Edible plant polysaccharide emulsion and preparation method thereof

Abstract

The invention belongs to the technical field of food processing, and particularly relates to an edible plant polysaccharide emulsion and a preparation method thereof. The edible emulsion containing the natural plant polysaccharide is prepared by compounding the soybean phospholipid and the natural plant polysaccharide such as mulberry leaf polysaccharide, and the stability of the edible emulsion is remarkably improved through the interface synergistic effect of the mulberry leaf polysaccharide and the soybean phospholipid. Experimental results show that the particle size is increased to 35 [mu] m after the emulsion independently using the mulberry leaf polysaccharide is stored for 7 days at 80 DEG C, while the average particle size D [3, 2] of the edible mulberry leaf polysaccharide emulsion prepared by the method and the raw material ratio is less than 25 [mu] m after the emulsion is stored for 7 days under the same condition, and the D [3, 2] is only increased by 0.5 [mu] m and the emulsion precipitation index 1t after the emulsion is stored for 90 days at 4 DEG C; in addition, the edible emulsion is high in biological efficacy, good in safety, suitable for various scenes such as beverages, seasoning sauce and functional food, and wide in market application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and particularly relates to an edible plant polysaccharide emulsion and a preparation method thereof. Background Art

[0002] In recent years, due to their unique biological activities (such as antioxidant, anti-inflammatory, immunomodulatory, etc.) and natural degradability, plant polysaccharides have shown broad application prospects in the fields of food, medicine, cosmetics, etc. In particular, the research on the preparation of edible emulsions using plant polysaccharides has gradually become a hot topic of concern in the academic and industrial circles.

[0003] Mulberry leaf polysaccharide, as a plant polysaccharide with rich sources, is rich in components such as β-glucan, pectin, alkaloids, steroids, etc., and has significant antioxidant activity and good biocompatibility. However, its characteristics of high water solubility and low interfacial activity limit its direct application in emulsion systems.

[0004] As a multiphase dispersion system, emulsions are widely used in the dissolution, encapsulation, and delivery of functional components. However, the current emulsion systems still face the following challenges in terms of stability, functionality, and safety: 1. Insufficient stability: Traditional emulsifiers (such as Tween-80, i.e., polysorbate 80, or glyceryl monostearate) are commonly used in emulsion preparation, but their emulsifying effects are often unstable, easily leading to phenomena such as system stratification, flocculation, or demulsification. 2. Limited functionality: Traditional emulsifiers have a low encapsulation efficiency for active ingredients, restricting the functionality of emulsions. For example, the loss rate of a common emulsion loaded with β-carotene can be as high as 70% after being exposed to light for 48 h; in addition, the use of chemical emulsifiers may reduce the bioavailability of active ingredients through mechanisms such as interfering with absorption. 3. Safety issues: The potential safety hazards of chemically synthesized emulsifiers have increasingly attracted attention, and their application is difficult to meet the development trend of the "clean label" food industry.

[0005] In addition, although plant-based emulsifiers (such as soy protein) have safety advantages, their extraction processes are complex, production costs are high, and their interfacial activity is easily affected by environmental factors (such as water activity, ionic strength, pH value), resulting in protein denaturation and loss of function.

[0006] Mulberry leaf polysaccharide can play an important emulsifying and stabilizing role in emulsion systems due to its rich natural β-glucan and other beneficial components. Therefore, developing natural emulsifiers or stabilizers based on mulberry leaf polysaccharide and constructing a high-performance plant polysaccharide emulsion system have become an important direction to break through the technical bottlenecks of traditional emulsions. Summary of the Invention

[0007] In order to overcome the deficiencies of traditional emulsion systems in terms of stability, functionality, and safety, the present invention provides an edible plant polysaccharide emulsion and a preparation method thereof. More specifically, the present invention provides an edible mulberry leaf polysaccharide emulsion and a preparation method thereof.

[0008] An edible plant polysaccharide emulsion provided by the present invention includes an aqueous phase and an oil phase. The aqueous phase contains plant polysaccharide and soybean phospholipid. In the aqueous phase, the concentration range of the plant polysaccharide is 0.003 - 0.1 g / mL, and the concentration range of the soybean phospholipid is 0.003 - 0.1 g / mL. The volume ratio of the oil phase to the aqueous phase is 0.5 - 3:1 - 3.

[0009] Preferably, in the aqueous phase, the concentration range of the plant polysaccharide is 0.01 - 0.06 g / mL, the concentration range of the soybean phospholipid is 0.01 - 0.05 g / mL, and the volume ratio of the oil phase to the aqueous phase is 0.5 - 3:3.

[0010] More preferably, in the aqueous phase, the concentration range of the plant polysaccharide is 0.01 - 0.04 g / mL, the concentration range of the soybean phospholipid is 0.02 - 0.03 g / mL, and the volume ratio of the oil phase to the aqueous phase is 2 - 2.5:3.

[0011] Preferably, the plant polysaccharide is any one of mulberry leaf polysaccharide and soybean soluble polysaccharide or a combination of the two.

[0012] Preferably, the edible plant polysaccharide emulsion further includes a pH regulator and an ionic strength regulator. The pH regulator is selected from at least one of citric acid, phosphate buffer solution, hydrogen phosphate buffer solution, hydrochloric acid, sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate; the ionic strength regulator is selected from any one of sodium chloride, sodium sulfate, potassium chloride, ammonium sulfate, ammonium chloride, and phosphate.

[0013] Preferably, the pH of the aqueous phase is adjusted to 2.0 - 8.0 using the pH regulator, and the dosage of the ionic strength regulator is 0.01 - 0.05 g added per milliliter of the aqueous phase.

[0014] Preferably, the oil phase is vegetable oil, and the vegetable oil includes but is not limited to the following: soybean oil, corn oil, sunflower oil, olive oil, linseed oil, walnut oil, peanut oil, rapeseed oil, sesame oil, palm oil, coconut oil, and grape seed oil.

[0015] The present invention also provides a method for preparing the above - mentioned edible plant polysaccharide emulsion, including the following steps: (1) Preparation of the aqueous phase: Dissolve the plant polysaccharide and soybean phospholipid in water, and stir at room temperature until completely dissolved to form a uniform aqueous phase. In the aqueous phase, the concentration range of the plant polysaccharide is 0.003 - 0.1 g / mL, and the concentration range of the soybean phospholipid is 0.003 - 0.1 g / mL; (2) Adjustment of pH and ionic strength: Use a pH regulator to adjust the pH of the aqueous phase in (1) to the range of 2.0 - 8.0, and add an ionic strength regulator. The dosage of the ionic strength regulator is 0.01 - 0.05 g / mL of the aqueous phase; (3) Addition of the oil phase: Add vegetable oil to the adjusted aqueous phase in (2) to obtain an oil-water mixture. Among them, the volume ratio of the vegetable oil to the aqueous phase is 0.5 - 3:1 - 3; (4) Preparation of the emulsion: Homogenize and degas the oil-water mixture in (3), and sterilize it to obtain the edible plant polysaccharide emulsion.

[0016] In the above preparation method, preferably, the homogenization in (4) is two-stage homogenization. Among them, the pressure of the first-stage homogenization is 20 - 40 MPa, the homogenization time is 2 - 8 min, the pressure of the second-stage homogenization is 60 - 100 MPa, and the homogenization time is 8 - 15 min.

[0017] As a further preference, the degassing in (4) is carried out by vacuum degassing, the vacuum degree is 0.06 - 1 Mpa, and the degassing time is 5 - 15 min. The sterilization is carried out by pasteurization, the sterilization temperature is 60 - 70°C, and the sterilization time is 20 - 40 min.

[0018] Furthermore, the present invention provides an edible mulberry leaf polysaccharide emulsion, which includes an aqueous phase and an oil phase. The aqueous phase contains mulberry leaf polysaccharide, soybean phospholipid, a pH regulator, and an ionic strength regulator; In the aqueous phase, the concentration range of the mulberry leaf polysaccharide is 0.003 - 0.1 g / mL, the concentration range of the soybean phospholipid is 0.003 - 0.1 g / mL, the concentration range of the ionic strength regulator is 0.01 - 0.05 g / mL, the pH regulator adjusts the pH of the aqueous phase to 2.0 - 8.0, and the volume ratio of the oil phase to the aqueous phase is 0.5 - 3:1 - 3.

[0019] In addition, the application of the above edible plant polysaccharide emulsion or edible mulberry leaf polysaccharide emulsion in food is also the key protection of the present invention. The food is selected from any one of beverages, seasonings, pastries, and candies. The application is specifically to add the edible plant polysaccharide emulsion or edible mulberry leaf polysaccharide emulsion to the food to make a food containing plant polysaccharide. The emulsion retains ≥90% of the biological activity, such as hypoglycemic activity.

[0020] The beneficial effects of the present invention are as follows: (1) The present invention uses natural plant polysaccharides and soy lecithin as stabilizers to prepare an edible mulberry leaf polysaccharide emulsion, which has high safety and no toxic side effects. At the same time, the natural functional components contained in mulberry leaf polysaccharides and soy lecithin endow the emulsion with functions such as blood glucose regulation and antioxidant properties. Compared with traditional chemically synthesized emulsifiers, it has multiple advantages such as environmental friendliness and biodegradability; (2) Through the synergistic effect of plant polysaccharides and soy lecithin, the present invention significantly improves the stability and bioactivity retention rate of the emulsion. The experimental results show that the obtained edible emulsion has a particle size within 25 μm and can remain stable at 4 - 80 °C. After storage at 4 °C for 90 days, D[3,2] only increases by 0.5 μm, the creaming index is <5%, and the emulsion retains ≥90% of its bioactivity, which is significantly better than single mulberry leaf polysaccharide emulsion (increase of 3.0 μm, creaming index of 15%) and single soy lecithin emulsion (increase of 2.5 μm, creaming index of 12%). After storage at 80 °C for 7 days, D[3,2] increases by 1.0 μm, and the creaming index is <10%, while the increase and creaming index of single-component emulsions are higher; (3) The edible plant polysaccharide emulsion provided by the present invention has advantages such as small emulsion particle size and high stability. At the same time, natural plant polysaccharides and soy lecithin are used as stabilizers in the emulsion, which has higher biological efficacy and good safety, and is suitable for various scenarios such as beverages, condiment sauces, and functional foods, with broad market application prospects. Description of the Drawings

[0021] Figure 1 It is a graph showing the influence of the addition amount of mulberry leaf polysaccharides on the quality of the edible mulberry leaf polysaccharide emulsion in Example 1 of the present invention; Figure 2 It is a graph showing the influence of the addition amount of soy lecithin on the quality of the edible mulberry leaf polysaccharide emulsion in Example 2 of the present invention; Figure 3 It is a graph showing the influence of the oil - water volume ratio on the quality of the edible mulberry leaf polysaccharide emulsion in Example 3 of the present invention; Figure 4 It is a graph showing the influence of the pH condition of the aqueous phase on the quality of the edible mulberry leaf polysaccharide emulsion in Example 4 of the present invention. Detailed Embodiments

[0022] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below in conjunction with specific embodiments.

[0023] Example 1 Influence of the Addition Amount of Mulberry Leaf Polysaccharides on the Quality of Edible Mulberry Leaf Polysaccharide Emulsion An edible mulberry leaf polysaccharide emulsion is prepared by the following method: (1) Preparation of the aqueous phase Weigh 0.01 g, 0.02 g, 0.03 g, 0.04 g, 0.05 g of mulberry leaf polysaccharide and 0.01 g of soybean phospholipid respectively. Dissolve the soybean phospholipid and different masses of mulberry leaf polysaccharide in 3 mL of water respectively, and stir at room temperature until completely dissolved to form a uniform aqueous phase. (2)Adjustment of pH and ionic strength Adjust the pH of the aqueous phase in step (1) to 8.0 using citric acid and sodium bicarbonate, without adding sodium chloride (i.e., the ionic strength is 0), and mix evenly. (3)Addition of the oil phase Add 3.0 mL of linseed oil to the aqueous phase with adjusted pH in step (2) to obtain an oil-water mixture. (4)Preparation of the emulsion Homogenize the oil-water mixture in step (3) using a two-stage homogenization process; the pressure for the first stage of homogenization is 30 MPa, and the homogenization time is 5 min; the pressure for the second stage of homogenization is 80 MPa, and homogenize for 10 min, then degas under vacuum at 0.08 Mpa for 10 min, and sterilize at 63 °C for 30 min to obtain an edible mulberry leaf polysaccharide emulsion.

[0024] The quality of the edible mulberry leaf polysaccharide emulsion obtained in this example is shown in the appendix Figure 1 and Table 1 below.

[0025] Table 1 Effects of the addition amount of mulberry leaf polysaccharide on the emulsifying properties of mulberry leaf polysaccharide emulsion Treatment Mulberry leaf polysaccharide (g) Soybean phospholipid (g) pH Sodium chloride (g) Oil-water ratio (v / v) Average particle size D[3,2] (μm) 1 0.01 0.01 8.0 0 3 / 3 20.7 2 0.02 0.01 8.0 0 3 / 3 23.1 3 0.03 0.01 8.0 0 3 / 3 23.0 4 0.04 0.01 8.0 0 3 / 3 24.0 5 0.05 0.01 8.0 0 3 / 3 22.6

[0026] As can be seen from Table 1, when the addition amount of mulberry leaf polysaccharide is 0.01 g, the obtained mulberry leaf polysaccharide emulsion has the best stability, is not easy to settle or coalesce, and the average particle size of the emulsion is the smallest, D[3,2] = 20.7 μm. In addition, Figure 1 Pictures of the emulsions prepared with different addition amounts of mulberry leaf polysaccharide are shown. From left to right, the addition amounts of mulberry leaf polysaccharide are 0.01, 0.02, 0.03, 0.04, 0.05 g respectively.

[0027] Figure 1 It shows that when the addition amount of polysaccharide is 0.01 g, the emulsifying volume is also the largest, the application performance is the best, and at the same time, the color of the bottom aqueous phase is the lightest (mulberry leaf polysaccharide is reddish-brown), indicating that the residual amount of mulberry leaf polysaccharide not participating in emulsification is the least.

[0028] Example 2 Effects of the addition amount of soybean phospholipid on the quality of the emulsion The difference from Example 1 is that: (1)The addition amount of mulberry leaf polysaccharide is 0.01 g, and the addition amounts of soybean phospholipid are set to 0.01 g, 0.02 g, 0.03 g, 0.04 g, and 0.05 g respectively. The remaining steps and operating conditions are the same as those in Example 1.

[0029] The quality of the obtained edible mulberry leaf polysaccharide emulsion is as shown in the appendix Figure 2 and Table 2 below.

[0030] Figure 2 It shows the stability of the mulberry leaf polysaccharide emulsion prepared under different addition amounts of soybean phospholipid. From left to right, the addition amounts of soybean phospholipid are 0.01 g, 0.02 g, 0.03 g, 0.04 g, and 0.05 g respectively. Figure 2 The results show that when the addition amount of soybean phospholipid is 0.03 g, the volume of the polysaccharide emulsion tends to be stable, and the emulsion stability is also better.

[0031] Table 2 Effect of soybean phospholipid addition amount on the emulsification characteristics of the emulsion Treatment Mulberry leaf polysaccharide (g) Soybean phospholipid (g) pH Sodium chloride (g) Oil-water ratio (v / v) Average particle size D[3,2] (μm) 1 0.01 0.01 8.0 0 3 / 3 21.6 2 0.01 0.02 8.0 0 3 / 3 23.1 3 0.01 0.03 8.0 0 3 / 3 21.7 4 0.01 0.04 8.0 0 3 / 3 21.3 5 0.01 0.05 8.0 0 3 / 3 30.3

[0032] As can be seen from Table 2, when the addition amount of soybean phospholipid is between 0.01 - 0.04 g, the average particle sizes of the obtained emulsions are not very different. When the addition amount of soybean phospholipid is 0.03 g, the average particle size of the prepared mulberry leaf polysaccharide emulsion is smaller, D[3,2] = 21.7 μm. At the same time, the volume of the emulsion is larger, and the emulsion application performance is the best.

[0033] Example 3 Effect of oil - water ratio on emulsion stability The difference from Example 1 is as follows: (1)In it, the addition amount of mulberry leaf polysaccharide is 0.01 g, and the addition amount of soybean phospholipid is 0.01 g; (3)In it, the addition amounts of the oil phase are set to 0.5 mL, 1 mL, 2 mL, 2.5 mL, and 3 mL respectively. The remaining steps and operating conditions are the same as those in Example 1.

[0034] The quality of the obtained edible mulberry leaf polysaccharide emulsion is as shown in the appendix Figure 3 and Table 3 below.

[0035] Figure 3 It shows the mulberry leaf polysaccharide emulsions prepared under different oil - water volume ratios. From left to right, the oil - water ratios are 0.5 / 3, 1 / 3, 2 / 3, 2.5 / 3, 3 / 3 (mL, v / v) respectively. Figure 3 The results show that with the increase of the oil - water volume ratio, the overall volume of the emulsion shows an upward trend. When the oil - water ratio reaches 2.5 / 3, the emulsification volume is the largest, and then it decreases.

[0036] Table 3 Effect of oil-water ratio on the emulsifying properties of mulberry leaf polysaccharide emulsion Treatment Mulberry leaf polysaccharide (g) Soybean phospholipid (g) pH Sodium chloride (g) Oil-water ratio (v / v) Average particle size D [3,2] (μm) 1 0.01 0.01 8.0 0 0.5 / 3 19.5 2 0.01 0.01 8.0 0 1 / 3 22.7 3 0.01 0.01 8.0 0 2 / 3 23.7 4 0.01 0.01 8.0 0 2.5 / 3 25.4 5 0.01 0.01 8.0 0 3 / 3 35.7

[0037] Table 3 combined Figure 3 It can be seen that when the oil-water ratio is 2.5 / 3, the volume of the emulsion is the largest, the embedding effect is better, and at the same time, the particle size of the emulsion is moderate and the stability is good.

[0038] Example 4 Effect of pH on the emulsifying properties of the emulsion The difference from Example 1 is that (1) The addition amount of mulberry leaf polysaccharide is 0.01 g, and the addition amount of soybean phospholipid is 0.01 g; (2) In it, a pH regulator is used to adjust the pH of the aqueous phase to 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, and 9.0 respectively, and the remaining steps and operating conditions are the same as those in Example 1.

[0039] The quality of the obtained edible mulberry leaf polysaccharide emulsion is as Figure 4 shown in Table 4 below.

[0040] Table 4 Effect of pH of the aqueous phase on the emulsifying properties of the edible mulberry leaf polysaccharide emulsion Treatment Mulberry leaf polysaccharide (g) Soybean phospholipid (g) pH Sodium chloride (g) Oil-water ratio (v / v) Average particle size D [3,2] (μm) 1 0.01 0.01 2.0 0 3 / 3 73.0 2 0.01 0.01 3.0 0 3 / 3 95.2 3 0.01 0.01 4.0 0 3 / 3 26.3 4 0.01 0.01 5.0 0 3 / 3 23.8 5 0.01 0.01 6.0 0 3 / 3 26.5 6 0.01 0.01 7.0 0 3 / 3 32.4 7 0.01 0.01 8.0 0 3 / 3 34.5 8 0.01 0.01 9.0 0 3 / 3 43.0

[0041] As can be seen from Table 4, when the pH is 5.0, the particle size of the emulsion is the smallest (23.8 μm) and the emulsifying effect is the best. Figure 4 Photographs of the mulberry leaf polysaccharide emulsion obtained under different pH conditions of the aqueous phase are shown. From left to right, the pH of the aqueous phase is 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, and 9.0 in turn. Figure 4 The results show that when the pH is 5.0, the emulsifying volume is the largest and the emulsifying effect is the best.

[0042] Example 5 Effect of ionic strength on the emulsifying properties of the emulsion The difference from Example 1 is that (1) The addition amount of mulberry leaf polysaccharide is 0.01 g, and the addition amount of soybean phospholipid is 0.01 g; (2) In it, the ionic strength regulator is sodium chloride, and the addition amounts of sodium chloride are 0.01 g, 0.02 g, 0.03 g, 0.04 g, and 0.05 g respectively, and the remaining steps and operating conditions are the same as those in Example 1.

[0043] The quality of the obtained edible mulberry leaf polysaccharide emulsion is shown in Table 5 below.

[0044] Table 5 Effect of ionic strength on the emulsifying properties of the edible mulberry leaf polysaccharide emulsion Treatment Mulberry leaf polysaccharide (g) Soybean phospholipid (g) pH Sodium chloride (g) Oil-water volume ratio (v / v) Particle size distribution D [3,2](μm) 1 0.01 0.01 8.0 0.01 3 / 3 23.2 2 0.01 0.01 8.0 0.02 3 / 3 18.5 3 0.01 0.01 8.0 0.03 3 / 3 17.3 4 0.01 0.01 8.0 0.04 3 / 3 21.5 5 0.01 0.01 8.0 0.05 3 / 3 19.1

[0045] When the sodium chloride addition amount is 0.03 g, the emulsion particle size is the smallest, and the stability of the mulberry leaf polysaccharide obtained at this time is the best.

[0046] Example 6 An edible mulberry leaf polysaccharide emulsion, the preparation method is as follows: (1) Preparation of the aqueous phase: Take 0.03 g of mulberry leaf polysaccharide and 0.02 g of soy lecithin, dissolve them in 3 mL of water, and stir at room temperature until completely dissolved to form a uniform aqueous phase; (2) Adjustment of pH and ionic strength: Use citric acid and sodium bicarbonate to adjust the pH of the aqueous phase in (1) to 5.0, and then add 0.02 g of sodium chloride and mix evenly; (3) Addition of the oil phase: Add 2.5 mL of linseed oil to the adjusted aqueous phase in (2) to obtain an oil-water mixture; (4) Preparation of the emulsion: The same as Example 1, to obtain the edible mulberry leaf polysaccharide emulsion.

[0047] After testing, the volume-surface area average particle size D[3,2] of the prepared edible mulberry leaf polysaccharide emulsion is 20 μm, the Zeta potential is -32 mV. After storing the mulberry leaf polysaccharide emulsion at 4°C for 90 days, the cream separation index is 3%, and the hypoglycemic activity retention rate of the mulberry leaf polysaccharide measured by the α-glucosidase inhibition method is 92%.

[0048] Example 7 An edible mulberry leaf polysaccharide emulsion, the preparation method is as follows: (1) Preparation of the aqueous phase: Take 0.04 g of mulberry leaf polysaccharide and 0.03 g of soy lecithin, dissolve them in 3 mL of water, and stir at room temperature until completely dissolved to form a uniform aqueous phase; (2) Adjustment of pH and ionic strength: Use citric acid and sodium bicarbonate to adjust the pH of the aqueous phase in (1) to 8.0, and then add 0.04 g of sodium chloride and mix evenly; (3) Addition of the oil phase: Add 2 mL of corn oil to the adjusted aqueous phase in (2) to obtain an oil-water mixture; (4) Preparation of the emulsion: The same as Example 1, to obtain the edible mulberry leaf polysaccharide emulsion.

[0049] After testing, the volume-surface area average particle size D[3,2] of the prepared edible mulberry leaf polysaccharide emulsion is 18 μm, the Zeta potential is -35 mV. After storing the mulberry leaf polysaccharide emulsion at 4°C for 90 days, the cream separation index is 5%, and the hypoglycemic activity retention rate of the mulberry leaf polysaccharide measured by the α-glucosidase inhibition method is 95%.

[0050] Example 8 An edible mulberry leaf polysaccharide emulsion is prepared as follows: (1) Preparation of the aqueous phase: Take 0.01 g of mulberry leaf polysaccharide and 0.03 g of soy lecithin, dissolve them in 3 mL of water, and stir at room temperature until completely dissolved to form a uniform aqueous phase; (2) Adjustment of pH and ionic strength: Use citric acid and sodium bicarbonate to adjust the pH of the aqueous phase in (1) to 5.0, and then add 0.03 g of sodium chloride and mix evenly; (3) Addition of the oil phase: Add 2.5 mL of linseed oil to the adjusted aqueous phase in (2) to obtain an oil-water mixture; (4) Preparation of the emulsion: Follow the same method as in Example 1 to obtain the edible mulberry leaf polysaccharide emulsion.

[0051] After testing, the volume-surface area average particle size D[3,2] of the prepared edible mulberry leaf polysaccharide emulsion is 20.0 μm, the Zeta potential is -38 mV. After storing the mulberry leaf polysaccharide emulsion at 4°C for 90 days, the creaming index is 3%, and the retention rate of the hypoglycemic activity of the mulberry leaf polysaccharide measured by the α-glucosidase inhibition method is 98%.

[0052] Comparative Example 1 Different from Example 8, in (1), 0.05 g of Tween-80 is used as an emulsifier to replace mulberry leaf polysaccharide and soy lecithin, and the other steps and conditions are the same as in Example 8.

[0053] After testing, the D[3,2] of the prepared edible emulsion is 28 μm, the creaming index is 25% (4°C, 30 days), and it has no biological activity.

[0054] Comparative Example 2 The only difference from Example 8 is that: In (1), only 0.01 g of mulberry leaf polysaccharide is added, soy lecithin is not added, and the other steps and operating conditions are the same as in Example 8.

[0055] Comparative Example 3 The only difference from Example 8 is that: In (1), mulberry leaf polysaccharide is not added, and only 0.03 g of soy lecithin is added, and the other steps and operating conditions are the same as in Example 8.

[0056] Comparative Example 4 The only difference from Example 8 is that: In (1), soy soluble polysaccharide is used to replace mulberry leaf polysaccharide, and the other steps and operating conditions are the same as in Example 8.

[0057] Comparative Example 5 The only difference from Example 8 is that: In (1), Tween-80 was used instead of soy lecithin, and the remaining steps and operating conditions were the same as in Example 8.

[0058] The stability of the edible mulberry leaf polysaccharide emulsion obtained in Example 8 and each comparative example is shown in Table 6 below.

[0059] Table 6 Stability test of edible mulberry leaf polysaccharide emulsion

[0060] Note: D[3,2] is the volume area average particle size.

[0061] The results in Table 6 show that the edible mulberry leaf polysaccharide emulsion prepared under the conditions of Example 8 had the smallest particle size change and the lowest creaming index under long-term storage (4°C, 90 days) and high temperature (80°C, 7 days) conditions, and its stability was significantly better than that of the comparative examples.

[0062] Moreover, the particle size of the obtained edible mulberry leaf polysaccharide emulsion was within 25 μm, and it could remain stable at 4 - 80°C. After storing at 4°C for 90 days, D[3,2] only increased by 0.5 μm, the creaming index was <5%, and the emulsion retained ≥90% of its biological activity, which was significantly better than that of single mulberry leaf polysaccharide (increase of 3.0 μm, creaming index of 15%) and single soy lecithin (increase of 2.5 μm, creaming index of 12%). After storing at 80°C for 7 days, D[3,2] increased by 1.0 μm, and the creaming index was <10%, while the increase rate and creaming index of the single component were higher.

[0063] Comparative Examples 2 - 5 show that neither single components nor substitutes can achieve the excellent performance of the present invention.

[0064] By optimizing mulberry leaf polysaccharide (0.01 g), soy lecithin (0.03 g), oil-water volume ratio (2.5 / 3), pH (5.0), and ionic strength (sodium chloride 0.03 g), the present invention prepared an edible mulberry leaf polysaccharide emulsion with high stability and excellent biological activity retention rate.

Claims

1. An edible plant polysaccharide emulsion, characterized in that, It includes an aqueous phase and an oil phase. The aqueous phase contains plant polysaccharides and soy lecithin. In the aqueous phase, the concentration range of the plant polysaccharides is 0.003 - 0.1 g / mL, and the concentration range of the soy lecithin is 0.003 - 0.1 g / mL. The volume ratio of the oil phase to the aqueous phase is 0.5 - 3:1 - 3.

2. The edible plant polysaccharide emulsion according to claim 1, characterized in that, The plant polysaccharides are any one of mulberry leaf polysaccharides and soy soluble polysaccharides or a combination of the two.

3. The edible plant polysaccharide emulsion according to claim 1, characterized in that, It also includes a pH regulator and an ionic strength regulator. The pH regulator is selected from at least one of citric acid, phosphate buffer solution, hydrogen phosphate buffer solution, hydrochloric acid, sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate; The ionic strength regulator is selected from any one of sodium chloride, sodium sulfate, potassium chloride, ammonium sulfate, ammonium chloride, and phosphates.

4. The edible plant polysaccharide emulsion according to claim 3, wherein The pH of the aqueous phase is adjusted to 2.0 - 8.0 using the pH regulator; The dosage of the ionic strength regulator is 0.01 - 0.05 g added per milliliter of the aqueous phase.

5. An edible plant polysaccharide emulsion according to claim 1, characterized in that, The oil phase is vegetable oil, and the vegetable oil includes but is not limited to the following: soybean oil, corn oil, sunflower oil, olive oil, linseed oil, walnut oil, peanut oil, rapeseed oil, sesame oil, palm oil, coconut oil, and grape seed oil.

6. A method for preparing an edible plant polysaccharide emulsion as described in any one of claims 1-5, characterized in that, It includes the following steps: (1) Preparation of the aqueous phase: Dissolve the plant polysaccharides and soy lecithin in water, and stir at room temperature until completely dissolved to form a uniform aqueous phase. In the aqueous phase, the concentration range of the plant polysaccharides is 0.003 - 0.1 g / mL, and the concentration range of the soy lecithin is 0.003 - 0.1 g / mL; (2) Adjustment of pH and ionic strength: Adjust the pH of the aqueous phase in (1) to the range of 2.0 - 8.0 using a pH regulator, and add an ionic strength regulator. The dosage of the ionic strength regulator is 0.01 - 0.05 g / mL of the aqueous phase; (3) Addition of the oil phase: Add vegetable oil to the adjusted aqueous phase in (2) to obtain an oil - water mixture. Among them, the volume ratio of the vegetable oil to the aqueous phase is 0.5 - 3:1 - 3; (4) Preparation of the emulsion: Homogenize the oil - water mixture in (3), perform vacuum degassing after homogenization, and then perform pasteurization to obtain the edible plant polysaccharide emulsion.

7. The preparation method according to claim 6, characterized in that, The homogenization in (4) is two - stage homogenization. Among them, the pressure of the first - stage homogenization is 20 - 40 MPa, and the homogenization time is 2 - 8 min. The pressure of the second - stage homogenization is 60 - 100 MPa, and the homogenization time is 8 - 15 min.

8. An edible mulberry leaf polysaccharide emulsion, characterized in that, It includes an aqueous phase and an oil phase. The aqueous phase contains mulberry leaf polysaccharides, soy lecithin, a pH regulator, and an ionic strength regulator; In the aqueous phase, the concentration range of the mulberry leaf polysaccharides is 0.003 - 0.1 g / mL, the concentration range of the soy lecithin is 0.003 - 0.1 g / mL, the concentration range of the ionic strength regulator is 0.01 - 0.05 g / mL, the pH regulator adjusts the pH of the aqueous phase to 2.0 - 8.0, and the volume ratio of the oil phase to the aqueous phase is 0.5 - 3:1 - 3.

9. Use of the edible plant polysaccharide emulsion according to any one of claims 1-5 or the edible mulberry leaf polysaccharide emulsion according to claim 8 in food, characterized in that, Add the edible plant polysaccharide emulsion or the edible mulberry leaf polysaccharide emulsion to food, and the food is selected from any one of beverages, condiments, pastries, and candies.

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