Preparation method of yellow bell pepper oleoresin emulsion

Abstract

The invention relates to the technical field of food processing, in particular to a preparation method of yellow bell pepper oleoresin emulsion. The preparation method comprises the following steps: dissolving capsicum oleoresin in an oily solvent as an oil phase; taking a sodium caseinate solution as a water phase; mixing the oil phase and the water phase, adding xanthan gum, and dispersing and homogenizing under the condition that the pH is 4-6; the mass ratio of the oil phase to the water phase is 1: (7-12), and the content of sodium caseinate in the sodium caseinate solution is 1-5 m / v%. According to the preparation method of the capsicum oleoresin emulsion, capsicum oleoresin is prepared into a stable and high-quality emulsion form through pH value adjustment and a specific emulsification mode, and upgrading of the capsicum industry is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to a method for preparing a yellow bell pepper oleoresin emulsion. Background Art

[0002] Yellow lantern pepper (Capsicum chinense Jacq.) originated in the Amazon Basin of South America. It is a perennial herbaceous plant of the genus Capsicum Linnaeus in the Solanaceae family. It is also known as the Yellow Emperor pepper and the Chinese pepper. It is a rare local pepper variety with local characteristics and is mainly developed into a seasoning (yellow lantern pepper sauce). Pepper has a high nutritional and health value. Its fruits and rhizomes can be used as medicine, which has the effects of strengthening the stomach, digesting food, reducing swelling, and promoting blood circulation. Pepper fruits are rich in polyphenols (flavonoids), carotenoids, capsaicin compounds, vitamin C and vitamin E and other functional ingredients. Compared with other varieties of peppers, yellow lantern pepper is rich in capsaicin, and its spiciness and nutrition are significantly higher.

[0003] Capsicum oleoresin is an oily liquid mixture obtained by extracting and concentrating from peppers. Its main active ingredient is capsaicinoids. In addition, it also contains small amounts of other chemicals such as fatty acids, proteins, pectin, polysaccharides, etc. Oleoresin will oxidize when exposed to factors such as oxygen, light and high temperature. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method for preparing a yellow bell pepper oleoresin emulsion. The capsicum oleoresin is prepared into a stable and high-quality emulsion form by adjusting the pH value and a specific emulsification method, which is of great significance to the industry of further processing of the capsicum oleoresin.

[0005] Yellow lantern capsicum oleoresin has the problems of viscous texture, poor fluidity, strong irritation and low stability at different pH values. The present invention studies and obtains an emulsification method to prepare yellow lantern capsicum oleoresin into an emulsion form for protection and carrying the oleoresin, which can significantly improve its stability, promote the processing of capsicum oleoresin products, and expand its application range.

[0006] In a first aspect, the present invention provides a method for preparing a capsicum oleoresin emulsion, comprising: Dissolving capsicum oleoresin in an oily solvent as an oil phase; using sodium caseinate solution as an aqueous phase; mixing the oil phase and the aqueous phase, adding xanthan gum, and dispersing and homogenizing at a pH of 4 to 6; The mass ratio of the oil phase to the water phase is 1:(7-12), and the content of sodium caseinate in the sodium caseinate solution is 1-5 m / v%.

[0007] Furthermore, capsicum oleoresin is dissolved in ethanol as an oil phase; the content of capsicum oleoresin in the oil phase is 40-60 w / v%.

[0008] Furthermore, the conditions for dispersing and homogenizing include: dispersing and homogenizing at a rotation speed of 10000-12000 rpm for 5-10 minutes.

[0009] Furthermore, based on the overall mixed system, the amount of xanthan gum used is 0.3-2 m / v%.

[0010] Furthermore, the capsicum oleoresin is prepared by the following method: The pepper is dried with hot air at 60-70°C and then sieved to obtain pepper powder, which is then hydrated and extracted using an enzyme-ultrasound-assisted ethanol method to obtain pepper pulp; the pepper residue is removed and the solvent is removed.

[0011] Furthermore, after hot air drying and passing through a 70-90 mesh sieve, the obtained chili pieces have a moisture content of 5-8%.

[0012] This drying temperature is the best temperature for drying peppers, with minimal capsaicin loss, reduced impurity content, and improved quality of pepper oleoresin.

[0013] Further, the hydration treatment includes: The chili powder and the ethanol solution are mixed, treated at 0-8° C. for 12-20 hours, and then centrifuged at 9000-12000 rpm for 15-30 minutes to obtain a precipitate; The mass ratio of the chili powder to the ethanol solution is 1:(8-15), and the ethanol content in the ethanol solution is 8-15w / v%.

[0014] The invention uses an ethanol solution to perform hydration pretreatment on dried peppers. The purpose of hydration is to open pores in the dense structure of peppers, dissolve water-soluble impurities, and promote the subsequent enzymatic hydrolysis rate to release intracellular capsaicinoid substances to the maximum extent, thereby obtaining high-capsaicin capsicum oleoresin.

[0015] Furthermore, in the enzyme method-ultrasonic assisted ethanol method, the extraction solvent is a 60~100 w / v% ethanol solution, and the amount used is 4~12 times the mass of the chili powder; the enzyme used is the composite plant hydrolase ViscozymeL, and the amount used is 0.5~2% of the mass of the chili powder; the ultrasonic time is 30~90min, the ultrasonic power is 400~500W, and the ultrasonic temperature is 48~55°C.

[0016] The present invention uses enzyme-assisted ultrasonic extraction technology to extract capsicum oleoresin, which can extract capsicum oleoresin from pepper to the maximum extent. The dosage of composite plant hydrolase Viscozyme L is preferably 0.5-2.5 w / v% of the pepper powder, and the enzyme activity is above 100 FBG / g. Under the above conditions, capsicum oleoresin and capsaicin are extracted to the maximum extent.

[0017] Furthermore, a vacuum filtration method is used to remove the chili residue, and the pressure condition of the vacuum filtration method is 0.1~0.8Mpa; a vacuum rotary evaporation method is used to remove the solvent, and the vacuum pump pressure condition of the vacuum rotary evaporation method is 0.1~0.9Mpa, the temperature condition of the rotary evaporator is 55~65°C, and the drying method is 45~55°C hot air drying.

[0018] The invention performs vacuum filtration and rapid filtration on the capsicum oleoresin solution. The above conditions ensure the high quality of the capsicum oleoresin. In addition, the drying method is simple and convenient.

[0019] Furthermore, the pepper is yellow lantern pepper.

[0020] In a second aspect, the present invention provides a capsicum oleoresin emulsion prepared by the preparation method.

[0021] The present invention has the following beneficial effects: The present invention prepares capsicum oleoresin into a stable and high-quality emulsion form by adjusting the pH value and using a specific emulsification method. The obtained capsicum oleoresin emulsion is verified by indicators such as particle size, PDI value, Zeta potential, microstructure and apparent viscosity, has excellent stability, can be further used in the production of meat products, pickled vegetable products or condiments, and has important value in the field of food processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a comparison result of the average particle size and polydispersity index (PDI) of the emulsion using different pH values ​​in the emulsion preparation process provided in Example 2 of the present invention.

[0024] Figure 2 This is a comparison result of the Zeta potential of the emulsions using different pH values ​​in the process of preparing the emulsions provided in Example 2 of the present invention.

[0025] Figure 3 This is a comparison result of fluorescence microscopic images of emulsions using different pH values ​​in the process of preparing the emulsion provided in Example 2 of the present invention.

[0026] Figure 4 This is a comparison result of the viscosity of the emulsions using different pH values ​​in the process of preparing the emulsions provided in Example 2 of the present invention.

[0027] Figure 5 This is a diagram showing the effect of preparing yellow lantern capsicum oleoresin emulsion using different emulsifiers provided in Example 3 of the present invention.

[0028] Figure 6 This is a diagram showing the effect of preparing yellow lantern capsicum oleoresin emulsion using different emulsifiers provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The experimental methods involved in the following examples, unless otherwise mentioned, are all conventional methods in the art, for example, reference may be made to experimental manuals in the art, or the conditions recommended in the manufacturer's instructions.

[0031] Unless otherwise specified, the experimental materials and reagents involved in the following examples can be obtained from commercial sources.

[0032] The units W / V% and M / V% used in the following examples have the same meanings, both representing the mass (g) of the solute in a unit volume (100 mL) of solution.

[0033] Example 1

[0034] This embodiment provides a method for preparing yellow lantern capsicum oleoresin, which specifically includes the following process: Step 1: Take 10 g of 60°C dried pepper and 100 mL of 10% ethanol solution, stir to mix well so that there is no powder agglomeration in the slurry, and place it at 4°C for hydration reaction for 12 hours.

[0035] Step 2: The hydrated slurry is centrifuged at a speed of 10,000 r / min for 20 min to remove the upper hydration solution and keep the lower pepper precipitate for later use.

[0036] Step 3: Use enzyme-ultrasound-assisted ethanol extraction, add 100 mL of 90% ethanol extraction solution to the lower layer of pepper precipitation after centrifugation, adjust the pH to 5.0, add 1% of the weight of the yellow lantern pepper raw material composite plant hydrolase Viscozyme L, and perform ultrasonic extraction with an ultrasonic power of 450 W, an ultrasonic temperature of 50°C, and an ultrasonic time of 60 min.

[0037] Step 4: Use vacuum filtration to separate the oleoresin extract and the chili residue. The vacuum pump pressure condition is 0.1~0.8Mpa, the filter membrane pore size is less than 0.15mm, and the filtrate is collected.

[0038] Step 5: Use a vacuum rotary evaporator to concentrate the filtrate to remove the solvent. The vacuum concentration pump pressure condition is 0.1~0.9Mpa, and the rotary evaporator temperature condition is 60°C. The concentrated extract is placed in a 50°C oven and dried to constant weight. The oil resin yield is 20.82%, the total capsaicin content is measured to be 28.86g / kg, and the spiciness is 445021.2SHU.

[0039] Example 2

[0040] This embodiment provides a method for preparing a yellow lantern capsicum oleoresin emulsion, comprising the following process: Step 1: dilute the capsicum oleoresin obtained in Example 1 to prepare a 50% (W / V) capsicum oleoresin ethanol solution for later use.

[0041] Step 2: Add sodium caseinate to phosphate buffer (0.01 mol / L sodium phosphate buffer, pH 7.0) and stir for 12 hours to fully dissolve and set aside. The final concentration is 2% (M / V).

[0042] Step 3: Add the oleoresin ethanol solution of step 1 to the sodium caseinate solution prepared in step 2, add 0.5% (M / V) xanthan gum as a thickener, adjust the pH value within the range of 3 to 11, and use a high-speed disperser homogenizer to disperse the oil phase (10%wt) and the water phase (90%wt) at 11.000 rpm for 6 minutes to prepare an emulsion.

[0043] The present invention further studies the effect of pH value on the stability of the prepared capsicum oleoresin (in the pH value adjustment process of the above process, the pH value is adjusted to 3, 5, 7, 9, and 11 respectively), and characterizes the basic properties of the emulsion such as the particle size, PDI value, Zeta-potential, microstructure, and apparent viscosity of the emulsion. The detection conditions are as follows: 1. The particle size, PDI value and Zeta potential were tested by Zeta potential analyzer. The sample was diluted 100 times before testing. The instrument parameters were set to a measuring temperature of 25 °C and an equilibrium time of 120 s.

[0044] 2. The microstructure was detected by fluorescence microscopy. Before observation, the freshly prepared emulsion was stained with 0.02% (w / v) Nile red at 4°C for 12 h, and then the stained sample was transferred to a microscope slide for observation.

[0045] 3. The apparent viscosity was measured by rheometer at a temperature of 25°C using a flowmeter equipped with parallel plates (50 mm in diameter, 1 mm in gap) at a speed of 0.1 to 100 s. -1 The apparent viscosity of capsicum oleoresin emulsion was measured within a range of .

[0046] Test results (such as Figure 1-Figure 4 )show: (1) At pH = 5, the emulsion PDI value is the smallest and the absolute value of Zeta potential is the highest, and at pH = 7, the particle size value is the smallest.

[0047] (2) At pH = 5, the oil droplets of the oleoresin emulsion are small and concentrated. At pH = 3, the emulsion is severely aggregated. At pH = 7, pH = 9, and pH = 11, the oil droplets of the emulsion are small but dispersed.

[0048] (3) Among the capsicum oleoresin emulsions with pH values ​​ranging from 3 to 11, the pH 5 emulsion had the highest apparent viscosity value.

[0049] From the above results, it can be seen that Example 1 of the present invention adopts an emulsification method to stabilize capsicum oleoresin and prepare an emulsion. The effect of pH value on the stability of the emulsion is characterized according to the basic characteristics of the emulsion. The emulsion has good stability at pH = 5, the emulsion particle size is 335.73 nm at pH = 5, the PDI value is the minimum at 0.54, the absolute value of Zeta-potential and the apparent viscosity value are both the highest, and the fluorescence microscopy results also show that the emulsion oil droplets are small and concentrated, indicating that the yellow lantern capsicum oleoresin emulsion based on pH adjustment has the best stability at a pH value of 5.

[0050] Example 3

[0051] The present invention further studies the influence of different emulsifiers on the stability of emulsions. The same detection method as in Example 2 is used, specifically replacing the sodium caseinate in Example 1 with an equal or appropriate amount of whey protein isolate WPI, Tween 80, gum arabic GA, soy lecithin SL and maltodextrin MD, and the same wide range of pH values ​​of 3 to 11 as in Example 2 is verified. The results show that after the emulsifier is replaced, no stable emulsion is formed, and some of them have stratification phenomenon ( Figure 5 and Figure 6 for some examples).

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a capsicum oleoresin emulsion, characterized in that: include: dissolving capsicum oleoresin in an oily solvent as an oil phase; Sodium caseinate solution was used as the aqueous phase; The oil phase and the water phase are mixed, xanthan gum is added, and the mixture is dispersed and homogenized at a pH of 4 to 6; The mass ratio of the oil phase to the water phase is 1:(7-12), and the content of sodium caseinate in the sodium caseinate solution is 1-5 m / v%.

2. The preparation method according to claim 1, characterized in that: Dissolve capsicum oleoresin in ethanol as the oil phase; the content of capsicum oleoresin in the oil phase is 40-60 w / v%.

3. The preparation method according to claim 1 or 2, characterized in that: The conditions for dispersing and homogenizing include: dispersing and homogenizing at a rotation speed of 10000-12000 rpm for 5-10 minutes.

4. The preparation method according to any one of claims 1 to 3, characterized in that Based on the overall mixed system, the amount of xanthan gum used is 0.3-2 m / v%.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The capsicum oleoresin is prepared by the following method: The pepper is dried with hot air at 60-70°C and then sieved to obtain pepper powder, which is then hydrated and extracted using an enzyme-ultrasound-assisted ethanol method to obtain pepper pulp; the pepper residue is removed and the solvent is removed.

6. The preparation method according to claim 5, characterized in that: The hydration treatment comprises: The chili powder and the ethanol solution are mixed, treated at 0-8° C. for 12-20 hours, and then centrifuged at 9000-12000 rpm for 15-30 minutes to obtain a precipitate; The mass ratio of the chili powder to the ethanol solution is 1:(8-15), and the ethanol content in the ethanol solution is 8-15 w / v%.

7. The preparation method according to claim 5 or 6, characterized in that: In the enzyme method-ultrasound-assisted ethanol method, the extraction solvent is a 60-100 w / v% ethanol solution, and the amount used is 4-12 times the mass of the chili powder; the enzyme used is the composite plant hydrolase Viscozyme L, and the amount used is 0.5-2% of the mass of the chili powder; the ultrasonic time is 30-90 min, the ultrasonic power is 400-500 W, and the ultrasonic temperature is 48-55° C.

8. The preparation method according to any one of claims 5 to 7, characterized in that: A vacuum filtration method is used to remove the chili residue, and the pressure condition of the vacuum filtration method is 0.1~0.8Mpa; a vacuum rotary evaporation method is used to remove the solvent, and the vacuum pump pressure condition of the vacuum rotary evaporation method is 0.1~0.9Mpa, the temperature condition of the rotary evaporator is 55~65°C, and the drying method is 45~55°C hot air drying.

9. The preparation method according to any one of claims 1 to 8, characterized in that: The pepper is yellow lantern pepper.

10. A capsicum oleoresin emulsion, characterized in that The invention is prepared by the preparation method according to any one of claims 1 to 9.

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