A comprehensive extraction and separation method of high-value components in cyperus esculentus and products and applications thereof

Abstract

This invention relates to a comprehensive extraction and separation method for high-value components from tiger nuts, as well as its products and applications. The comprehensive extraction and separation method includes the following steps: drying and pulverizing tiger nuts, mixing them with water, and performing a first shaking extraction; mixing the first extract with a food-grade organic solvent and performing a second shaking extraction; centrifuging the second extract to obtain a phase-separated material system; and separating and purifying the phase-separated material system to obtain five high-value components: tiger nut oil, tiger nut gum, tiger nut starch, tiger nut sugar, and tiger nut fibroin. In this invention, tiger nuts are first mixed with water to extract the sugar content, then a food-grade organic solvent is added, and centrifugation allows for the simultaneous separation of five high-value crude components in an integrated manner. Furthermore, the entire extraction and separation process is completed within a single process, ensuring the purity of each component while significantly improving the yield, reducing overall costs, and facilitating large-scale scaling.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive processing technology of oil crops, specifically relating to a comprehensive extraction and separation method for high-value components in tiger nuts, as well as its products and applications. Background Technology

[0002] Tiger nuts (Cyperus esculentus L.), also known as tiger nut, are perennial herbaceous plants belonging to the Cyperus genus of the Cyperaceae family. Tiger nuts possess advantages such as wide adaptability, short growing season, large biomass, and high oil content. The stems and leaves can be used for silage, and the tubers can be eaten raw or cooked. Furthermore, tiger nuts can be pressed for oil, and the resulting oil cake can be used as animal feed. Therefore, tiger nuts, as a new type of crop integrating grain, oil, livestock, and feed, have high economic value and development potential. As a new oilseed plant rich in nutrients and various bioactive substances, tiger nuts have attracted widespread attention in the food, nutrition, and livestock production sectors due to their high oleic acid and starch content, as well as their antioxidant, hypoglycemic, and antibacterial activities. Tiger nuts can be used to extract oil. Studies have shown that tiger nut oil has a similar fatty acid composition to olive oil. Tiger nut oil is clear and transparent, with a mellow and fragrant taste, stable chemical properties, and superior quality to rapeseed oil. Its nutritional value is similar to that of peanut oil and olive oil, and it has unique preventive and therapeutic effects on diseases such as hyperlipidemia, cardiovascular disease, and metabolic disorders. The phospholipids and phytosterols contained in tiger nuts have significant antioxidant effects. Tiger nut starch is a slow-digesting starch, and slow-digesting starch foods are low glycemic index foods, which can be used to maintain stable postprandial blood sugar, effectively reduce postprandial glycemic load, and improve the body's sensitivity to insulin. Furthermore, tiger nut starch has good freeze-thaw properties, and can maintain the stability and homogeneity of the system after repeated freezing and thawing. Tiger nut sugar mainly contains sucrose, glucose, fructose, and raffinose. Tiger nut fiber protein is rich in various amino acids, has rich nutritional value, high digestibility, and is a good source of healthy food.

[0003] Currently, the production and separation processes for components such as starch, oil, and sugar in tiger nuts are not only complex but also result in low primary product yield and high overall processing costs. Furthermore, the phospholipids and phytosterols contained in tiger nuts have high economic value but are often discarded as waste during extraction and have not been fully utilized. Therefore, it is of great significance to develop an extraction and separation process that can efficiently separate the main components of tiger nuts while maximizing the retention of their high-value components. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a comprehensive extraction and separation method for high-value components in tiger nuts, as well as the resulting products and applications.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a comprehensive extraction and separation method for high-value components in tiger nuts, the comprehensive extraction and separation method comprising the following steps:

[0007] After drying and pulverizing tiger nuts, they are mixed with water and subjected to a first shaking extraction. The first extract is then mixed with a food-grade organic solvent and subjected to a second shaking extraction. The second extract is centrifuged to obtain a phase-separated material system. The phase-separated material system is then separated and purified to obtain five high-value components: tiger nut oil, tiger nut gum, tiger nut starch, tiger nut sugar, and tiger nut fiber protein.

[0008] The food-grade organic solvent includes any one or a combination of at least two of petroleum ether, n-hexane, cyclohexane, dichloromethane, trichloromethane, or ethyl acetate.

[0009] The aforementioned "tiger gum" mainly contains phospholipids, sterols, and other substances, and has high economic value.

[0010] In this invention, tiger nuts are first mixed with water to extract the sugars contained in the tiger nuts, and then processed with food-grade organic solvents. Centrifugation can simultaneously separate five high-value crude components: tiger nut oil, tiger nut gum, tiger nut starch, tiger nut sugar, and tiger nut fiber protein. Furthermore, the entire extraction and separation process is completed within a single process, which ensures the purity of each component while significantly improving the yield of each component, reducing overall costs, and facilitating large-scale scaling.

[0011] When food-grade organic solvents are added first, the organic solvent occupies a large proportion of the tiger nut particles, resulting in a turbid aqueous phase after centrifugation, which cannot achieve clear stratification and affects the extraction of starch, sugar, and fibrin phases. When water and food-grade organic solvents are added simultaneously, they compete for contact with the tiger nut particles. After centrifugation, emulsification occurs at the interface between the organic solvent phase (oil phase + colloidal phase) and the aqueous phase (starch phase + sugar phase + protein phase), and the stratification boundary is not obvious, affecting subsequent separation and greatly reducing the yield of the colloidal phase. When only food-grade organic solvents are used for treatment, the material system after centrifugation is divided into solid and liquid phases. The upper liquid phase is the oil phase, and the remaining four components are the solid phase. The solid phase does not continue to separate and cannot be further separated.

[0012] Preferably, the particle size of the crushed tiger nuts is 20-50 mesh, for example, 20 mesh, 25 mesh, 30 mesh, 35 mesh, 40 mesh, 45 mesh, 50 mesh, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0013] Preferably, the ratio of dried and pulverized tiger nuts to water is 1g:(3-10)mL, for example, it can be 1g:3mL, 1g:3.5mL, 1g:4mL, 1g:4.5mL, 1g:5mL, 1g:5.5mL, 1g:6mL, 1g:6.5mL, 1g:7mL, 1g:7.5mL, 1g:8mL, 1g:8.5mL, 1g:9mL, 1g:9.5mL, 1g:10mL, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0014] The present invention uses the above-mentioned specific material-liquid ratio of tiger nuts to water to extract tiger nut sugar, which has a better tiger nut sugar extraction and separation effect, and can further optimize and ensure good phase separation of the five high-value components after subsequent centrifugation.

[0015] When the water content is too low, the material system becomes a paste, making it difficult to achieve clear separation and stratification of subsequent layers; when the water content is too high, not only is the yield of each component not significantly improved, but the material cost is also greatly increased, which is not conducive to subsequent large-scale application.

[0016] Preferably, the temperature of the first oscillation extraction is 20-60℃, for example, it can be 20℃, 22℃, 24℃, 25℃, 26℃, 28℃, 29℃, 30℃, 35℃, 40℃, 50℃, 60℃, etc.; the time is 8-15min, for example, it can be 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, etc. Other specific point values ​​within this range can be selected, and will not be elaborated here.

[0017] Preferably, the ratio of the dried and pulverized tiger nuts to the food-grade organic solvent is 1g:(1-5)mL, for example, it can be 1g:1mL, 1g:1.5mL, 1g:2mL, 1g:2.5mL, 1g:3mL, 1g:3.5mL, 1g:4mL, 1g:4.5mL, 1g:5mL, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0018] Preferably, the temperature of the second oscillation extraction is 20-60℃, for example, it can be 20℃, 22℃, 24℃, 25℃, 26℃, 28℃, 29℃, 30℃, 35℃, 40℃, 50℃, 60℃, etc.; the time is 5-10min, for example, it can be 5min, 5.5min, 6min, 6.5min, 7min, 7.5min, 8min, 8.5min, 9min, 9.5min, 10min, etc. Other specific point values ​​within this range can be selected, and will not be elaborated here.

[0019] In this invention, a specific amount of food-grade organic solvent is used to extract and separate the high-value components of tiger nuts from the sugar-extracting solution. At the same time, with specific extraction temperature and extraction time, clear phase separation and stratification of the five components can be achieved during the subsequent centrifugation process, realizing the purpose of integrated separation. The processing technology is simpler, and the high losses caused by multiple processing are avoided, thereby improving the product yield and facilitating large-scale production.

[0020] Preferably, the centrifugation temperature is 4-30℃, for example, it can be 4℃, 8℃, 10℃, 12℃, 15℃, 18℃, 20℃, 22℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, etc.; the rotation speed is 3000-10000g, for example, it can be 3000g, 4000g, 5000g, 5250g, 5500g, 5750g, 6000g, 6250g, 6500g, 67... 50g, 7000g, 7250g, 7500g, 7750g, 8000g, 9000g, 10000g, etc.; the time is 5-15min, for example, 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, etc. Other specific point values ​​within this range can be selected, which will not be elaborated here.

[0021] When the centrifugation time is too short, the stratification effect between the phases of the material system is unstable, the interface is blurred, and the subsequent separation is affected. When the centrifugation time is too long, not only is the yield of each component not significantly improved, but the entire separation process time and energy consumption are also extended, which greatly increases the process cost and is not conducive to subsequent large-scale application.

[0022] Preferably, the method for separating the phase-separated material system specifically includes the following steps:

[0023] (1) Take the first layer of the centrifuged material system from top to bottom, and prepare tiger nut oil by desolventizing. The food-grade organic solvent is recycled for the second shaking extraction.

[0024] (2) Take the second layer of the material system after centrifugation from top to bottom, heat it to 40-60℃, centrifuge to separate the upper oil phase, and desolvent the upper oil phase to obtain tiger nuts oil and combine it with the tiger nuts oil in step (1). After centrifugation, the lower gel phase is centrifuged at low temperature, and the upper material after centrifugation is taken to obtain tiger nuts gum.

[0025] (3) Take the third layer of the material system after centrifugation from top to bottom, centrifuge it, and return the supernatant to the fourth layer of the material system from top to bottom. After centrifugation, filter the precipitate through gauze and freeze dry to obtain tiger pea starch.

[0026] (4) Take the fifth layer of the material system after centrifugation from top to bottom, centrifuge it, and return the supernatant to the fourth layer of the material system from top to bottom. After centrifugation, filter the precipitate through gauze and freeze-dry it to obtain tiger nut fiber protein.

[0027] (5) Take the fourth layer of the material system after centrifugation from top to bottom, centrifuge it, concentrate the supernatant, mix it with anhydrous ethanol, let it stand to settle, centrifuge at low temperature, and freeze-dry the supernatant to obtain tiger nuts.

[0028] The steps (1), (2), (3), and (4) are not in any particular order.

[0029] In step (4), tiger nut fiber protein is a mixture of tiger nut fiber and protein meal; in step (5), the fourth layer of material also includes the clear liquid included in other layers.

[0030] The “40-60℃” can be, for example, 40℃, 42℃, 45℃, 48℃, 50℃, 52℃, 55℃, 58℃, 60℃, etc. Other specific values ​​within this range can be selected, and will not be elaborated on here.

[0031] Preferably, the drying process includes any one of freeze drying, spray drying, fluidized bed drying, vacuum drying, or hot air drying.

[0032] Preferably, the centrifugation conditions described in steps (2), (3), (4) and (5) are independently: temperature of 18-30℃, rotation speed of 5000-10000g, and time of 5-15min;

[0033] The "18-30℃" mentioned above can be, for example, 18℃, 19℃, 20℃, 22℃, 24℃, 25℃, 26℃, 28℃, 29℃, 30℃, etc.

[0034] The "5000-10000g" mentioned above can be, for example, 5000g, 5250g, 5500g, 5750g, 6000g, 6250g, 6500g, 6750g, 7000g, 7250g, 7500g, 7750g, 8000g, 8500g, 9000g, 9500g, 10000g, etc.

[0035] The "5-15min" mentioned above can be, for example, 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, etc. Other specific point values ​​within this range can be selected, which will not be elaborated here.

[0036] Preferably, the low-temperature centrifugation conditions described in steps (2) and (5) are independently as follows: the temperature is 1-10℃, for example, it can be 1℃, 1.5℃, 2℃, 2.5℃, 3℃, 3.5℃, 4℃, 4.5℃, 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, etc.; the rotation speed is 6000-9000g, for example, it can be 6000g, 6250g, 6500g, 6750g, 7000g, 7250g, 7500g, 7750g, 8000g, 8250g, 8500g, 8750g, 9000g, etc.; the time is 5-15min, for example, it can be 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, etc. Other specific point values ​​within this range can be selected, and will not be described in detail here.

[0037] Preferably, the temperature for static settling in step (5) is 1-10℃, for example, it can be 1℃, 1.5℃, 2℃, 2.5℃, 3℃, 3.5℃, 4℃, 4.5℃, 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, etc.; the time is 40-180min, for example, it can be 45min, 48min, 50min, 55min, 60min, 62min, 65min, 68min, 70min, 72min, 75min, 78min, 80min, 90min, 100min, 110min, 120min, 150min, 160min, 180min, etc. Other specific point values ​​within this range can be selected, and will not be described in detail here.

[0038] Secondly, the present invention provides tiger nut oil, wherein the tiger nut extract is prepared by the comprehensive extraction and separation method described in the first aspect.

[0039] Thirdly, the present invention provides an application of the tiger nut oil described in the first aspect in the preparation of antioxidant products.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] In this invention, tiger nuts are first mixed with water to extract the sugars contained in the tiger nuts, and then processed with food-grade organic solvents. Centrifugation can simultaneously separate five high-value crude components: tiger nut oil, tiger nut gum, tiger nut starch, tiger nut sugar, and tiger nut fiber protein. Furthermore, the entire extraction and separation process is completed within a single process, which ensures the purity of each component while significantly improving the yield of each component, reducing overall costs, and facilitating large-scale scaling. Attached Figure Description

[0042] Figure 1This is a flowchart of the comprehensive extraction and separation process of high-value components from tiger nuts;

[0043] Figure 2 This is a diagram showing the separation and purification results of the five components extracted in Example 1;

[0044] Figure 3 The diagram showing the stratification and phase separation of each material after centrifugation in Example 1;

[0045] Figure 4 This is a scanning electron microscope image of the tiger nut gum, tiger nut starch, and tiger nut fibrin extracted in Example 1. Detailed Implementation

[0046] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0047] Example 1

[0048] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts, the method comprising the following steps:

[0049] (1) Dry and pulverize tiger nuts to a particle size of 30 mesh, mix with water and extract at 25°C with shaking for 10 min. The material-to-liquid ratio is 1 g: 5.35 mL to obtain the first extract.

[0050] (2) Add petroleum ether to the first extract (the ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1g:4mL), shake and extract at 25℃ for 6min, then centrifuge at 7000g for 12min at 18℃. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase and fiber / protein phase.

[0051] (3) The first layer (oil phase) of the material system after centrifugation is extracted from top to bottom and desolventized under vacuum to prepare tiger nut oil. The petroleum ether is recovered and used for the shaking extraction in step (2).

[0052] After centrifugation, the material system is separated into two layers from top to bottom. The second layer (colloidal phase) is collected, heated to 60℃, and then centrifuged at 25℃ for 10 minutes at 8000g to separate the upper oil phase. The oil phase is then prepared by vacuum desolventizing, and petroleum ether is recycled for step (2) shaking extraction. The lower colloidal phase is centrifuged at 4℃ for 10 minutes at 8000g. The upper material is then freeze-dried to obtain tiger gum containing phospholipids, sterols and other substances. The remaining clear liquid is returned to the fourth layer (sugar phase).

[0053] After centrifugation, the material system was separated into three layers from top to bottom. The third layer (starch phase) was collected and centrifuged at 8000g for 10 minutes at 25℃. The supernatant was transferred to the fourth layer (sugar phase). The precipitate was filtered through gauze and then freeze-dried to obtain tiger pea starch.

[0054] After centrifugation, the material system was separated into five layers from top to bottom. The fifth layer (fiber / protein phase) was collected and centrifuged at 8000g for 10 minutes at 25℃. The supernatant was transferred to the fourth layer (sugar phase). The precipitate was filtered through gauze and then freeze-dried to obtain tiger nut fiber protein.

[0055] After centrifugation, the fourth layer (sugar phase, containing all phases) of the material system was collected from top to bottom. It was centrifuged at 8000g for 10 min at 25℃, and the precipitate was freeze-dried to obtain tiger nut starch component, which was included in tiger nut starch products. The supernatant was vacuum dehydrated and concentrated to 10% of its original volume, and then 5 times its volume of anhydrous ethanol was added for precipitation (standing at 4℃ for 2 h). It was centrifuged at 8000g for 10 min at 4℃, and the precipitate was freeze-dried to obtain tiger nut sugar component 1. The supernatant was desolventized under vacuum, and the aqueous solution was freeze-dried to obtain tiger nut sugar component 2. The two were combined to obtain tiger nut sugar.

[0056] Example 2

[0057] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts, the method comprising the following steps:

[0058] (1) Dry and pulverize tiger nuts to a particle size of 40 mesh, mix with water and extract at 35°C with shaking for 14 min. The material-to-liquid ratio is 1 g: 4 mL to obtain the first extract.

[0059] (2) Add n-hexane to the first extract (the ratio of dried and crushed tiger nuts to n-hexane in step (1) is 1g:2mL), shake and extract at 35℃ for 8min, then centrifuge at 4000g for 15min at 4℃. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase and fiber / protein phase.

[0060] (3) The first layer (oil phase) of the material system after centrifugation is extracted from top to bottom and desolventized under vacuum to prepare tiger nut oil. The n-hexane is recycled for step (2) shaking extraction.

[0061] After centrifugation, the material system is separated into two layers from top to bottom. The second layer (colloidal phase) is then taken out. After heating to 40℃, the upper oil phase is separated by centrifugation at 28℃ and 6000g for 14min. The oil phase is then separated by vacuum desolventizing to obtain tiger nut oil. The n-hexane is recovered and used for shaking extraction in step (2). The lower colloidal phase is centrifuged at 2℃ and 6000g for 15min. The upper material is then freeze-dried to obtain tiger nut gum containing phospholipids, sterols and other substances. The remaining clear liquid is transferred to the fourth layer (sugar phase).

[0062] After centrifugation, the material system was separated into three layers from top to bottom. The third layer (starch phase) was collected and centrifuged at 28°C and 6000g for 14 minutes. The supernatant was transferred to the fourth layer (sugar phase). The precipitate was filtered through gauze and then freeze-dried to obtain tiger pea starch.

[0063] After centrifugation, the material system was separated into five layers from top to bottom. The fifth layer (fiber / protein phase) was collected and centrifuged at 28°C and 6000g for 14 minutes. The supernatant was transferred to the fourth layer (sugar phase). The precipitate was filtered through gauze and then freeze-dried to obtain tiger nut fiber protein.

[0064] After centrifugation, the fourth layer (sugar phase, containing all phases) of the material system was collected from top to bottom. It was centrifuged at 6000g for 14 min at 28℃, and the precipitate was freeze-dried to obtain tiger nut starch. The supernatant was vacuum dehydrated and concentrated to 10% of its original volume. Five times the volume of anhydrous ethanol was added for sedimentation (standing at 4℃ for 1 h). It was centrifuged at 6000g for 15 min at 2℃, and the precipitate was freeze-dried to obtain tiger nut sugar component 1. The supernatant was desolventized under vacuum, and the aqueous solution was freeze-dried to obtain tiger nut sugar component 2. The two were combined to obtain tiger nut sugar.

[0065] Example 3

[0066] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts, the method comprising the following steps:

[0067] (1) Dry and pulverize tiger nuts to a particle size of 20 mesh, mix with water and extract at 50°C with shaking for 8.5 min. The material-to-liquid ratio is 1 g: 7 mL to obtain the first extract.

[0068] (2) Add cyclohexane to the first extract (the ratio of dried and crushed tiger nuts to ethyl acetate in step (1) is 1g:5mL), shake and extract at 50℃ for 9min, then centrifuge at 9000g for 8min at 27℃. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase and fiber / protein phase.

[0069] (3) The first layer (oil phase) of the material system after centrifugation is extracted from top to bottom and desolventized under vacuum to prepare tiger nut oil. Cyclohexane is recycled for step (2) shaking extraction.

[0070] After centrifugation, the material system was separated into two layers from top to bottom. The second layer (colloidal phase) was collected, heated to 50°C, and then centrifuged at 10000g for 15 minutes at 20°C to separate the upper oil phase. The oil phase was prepared by vacuum desolventizing and ethyl acetate was recycled for step (2) shaking extraction. The lower colloidal phase was centrifuged at 6000g for 15 minutes at 2°C. The upper material was taken and freeze-dried to obtain tiger gum containing phospholipids, sterols and other substances. The remaining clear liquid was returned to the fourth layer (sugar phase).

[0071] After centrifugation, the material system was separated into three layers from top to bottom. The third layer (starch phase) was collected and centrifuged at 10000g for 15 minutes at 20℃. The supernatant was transferred to the fourth layer (sugar phase). The precipitate was filtered through gauze and then freeze-dried to obtain tiger pea starch.

[0072] After centrifugation, the material system was separated into five layers from top to bottom. The fifth layer (fiber / protein phase) was collected and centrifuged at 10000g for 15 minutes at 20℃. The supernatant was transferred to the fourth layer (sugar phase). The precipitate was filtered through gauze and then freeze-dried to obtain tiger nut fiber protein.

[0073] After centrifugation, the fourth layer (sugar phase, containing all phases) of the material system was collected from top to bottom. It was centrifuged at 10,000g for 15 min at 20°C, and the precipitate was freeze-dried to obtain tiger nut starch. The supernatant was vacuum dehydrated and concentrated to 10% of its original volume. Five times the volume of anhydrous ethanol was added for sedimentation (standing at 4°C for 1 h). It was centrifuged at 6,000g for 15 min at 2°C, and the precipitate was freeze-dried to obtain tiger nut sugar component 1. The supernatant was desolventized under vacuum, and the aqueous solution was freeze-dried to obtain tiger nut sugar component 2. The two were combined to obtain tiger nut sugar.

[0074] Example 4

[0075] This embodiment provides a comprehensive extraction and separation method for high-value components in tiger nuts. The method includes the following steps: tiger nuts crushed in Example 1 are mixed with water and extracted by shaking at 25°C for 10 min, with a material-to-liquid ratio of 1 g: 1 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and after extraction by shaking at 25°C for 6 min, the mixture is centrifuged at 7000 g for 12 min at 18°C. The material system is divided into three layers from top to bottom: oil phase, colloidal phase, and mixed phase (starch + sugar phase + fibrin). The oil phase and colloidal phase are separated and extracted using the extraction process of the relevant two phases in step (3) of Example 1.

[0076] Example 5

[0077] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with water and extracted by shaking at 25°C for 10 min, with a material-to-liquid ratio of 1 g:15 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g:4 mL), and after extraction by shaking at 25°C for 6 min, the mixture is centrifuged at 7000 g for 12 min at 18°C. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase, and fiber / protein phase. The subsequent five-phase separation and extraction process and related parameters are the same as step (3) in Example 1.

[0078] Example 6

[0079] This embodiment provides a comprehensive extraction and separation method for high-value components in tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted at 25°C with shaking for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 0.5 mL), and extracted with shaking at 25°C for 6 min. Then, the mixture is centrifuged at 7000 g for 12 min at 18°C. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase, and fiber / protein phase. The subsequent five-phase separation and extraction process and related parameters are the same as step (3) in Example 1.

[0080] Example 7

[0081] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with water and extracted at 25°C with shaking for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 12 mL), and after extraction with shaking at 25°C for 6 min, the mixture is centrifuged at 7000 g for 12 min at 18°C. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase, and fiber / protein phase. The subsequent five-phase separation and extraction process and related parameters are the same as step (3) in Example 1.

[0082] Example 8

[0083] This embodiment provides a comprehensive extraction and separation method for high-value components in tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted at 25°C with shaking for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and extracted with shaking at 12°C for 6 min. Then, the mixture is centrifuged at 7000 g for 12 min at 18°C. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase, and fiber / protein phase. The subsequent five-phase separation and extraction process and related parameters are the same as step (3) in Example 1.

[0084] Example 9

[0085] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted at 25°C with shaking for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and extracted with shaking at 80°C for 6 min. Then, the mixture is centrifuged at 7000 g for 12 min at 18°C. In the material system, starch gelatinizes and undergoes Maillard reaction with the other components, resulting in adhesion and making separation difficult for subsequent purification and extraction operations.

[0086] Example 10

[0087] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted at 25°C with shaking for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and after extraction with shaking at 25°C for 2 min, the mixture is centrifuged at 7000 g for 12 min at 18°C. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase, and fiber / protein phase. The subsequent five-phase separation and extraction process and related parameters are the same as step (3) in Example 1.

[0088] Example 11

[0089] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted by shaking at 25°C for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and after extraction by shaking at 25°C for 15 min, the mixture is centrifuged at 7000 g for 12 min at 18°C. After centrifugation, emulsification occurs in the material system, making it difficult to separate for subsequent purification and extraction operations.

[0090] Example 12

[0091] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted by shaking at 25°C for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and after extraction by shaking at 25°C for 6 min, the mixture is centrifuged at 2000 g for 12 min at 18°C. After centrifugation, the phases of the material system show poor separation, with blurred interfaces, making it difficult to separate for subsequent purification and extraction operations.

[0092] Example 13

[0093] This embodiment provides a comprehensive extraction and separation method for high-value components in tiger nuts. The method includes the following steps: tiger nuts crushed in Example 1 are mixed with deionized water and extracted by shaking at 25°C for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and after extraction by shaking at 25°C for 6 min, the mixture is centrifuged at 10000 g for 12 min at 18°C. The material system is divided into three layers from top to bottom: an oil phase, a colloidal phase, and a mixed phase (starch + sugar phase + fibrin). The oil phase and colloidal phase are separated and extracted using the extraction process for the relevant two phases in step (3) of Example 1.

[0094] Example 14

[0095] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted at 25°C with shaking for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and after extraction with shaking at 25°C for 6 min, the mixture is centrifuged at 7000 g for 2 min at 18°C. The boundaries of the material system are relatively fragile, and some liquid phases appear turbid.

[0096] Example 15

[0097] This embodiment provides a comprehensive extraction and separation method for high-value components from tiger nuts. The method includes the following steps: Tiger nuts crushed in Example 1 are mixed with deionized water and extracted at 25°C with shaking for 10 min, with a material-to-liquid ratio of 1 g: 5.35 mL, to obtain a first extract. Petroleum ether is added to the first extract (the material-to-liquid ratio of dried and crushed tiger nuts to petroleum ether in step (1) is 1 g: 4 mL), and after extraction with shaking at 25°C for 6 min, the mixture is centrifuged at 7000 g for 25 min at 18°C. The material system is divided into five layers from top to bottom: oil phase, colloidal phase, starch phase, sugar phase, and fiber / protein phase. The subsequent five-phase separation and extraction process and related parameters are the same as step (3) in Example 1.

[0098] Comparative Example 1

[0099] This embodiment provides a comprehensive extraction and separation method for high-value components in tiger nuts. The method includes the following steps: Tiger nuts crushed as described in Example 1 are mixed with petroleum ether and extracted at 25°C with shaking for 6 minutes (the ratio of dried crushed tiger nuts to petroleum ether is 1g:4mL); then water is added and extracted at 25°C with shaking for 10 minutes (the ratio of dried crushed tiger nuts to deionized water is 1g:5.35mL); the mixture is then centrifuged at 7000g for 12 minutes at 18°C. The material system is divided into four layers from top to bottom: oil phase, colloidal phase, mixed phase (starch + sugar phase), and fiber / protein phase. The oil phase, colloidal phase, and fiber / protein phase are separated and extracted using the extraction process for the relevant phase in step (3) of Example 1.

[0100] Comparative Example 2

[0101] This embodiment provides a comprehensive extraction and separation method for high-value components in tiger nuts. The method includes the following steps: tiger nuts crushed in Example 1 are mixed with petroleum ether and water and extracted by shaking at 25°C for 16 min. The material-to-liquid ratio of dried crushed tiger nuts to water is 1 g: 5.35 mL, and the material-to-liquid ratio of dried crushed tiger nuts to petroleum ether is 1 g: 4 mL. The mixture is centrifuged at 7000 g for 12 min at 18°C. After centrifugation, emulsification occurs at the interface between the aqueous and organic phases in the material system, making it difficult to separate for subsequent purification and extraction operations.

[0102] Comparative Example 3

[0103] This embodiment provides a comprehensive extraction and separation method for high-value components in tiger nuts. The method includes the following steps: Tiger nuts crushed as described in Example 1 are mixed with petroleum ether and extracted by shaking at 25°C for 6 minutes (the ratio of dried crushed tiger nuts to petroleum ether is 1g:4mL). The mixture is then centrifuged at 7000g for 12 minutes at 18°C. The centrifuged material system separates into solid and liquid phases. The upper liquid phase (oil phase) is collected and vacuum desolventized to obtain tiger nut oil. The petroleum ether is reused in step (2) for shaking extraction. The solid phase fails to separate further and cannot be further separated.

[0104] Test Example 1

[0105] The yields of the high-value components extracted and separated in Examples 1-15 and Comparative Examples 1-3 were calculated using the following formula:

[0106] Yield (%) = (mass of extracted and separated components / initial mass of tiger nuts (dry basis)) × 100%, and the results are shown in Table 1:

[0107] The comprehensive extraction and separation process of various components in tiger nuts involved in this invention is as follows: Figure 1 As shown in the figure; the separation and purification results of the five components extracted in Example 1, the phase separation state of each material after centrifugation, and the scanning electron microscope images of tiger nut gum, tiger nut starch, and tiger nut fibroin are respectively shown in the figure. Figure 2 , Figure 3 and Figure 4 As shown.

[0108] Table 1

[0109] Tetnut oil Tetrasop Tiger pea starch Tetsuy Tiger nut fiber protein Example 1 20.5％ 4.4％ 30.2％ 22.1％ 18.4％ Example 2 21.2％ 4.6％ 29.8％ 21.9％ 19.1％ Example 3 20.9％ 4.3％ 30.5％ 21.8％ 19.5％ Example 4 16.3％ 2.9％ / / / Example 5 19.6％ 4.1％ 29.7％ 20.3％ 18.2％ Example 6 15.2％ 3.1％ 26.3％ 19.2％ 17.5％ Example 7 19.6％ 3.8％ 25.6％ 18.3％ 18.1％ Example 8 17.2％ 4.2％ 27.6％ 21.6％ 23.4％ Example 9 / / / / / Example 10 15.5％ 3.5％ 25.7％ 18.5％ 15.7％ Example 11 20.1％ / / / / Example 12 / / / / / Example 13 15.6％ 3.1％ / / / Example 14 / / / / / Example 15 20.3％ 4.1％ 29.0％ 20.9％ 18.7％ Comparative Example 1 20.2％ 2.2％ / / 15.8％ Comparative Example 2 19.5％ 2.5％ / / / Comparative Example 3 20.6％ / / / /

[0110] The data in the table shows that:

[0111] (1) By comparing Examples 1 to 3, it can be seen that the comprehensive extraction and separation method provided by the present invention can not only separate five high-value crude components such as tiger nut oil, tiger nut gum, tiger nut starch, tiger nut sugar and tiger nut fiber in one integrated process, but also complete the entire extraction and separation process in one process, which greatly improves the yield of each component, and the process can be applied to large-scale production.

[0112] (2) By comparing Example 1 with Examples 4-5, it can be seen that when tiger nuts are mixed with water to extract tiger nut sugar using the above-mentioned specific material-liquid ratio, the extraction and separation effect of tiger nut sugar is better. This can further optimize and ensure good phase separation of the five high-value components after subsequent centrifugation, and extract and separate the five components with high yield.

[0113] (3) By comparing Example 1 with Examples 6-11, it can be seen that the present invention uses a specific amount of food-grade organic solvent to extract and separate the high-value components in tiger nuts from the water-soaked sugar treatment liquid. At the same time, with specific extraction temperature and extraction time, the five components can be clearly separated into phases and layers during the subsequent centrifugation process, achieving the purpose of integrated separation. The processing technology is simpler, and the high loss caused by multiple processing is avoided, further improving the yield of the product.

[0114] (4) By comparing Example 1 with Examples 12-15, it can be seen that when the centrifugation speed and time are not within a specific range, the phase separation effect of the material system is worse than that of Example 1, which further affects the purification yield of each component.

[0115] (5) By comparing Example 1 with Comparative Examples 1-3, it can be seen that in this invention, tiger nuts are first mixed with water to extract the sugar contained in tiger nuts, and then processed with food-grade organic solvents. This method can make the entire material system have a clearer phase separation of the five substances, which is convenient for further separation and purification.

[0116] Test Example 2

[0117] In this test example, the tiger nuts oil extracted and separated in Examples 1-3 was sealed and stored at 4°C for 40 days. The acid value and peroxide value were then tested according to the test methods in national standards GB 5009.229-2016 and GB5009.227-2016, respectively. The results are shown in Table 2.

[0118] Table 2

[0119] Acid value (mg / g) Peroxide value (g / 100g) Example 1 1.6 0.0044 Example 2 1.8 0.0051 Example 3 1.7 0.0056

[0120] The data in the table show that the tiger nut oil extracted with high yield by this invention also has excellent purity. Furthermore, the peroxide value in the tiger nut oil sample stored at 4℃ for 40 days is as low as 0.0044 g / 100 g. This demonstrates that the comprehensive extraction and separation method for tiger nuts provided by this invention not only completes the entire extraction and separation process within a single process, but also significantly improves product yield, reduces overall costs, and facilitates large-scale production. Simultaneously, the tiger nut oil prepared by this method also exhibits high purity and stability.

[0121] The applicant declares that the technical solution of this invention is illustrated by the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

[0122] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0123] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A comprehensive extraction and separation method for high-value components from tiger nuts, characterized in that, The comprehensive extraction and separation method includes the following steps: After drying and pulverizing tiger nuts, they are mixed with water and subjected to a first shaking extraction. The first extract is then mixed with a food-grade organic solvent and subjected to a second shaking extraction. The second extract is centrifuged to obtain a phase-separated material system. The phase-separated material system is then separated and purified to obtain five high-value components: tiger nut oil, tiger nut gum, tiger nut starch, tiger nut sugar, and tiger nut fiber protein. The food-grade organic solvent includes any one or a combination of at least two of petroleum ether, n-hexane, cyclohexane, dichloromethane, trichloromethane, or ethyl acetate.

2. The comprehensive extraction and separation method according to claim 1, characterized in that, The tiger nuts are crushed to a particle size of 20-50 mesh.

3. The comprehensive extraction and separation method according to claim 1, characterized in that, The ratio of dried and pulverized tiger nuts to water is 1g:(3-10)mL.

4. The comprehensive extraction and separation method according to claim 1, characterized in that, The temperature for the first oscillation extraction is 20-60℃, and the time is 8-15 min.

5. The comprehensive extraction and separation method according to claim 1, characterized in that, The ratio of the dried and pulverized tiger nuts to the food-grade organic solvent is 1g:(1-5)mL; Preferably, the temperature of the second oscillation extraction is 20-60℃, and the time is 5-10 min.

6. The comprehensive extraction and separation method according to claim 1, characterized in that, The centrifugation temperature is 4-30℃, the rotation speed is 3000-10000g, and the time is 5-15min.

7. The comprehensive extraction and separation method according to claim 1, characterized in that, The method for separating the phase-separated material system specifically includes the following steps: (1) Take the first layer of the material system after centrifugation from top to bottom, and prepare tiger nut oil by solvent removal; (2) Take the second layer of the material system after centrifugation from top to bottom, heat it to 40-60℃, centrifuge to separate the upper oil phase, and desolvent the upper oil phase to obtain tiger nuts oil and combine it with the tiger nuts oil in step (1). After centrifugation, the lower gel phase is centrifuged at low temperature, and the upper material after centrifugation is taken to obtain tiger nuts gum. (3) Take the third layer of the material system after centrifugation from top to bottom, centrifuge it, and return the supernatant to the fourth layer of the material system from top to bottom. After centrifugation, filter the precipitate through gauze and dry it to obtain tiger pea starch. (4) Take the fifth layer of the material system after centrifugation from top to bottom, centrifuge it, and return the supernatant to the fourth layer of the material system from top to bottom. After centrifugation, filter the precipitate through gauze and freeze-dry it to obtain tiger nut fiber protein. (5) Take the fourth layer of the material system after centrifugation (including the clear liquid produced when the third and fifth phases are separated into solid and liquid phases), centrifuge it, concentrate the supernatant, mix it with anhydrous ethanol, let it stand to settle, centrifuge at low temperature, and freeze-dry the supernatant to obtain tiger nuts. The steps (1), (2), (3), and (4) are not in any particular order.

8. The comprehensive extraction and separation method according to claim 7, characterized in that, The centrifugation conditions described in steps (2), (3), (4) and (5) are independently: temperature 18-30℃, rotation speed 5000-10000g, and time 5-15min; Preferably, the conditions for low-temperature centrifugation in steps (2) and (5) are independently: temperature 1-10℃, rotation speed 6000-9000g, and time 5-15min; Preferably, the temperature for static settling in step (5) is 1-10℃ and the time is 40-180min.

9. A type of tiger nut oil, characterized in that, The tiger nut extract is prepared by the comprehensive extraction and separation method according to any one of claims 1-8.

10. The use of tiger nut oil according to claim 9 in the preparation of antioxidant products.

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