A method for preparing a momordica grosvenori sweet composition from momordica grosvenori and application thereof

Abstract

The application provides a method for preparing a momordica grosvenori sweet composition from momordica grosvenori and application thereof. The method for extracting the sweet composition from the momordica grosvenori preferably comprises the following steps: ripening of immature momordica grosvenori, juice extraction, pure water extraction, impurity removal, concentration and purification, and the like to obtain the sweet composition. The application also comprises a compound sweetener containing the sweet composition, which can be widely applied in food, beverage, health care product, daily chemical product, and the like. The application controls the contents of mogroside III and mogroside IIe, so that the momordica grosvenori sweet composition has a better taste. In the preparation process of the sweet composition, only pure water is used, and no organic solvent such as ethanol is used, so that the production process is more green and healthy.

Description

Technical Field

[0001] This invention belongs to the field of plant active ingredient extraction and separation technology, and more specifically, relates to a method for preparing a monk fruit sweet composition from monk fruit, and also relates to a compound sweet preparation containing the monk fruit sweet composition obtained by the above method. Background Technology

[0002] Monk fruit (Siraitia grosvenorii (Swingle) C. Jeffrey, formerly known as Momordicagrosvenorii), also called smooth-fruited monk fruit, is the fruit of a perennial vine belonging to the Cucurbitaceae family. It is dioecious, flowering in summer and fruiting in autumn. It is mainly produced in Guilin, Guangxi; Yongzhou, Shaoyang, and Huaihua, Hunan; and Guangdong, China. Varieties include green-skinned monk fruit, long-skinned monk fruit, winter melon fruit, lajiang fruit, red-haired fruit, and tung oil fruit. The green-skinned variety is the most commonly cultivated. In recent years, seedless monk fruit (triploid seedless monk fruit and parthenocarpic seedless monk fruit) has also been cultivated in some areas. Monk fruit is also one of the first batch of medicinal and edible materials approved by the state. Its main effects are moistening the lungs, relieving cough, promoting saliva production, and resolving phlegm. The main sweet components in monk fruit are a class of saponins with mogroside (a cucurbitane triterpenoid) as the aglycone. These saponins include sweet saponins (containing four or more glucose groups) and tasteless or off-flavor and bitter saponins (containing three or fewer glucose groups). Sweet monk fruit saponins include 11-O-mogroside V, neomogroside, mogroside V, isomogroside V, sarcoside I, mogroside VI, mogroside IVe, and mogroside IVa; tasteless or bitter saponins include total monk fruit glycosides III (including mogroside III, mogroside IIIa1, mogroside IIIe, and mogroside IIIe) and total monk fruit glycosides II (including mogroside IIe, mogroside IIa, mogroside IIa1, mogroside IIe, and mogroside IIb). It contains various saponins, including 11-O-mogroside IIe, total mogroside I (including mogroside Ia1, mogroside Ie1, etc.). Among these saponins, mogroside V has the highest content. Mogroside V has the characteristics of good stability, almost zero calories, sweetness up to 250-300 times that of sucrose, long-lasting sweetness, no aftertaste of bitterness or astringency. As a natural sweetener, it has been widely used in high-end beverages, foods, and health products, and is being recognized by more and more people. Its status in the international context of blood sugar reduction is becoming more and more obvious.

[0003] CN101007042B discloses a method for preparing a decolorized and debittered monk fruit extract, which involves soaking and decocting the monk fruit in 14 times its volume of water, followed by resin adsorption and ethanol desorption to obtain the product. CN103923152B discloses a method for extracting mogroside V, using fresh monk fruit as raw material. The fresh monk fruit is washed, crushed, saccharified, extracted, and then subjected to sedimentation and centrifugation. Macroporous resin adsorption and separation are performed using a multi-resin column array for selective adsorption, and the eluent is collected in batches according to its content. The batches are then combined and processed, purified with ion exchange resin, concentrated, and the ethanol is recovered. The product is then purified with silica gel, concentrated, and spray-dried to obtain the final product. US Patent US6124442 discloses a method for preparing a dried composition containing mogrosides from monk fruit. The extracted liquid is mixed with a solution with an oxidation state, then precipitated. The clarified liquid is deposited on macroporous resin, and the resin is eluted with alcohol. The resulting eluent is concentrated and dried to obtain a dried composition containing triterpenoid glycosides. US Patent 20110021456 provides a method for preparing a light-colored, sweet composition derived from monk fruit without bitter impurities. The method involves extraction, clarification, adsorption of monk fruit glycosides using macroporous resin, desorption using a gradient of ethanol, heating to generate melanoidins, and decolorization using an ion exchange resin. US Patent 2014044843A1 provides a method for preparing monk fruit sweet juice, involving extraction, clarification, and purification of the extract using anion and cation exchange resins to obtain a pure-tasting sweet juice composition.

[0004] Most of the inventions mentioned above for preparing mogrosides involve long-term storage to allow the monk fruit to mature, or the addition of enzymes to the monk fruit extract to accelerate the saccharification process. Then, macroporous adsorption resins are used to adsorb the mogrosides, followed by desorption with an alcohol solution, thus concentrating or purifying them. Finally, ion exchange resins are used to remove colored impurities such as polyphenols and flavonoids while adjusting the pH to a suitable level. These processes use exogenous enzymes, and solvents such as ethanol are used in the purification process. Furthermore, the removal of colored substances using ion exchange resins is a chemical reaction that can affect other components remaining in the product besides mogrosides. These steps all pose obstacles to the production of organic monk fruit extracts. Moreover, the products obtained using such processes still contain high levels of mogroside III, mogroside IIe, mogroside Ia1, and their isomers, which contribute to unpleasant odors. Summary of the Invention

[0005] The first objective of this invention is to provide a method for extracting a sweet composition from monk fruit, the method comprising the following steps:

[0006] Mature and unripe monk fruit are placed together in a weight ratio of 1:4 to 1:8 and sealed at 25 to 38°C for 2 to 4 days. Then, they are placed in a ventilated environment for 1 to 4 days to obtain monk fruit raw material. The raw material is juiced to obtain juice and pulp. The juice and the extract obtained by extracting the pulp with pure water are combined, impurities are removed, and the mixture is concentrated and purified to obtain the final product.

[0007] When harvesting monk fruit in plantations, the yellowing of the fruit stalk is generally used to determine whether the fruit is ready for picking. Experience suggests that a yellow stalk indicates the fruit is over 3 months old (from fruit formation to harvest), meeting the requirements for harvesting. However, most of these harvested monk fruit are still green or only partially pale yellow. In such fresh fruit, the main sweet components, such as mogroside V, mogroside VI, 11-O-mogroside V, and isomogroside V, have not yet reached their maximum content. Furthermore, the fruit still contains some bitter mogrosides such as IIe, 11-O-mogroside II, and Ia1, and the content of sour and astringent components is also high. It generally takes about two weeks for the monk fruit's own biotransformation to increase the content of sweet mogrosides.

[0008] Preferably, this invention uses ethylene produced by the mature monk fruit itself to ripen green monk fruit. The ripening method includes: a) Selecting ripe, golden-yellow monk fruit and arranging it alternately with green monk fruit at an appropriate weight to ensure that the ethylene released by the mature monk fruit can fully contact the green monk fruit. The weight ratio of mature monk fruit to green monk fruit is 1:4 to 1:8. Ripening is carried out for 2 to 4 days in a sealed environment that maintains a high concentration of ethylene and keeps the temperature warm, within a range of 25 to 38°C. b) Then, it is placed in a well-ventilated environment at room temperature for 1 to 4 days. The air conditions ensure that the fruit peel surface is dry, preventing mold growth, and allow the monk fruit to fully undergo aerobic respiration, which is beneficial to the biotransformation process within the monk fruit.

[0009] Preferably, ripening is achieved by directly introducing ethylene gas. Under sealed conditions, the temperature is in the range of 25 to 38°C, and the ethylene concentration is in the range of 500 ppm to 1500 ppm. After ripening for 2 to 4 days, the product is placed in a ventilated environment and left at room temperature for another 1 to 4 days.

[0010] Through the aforementioned 3-8 day ripening process, the raw, sour, astringent, and bitter tastes of fresh monk fruit are significantly improved, while the sweetness is noticeably enhanced. The content of both bitter and non-sweet mogrosides in the fresh monk fruit is significantly reduced, with mogroside III and mogroside IIe reduced to below 10% of their original levels. The content of mogroside V and 11-O-mogroside V in the raw material can be increased to approximately 180% of their original levels.

[0011] The fresh *Siraitia* fruit used in this invention can be from the *Siraitia* subgenus and *Siraitia scabra* subgenus within the *Siraitia* tribe of the Cucurbitaceae family, or it can be a polyploid *Siraitia* or a seedless *Siraitia*. The *Siraitia* subgenus includes *Siraitia agrosvenorii* (Swingle) C. Jeffrey ex Lu et ZYZhang, mainly produced in Guangxi, Guizhou, southern Hunan, Guangdong, and Jiangxi; and *Siraitia siamensis* (Craib) C. Jeffrey ex Zhong et D. Fang, produced in western Guangxi and southeastern Yunnan, and also found in northern Vietnam and Thailand. The subgenus *Siraitia borneensis* includes *Siraitia borneensis* (Merr.) C. Jeffrey ex Lu et ZYZhang, found in Guangdong, Yunnan (Xichou), and Tibet (Medog), as well as Thailand and Malaysia; *Siraitia borneensis* (Merr.) C. Jeffrey ex Lu et ZYZhang var. Borneensis; *Siraitia borneensis* (Merr.) C. Jeffrey ex Lu et ZYZhang var. lobophylla AMLu et ZYZhang, found in Lüchun, Yunnan; *Siraitia borneensis* (Merr.) C. Jeffrey ex Lu et ZYZhang var. yunnanensis AMLu et ZYZhang, found in Eshan, Yunnan; and *Siraitia taiwaniana* (Hayata) C. Jeffrey ex Lu et ZYZhang, found in Taiwan.

[0012] Organic monk fruit refers to monk fruit grown in strict accordance with organic production regulations, prohibiting the use of any chemically synthesized pesticides, fertilizers, growth regulators, or other chemical substances, as well as genetic engineering and its products. Instead, it follows the natural laws and ecological principles of monk fruit growth and has been certified by an organic food certification body and issued an organic food certificate.

[0013] Preferably, the present invention selects the green-skinned fruit, long-skinned fruit, and triploid seedless fruit of monk fruit, which are widely cultivated and have high content of sweet components such as mogrosides in their fruit. More preferably, organic green-skinned fruit, organic long-skinned fruit, and organic triploid seedless monk fruit are selected.

[0014] In this invention, the extraction is performed using a continuous countercurrent method or an extraction tank.

[0015] Monk fruit contains approximately 70% water, primarily in the pulp, and its sweet components, such as mogrosides, are also mainly concentrated in the pulp. Therefore, juicing can extract most of these sweet components along with the juice. The remaining pulp is then extracted, significantly reducing extraction time and solvent usage, making the process more convenient, faster, and more efficient. Monk fruit seeds contain a large amount of oil. If the seeds are damaged during the crushing and pressing process, these oils will be carried into the extract, increasing the difficulty of subsequent separation and purification, and affecting the taste of the equipment and the product. Juicing by pressing ensures the integrity of the monk fruit seeds. The pressed juice is directly sent to the next extraction stage, while the pulp after pressing needs to be dispersed before being sent to the next extraction stage to prevent the formation of dense pulp cakes, which would affect extraction efficiency.

[0016] The pressed pomace is extracted with water using a continuous countercurrent extraction method to obtain the extract. Countercurrent extraction refers to the continuous movement of both the material and the solvent during the extraction process, but in opposite directions. The material enters from the beginning and exits from the end, while the solvent enters from the end and exits from the beginning, ensuring continuous solvent renewal and maintaining good mass transfer between the material and solvent. The main characteristics of continuous countercurrent extraction are short extraction time and low solvent consumption. The countercurrent extraction process for pomace typically takes 30–40 minutes, with the weight ratio of pomace to pure water (w / w) being 1:1 to 1:2. The extraction temperature is between 50 and 90°C. The extract is cooled to below 50°C using a plate and frame heat exchanger before being sent to the next process. More preferably, the extraction temperature is around 50°C, as a high temperature is not required for complete extraction of the sweet components from the pomace. The extraction time for contacting the fruit pomace with pure water is 15-30 minutes, and the ratio of fruit pomace weight to pure water usage (w / w ratio) during the extraction process is 1:1.

[0017] In a preferred embodiment of the present invention, the above-mentioned continuous countercurrent extraction method employs two continuous countercurrent extractors connected in series. Each countercurrent extractor is followed by two juicers connected in series, allowing the pomace to be extracted countercurrently. Juice is then extracted, and the pomace from the second extraction (the first extraction involves crushing and pressing whole fresh monk fruit to produce juice and pomace) is mechanically dispersed and then subjected to countercurrent extraction again. Finally, the pomace is extracted to obtain monk fruit waste without sweetness. In this method, the pomace after the second extraction allows water containing low concentrations of sweet components to more easily penetrate the pomace, significantly shortening the extraction time.

[0018] In a preferred embodiment of the present invention, a multi-functional extraction tank can also be used to extract the pomace, extracting 2 to 3 times, with each extraction lasting 0.5 to 1.5 hours, at an extraction temperature of 80-100°C, and the material-to-liquid ratio (w / w) for each extraction being 1:1 to 1:2. The extract is filtered through a 200-mesh steel sieve at the bottom of the extraction tank and then cooled by a plate and frame heat exchanger before being sent to subsequent processes.

[0019] In this invention, the impurity removal specifically includes the following steps: a) centrifugation to remove pulp tissue from the extract; b) filtering the centrifuged liquid using a ceramic membrane with a pore size of 50-100 nm to obtain a filtrate; c) adsorbing impurities in the filtrate using a macroporous adsorption resin chromatography column.

[0020] The juice and extract obtained from pressing monk fruit contain a large amount of pulp tissue. Directly filtering this through a ceramic membrane would increase the burden on the membrane and significantly increase the frequency of cleaning. Therefore, it is necessary to remove this pulp tissue. Centrifugation is commonly used, employing methods such as horizontal screw centrifuges, disc centrifuges, or tubular centrifuges. Preferably, a horizontal screw centrifuge is used at a speed of 2000–3000 rpm. Horizontal screw centrifuges offer suitable speed, large throughput, and easy cleaning, effectively removing the pulp tissue.

[0021] To remove suspended particles, protopectin, plant fiber, macromolecular proteins, macromolecular polysaccharides, and other substances from the juice and extract obtained by pressing, a ceramic membrane is used for filtration. Preferably, a ceramic membrane with a pore size of 50–100 nm is used for filtration, and the temperature of the liquid to be filtered is controlled below 50°C. This pore size of the ceramic membrane can significantly retain macromolecular substances and water-insoluble components, while the sweet components in monk fruit can pass through the ceramic membrane, thereby achieving the effect of removing some impurities.

[0022] In this invention, the step of "adsorbing impurities in the filtrate using a macroporous adsorption resin chromatography column" specifically includes the following steps:

[0023] a) Use a non-polar macroporous adsorption resin chromatography column or a weakly polar macroporous adsorption resin chromatography column to adsorb substances in the filtrate that are less polar than the main sweet components of monk fruit: such as mogroside III, mogroside IIe, mogroside Ia1, and other impurities with unpleasant taste. Start collecting the eluent when there is leakage of mogroside V.

[0024] b) Use a polar macroporous adsorption resin chromatography column to adsorb the more polar impurities in the effluent collected in step a), such as polyphenols and organic acids, and collect the effluent in portions.

[0025] c) Wash the chromatography column from step b) with pure water, collect the washings in portions, selectively combine the washings with the eluent collected in step b), take the component with good taste for concentration and purification, and discard the component with poor taste.

[0026] The permeate from the ceramic membrane is fed to a macroporous adsorption resin chromatography column for further impurity removal and purification of the sweet components of monk fruit. Generally, macroporous adsorption resins can adsorb mogrosides, but the adsorption capacity varies. Non-polar and weakly polar macroporous adsorption resins have relatively large adsorption capacities for mogrosides, while moderately polar and polar macroporous adsorption resins have relatively smaller adsorption capacities. Compared to the sweet components in monk fruit, non-polar or weakly polar macroporous adsorption resins more readily adsorb less polar flavonoids, slightly soluble fatty acids in water, and terpenes that are not sweet or even have a bitter taste: such as the triterpenoid aglycones of mogrosides, total mogroside I, total mogroside II, and total mogroside III.

[0027] The non-polar macroporous adsorption resin is preferably D101 and / or LX-60. The weakly polar macroporous adsorption resin is preferably HPD-722 and / or AB-8. The polar macroporous resin is preferably LX-17, and more preferably LX-17 with a mesh size of 60-120.

[0028] The volumetric mass ratio (L / kg) of the resin in the nonpolar macroporous adsorption resin column to the total amount of monk fruit is preferably 1:2 to 1:5, and the flow rate is preferably 1 to 3 BV / h.

[0029] The preferred ratio (L / kg) of resin dosage in the polar macroporous adsorption resin column to the volumetric mass ratio (L / kg) of mogroside V in the supernatant is 50:1 to 200:1.

[0030] Even when a large amount of mogroside V has been adsorbed onto a nonpolar or weakly polar macroporous adsorption resin chromatography column, and leakage of mogroside V has begun in the effluent, indicating that the adsorption capacity of the resin column for mogroside V is approaching saturation, continued loading of filtrate onto the column using a ceramic membrane still allows the resin chromatography column to adsorb non-mogroside sweet components. After mogroside V reaches saturation in the resin, as more filtrate continues to be loaded onto the column, more impurities are adsorbed, and the mogroside V adsorbed in the resin is replaced by other impurities. Taking the same volume of effluent and the loading solution, adding the same weight of excipients, concentrating and drying, revealed a significant increase in the content of mogroside V and 11-O-mogroside V in the effluent, while the content of mogroside III and mogroside IIe decreased significantly. Furthermore, the taste of the effluent was noticeably less bitter and lingering on the tongue compared to the loading solution. Effluent was collected from the point of mogroside V leakage until the corresponding filtrate had completely passed through the chromatography column.

[0031] In this invention, a polar macroporous adsorption resin column is used to adsorb highly polar impurities in the effluent described above. The ratio of resin volume (L) to the weight (kg) of mogroside V in the column buffer is 50:1 to 200:1, and the adsorption rate is 1 to 3 BV / h. The column is then washed with pure water, and the effluent and washings are collected separately. Preferably, the polar macroporous resin is of type LX-17. More preferably, a polar macroporous adsorption resin column of type LX-17 with a mesh size of 60-120 is used to adsorb impurities.

[0032] The impurities in the effluent collected from these non-polar or weakly polar resins are mostly polyphenols, some organic acids, some highly polar flavonoids, some small-molecule proteins, some peptides, and some amino acids. Highly polar impurities are adsorbed by the polar macroporous adsorption resin, and water has difficulty desorbing them. Monosaccharides, disaccharides, and some amino acids in the sweet components of monk fruit are not easily adsorbed and are easily carried directly out of the aqueous solution. Mogrosides, however, are both adsorbed by the polar macroporous resin and desorbed by the aqueous solution, resulting in dynamic adsorption and desorption between the polar macroporous resin and the aqueous solution. Therefore, the polar macroporous adsorption resin can perform chromatographic purification of mogrosides. By selectively merging components with high levels of mogroside V collected separately and removing components with high levels of unpleasant-tasting mogroside III and mogroside IIe collected separately, the content of components affecting the taste of the product is further reduced.

[0033] The "concentration and purification" process described in this invention specifically includes the following steps: purifying the solution after impurities have been removed using a nanofiltration membrane with a pore size of 1-2 nm. Nanofiltration membrane materials are generally cellulose acetate, sulfonated polysulfone, sulfonated polyethersulfone, polyvinyl alcohol, polyamide, ceramics, metals, etc. Preferably, a ceramic membrane with a pore size of 1-2 nm is used. This process removes most of the water, inorganic salts, amino acids, monosaccharides, disaccharides, organic acids, etc.

[0034] After nanofiltration concentration, the retentate still contains inorganic salts, amino acids, monosaccharides, disaccharides, organic acids, and other components. It is usually necessary to dilute the concentrate with an appropriate amount of pure water, repeat the nanofiltration concentration and purification process multiple times to remove these components. More preferably, twice the volume of the concentrate is added each time, repeating 1-4 times.

[0035] Typically, the solids content of the concentrate obtained from nanofiltration membrane retrieval is only about 10% to 20% w / w. High moisture content easily leads to microbial growth and makes it difficult to store. Therefore, other concentration methods are needed to make the concentrate more viscous for easier storage and transportation. In a preferred embodiment of the present invention, a multifunctional vacuum concentration tank is used at a temperature of about 65°C and a vacuum degree of about -0.08 MPa to concentrate the retrieval solution into a 60Brix to 70Brix extract.

[0036] To meet market demand, the concentrate needs further drying to obtain powder or solid. Preferably, a centrifugal spray drying tower is used, with a feed solids content of approximately 30%, an atomizer speed of 20,000 r / min, an inlet air temperature of 180°C, and an outlet air temperature of 95°C, yielding a monk fruit sweetener powder with a bulk density (loose density) of 20 g / 100 ml to 50 g / 100 ml. Alternatively, a vacuum drying oven is used, with a feed solids content of approximately 50%, a temperature of approximately 65°C, and a vacuum degree of approximately -0.09 MPa, resulting in a monk fruit sweetener in a loose, irregular solid form. Alternatively, a refrigerated vacuum dryer, a fluidized bed dryer, or a circulating hot air dryer can also be used for drying.

[0037] The method of this invention is suitable for large-scale production of monk fruit sweet compositions, and is also suitable for producing organic monk fruit sweet compositions using organic monk fruit raw materials. Similarly, different batches and specifications of monk fruit sweet compositions produced from the same raw materials (distinguishing between ordinary and organic monk fruit) can be mixed to meet market requirements for specific contents (such as 25% mogroside V, 80% mogroside V, etc.).

[0038] A second objective of the present invention is to provide a compound sweetener (compound sweetener), which may be composition A or a mixture of composition A and composition B.

[0039] Composition A: The monk fruit raw material is a monk fruit sweet composition obtained by the method described above in "A Method for Preparing a Monk Fruit Sweet Composition from Monk Fruit". The main components of this sweet composition include 10% to 85% mogroside V, 0.2% to 2% mogroside VI, 1% to 12% 11-O-mogroside V, 0.5% to 5% isomogroside V, 0.1% to 3% sarmandin I, 0.1% to 3% mogroside IVa, 0.2% to 3% mogroside IVe, 0% to 12% sucrose, 0% to 8% fructose, 0% to 6% glucose, 0% to 10% mannitol, and mogroside III ≤ 0.5% and mogroside IIe ≤ 0.1%.

[0040] Composition B: One or more ingredients, which may be sweeteners, flavorings, flavorings, colorings, plant extracts, excipients, etc.

[0041] Preferably, the compound sweetener is composition A, and the raw materials used are green-skinned fruit, long-skinned fruit and triploid seedless monk fruit from common monk fruit.

[0042] More preferably, the compound sweetener is composition A, and the raw materials used are organic green-skinned fruit, organic long-skinned fruit and organic triploid seedless monk fruit from organic monk fruit.

[0043] In some preferred embodiments, the compound sweetener is component A, which contains 75% to 83% mogroside V, 0.4% to 1% mogroside VI, 8% to 12% 11-O-mogroside V, 2.5% to 4% isomogroside V, 1.5% to 2% symmenidine I, 0.5% to 2% mogroside IVa, 1% to 2% mogroside IVe, 0% mogroside III, 0% mogroside IIe, and 0% sucrose, fructose, glucose, and mannitol. This compound sweetener contains virtually no mogroside III and mogroside II, which have off-flavors and bitterness, and contains no monosaccharides or disaccharides, thus exhibiting high sweetness, pure sweetness, no off-flavors, and ultra-low calories.

[0044] In some preferred embodiments, the compound sweetener is component A, which contains 47% to 54% mogroside V, 1% to 1.6% mogroside VI, 5% to 8% 11-O-mogroside V, 2.5% to 4% isomogroside V, 1.5% to 2% symmenidine I, 0.5% to 2% mogroside IVa, 1% to 2% mogroside IVe, mogroside III ≤ 0.2%, mogroside IIe 0%, 0.1% to 1% sucrose, 0.1% to 1% fructose, 0.1% to 1% glucose, and 0.1% to 1% mannitol. This compound sweetener still contains trace amounts of total mogroside III and total mogroside II; therefore, retaining small amounts of sucrose, fructose, glucose, mannitol, and other sugars enhances the initial sweetness of the compound sweetener, reduces off-flavors, and makes the taste closer to sucrose.

[0045] In some preferred embodiments, the compound sweetener is component A, which contains 23% to 28% mogroside V, 0.2% to 0.6% mogroside VI, 2% to 4% 11-O-mogroside V, 1% to 2% isomogroside V, 0.3% to 1% sarcosin I, 0.5% to 1% mogroside IVa, 0.5% to 1% mogroside IVe, mogroside III ≤ 0.5%, mogroside IIe ≤ 0.1%, 2% to 6% sucrose, 2% to 4% fructose, 1% to 4% glucose, and 1% to 4% mannitol. This compound sweetener still contains a small amount of total mogroside III and total mogroside II. Therefore, retaining an appropriate amount of sugars naturally present in the mogroside raw material, such as sucrose, fructose, glucose, and mannitol, can make the initial sweetness of the compound sweetener stronger, which can appropriately reduce bitterness, mask off-flavors, and make the taste closer to sucrose.

[0046] In a preferred embodiment of the present invention, the sweetener can exist in powder form, with a bulk density of 20 g / 100 ml to 50 g / 100 ml. Within this bulk density range, the sweetener powder dissolves rapidly in water; 1 g dissolves completely in 100 ml of room temperature water in just 30-50 seconds. The powder color varies from yellow to light yellow, then to off-white, and finally to pure white, depending on the mogroside V content in the sweetener composition. The mogroside sweetener composition can also exist in liquid form, with the liquid color varying from brown to yellow, then to light yellow, and finally to colorless, depending on the mogroside V content in the sweetener composition. Preferably, the mogroside sweetener composition exists as a 60-70 Brix aqueous solution. The sweetener composition can also exist in an irregular solid form, preferably as a loosely packed solid.

[0047] Those skilled in the art can add the above-mentioned compound sweeteners to food, beverages, health products, daily chemical products or pharmaceuticals as needed.

[0048] The third objective of this invention is to provide food, beverages, health products, daily chemical products, pharmaceuticals, etc., containing the above-mentioned sweetening composition.

[0049] This invention effectively controls the content of mogrosides III and IIe through a specific preparation method, resulting in a better taste for the mogroside sweet composition. Furthermore, the preparation process of the sweet composition of this invention uses only pure water and does not use organic solvents such as ethanol, making the production process greener and healthier. Attached Figure Description

[0050] Figure 1 The HPLC chromatogram of the powder obtained in Comparative Example 1 is shown below.

[0051] Figure 2The HPLC chromatogram of the sweet composition obtained in Example 1 is shown below.

[0052] Figure 3 The HPLC chromatogram of the sweet composition obtained in Example 2 is shown below.

[0053] Figure 4 The HPLC chromatogram of the sweet composition obtained in Example 3 is shown below.

[0054] Figure 5 The images show the HPLC chromatograms of the sweet composition obtained in Example 2 and the powder obtained in Comparative Example 1. Detailed Implementation

[0055] The specific embodiments of the present invention will be described in further detail below with reference to the examples. These examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0056] Example 1

[0057] This embodiment provides a method for preparing a monk fruit sweet composition from monk fruit, specifically including the following steps:

[0058] 1) Ripening: Select 300kg of fully ripe, golden-yellow monk fruit and 1200kg of unripe monk fruit (fruit age over 3 months) and arrange them alternately in a 1:4 weight ratio to ensure that the ethylene released by the ripe monk fruit can fully contact the unripe monk fruit. Cover them with plastic film to isolate the monk fruit from the outside air, which helps to maintain a high concentration of ethylene and keep warm. After ripening for 3 days at a temperature between 25 and 38℃, remove the plastic film and ripen again for 3 days under well-ventilated room temperature conditions. Select new golden-yellow monk fruit to ripen the next batch. A very small number of unripe unripe fruits are selected for the next batch to ripen. The remaining 1200kg are sent to the juicing process.

[0059] 2) Juicing: The monk fruit is juiced using an extrusion juicer to ensure the integrity of the seeds. 410 kg of juice with a sugar content of 16 Brix is ​​obtained and sent to a ceramic membrane filter. The resulting pulp cake is mechanically dispersed to prevent clumping.

[0060] 3) Extraction: The dispersed 790kg of fruit pomace is fed into the following combined equipment: a continuous countercurrent extraction unit A is connected in series with juicer A, followed by a continuous countercurrent extraction unit B, and then juicer B again. This allows the fruit pomace to be extracted countercurrently, then juiced, then extracted countercurrently again, and finally juiced to obtain non-sweet monk fruit waste. The extraction temperature is 50℃, the extraction time of the fruit pomace in contact with pure water is 20 minutes, and the amount of pure water used for extraction is 790L.

[0061] 4) Centrifugation: The juice and extract obtained by squeezing monk fruit are centrifuged in a horizontal screw centrifuge at a speed of 3000 r / min and an inner diameter of 400 mm.

[0062] 5) Filtration: The centrifuged liquid is filtered using a ceramic membrane with a pore size of 50 nm, and the temperature of the liquid to be filtered is controlled below 50℃.

[0063] 6) Impurity Adsorption: The filtrate is passed through a stainless steel chromatography column at a flow rate of 2 BV / h. The column is packed with 400 L of D101 non-polar macroporous adsorption resin, and the temperature of the filtrate is approximately 40°C. Initially, sweet components such as mogroside V, 11-O-mogroside V, and symmancoside I are adsorbed into the resin. The effluent mainly consists of sugars, organic acids, inorganic salts, and amino acids, which can be processed into syrup for other commercial products. When mogroside V begins to leak and appears in the effluent, the effluent is collected until the filtrate has completely passed through the column. The column is then washed with approximately 450 L of pure water, and the effluents are collected and combined, totaling 1200 L.

[0064] The eluent was passed through a stainless steel chromatography column at a flow rate of 0.5 BV / h. The column was packed with 1200 L of 80-mesh LX-17 polar macroporous adsorption resin. The eluent from the polar macroporous resin column was collected in 300 L segments, for a total of 4 segments. After column loading, 2400 L of pure water was washed with 1 BV / h. The wash water was collected in 300 L segments, for a total of 8 segments. The eluent and wash water were named Segment 1, Segment 2, and so on up to Segment 12, according to the order of collection. Segments 1 and 2 did not contain mogrosides; their main components were monosaccharides and disaccharides, which could be concentrated into syrup for other commercial products. Segments 7, 8, and 9 were combined, totaling 900 L.

[0065] 7) Nanofiltration: The combined 900L of liquid was nanofiltered using a ceramic membrane with a pore size of 1nm. The liquid was concentrated to a retentate of about 100L, then diluted with 200L of pure water. The nanofiltration was continued to concentrate the liquid to about 100L. This process of dilution and concentration was repeated 3 times to obtain 100L of colorless and transparent liquid.

[0066] 8) Concentration and Drying: 100L of liquid is further concentrated in a multi-functional vacuum concentrator at a temperature of about 65℃ and a vacuum degree of about -0.08MPa until the solid content of the feed is 30%. The atomizer speed is 20000r / min, the inlet air temperature is 180℃, and the outlet air temperature is 95℃. A pure white monk fruit sweet composition powder with a bulk density (loose density) of 26g / 100ml and a specification of 80% monk fruit glycoside V is obtained, which is the sweet composition.

[0067] Step 6) The remaining segments 3-6 and 10-12 from the impurity adsorption process are combined to a total of 2100L and sent to the nanofiltration process. After concentration and drying, a product of approximately 35% mogroside V can be obtained. Alternatively, each segment can be separately subjected to nanofiltration, concentration, and drying to obtain different specifications of mogroside V with 10% to 65% concentration. These segments can also be combined and added to the next batch, then re-coated onto a polar resin column to obtain a product with a higher content.

[0068] Example 2:

[0069] This embodiment provides a method for preparing a monk fruit sweet composition from monk fruit, specifically including the following steps:

[0070] 1) Ripening: Select 250kg of fully ripe, golden-yellow monk fruit and 1000kg of unripe monk fruit (fruit age over 3 months) and arrange them alternately in a 1:4 weight ratio to ensure that the ethylene released by the ripe monk fruit can fully contact the unripe monk fruit. Cover them with plastic film to isolate the monk fruit from the outside air, which helps to maintain a high concentration of ethylene and keep warm. After ripening for 2 days at a temperature between 25 and 38℃, remove the plastic film and ripen again for 2 days under well-ventilated room temperature conditions. Select new golden-yellow monk fruit to ripen the next batch. A very small number of unripe unripe fruits are selected for the next batch to ripen. The remaining 1000kg are sent to the juicing process.

[0071] 2) Juicing: The monk fruit is juiced using an extrusion juicer to ensure the integrity of the seeds. 350 kg of juice with a sugar content of 17 Brix is ​​obtained and sent to a ceramic membrane filter. The resulting pulp cake is dispersed mechanically to prevent clumping.

[0072] 3) Extraction: 650 kg of dispersed fruit pomace is fed into a continuous countercurrent extraction unit. The extraction time between the fruit pomace and pure water is 40 minutes, and 650 L of pure water is used in the extraction process. The extraction temperature is 70℃, and the extract is cooled to below 50℃ using a plate and frame heat exchanger.

[0073] 4) Centrifugation: The juice and extract obtained by squeezing monk fruit are centrifuged in a horizontal screw centrifuge at a speed of 2500 r / min and an inner diameter of 400 mm.

[0074] 5) Filtration: The centrifuged liquid is filtered using a ceramic membrane with a pore size of 50 nm, and the temperature of the liquid to be filtered is controlled below 50℃.

[0075] 6) Impurity Adsorption: The filtrate is passed through a stainless steel chromatography column at a flow rate of 1.5 BV / h. The column is packed with 300 L of HPD-722 weakly polar macroporous adsorption resin. The temperature of the filtrate is approximately 40°C. Initially, sweet components such as mogroside V, 11-O-mogroside V, and symmancoside I are adsorbed into the resin. The effluent mainly consists of sugars, organic acids, inorganic salts, and amino acids, which can be processed into syrup for other commercial products. When mogroside V begins to leak and appear in the effluent, the effluent is collected until the filtrate has completely passed through the column. The column is then washed with approximately 450 L of pure water, and the effluents are collected and combined, totaling 1050 L.

[0076] The eluent is passed through a stainless steel chromatography column at a flow rate of 1 BV / h. The column is packed with 1000 L of 60-mesh, LX-17 polar macroporous adsorption resin. The first 1000 L of eluent does not contain mogrosides; its main components are monosaccharides and disaccharides, which can be concentrated into syrup for other commercial products. The last 400 L of eluent is collected. After column loading, 2000 L of the eluent is washed with pure water at a flow rate of 2 BV / h, and the wash solution is collected. The last 400 L of eluent is combined with all the wash solution, for a total of 2400 L.

[0077] 7) Nanofiltration: The combined 2400L liquid was nanofiltered using a ceramic membrane with a pore size of 2nm. The liquid was concentrated to a retentate of about 100L, then diluted with 200L of pure water. The nanofiltration was continued to concentrate the liquid to about 100L. This process of dilution and concentration was repeated twice to obtain 100L of slightly yellow transparent liquid.

[0078] 8) Concentration and Drying: 100L of liquid is further concentrated in a multi-functional vacuum concentrator at a temperature of about 65℃ and a vacuum degree of about -0.08MPa until the solid content of the feed is 30%. The atomizer speed is 18000r / min, the inlet air temperature is 180℃, and the outlet air temperature is 95℃, resulting in a white mogroside V sweet-tasting powder with a bulk density of 33g / 100ml and a specification of 50% mogroside V.

[0079] Example 3:

[0080] This embodiment provides a method for preparing a monk fruit sweet composition from monk fruit, specifically including the following steps:

[0081] 1) Ripening: Select 320kg of fully ripe, golden-yellow monk fruit and 1600kg of unripe monk fruit (fruit age over 3 months) and arrange them alternately at a weight ratio of 1:5 to ensure that the ethylene released by the ripe monk fruit can fully contact the unripe monk fruit. Cover them with plastic film to isolate the monk fruit from the outside air, which helps to maintain a high concentration of ethylene and keep warm. After ripening for 3 days at a temperature between 25 and 38℃, remove the plastic film and ripen again for 1 day under well-ventilated room temperature conditions. Select new golden-yellow monk fruit to ripen the next batch. A very small number of unripe unripe fruits are selected for the next batch to ripen. The remaining 1600kg are sent to the juicing process.

[0082] 2) Juicing: The monk fruit is juiced using an extrusion juicer to ensure the integrity of the seeds. 550 kg of juice with a sugar content of 15 Brix is ​​obtained and sent to a ceramic membrane filter. The resulting pulp cake is dispersed mechanically to prevent clumping.

[0083] 3) Extraction: 1050 kg of dispersed fruit pomace was extracted using a multi-functional extraction tank, three times. The first extraction lasted 1.5 hours at 100℃, and the second and third extractions each lasted 1 hour at 80℃. 2100 L of pure water was used for each extraction. The extract was filtered through a 200-mesh steel sieve at the bottom of the extraction tank. The combined extracts, totaling 5700 L, were cooled to approximately 50℃ using a plate and frame heat exchanger before being sent to the centrifugation process.

[0084] 4) Centrifugation: The juice and extract obtained by squeezing monk fruit are centrifuged in a horizontal screw centrifuge at a speed of 2000 r / min and an inner diameter of 400 mm.

[0085] 5) Filtration: The centrifuged liquid is filtered using a ceramic membrane with a pore size of 100 nm, and the temperature of the liquid to be filtered is controlled below 50℃.

[0086] 6) Impurity Adsorption: The filtrate is passed through a stainless steel chromatography column at a flow rate of 3 BV / h. The column is packed with 400 L of LX-60 non-polar macroporous adsorption resin, and the temperature of the filtrate is approximately 45°C. Initially, sweet components such as mogroside V, 11-O-mogroside V, and symmancoside I are adsorbed into the resin. The effluent mainly consists of sugars, organic acids, inorganic salts, and amino acids, which can be processed into syrup for other commercial products. When mogroside V begins to leak and appear in the effluent, the effluent is collected until the filtrate has completely passed through the column. The column is then washed with approximately 450 L of pure water, and the effluents are collected and combined, totaling 5400 L.

[0087] The eluent was passed through a stainless steel chromatography column at a flow rate of 2 BV / h. The column was packed with 900 L of LX-17 polar macroporous adsorption resin. The first 1800 L of eluent did not contain mogrosides; its main components were monosaccharides and disaccharides, which could be concentrated into syrup for other commercial products. The subsequent 3600 L of eluent was collected. After column loading, 1200 L of eluent was washed with pure water at a flow rate of 2 BV / h, and the wash water was collected. The collected 3600 L of eluent and 1200 L of wash water were combined, for a total of 4800 L.

[0088] 7) Nanofiltration: The combined 4800L liquid was nanofiltered using a ceramic membrane with a pore size of 2nm. The liquid was concentrated to a retentate of about 200L, then diluted with 400L of pure water. The nanofiltration was continued to concentrate the liquid to about 200L. This process of dilution and concentration was repeated once more to obtain 200L of yellow transparent liquid.

[0089] 8) Concentration and Drying: The 200L liquid was further concentrated in a multi-functional vacuum concentrator at a temperature of about 65℃ and a vacuum degree of about -0.08MPa until the solid content of the feed was 30%. The atomizer speed was 16000r / min, the inlet air temperature was 180℃, and the outlet air temperature was 95℃, resulting in a light yellow monk fruit sweet-tasting powder with a bulk density (loose density) of 42g / 100ml and a specification of 25% monk fruit glycoside V.

[0090] Comparative Example 1

[0091] According to the method described in Example 1 of patent CN101522058A, mogrosides were prepared from fresh mogrosides to obtain a slightly yellow powder.

[0092] The powders obtained in Examples 1, 2, and 3 and Comparative Example 1 were analyzed using the HPLC method for mogroside V in the 2015 edition of the Chinese Pharmacopoeia: acetonitrile-water (23:77) as the mobile phase, detection wavelength 203 nm, column temperature 30 °C, flow rate 1 ml / min, injection volume 10 μL, and chromatographic column: C18 column (4.6 mm * 150 mm, 5 μm). The contents of mogroside VI, 11-O-mogroside V, mogroside V, isomogroside V, symmonoside I, mogroside IVa, mogroside IVe, mogroside III, and mogroside IIe were determined.

[0093] The powders obtained in Examples 1, 2, and 3 and Comparative Example 1 were analyzed by ion chromatography (AOAC 995.13) to determine the contents of sucrose, fructose, glucose, and mannitol.

[0094] The powders obtained in Examples 1, 2, and 3, and Comparative Example 1, were added to pure water to prepare solutions with the same concentration of mogroside V (0.5 mg / ml). A post-bitterness tasting group of 20 people (10 men and 10 women, aged 20-61) conducted blind tests on the above four different solutions and then scored them. The tasting method was to first rinse the mouth with pure water, then fully contact the solution to be tasted with the tongue and oral cavity for 10 seconds, and then swallow (to ensure that the solution could be in contact with the back of the tongue). The score was then given. The mouth should be rinsed before the next tasting, and there should be an interval of at least 1 minute between the two tastings. The scoring criteria were that the milder the post-bitterness, the higher the score, and the stronger the post-bitterness, the lower the score: no bitterness (10 points), bitterness not obvious (9 points, 8 points, 7 points, the score varies depending on the degree of slight bitterness), slightly bitter (6 points, 5 points, 4 points), and quite bitter (3 points, 2 points, 1 point).

[0095] The results are shown in the table below:

[0096] Table 1. Content Results of Examples and Comparative Examples

[0097]

[0098]

[0099] From Table 1, Figures 1 to 5 It can be concluded that: 1. The monk fruit sweetening compositions obtained in Examples 2 and 3 contain sugars such as sucrose, fructose, glucose, and mannitol, while Example 1 does not. The higher the content of mogroside V, the lower the sugar content, down to 0%. The content of mogroside V in the comparative example is similar to that in Example 2, but it does not contain the aforementioned sugars. A product containing approximately 10-60% mogroside V contains small amounts of monosaccharides and disaccharides, which can enrich the sweetness and make the taste closer to sucrose; 2. None of the examples contain mogroside IIe, and the higher the content of mogroside V, the lower the content of mogroside III. In Example 1, the product with a high content of 80.62% contained 0% mogroside III, and its chromatogram did not show peaks for mogroside IIIe and mogroside IIIa1. The fewer these unpleasant-tasting or even strongly bitter substances, the higher the taste evaluation score. 3. The content of mogroside V in Example 2 and Comparative Example 1 was similar. Example 2 contained lower levels of symmonoside I and mogroside IVa (which are less polar than mogroside V), and lower levels of mogroside IVe than Comparative Example 1. It also did not contain mogroside III and mogroside IIe (which are less polar than mogroside IV), whereas Comparative Example 1 contained these. Figure 5The peak value of mogroside IIIa1 in Example 2 was also lower than that in Comparative Example 1. Therefore, it can be seen that this method reduces the content of bitter glycosides and unpleasant-tasting glycosides by ripening the raw materials, promoting their conversion into mogrosides. In the subsequent adsorption of impurities, the non-polar or weakly polar resin saturated with mogroside V can significantly adsorb total mogroside III and total mogroside II, reducing or even removing unpleasant-tasting components and improving the taste of the product. However, this method can also adsorb some of the total mogroside IV (symmonoside I, mogroside IVa, mogroside IVe, etc.). The bitter glycosides and total mogroside IV can be separated through subsequent process improvements to develop new products.

[0100] Finally, the method of this invention is merely a preferred embodiment and is not intended to limit the scope of protection of this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for extracting a sweet composition from monk fruit, characterized in that, The process includes the following steps: Mature and unripe monk fruit are placed together at a weight ratio of 1:4 to 1:8 and sealed at 25-38°C for 2-4 days. Then, the mixture is placed in a ventilated environment for 1-4 days to obtain monk fruit raw material. The raw material is juiced to obtain juice and pulp. The juice and the extract obtained by extracting the pulp with pure water are combined, impurities are removed, and the mixture is concentrated and purified to obtain the final product. The impurity removal process specifically includes the following steps: a) centrifugation to remove pulp tissue from the juice and extract; b) filtering the centrifuged liquid using a ceramic membrane with a pore size of 50-100 nm to obtain a filtrate; c) adsorbing impurities in the filtrate using a macroporous adsorption resin chromatography column. The process of using a macroporous adsorption resin chromatography column to adsorb impurities in the filtrate specifically includes the following steps: 1) Use a non-polar macroporous adsorption resin chromatography column or a weakly polar macroporous adsorption resin chromatography column to adsorb substances in the filtrate that are less polar than the main sweet components of monk fruit. Start collecting the eluent when there is leakage of mogroside V. 2) Use a polar macroporous adsorption resin chromatography column to adsorb the impurities polyphenols and organic acids in the effluent collected in step 1), and collect the effluent in portions. 3) Wash the chromatography column in step 2) with pure water, collect the washing liquid in portions, selectively combine the washing liquid with the eluent collected in step 2), take the component with good taste, concentrate and purify it, and discard the component with poor taste. The component with good taste refers to the component with high content of mogroside V, and the component with poor taste refers to the component with high content of mogroside III and mogroside IIe. The resin type in the non-polar macroporous adsorption resin chromatography column is D101 or LX-60; the resin type in the weakly polar macroporous adsorption resin chromatography column is HPD-722 or AB-8; the resin type in the polar macroporous adsorption resin chromatography column is LX-17 with a mesh size of 60-120; the volume ratio (L / kg) of the resin used in the non-polar or weakly polar macroporous adsorption resin chromatography column to the total amount of monk fruit is 1:2 to 1:5, and the flow rate is 1 to 3 BV / h; the volume ratio (L / kg) of the resin used in the polar macroporous adsorption resin chromatography column to mogroside V in the loading solution is 50:1 to 200:

1.

2. The method according to claim 1, characterized in that, The monk fruit mentioned is green-skinned monk fruit, long-skinned monk fruit, or triploid seedless monk fruit.

3. The method according to claim 2, characterized in that, The extraction is performed using a continuous countercurrent extraction method or an extraction tank. The continuous countercurrent extraction method specifically includes the following steps: using water as a solvent for continuous countercurrent extraction, the ratio of fruit pomace to water is 1:1 to 1:2, the extraction temperature is 50 to 90°C, and the extraction time is 30 to 40 minutes. In the continuous countercurrent extraction method, two continuous countercurrent extraction machines are connected in series, and each countercurrent extraction machine unit is further connected in series with two juicer presses to combine the juice and extract.

4. The method according to any one of claims 1 to 3, characterized in that, The concentration and purification specifically includes the following steps: using a nanofiltration membrane with a pore size of 1-2 nm to concentrate and purify the solution after removing impurities; the nanofiltration membrane is made of ceramic.

5. A monk fruit sweetening composition, characterized in that, Prepared by the method according to any one of claims 1 to 4, comprising the following components: 10% to 85% mogroside V, 0.2% to 2% mogroside VI, 1% to 12% 11-O-mogroside V, 0.5% to 5% isomogroside V, 0.1% to 3% sarmancoside I, 0.1% to 3% mogroside IVa, 0.2% to 3% mogroside IVe, 0% to 12% sucrose, 0% to 8% fructose, 0% to 6% glucose, and 0% to 10% mannitol, wherein mogroside III ≤ 0.5% and mogroside IIe ≤ 0.1%.

6. A compound sweetener, characterized in that, The invention includes the monk fruit sweetening composition and additives as described in claim 5, wherein the additives are one or more of sweeteners, flavorings, colorings, plant extracts, and excipients.

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