Salt-reducing base material as well as preparation method and application thereof

Abstract

The invention discloses a salt reducing base material as well as a preparation method and application thereof. The preparation method of the salt-reducing base material comprises the following steps: adding water into bean dregs, dispersing, adjusting the pH value to 2.5-8.0, cooking, carrying out enzymolysis and / or ball milling, carrying out alcohol precipitation, taking solids, drying, and crushing, so as to obtain the salt-reducing base material. The salt reducing base material has the advantages of being excellent in salt reducing effect, free of influence on flavor and taste of food, high in water binding capacity and expansibility, suitable for thick food, simple in preparation process, low in production cost and the like, is rich in dietary fiber, polysaccharide, peptide substances and other ingredients beneficial to human health, and is suitable for large-scale industrial production and application.

Description

Technical Field

[0001] The present invention relates to the technical field of food salt reduction, and particularly relates to a salt-reducing base material, a preparation method thereof and an application thereof. Background Art

[0002] Table salt is a commonly used condiment in daily life. It can not only improve the flavor of food, but also play a role in food preservation. However, excessive intake of table salt by the human body can cause diseases such as hypertension, cardiovascular and cerebrovascular diseases, kidney function diseases, osteoporosis, etc. due to the long-term retention of sodium, seriously affecting human health. Therefore, food salt reduction has gradually become a development trend and a research hotspot.

[0003] At present, the commonly used salt reduction strategies mainly include the following: 1) replacing table salt with non-sodium salts (such as potassium chloride, sodium glutamate, etc.); 2) enhancing the synergy of taste and smell by adding flavoring substances (such as nucleotides, salty peptides, etc.), thereby reducing the amount of table salt in food; 3) changing the crystal structure of table salt (such as hollow salt); 4) restructuring the food texture. However, the existing salt reduction strategies generally have great limitations and are greatly restricted in practical applications. For example, potassium chloride has a bitter and metallic taste, which will affect the taste of food; sodium glutamate will cause safety problems; hollow salt and flavoring substances will significantly increase the production cost of food; the operation of restructuring food texture is relatively complex and the cost is high. In addition, high-viscosity foods (such as oyster sauce, tomato sauce, soybean paste, etc.) have a very high viscosity, which will cause the perception of most flavoring substances to be blocked, and the perception of saltiness will be significantly weakened, which makes it more difficult to reduce the salt in high-viscosity foods.

[0004] Therefore, it is of great significance to develop a salt-reducing base material with excellent salt reduction effect, which does not affect the flavor and taste of the food itself and is applicable to high-viscosity foods. Summary of the Invention

[0005] The purpose of the present invention is to provide a salt-reducing base material, a preparation method thereof and an application thereof.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A preparation method of a salt-reducing base material includes the following steps: dispersing soybean dregs in water, adjusting the pH value to 2.5 - 8.0, steaming, enzymolysis and / or ball milling, alcohol precipitation, taking the solid matter for drying and pulverizing to obtain the salt-reducing base material.

[0008] Preferably, the mass ratio of the soybean dregs to water is 0.02 - 0.10:1.

[0009] Preferably, the regulator used for adjusting the pH value is at least one of hydrochloric acid and citric acid.

[0010] Preferably, the temperature of the steaming is 110°C to 150°C, and the steaming time is 10 min to 60 min.

[0011] Preferably, the enzyme used for enzymatic hydrolysis is at least one of protease, xylanase, cellulase, and pectinase.

[0012] Preferably, the weight of the enzyme used for enzymatic hydrolysis is 0.1% to 1.0% of the weight of the soybean residue.

[0013] Preferably, the enzymatic hydrolysis is carried out under the conditions that the temperature of the system is 40°C to 60°C, the pH value of the system is 4.0 to 8.0, and the enzymatic hydrolysis time is 1 h to 2.5 h.

[0014] Preferably, the ball milling is carried out under the condition that the shear rate is 100 rpm to 500 rpm, and the ball milling time is 15 min to 50 min.

[0015] Preferably, the alcohol precipitation is carried out under the conditions that the temperature of the system is 4°C to 15°C and the volume percentage of ethanol in the system is 50% to 90%, and the alcohol precipitation time is 20 min to 50 min.

[0016] A salt-reduced base material is prepared by the above preparation method.

[0017] A high-viscosity food contains the above salt-reduced base material.

[0018] Preferably, the high-viscosity food is one of oyster sauce, tomato sauce, and soybean paste.

[0019] Preferably, the addition amount of the salt-reduced base material in the high-viscosity food is 0.5 wt% to 2.5 wt%.

[0020] The beneficial effects of the present invention are as follows: The salt-reduced base material of the present invention has excellent salt-reducing effect, does not affect the flavor and taste of the food itself, has high water retention and swelling properties, is suitable for high-viscosity foods, has a simple preparation process, low production cost, etc., and is rich in dietary fiber, polysaccharides, peptide substances and other components beneficial to human health, and is suitable for large-scale industrial production and application.

[0021] Specifically:

[0022] 1) The present invention uses soybean dregs as raw materials, and through processes such as steaming, enzymatic hydrolysis, and / or ball milling, selectively and efficiently releases the fiber components, polysaccharide components, and salty peptide components with high negative charges in the soybean dregs. The obtained salt-reducing base material has a high negative charge, can better adsorb sodium ions, induces the formation of a sodium-rich center with a locally high concentration of sodium ions in the food, enhances the adsorption of sodium ions on the surface of the tongue mucosa, enables sodium ions to contact the taste receptors (taste cells in taste buds) more quickly and lastingly, weakens the hindrance effect of starch molecules in high-viscosity foods on sodium ions (starch molecules will interact with sodium ions, thereby hindering the perception of sodium ions by taste buds), enhances the salty taste perception, and exhibits an excellent salt-reducing effect;

[0023] 2) The salt-reducing base material of the present invention has no bad flavor, high water-holding capacity and swelling property. It can exert an excellent salt-reducing and salt-increasing effect without affecting the viscosity of high-viscosity foods (the salt-reducing base material of the present invention has good processing performance and can improve the fluid properties of high-viscosity foods), and significantly reduces the salt consumption of high-viscosity foods (the salt consumption can be reduced by up to 30%);

[0024] 3) The salt-reducing base material of the present invention is extracted from soybean dregs and is rich in physiologically active substances such as soluble polysaccharides, insoluble dietary fibers, and peptide substances, and has significant effects in preventing and alleviating constipation, improving the intestinal flora, etc., and can be used as a natural dietary fiber supplement;

[0025] 4) The salt-reducing base material of the present invention is extracted from soybean dregs, a by-product in the food processing process. Soybean dregs are widely sourced and low-cost, and are usually added as a low-value dietary fiber supplement to the feed of ruminants. Making it into a salt-reducing base material improves the utilization rate of soybean dregs and realizes the high-value utilization of soybean dreg resources. Description of the Drawings

[0026] Figure 1 It is a graph showing the water-holding capacity test results of the salt-reducing base materials in Examples 1 to 3 and the comparative example.

[0027] Figure 2 It is a graph showing the swelling property test results of the salt-reducing base materials in Examples 1 to 3 and the comparative example.

[0028] Figure 3 It is a graph showing the ζ-potential test results of the dispersions prepared from the salt-reducing base materials in Examples 1 to 3 and the comparative example.

[0029] Figure 4 It is a fluorescence graph of the salt-reducing base materials in Examples 1 to 3 and the comparative example adsorbing sodium ions.

[0030] Figure 5 It is a graph showing the test results of the effect of the salt-reducing base materials in Examples 1 to 3 and the comparative example in promoting the penetration of sodium ions.

[0031] Figure 6 Graphs showing the test results of the effect of the sodium-reducing base materials in Examples 1-3 and the comparative example on promoting the adhesion and retention of sodium ions.

[0032] Figure 7 Graphs showing the test results of the salt substitution amounts of the sodium-reducing base material in Example 2 for starch, oyster sauce, tomato sauce, and soybean paste.

[0033] Figure 8 Graphs showing the test results of the shear viscosity of oyster sauce, tomato sauce, and soybean paste before and after adding the sodium-reducing base material in Example 2. Detailed implementation manners

[0034] The present invention will be further explained and described below in conjunction with specific embodiments.

[0035] Example 1:

[0036] A sodium-reducing base material, and its preparation method is as follows:

[0037] Add soybean dregs into water, and the mass ratio of soybean dregs to water is 0.05:1. Stir for 30 min to make a soybean dregs dispersion liquid. Then adjust the pH value of the soybean dregs dispersion liquid to 4.5 with hydrochloric acid with a concentration of 2 mol / L. Then transfer the soybean dregs dispersion liquid to an autoclave, heat up to 120 °C and keep warm for 30 min, cool down, then add xylanase, and the addition amount of xylanase is 0.45% of the weight of the soybean dregs. Then carry out a constant temperature water bath treatment at 50 °C for 2 h, then heat up to 90 °C for a water bath treatment for 10 min to inactivate the enzyme. Then add an ethanol-water mixture (the volume ratio of ethanol to water is 95:5) to the system until the volume percentage content of ethanol in the system is 75%. Then carry out alcohol precipitation at 10 °C for 40 min. Then take the solid matter and dry it at 60 °C for 4 h, and then grind it into powder with a grinder to obtain the sodium-reducing base material.

[0038] Example 2:

[0039] A sodium-reducing base material, and its preparation method is as follows:

[0040] Add the soybean dregs to water with a mass ratio of soybean dregs to water of 0.05:1, stir for 30 min to prepare a soybean dreg dispersion, then adjust the pH value of the soybean dreg dispersion to 4.5 with 2 mol / L hydrochloric acid. Then transfer the soybean dreg dispersion to an autoclave, heat it to 120 °C and keep it warm for 30 min, cool it, then add xylanase with an addition amount of 0.45% of the weight of the soybean dregs, then perform a constant temperature water bath treatment at 50 °C for 2 h, then heat it to 90 °C for a water bath treatment for 10 min to inactivate the enzyme, then transfer it to a ball mill, adjust the shear rate to 300 rpm for high-speed shearing for 30 min, then add an ethanol-water mixture (volume ratio of ethanol to water is 95:5) to the system until the volume percentage of ethanol in the system is 75%, then perform alcohol precipitation at 10 °C for 40 min, then take the solid and dry it at 60 °C for 4 h, and then grind it into powder with a grinder to obtain the salt-reducing base material.

[0041] Example 3:

[0042] A salt-reducing base material, and its preparation method is as follows:

[0043] Add the soybean dregs to water with a mass ratio of soybean dregs to water of 0.05:1, stir for 30 min to prepare a soybean dreg dispersion, then adjust the pH value of the soybean dreg dispersion to 4.5 with 2 mol / L hydrochloric acid. Then transfer the soybean dreg dispersion to an autoclave, heat it to 120 °C and keep it warm for 30 min, cool it, then transfer it to a ball mill, adjust the shear rate to 300 rpm for high-speed shearing for 30 min, then add an ethanol-water mixture (volume ratio of ethanol to water is 95:5) to the system until the volume percentage of ethanol in the system is 75%, then perform alcohol precipitation at 10 °C for 40 min, then take the solid and dry it at 60 °C for 4 h, and then grind it into powder with a grinder to obtain the salt-reducing base material.

[0044] Comparative example:

[0045] A salt-reducing base material, and its preparation method is as follows:

[0046] Add the soybean dregs to water with a mass ratio of soybean dregs to water of 0.05:1, stir for 30 min to prepare a soybean dreg dispersion, then adjust the pH value of the soybean dreg dispersion to 4.5 with 2 mol / L hydrochloric acid. Then transfer the soybean dreg dispersion to an autoclave, heat it to 120 °C and keep it warm for 30 min, cool it, then add an ethanol-water mixture (volume ratio of ethanol to water is 95:5) to the system until the volume percentage of ethanol in the system is 75%, then perform alcohol precipitation at 10 °C for 40 min, then take the solid and dry it at 60 °C for 4 h, and then grind it into powder with a grinder to obtain the salt-reducing base material.

[0047] Performance test:

[0048] 1) Physical and chemical property test of the salt-reducing base material:

[0049] a) Water-holding capacity (evaluating the ability of the salt-reduced base material to retain moisture) test: Mix 0.1 g of the salt-reduced base material with 10 mL of distilled water, add the mixture to a centrifuge tube, let it stand for 24 h, centrifuge for 30 min at a centrifugal force of 3000 g, remove the supernatant, and then weigh it. Calculate the water-holding capacity (WHC) of the salt-reduced base material. The test results Figure 1 are shown as follows.

[0050] The formula for calculating the water-holding capacity (WHC; unit: g / g) is as follows: WHC = (m2 - m1) / m0, where m0 is the initial weight of the test sample (unit: g), m1 is the weight of the centrifuge tube (unit: g), and m2 is the total weight of the centrifuge tube and the test sample after water absorption (unit: g).

[0051] It can be seen from Figure 1 the results that the salt-reduced base materials in Examples 1 - 3 all have relatively high water-holding capacity (especially the salt-reduced base material in Example 2, which has the highest water-holding capacity), while the water-holding capacity of the salt-reduced base material in the comparative example is relatively poor. This shows that enzymatic hydrolysis and ball milling help to selectively and efficiently release the highly negatively charged fiber components, polysaccharide components, and salty peptide components in the soybean dregs, thereby improving the water-holding capacity of the prepared salt-reduced base material.

[0052] b) Swelling capacity (evaluating the ability of the salt-reduced base material to bind moisture) test: Add 0.2 g of the salt-reduced base material to a centrifuge tube with a volume of 15 mL, record the initial volume, then add 10 mL of distilled water, shake and mix well, let it stand for 24 h, and then record the volume of the hydrated sample (i.e., the sample after water absorption). Calculate the swelling capacity (WSC; each sample is repeatedly measured 3 times, and the average value is taken) of the salt-reduced base material. The test results Figure 2 are shown as follows.

[0053] The formula for calculating the swelling capacity (WSC; unit: mL / g) is as follows: WSC = (V1 - V0) / m0, where V0 is the initial volume of the test sample (unit: mL), V1 is the volume of the test sample after water absorption (unit: mL), and m0 is the initial weight of the test sample (unit: g).

[0054] It can be seen from Figure 2 the results that the swelling capacity of the salt-reduced base materials in Examples 1 - 3 (especially the salt-reduced base material in Example 2) is significantly better than that of the salt-reduced base material in the comparative example, indicating that enzymatic hydrolysis and ball milling help to unfold the structures of components such as fiber components, polysaccharide components, and salty peptide components in the salt-reduced base material, thereby improving the binding ability of the prepared salt-reduced base material to water.

[0055] c) ζ-potential test: Disperse the salt-reduced base material with distilled water to prepare a dispersion with a concentration of 1 mg / mL, and then use a potentiometer and nanoparticle size analyzer to measure the ζ-potential of the dispersion. The test results are as Figure 3 shown as follows.

[0056] It can be seen from Figure 3 that the absolute value of the ζ-potential of the dispersion prepared from the sodium-reduced base materials in Examples 1 to 3 (especially the sodium-reduced base material in Example 2) is greater than that of the dispersion prepared from the sodium-reduced base material in the comparative example, indicating that the sodium-reduced base materials in Examples 1 to 3 can more effectively adsorb positively charged sodium ions, which is beneficial to being perceived by taste receptors, and beneficial to the penetration and adsorption of sodium on the thin saliva layer on the tongue surface, thereby increasing the perception of saltiness.

[0057] 2) Fluorescence test for the adsorption of sodium ions by the sodium-reduced base material:

[0058] The sodium-reduced base material and sodium fluorescein were dispersed with distilled water to prepare a dispersion with a mass percentage content of the sodium-reduced base material of 1.0% and a mass percentage content of sodium fluorescein of 0.006%. After centrifugation for 20 min at a centrifuge speed of 8000 rpm, the supernatant was removed. Then, 30 μL of the dispersion was observed and photographed under a fluorescence microscope at a magnification of 20 times. The fluorescence image of the sodium-reduced base material adsorbing sodium ions is as shown in Figure 4 the figure.

[0059] It can be seen from Figure 4 that strong fluorescence spots can be observed in the dispersion prepared from the sodium-reduced base materials in Examples 1 to 3 (especially the sodium-reduced base material in Example 2), indicating that there are enrichment regions of sodium ions in the dispersion. The uneven distribution and local high concentration of sodium ions can provide more sufficient conditions for taste receptors to perceive saltiness.

[0060] 3) Test for the effect of the sodium-reduced base material on promoting the penetration of sodium ions:

[0061] Prepare 1 mL of artificial saliva (AS). The formula of AS is: CaCl2 (1.8 mM), KCl (30.85 mM), NaCl (5.9 mM), Na2HPO4 (5.2 mM), NaHCO3 (6.4 mM), and porcine gastric mucin (0.25 wt%). The diffusion of sodium ions in artificial saliva was systematically investigated using a system. The diffusion chamber was made of polycarbonate with an area of 33.18 mm 2 (pore size 0.4 μm). Add 100 μL of AS to the donor chamber, place 1.0 mL of AS in the receptor chamber, and then carefully add 50 μL of NaCl-sample-AS (150 mM of NaCl, 1.0 wt% of the sample) to the donor chamber. The small plate was placed in a constant temperature water bath at 37 °C for equilibration incubation. At preset time points (5 min), 50 μL of the test solution was accurately pipetted from the receptor chamber, and the concentration of sodium ions was quantitatively analyzed using a sodium ion meter. The test results of sodium ion penetration are as shown in Figure 5 the figure.

[0062] It can be seen from Figure 5 that: The sodium-reducing base materials in Examples 1 to 3 (especially the sodium-reducing base material in Example 2) have a better effect on promoting sodium ion diffusion than the sodium-reducing base materials in the comparative examples. The acceleration of the sodium ion diffusion rate will enable sodium ions to reach the taste receptors faster, thereby enhancing the salty taste.

[0063] 4) Test on the effect of the sodium-reducing base material on promoting sodium ion adhesion and retention:

[0064] An in vitro sodium ion adhesion and retention test was carried out using a pig tongue. The pig tongue epidermis was cut into thin slices of 1 cm×1 cm×2 mm. 1 mL of artificial saliva was dropped on the surface of the pig tongue and balanced for 1 min. Then, 30 μL of the sodium-reducing base material dispersion labeled with sodium fluorescein (the mass percentage of the sodium-reducing base material was 1.0%, and the mass percentage of sodium fluorescein was 0.006%) was dropped on the surface of the pig tongue and balanced for 30 s. After rinsing with artificial saliva, the tissue was photographed using a fluorescence microscope. The test results of the effect of the sodium-reducing base material on promoting sodium ion adhesion and retention are as Figure 6 shown.

[0065] It can be seen from Figure 6 that: Under the same amount of artificial saliva rinsing, the dispersion made of the sodium-reducing base materials in Examples 1 to 3 (especially the sodium-reducing base material in Example 2) has significantly stronger retention on the surface of the pig tongue than the dispersion made of the sodium-reducing base materials in the comparative examples (the easier the sodium fluorescein is eluted, the weaker the adhesion and retention of sodium ions). This shows that enzymolysis and ball milling help to improve the property of the sodium-reducing base material to promote sodium ion adhesion and retention on the pig tongue.

[0066] 5) Test on the sodium-reducing effect of the sodium-reducing base material:

[0067] a) Sensory evaluation:

[0068] Personnel screening: Citric acid solution (concentration 0.1 wt%), alum solution (concentration 0.05 wt%), glucose solution (concentration 1.0 wt%), monosodium glutamate solution (concentration 0.10 wt%) and sodium chloride solution (concentration 0.35 wt%) were prepared, and then the prepared solutions were randomly distributed to volunteers for tasting. 19 volunteers (13 females and 6 males, aged between 23 and 30 years old) who could correctly judge the taste of the above solutions were selected;

[0069] Personnel training: The selected volunteers are required to fast from stimulating foods (such as spicy, high-sugar or caffeine-containing foods) 2 hours before the formal experiment to reduce taste interference. In the quantitative saltiness analysis, the selected volunteers are trained. First, score and assign values to different standard NaCl concentrations. The salt solution concentrations are 0.1%, 0.4%, 0.6%, 0.8% and 1.0% respectively, and the corresponding saltiness scores are 1 point, 3 points, 5 points, 7 points and 9 points respectively. The volunteers are required to quantitatively score the saltiness intensity of the unknown samples by the comparison method with the reference solution as the benchmark. Each volunteer holds 5 mL of the sample solution in the mouth for 10 s and then spits it out. Thoroughly rinse the mouth with water for 2 min between each sampling and provide a 35-s rest time. The group members judge the saltiness score of the sample by repeatedly comparing the saltiness intensity of the reference NaCl solution.

[0070] b) Add the salt-reducing base material in Example 2 to starch (gelatinized starch), oyster sauce, tomato sauce and soybean paste, with an addition amount of 1 wt%, and then conduct saltiness scoring and calculate the salt substitution percentage. The test results are as Figure 7 shown.

[0071] The formula for calculating the salt substitution percentage is as follows: Salt substitution percentage (%) = weight of substituted salt / weight of total salt × 100%.

[0072] It can be Figure 7 seen that: The salt-reducing base material in Example 2 has a good salt-reducing and salt-increasing effect. The salt substitution amounts in starch, oyster sauce, tomato sauce and soybean paste are all about 23%, and the salt-reducing and salt-increasing effect is obvious.

[0073] c) Add the salt-reducing base material in Example 2 to oyster sauce, tomato sauce and soybean paste, with an addition amount of 1 wt%, and then use a Haake rheometer to measure the shear viscosity of oyster sauce, tomato sauce and soybean paste at room temperature respectively. The shear viscosity test results of oyster sauce, tomato sauce and soybean paste before and after adding the salt-reducing base material are as Figure 8 shown.

[0074] It can be Figure 8 seen that: At the same shear rate, the addition of the salt-reducing base material does not bring a significant change in the shear viscosity of oyster sauce, tomato sauce and soybean paste, indicating that the salt-reducing base material in Example 2 can achieve the salt-reducing effect without affecting the viscosity of oyster sauce, tomato sauce and soybean paste, realizing the high-value utilization of soybean dregs.

[0075] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for preparing a salt-reducing base material, characterized in that: The method comprises the following steps: dispersing bean dregs with water, adjusting the pH value to 2.5-8.0, steaming, enzymolysis and / or ball milling, alcohol precipitation, drying and crushing the solid matter to obtain the salt-reducing base material.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the bean dregs to water is 0.02-0.10:

1.

3. The preparation method according to claim 1, characterized in that: The cooking temperature is 110° C. to 150° C., and the cooking time is 10 min to 60 min.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The enzyme used in the enzymolysis is at least one of protease, xylanase, cellulase and pectinase.

5. The preparation method according to any one of claims 1 to 3, characterized in that: The enzymolysis is carried out under the conditions that the system temperature is 40° C. to 60° C. and the system pH value is 4.0 to 8.0, and the enzymolysis time is 1 hour to 2.5 hours.

6. The preparation method according to any one of claims 1 to 3, characterized in that: The ball milling is carried out at a shear rate of 100 rpm to 500 rpm, and the ball milling time is 15 min to 50 min.

7. A salt-reducing base material, characterized in that: Prepared by the preparation method according to any one of claims 1 to 6.

8. A high-viscosity food, characterized in that: Contains the salt-reducing base material according to claim 7.

9. The high-viscosity food according to claim 8, characterized in that: The high-viscosity food is one of oyster sauce, tomato sauce and soybean sauce.

10. The high-viscosity food according to claim 8 or 9, characterized in that: The added amount of the salt-reducing base in the high-viscosity food is 0.5wt% to 2.5wt%.

Images