in a high temperature environment, making it lose its umami taste. Therefore, the research on new varieties of flavor enhancers has been favored by more and more researchers.

[0003] Quinoa is a food crop native to South America with very high nutritional value. It is rich in protein, polyphenols, flavonoids, saponins and phytosterols. Its bran is also rich in protein, starch, oil and saponins. According to research, the content of saponins in quinoa bran is about 3% to 8%. Quinoa saponins have a wide range of biological activities, including antibacterial, antioxidant, antiviral, anti-cytotoxic, anti-cancer, and immune enhancement. In addition, under high temperature conditions, quinoa saponins will be converted into low-polarity saponins, which have better biological activity. At present, most of the research on quinoa saponins at home and abroad is concentrated in the fields of medicine, functional foods and health care drugs, and its application in the field of food additives is relatively small. Therefore, studying quinoa saponins and using them as natural flavor enhancers in the field of food additives will have broad application prospects. Summary of the invention

[0004] In order to solve the above technical problems, the technical solution adopted in the present application is to provide a quinoa saponin with umami taste and a preparation method and application thereof.

[0005] A first aspect of the embodiment of the present application provides a method for preparing quinoa saponin with umami taste, comprising the following steps:

[0006] (1) adding quinoa bran to an anhydrous methanol solution, ultrasonically shaking under stirring, and filtering to obtain a crude extract;

[0007] (2) concentrating and freeze-drying the crude extract to obtain powder A;

[0008] (3) Powder A is dissolved in distilled water, then added to a macroporous resin, and eluted with anhydrous ethanol solutions of different concentrations to obtain an eluate, and then the eluate is concentrated and freeze-dried to obtain powder B;

[0009] (4) Powder B is dissolved in an anhydrous methanol solution, and then added to a chromatographic column, and eluted with anhydrous methanol solutions of different concentrations in turn to obtain an eluate, and then the eluate is concentrated and freeze-dried to obtain quinoa saponins with umami taste.

[0010] Preferably, in step (1), the anhydrous methanol solution is 75% anhydrous methanol, and the volume ratio of quinoa bran to 75% anhydrous methanol is 1:5 to 1:7.

[0011] Preferably, in step (1), the ultrasonic oscillation temperature is 24° C., and the ultrasonic oscillation time is 30 to 90 min; and diatomaceous earth is used for filtration after the ultrasonic oscillation.

[0012] Preferably, in step (2), the crude extract is concentrated using a rotary evaporation process, the concentration temperature is 60° C., and the rotation rate is 60 r / min.

[0013] Preferably, in step (3), the volume ratio of powder A to distilled water is 1:1 to 1:2; 0% anhydrous ethanol, 30% anhydrous ethanol, 60% anhydrous ethanol, and 90% anhydrous ethanol are used in sequence for elution to obtain an eluate, and the 60% anhydrous ethanol eluate is concentrated.

[0014] Preferably, in step (4), the anhydrous methanol solution is 40% anhydrous methanol, the volume ratio of powder B to 40% anhydrous methanol is 1:1 to 1:2; and the chromatographic column is a reverse C18 chromatographic column.

[0015] Preferably, in step (4), 40% anhydrous methanol, 60% anhydrous methanol, 80% anhydrous methanol and 100% anhydrous methanol are used in sequence for elution to obtain an eluate, and the eluate of 60% anhydrous methanol is concentrated.

[0016] Preferably, in steps (2)-(4), the freeze-drying temperature is -80°C.

[0017] The second aspect of the embodiment of the present application provides a quinoa saponin with umami taste prepared by any of the preparation methods described above, wherein the quinoa saponin is a compound composed of a quinoa saponin monomer with sapogenin as the parent core and carrying three sugar chains, and a derivative with sapogenin as the parent core and carrying different numbers of sugar chains, wherein the structural formula of the quinoa saponin monomer is as follows:

[0018]

[0019] The third aspect of the embodiments of the present application provides the use of quinoa saponins with umami taste prepared by any of the preparation methods described above, wherein the quinoa saponins are used as food additives to improve the umami taste of beverages, including yogurt or beverages.

[0020] The invention provides a quinoa saponin with umami taste and a preparation method and application thereof. Quinoa bran is used as a raw material, and quinoa saponin with umami taste is prepared by ultrasonic extraction, macroporous resin elution, and reverse C18 chromatographic column elution. The quinoa saponin is used as a food additive in yogurt, which has the effect of improving the umami taste of the yogurt and can significantly improve the taste of the yogurt. The beneficial effects are:

[0021] (1) The present invention uses two elution processes of macroporous resin elution and reverse C18 chromatographic column elution, and three low-temperature freeze-drying processes to maximize the purity of quinoa saponins and improve the comprehensive utilization rate of saponins in quinoa bran; in addition, the preparation method of the present invention can quickly obtain quinoa saponins, which is conducive to the industrial production of quinoa saponins.

[0022] (2) The quinoa saponin with umami taste prepared by the present invention is a natural umami flavor enhancer with high safety, which is in line with the current social health and healthy diet concept. At the same time, it still has good biological activity at high temperatures, which expands the application scope of umami flavor enhancers. In addition, the present invention provides a theoretical basis for the application of saponin in food additives, which promotes the development of food additives.

[0023] (3) The quinoa saponin prepared by the present invention uses quinoa bran as raw material, which improves the application value of quinoa bran and promotes the healthy and sustainable development of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 is the liquid chromatogram of powder A;

[0026] Figure 2 is the liquid chromatogram of powder B;

[0027] Figure 3 This is the liquid chromatogram of quinoa saponins;

[0028] Figure 4 is the mass spectrum of quinoa saponin;

[0029] Figure 5 This is a taste radar chart of quinoa bran, powder A, powder B and quinoa saponin;

[0030] Figure 6 This is the taste radar chart of quinoa saponin yogurt;

[0031] Figure 7 This is the sensory evaluation chart of quinoa saponin yogurt. DETAILED DESCRIPTION

[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. The methods used in the present invention are conventional methods unless otherwise specified; the raw materials and devices used are conventional commercial products unless otherwise specified.

[0033] Example 1 Preparation of Quinoa Saponins with Umami Flavor

[0034] A method for preparing quinoa saponin with umami taste comprises the following steps:

[0035] (1) adding quinoa bran to 75% anhydrous methanol, wherein the volume ratio of quinoa bran to 75% anhydrous methanol is 1:5, and then ultrasonically vibrating under stirring, wherein the ultrasonic vibration temperature is 24° C., and the ultrasonic vibration time is 60 min; after the ultrasonic vibration is completed, filtering is performed using diatomaceous earth to obtain a crude extract;

[0036] (2) concentrating the crude extract by rotary evaporation, with the concentration temperature being 60° C. and the rotation speed being 60 r / min, to obtain a concentrated solution; freeze-drying the concentrated solution at −80° C. to obtain powder A;

[0037] (3) 200 g of powder A was dissolved in 500 mL of distilled water, and then wet-loaded into AB-2 macroporous resin, and eluted with 0% anhydrous ethanol, 30% anhydrous ethanol, 60% anhydrous ethanol, and 90% anhydrous ethanol in sequence to obtain an eluate, and the eluate with 60% anhydrous ethanol was concentrated to obtain a concentrated solution; the concentrated solution was placed at -80°C for freeze-drying to obtain powder B;

[0038] (4) Dissolve 50 g of powder B in 50 mL of 40% anhydrous methanol, then wet-load the mixture into a reverse C18 chromatographic column, and sequentially elute with 40% anhydrous methanol, 60% anhydrous methanol, 80% anhydrous methanol, and 100% anhydrous methanol to obtain an eluent, and concentrate the eluent with 60% anhydrous methanol to obtain a concentrated solution; freeze-dry the concentrated solution at -80°C to obtain quinoa saponins with an umami taste.

[0039] Liquid chromatography analysis was performed on powder A, powder B and quinoa saponin, and the liquid chromatograms thereof were measured as follows: Figure 1 , Figure 2 , Figure 3 As shown; the mass spectrometry analysis of quinoa saponin was performed, and the mass spectrum was measured as shown Figure 4 shown.

[0040] See also Figure 1 , is the liquid chromatogram of powder A. Figure 1 It can be seen that powder A contains multiple saponins, that is, quinoa bran contains multiple saponins.

[0041] See also Figure 2 , is the liquid chromatogram of powder B. Figure 2 It can be seen that macroporous resin Figure 1 Saponins with RT35min~RT50min served the purpose of enrichment.

[0042] See also Figure 3 , is the liquid chromatography diagram of quinoa saponins. Figure 3 It can be seen that the quinoa saponin prepared in Example 1 has a higher purity. From the liquid chromatography data, it can be seen that the purity of quinoa saponin can reach 95%.

[0043] See also Figure 4 , is the mass spectrum of quinoa saponins. Figure 3 and Figure 4 It can be seen that the quinoa saponin with umami taste prepared in Example 1 is a compound composed of a quinoa saponin monomer with phytolaccagenin as the parent core and carrying three sugar chains, and a derivative with phytolaccagenin as the parent core and carrying different numbers of sugar chains, wherein the structural formula of the quinoa saponin monomer is as follows:

[0044]

[0045] Example 2 Determination of the umami taste of quinoa saponins

[0046] Quinoa bran, powder A, powder B and quinoa saponin were added to ultrapure water to prepare solutions with a concentration of 0.5 mg / mL. The four solutions were then poured into a special beaker for the electronic tongue. The taste was detected by the electronic tongue. Each solution was tested five times. The average of the last three test results was taken as the test data. The taste radar chart of the four substances was drawn, as shown in the figure. Figure 5 shown.

[0047] Among them, the electronic tongue was purchased from Japan's Insent Company, model SA402B, which is equipped with 6 test sensors and 2 reference sensors. The AAE, CTO, CAO, AE1, COO and GL1 test sensors are used to detect umami, saltiness, sourness, astringency, bitterness and sweetness, respectively.

[0048] See also Figure 5 , which is the taste radar chart of quinoa bran, powder A, powder B and quinoa saponin. Figure 5 It can be seen that the response values ​​of quinoa saponins in bitterness and astringency are significantly lower than those of quinoa bran, powder A and powder B, and the response value of quinoa saponins in umami is higher than that of powder A and powder B, and slightly lower than that of quinoa bran.

[0049] Example 3 Application of quinoa saponin as a food additive in improving the umami taste of yogurt

[0050] Quinoa saponin was added to fresh milk at a mass fraction of zero, one thousandth, five thousandths, and ten thousandths, and then fermentation bacteria powder was quickly added, gently stirred, and placed at 42°C for 8 hours to obtain four types of quinoa saponin yogurts. The taste of the four types of quinoa saponin yogurts was tested, and the test process and results are as follows:

[0051] (1) Determination of the umami taste of quinoa saponin yogurt

[0052] The above four quinoa saponin yogurts were diluted with ultrapure water, with the volume ratio of quinoa saponin yogurt to ultrapure water being 1:2. After being fully stirred, they were filtered with double-layer gauze, and then poured into the electronic tongue beakers respectively. The taste was detected by the electronic tongue. Each solution was tested five times, and the average of the last three test results was taken as the test data to draw the taste radar chart of the above four yogurts, as shown below. Figure 6 shown.

[0053] (2) Sensory evaluation

[0054] The four quinoa saponin yogurts were placed in a refrigerator at 4°C for 12 hours, and then sensory evaluation was performed to obtain the umami taste score, and a sensory evaluation chart of the four yogurts was drawn. The sensory evaluation panel consisted of 10 members (5 men and 5 women, aged between 20 and 30 years old). The sensory evaluation criteria are shown in Table 1.

[0055] Table 1 Sensory evaluation standard of quinoa saponin yogurt

[0056]

[0057]

[0058] See also Figure 6 , which is the taste radar chart of quinoa saponin yogurt. Figure 6 It can be seen that after adding quinoa saponin, the freshness of yogurt is significantly increased, and the greater the amount of quinoa saponin added, the greater the increase in the freshness of yogurt. When the amount of quinoa saponin added is 10% by mass, the freshness of yogurt is 10, showing obvious freshness. It can be seen that quinoa saponin has the effect of improving the freshness of yogurt.

[0059] See also Figure 7 , is the sensory evaluation diagram of quinoa saponin yogurt. Figure 7 It can be seen that after adding quinoa saponins, the umami taste score of yogurt increased significantly, and the greater the amount of quinoa saponins added, the higher the umami taste score of the yogurt.

[0060] Combination Figure 6 and Figure 7 It can be seen that quinoa saponins have the effect of improving the umami taste of yogurt, and with the increase in the amount of quinoa saponins added, the texture, color and smell of the yogurt do not change, but the taste of the yogurt is significantly improved.

[0061] The present invention also provides the use of quinoa saponin with umami taste prepared by the preparation method of Example 1 as a food additive in improving the umami taste of beverages, wherein the beverages include yogurt or beverages.

[0062] In summary, the present invention provides a quinoa saponin with umami taste and a preparation method and application thereof. Quinoa bran is used as a raw material, and quinoa saponin with umami taste is prepared through ultrasonic extraction, macroporous resin elution, and reverse C18 chromatographic column elution. Quinoa saponin is used as a food additive in yogurt, which has the effect of improving the umami taste of yogurt and can significantly improve the taste of yogurt.

[0063] Compared with the prior art, (1) the present invention retains the purity of quinoa saponins to the maximum extent through two elution processes of macroporous resin elution and reverse C18 chromatographic column elution, and three low-temperature freeze-drying processes, thereby improving the comprehensive utilization rate of saponins in quinoa bran; in addition, the preparation method of the present invention can quickly obtain quinoa saponins, which is conducive to the industrial production of quinoa saponins; (2) the quinoa saponins with umami taste prepared by the present invention are natural umami agents with high safety, which are in line with the current social health and healthy diet concepts, and still have good biological activity at high temperatures, thereby expanding the application scope of umami agents; in addition, the present invention provides a theoretical basis for the application of saponins in food additives, thereby promoting the development of food additives; (3) the quinoa saponins prepared by the present invention use quinoa bran as raw material, thereby improving the application value of quinoa bran and promoting the healthy and sustainable development of crops; and can be widely used in the field of food additive technology.

[0064] It should be noted that:

[0065] (1) In the above-mentioned Example 1, in step (1), the volume ratio of quinoa bran to 75% anhydrous methanol is 1:5. This is only used as a preferred embodiment. In actual production, the volume ratio of quinoa bran to 75% anhydrous methanol can be 1:5 to 1:7, and is adaptively adjusted according to actual conditions.

[0066] (2) In the above-mentioned embodiment 1, in step (1), the ultrasonic oscillation time is 60 minutes. This is only a preferred embodiment. In actual production, the ultrasonic oscillation time can be 30 to 90 minutes, and it is adaptively adjusted according to the actual situation.

[0067] (3) In the above Example 1, in step (3), 200 g of powder A is dissolved in 500 mL of distilled water. This is only a preferred embodiment. In actual production, the volume ratio of powder A to distilled water can be 1:1 to 1:2, and is adaptively adjusted according to actual conditions.

[0068] (4) In the above-mentioned Example 1, in step (3), the macroporous resin is AB-2 macroporous resin. This is only a preferred embodiment. In actual production, the macroporous resin can be other types of macroporous resins as long as the same separation effect can be achieved.

[0069] (5) In the above Example 1, in step (4), 50 g of powder B is dissolved in 50 mL of 40% anhydrous methanol. This is only a preferred embodiment. In actual production, the volume ratio of powder B to 40% anhydrous methanol can be 1:1 to 1:2, which is adaptively adjusted according to actual conditions.

[0070] (6) In the above-mentioned embodiment 3, the beverage is selected as yogurt, which is only a preferred embodiment. In actual production, the beverage can be yogurt or beverage, or other types of beverages.

[0071] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for preparing quinoa saponin with umami taste, characterized in that: The following steps are involved: (1) adding quinoa bran to anhydrous methanol solution, ultrasonically shaking under stirring, and filtering to obtain a crude extract; (2) Concentrating and freeze-drying the crude extract to obtain powder A; (3) Powder A is dissolved in distilled water, then added to a macroporous resin, and eluted with anhydrous ethanol solutions of different concentrations to obtain an eluate, which is then concentrated and freeze-dried to obtain powder B; (4) dissolving powder B in an anhydrous methanol solution, then adding it to a chromatographic column, eluting it with anhydrous methanol solutions of different concentrations in turn to obtain an eluate, and then concentrating and freeze-drying the eluate to obtain quinoa saponins with an umami taste; The structural formula of the quinoa saponin is as follows: 。 2. The method for preparing quinoa saponin with umami taste according to claim 1, characterized in that: In step (1), the anhydrous methanol solution is 75% anhydrous methanol, and the volume ratio of quinoa bran to 75% anhydrous methanol is 1:5 to 1:

7.

3. The method for preparing quinoa saponin with umami taste according to claim 1, characterized in that: In step (1), the ultrasonic oscillation temperature is 24° C., and the ultrasonic oscillation time is 30 to 90 min; after the ultrasonic oscillation, diatomaceous earth is used for filtration.

4. The method for preparing quinoa saponin with umami taste according to claim 1, characterized in that: In step (2), the crude extract is concentrated by rotary evaporation, the concentration temperature is 60° C., and the rotation rate is 60 r / min.

5. The method for preparing quinoa saponin with umami taste according to claim 1, characterized in that: In step (3), the volume ratio of powder A to distilled water is 1:1 to 1:2; 0% anhydrous ethanol, 30% anhydrous ethanol, 60% anhydrous ethanol, and 90% anhydrous ethanol are used in sequence for elution to obtain an eluate, and the eluate of 60% anhydrous ethanol is concentrated.

6. The method for preparing quinoa saponin with umami taste according to claim 1, characterized in that: In step (4), the anhydrous methanol solution is 40% anhydrous methanol, the volume ratio of powder B to 40% anhydrous methanol is 1:1 to 1:2; and the chromatographic column is a reverse C18 chromatographic column.

7. The method for preparing quinoa saponin with umami taste according to claim 1, characterized in that: In step (4), 40% anhydrous methanol, 60% anhydrous methanol, 80% anhydrous methanol and 100% anhydrous methanol are used in sequence for elution to obtain an eluate, and the eluate of 60% anhydrous methanol is concentrated.

8. The method for preparing quinoa saponin with umami taste according to claim 1, characterized in that: In steps (2) to (4), the freeze-drying temperature is -80°C.

9. A quinoa saponin with umami taste prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The structural formula of the quinoa saponin is as follows: 。 10. An application of quinoa saponin with umami taste prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The quinoa saponin is used as a food additive to improve the freshness of a drink, and the drink is yogurt or a beverage.

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