Pepper seed oil microcapsules and methods for their preparation

Abstract

The application discloses a kind of capsicum seed oil microcapsules and preparation method thereof, with capsicum protein nanoparticle and malt dextrin as wall material, capsicum protein nanoparticle, malt dextrin and distilled water are dissolved to be prepared into water phase;Among them, the weight ratio of wall material compound capsicum protein nanoparticle: malt dextrin = (1-1.5) : 1, solid soluble starch content is 5-10%;Emulsifier is dissolved with capsicum seed oil to be prepared into oil phase;Two are mixed evenly into emulsion, homogenization, pre-freezing, vacuum programmed freeze-drying is obtained capsicum seed oil microcapsule;Among them, the weight ratio of capsicum seed oil: wall material = (0.8-1) : 1, emulsifier is obtained by mixing propylene glycol fatty acid ester, sucrose ester and soybean phospholipid according to weight ratio (1-2) : 0.2:3, and the content of emulsifier is 1.5-2%.The application can reduce the surface oil content of microcapsule, improve the embedding rate, slow down the capsicum seed oil oxidation rancidity, and prolong the storage period of capsicum seed oil microcapsule.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of food processing. More particularly, the present application relates to a kind of chilli seed oil microcapsule and its preparation method. BACKGROUND

[0002] Chilli seed oil is an edible oil material extracted from chilli seeds, with high nutritional value. It contains 85-95% unsaturated fatty acids, more than 75% linoleic acid, and a large amount of phytosterols, amino acids, dietary fiber, vitamin E and other bioactive substances. It has good effects on inhibiting atherosclerosis, preventing diabetes, and also has the effects of lowering blood lipids and antioxidant. As a kind of plant oil with high nutritional value, chilli seed oil can be widely used in the field of medicine and health care.

[0003] Chilli seed oil is easily affected by external environment and oxidized, which can destroy nutrients and affect quality, and is not conducive to storage. Therefore, chilli seed oil can be microencapsulated to reduce the influence of external environment, reduce the loss of nutrients and improve the stability of the product. However, in the prior art, the chilli seed oil microcapsule has the problems of low oil loading and low embedding rate, and low embedding rate can cause high peroxide value and acid value, thereby reducing the stability of the product, which is not conducive to the development and utilization of chilli seed resources and the commercialization of chilli seed oil microcapsule. SUMMARY

[0004] An object of the present application is to solve at least the above problems and provide at least the advantages to be described later.

[0005] The present application provides a preparation method of chilli seed oil microcapsule, which aims to solve the problem of low embedding rate of chilli seed oil microcapsule and affect the storage stability.

[0006] In order to achieve these objects and other advantages of the present application, a preparation method of chilli seed oil microcapsule is provided, which adopts wall material including chilli protein nanoparticles and malt dextrin, and chilli protein nanoparticles and malt dextrin are completely dissolved in distilled water to prepare an aqueous phase; wherein the weight ratio of chilli protein nanoparticles to malt dextrin in the wall material compound is (1-1.5) : 1, and the soluble starch content of solid is 5-10%;

[0007] The core material is chilli seed oil: the emulsifier is completely dissolved in chilli seed oil to prepare an oil phase; wherein the emulsifier is obtained by mixing propylene glycol fatty acid ester, sucrose ester and soybean phospholipid according to the weight ratio of (1-2) : 0.2 : 3, and the content of emulsifier is 1.5-2%;

[0008] Mixing the water phase and the oil phase to form a mixed emulsion, homogenizing, pre-freezing, and vacuum programmed freeze-drying to obtain the capsicum seed oil microcapsules; wherein the weight ratio of capsicum seed oil to wall material is (0.8-1):1.

[0009] Preferably, the vacuum programmed freeze-drying is performed by gradually increasing the temperature from -50℃ to 50℃, with a temperature difference of 10℃ between adjacent two levels, and each level is kept for 1-4h.

[0010] Preferably, the pre-freezing is performed at -50℃ for 6h, and the vacuum programmed freeze-drying is performed for 20h, specifically, -50℃ for 3h, -40℃ for 2h, -30℃ for 1h, -20℃ for 1h, -10℃ for 1h, 0℃ for 1h, 10℃ for 1h, 20℃ for 1h, 30℃ for 2h, 40℃ for 3h, and 50℃ for 4h under a vacuum condition of 20Pa.

[0011] Preferably, the water phase is prepared by adding the capsicum protein nanoparticles and the maltodextrin into distilled water, and stirring in a 60℃ water bath until completely dissolved; and the oil phase is prepared by stirring the emulsifier and the capsicum seed oil in a 65℃ water bath until completely dissolved.

[0012] Preferably, the forming of the mixed emulsion and the homogenizing are performed by stirring for 30min using a constant-temperature magnetic stirrer, passing through a colloid mill for 3 times to form the mixed emulsion, and homogenizing for 3 times using a high-pressure homogenizer at 30MPa.

[0013] Preferably, the weight ratio of the wall material compounded capsicum protein nanoparticles to maltodextrin is 1:1, and the solid content of the soluble starch is 8%; and the weight ratio of the capsicum seed oil to the wall material is 1:1, and the content of the emulsifier is 2%.

[0014] Preferably, the capsicum protein nanoparticles are prepared by the following method:

[0015] The capsicum meal is soaked with deionized water at a weight ratio of (5-10):2 for 50-90min, and then beaten into a slurry, followed by adding deionized water in an amount of 2-3 times the weight of the slurry, and adding a NaOH solution with a concentration of 0.2-3M, mixing uniformly, configuring the pH of the mixed solution to be 8-9, and extracting under the conditions of a temperature of 40-55℃, an ultrasonic frequency of 20-30KHz, and an ultrasonic power of 100-200W for 2-3h, centrifuging at 2500-3500r / min for 10-20min to collect the filtrate; and adjusting the pH of the filtrate to be 4-5, and again centrifuging after standing for 10-20min to collect the precipitate, and desalting the precipitate in a dialysis bag in deionized water, and after the dialysis is completed, placing the dialysis bag on filter paper and absorbing the water with water-absorbing paper to obtain capsicum meal protein with a water content of 20-50%.

[0016] The pepper meal protein is mixed with deionized water, complex protease is added for enzymolysis, after the enzymolysis is completed, centrifugation is performed again, the supernatant is taken, and after vacuum freeze-drying, the pepper protein nanoparticle is obtained;

[0017] The weight ratio of the pepper meal protein, deionized water, papain, chymotrypsin and trypsin is 1:(4-8):0.01:0.01:0.01, the enzymolysis time is 5-6 hours, the enzymolysis pH value is 6-7, and the enzymolysis temperature is 45-55 DEG C.

[0018] Preferably, the wall material further comprises bone collagen peptide, and the weight ratio of the wall material compounded pepper protein nanoparticle, malt dextrin and bone collagen peptide is 1:1:0.2.

[0019] The application provides a pepper seed oil microcapsule prepared by the method.

[0020] The application at least has the following beneficial effects:

[0021] The pepper seed oil microcapsule has high oil loading, low surface oil content, high embedding rate, low peroxide value and low acid value; the pepper meal protein nanoparticle, bone collagen peptide, malt dextrin and compounded emulsifier must be used in combination to ensure the embedding effect of the pepper seed oil microcapsule, reduce the surface oil content, peroxide value and acid value and improve the embedding rate under high oil loading, effectively improve the quality of the pepper seed oil microcapsule, and facilitate the quality stability.

[0022] The pepper protein nanoparticle prepared by the application is prepared by taking the pepper meal as raw material, extracting by ultrasonic dialysis, and subjecting the pepper meal protein to enzymolysis by complex protease (papain, chymotrypsin and trypsin), so that the surface oil content and oxidation rancidity of the pepper seed oil microcapsule can be greatly reduced, the pepper seed oil has directivity, the embedding rate is further improved, and the pepper seed oil microcapsulation effect is better.

[0023] The application takes the pepper protein nanoparticle, bone collagen peptide and malt dextrin as the wall material, the bone collagen peptide gives the polar protein and different molecular weight peptide segments in the pepper protein nanoparticle better film forming property, the adhesion and hygroscopicity of the malt dextrin are combined, the wall material is adsorbed and formed on the surface of the pepper seed oil molecules, and the embedding effect and stability are improved.

[0024] Other advantages, objects and features of the application will be apparent from the following description, and will be understood by those skilled in the art through the study and practice of the application. DETAILED DESCRIPTION

[0025] The application will be further described in detail below with reference to the embodiments, so that those skilled in the art can implement the application according to the description.

[0026] It should be understood that the terms such as "have", "contain" and "include" used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0027] It should be noted that the experimental methods in the following embodiments are conventional methods, and the reagents and materials are commercially available unless otherwise specified.

[0028] Example 1

[0029] A chilli seed oil microcapsule is prepared by the following method:

[0030] Chilli protein nanoparticles and malt dextrin are added to distilled water, and stirred in a 60°C water bath until completely dissolved to prepare an aqueous phase, wherein the weight ratio of the wall material compounded chilli protein nanoparticles to malt dextrin is 1:1, and the solid content of the soluble starch is 8%;

[0031] Meanwhile, an emulsifier is weighed, which is obtained by mixing propylene glycol fatty acid ester, sucrose ester and soybean phospholipid at a weight ratio of 1:0.2:3, and the emulsifier is added to the chilli seed oil, and the content of the emulsifier is 2%, and then stirred in a 65°C water bath until completely dissolved to prepare an oil phase. Then, the two are mixed and stirred uniformly, stirred for 30 min using a constant temperature magnetic stirrer, passed through a colloid mill for 3 times to form a mixed emulsion, homogenized for 3 times under a high pressure homogenizer at 30 MPa, pre-frozen for 6 h at-50°C, and vacuum programmatic freeze-dried for 20 h at 20 Pa (-50°C for 3 h, -40°C for 2 h, -30°C for 1 h, -20°C for 1 h, -10°C for 1 h, 0°C for 1 h, 10°C for 1 h, 20°C for 1 h, 30°C for 2 h, 40°C for 3 h, 50°C for 4 h) to obtain a chilli seed oil microcapsule product; wherein the weight ratio of chilli seed oil to wall material is 1:1.

[0032] The chilli protein nanoparticles are prepared by the following method:

[0033] The chilli meal powder is crushed through a 100 mesh sieve to obtain a powder, deionized water is added to the powder at 15 times the weight of the powder, and a 1M NaOH solution is added, mixed uniformly, the pH of the mixed solution is adjusted to 8-9, and the mixed solution is extracted under the conditions of a temperature of 40°C, an ultrasonic frequency of 20KHz, and an ultrasonic power of 100W for 3h, centrifuged at 3500r / min for 10min, and the filtrate is collected; and the pH of the filtrate is adjusted to 4, and after standing for 20min, the filtrate is centrifuged again (at 3500r / min for 10min), and the precipitate is collected, desalted in a dialysis bag in deionized water, and after dialysis, vacuum freeze-dried to obtain chilli meal protein with a water content of 20%; wherein the conditions for vacuum freeze-drying are: pre-cooling time of 6h, pre-cooling temperature of-50°C, sublimation temperature of 5°C, and vacuum degree of 20Pa;

[0034] The pepper meal protein is mixed with deionized water, and complex protease is added for enzymolysis. After the enzymolysis is completed, centrifugation (3500 r / min for 10 min) is performed again, the supernatant is taken, and vacuum freeze-drying is performed to obtain the pepper protein nanoparticles; wherein the conditions for vacuum freeze-drying are as follows: precooling time 6 h, precooling temperature -50°C, sublimation temperature 5°C, freeze-drying time 30 h, and vacuum degree 20 Pa.

[0035] The weight ratio of the pepper meal protein, deionized water, and complex protease is 1:4:0.03, the enzymolysis time is 5 h, the enzymolysis pH value is 6-7, and the enzymolysis temperature is 45°C.

[0036] Example 2

[0037] A kind of pepper seed oil microcapsule, its preparation method is different from example 1, and the difference is that the method for preparing pepper protein nanoparticles is different, which is different in that: pepper meal powder is extracted by soaking and beating slurry, and the extract is concentrated by dialysis bag to obtain pepper meal protein, and papain, chymotrypsin and trypsin are used for enzymolysis.

[0038] Specifically, the pepper protein nanoparticles are prepared by the following method:

[0039] The pepper meal is soaked with deionized water at a weight ratio of 5:2 for 50 min, and stirring can be performed during the soaking process. The slurry is then beaten, and 2 times the weight of deionized water and a 1M NaOH solution are added. The mixture is mixed uniformly, and the pH of the mixed solution is adjusted to 8-9. The extraction is carried out at a temperature of 40°C, an ultrasonic frequency of 20KHz, and an ultrasonic power of 100W for 3h. Centrifugation is performed at 3500r / min for 10 min, and the filtrate is collected. The pH of the filtrate is adjusted to 4, and the mixture is allowed to stand for 20 min before being centrifuged again (3500r / min for 10 min). The precipitate is collected, desalted in deionized water using a dialysis bag, and then placed on filter paper. The water is absorbed using absorbent paper, and the water content of the obtained pepper meal protein is 20%.

[0040] The pepper meal protein is mixed with deionized water, and complex protease is added for enzymolysis. After the enzymolysis is completed, centrifugation (3500 r / min for 10 min) is performed again, the supernatant is taken, and vacuum freeze-drying is performed to obtain the pepper protein nanoparticles; wherein the conditions for vacuum freeze-drying are as follows: precooling time 6 h, precooling temperature -50°C, sublimation temperature 5°C, freeze-drying time 30 h, and vacuum degree 20 Pa.

[0041] The weight ratio of paprika meal protein: deionized water: papain: chymotrypsin: trypsin is 1:4:0.01:0.01:0.01, the enzymolysis time is 5h, the enzymolysis pH value is 6-7, and the enzymolysis temperature is 45℃.

[0042] The rest is the same as example 1.

[0043] Example 3

[0044] A paprika seed oil microcapsule, the preparation method of which is different from that of example 2, wherein the wall material further comprises bone collagen peptide, and the weight ratio of paprika protein nanoparticles: malt dextrin: bone collagen peptide in the wall material compound is 1:1:0.2; the paprika protein nanoparticles, bone collagen peptide and malt dextrin are added into distilled water, and stirred in a 60℃ water bath until completely dissolved to prepare an aqueous phase, and the rest is the same as example 2.

[0045] Example 4

[0046] A paprika seed oil microcapsule, the preparation of which is different from that of example 3, wherein the core-wall ratio is 0.8:1, the paprika meal protein is enzymolyzed by a commercially available compound protease, and the emulsifier compound ratio is different.

[0047] Specifically prepared by the following method:

[0048] The paprika protein nanoparticles, bone collagen peptide and malt dextrin are added into distilled water, and stirred in a 60℃ water bath until completely dissolved to prepare an aqueous phase, wherein the weight ratio of paprika protein nanoparticles: malt dextrin: bone collagen peptide in the wall material compound is 1:1:0.2, and the solid content of the soluble starch is 8%;

[0049] Meanwhile, the emulsifier is weighed, the emulsifier is obtained by mixing propylene glycol fatty acid ester, sucrose ester and soybean phospholipid according to a weight ratio of 2:0.2:3, the emulsifier is added into the paprika seed oil, and stirred in a 65℃ water bath until completely dissolved to prepare an oil phase, then the two are mixed and stirred uniformly, a constant-temperature magnetic stirrer is used for stirring for 30min, a colloid mill is used for 3 times of passing to form a mixed emulsion, a high-pressure homogenizer is used for homogenization for 3 times under 30MPa, pre-freezing is performed at-50℃ for 6h, and vacuum programmatic freeze-drying is performed at 20Pa for 20h(-50℃ for 3h, -40℃ for 2h, -30℃ for 1h, -20℃ for 1h, -10℃ for 1h, 0℃ for 1h, 10℃ for 1h, 20℃ for 1h, 30℃ for 2h, 40℃ for 3h, 50℃ for 4h) to obtain a paprika seed oil microcapsule product; wherein the weight ratio of paprika seed oil: wall material is 0.8:1, and the content of the emulsifier is 2%.

[0050] The paprika protein nanoparticles are prepared by the following method:

[0051] The pepper meal is soaked with deionized water in a weight ratio of 5:2 for 50 min, stirring can be carried out during the soaking process, and then the slurry is beaten into a slurry solution. Then 2 times the weight of the slurry solution of deionized water and 1M NaOH solution are added, and the mixture is mixed uniformly. The pH of the mixed solution is adjusted to 8-9, and the extraction is carried out under the conditions of a temperature of 40°C, an ultrasonic frequency of 20KHz, and an ultrasonic power of 100W for 3h. The filtrate is collected by centrifugation at 3500r / min for 10min. The pH of the filtrate is adjusted to 4, and the precipitate is collected by centrifugation (3500r / min for 10min) after standing for 20min. The precipitate is desalted in a dialysis bag in deionized water. After dialysis, the dialysis bag is placed on filter paper, and the water is absorbed with absorbent paper to obtain pepper meal protein with a water content of 20%.

[0052] The pepper meal protein is mixed with deionized water, and compound protease is added for enzymolysis. After the enzymolysis is completed, the supernatant is collected by centrifugation (3500r / min for 10min), and pepper protein nanoparticles are obtained after vacuum freeze-drying. The conditions for vacuum freeze-drying are as follows: precooling time of 6h, precooling temperature of -50°C, sublimation temperature of 5°C, freeze-drying time of 30h, and vacuum degree of 20Pa.

[0053] The weight ratio of pepper meal protein, deionized water, and compound protease is 1:4:0.03, the enzymolysis time is 5h, the enzymolysis pH value is 6-7, and the enzymolysis temperature is 45°C.

[0054] Example 5

[0055] A pepper seed oil microcapsule is prepared, and the difference from example 3 is that the core-wall ratio is 0.8:1, the wall material is a compound of pepper protein nanoparticles and malt dextrin with a weight ratio of 1:1, and the emulsifier compound ratio is different.

[0056] The pepper seed oil microcapsule is prepared by the following method:

[0057] The pepper protein nanoparticles and malt dextrin are added to distilled water, and stirring is carried out in a 60°C water bath until complete dissolution to prepare an aqueous phase. The weight ratio of the wall material compound of pepper protein nanoparticles and malt dextrin is 1:1, and the solid content of soluble starch is 8%.

[0058] Meanwhile, the emulsifier is prepared by mixing propylene glycol fatty acid ester, sucrose ester and soybean phospholipid in a weight ratio of 2:0.2:3, and the emulsifier is added to the chilli seed oil to prepare an oil phase by stirring in a 65℃ water bath until completely dissolved. Then the two are mixed and stirred uniformly, and stirred for 30 min using a constant temperature magnetic stirrer, passed through a colloid mill for 3 times to form a mixed emulsion, homogenized for 3 times under 30 MPa using a high pressure homogenizer, pre-frozen for 6 h at-50℃, and subjected to vacuum programmatic freeze drying for 20 h at 20 Pa (-50℃ for 3 h, -40℃ for 2 h, -30℃ for 1 h, -20℃ for 1 h, -10℃ for 1 h, 0℃ for 1 h, 10℃ for 1 h, 20℃ for 1 h, 30℃ for 2 h, 40℃ for 3 h, 50℃ for 4 h) to obtain a chilli seed oil microcapsule product; wherein the weight ratio of chilli seed oil to wall material is 0.8:1, and the content of the emulsifier is 2%.

[0059] The chilli meal is soaked with deionized water in a weight ratio of 5:2 for 50 min, and the soaking process can be stirred. The slurry is then prepared, and then 2 times the weight of deionized water and a 1M NaOH solution are added, and the mixture is mixed uniformly. The pH of the mixed solution is adjusted to 8-9, and the extraction is carried out under the conditions of a temperature of 40℃, an ultrasonic frequency of 20KHz and an ultrasonic power of 100W for 3h. The filtrate is collected by centrifugation at 3500r / min for 10 min. The pH of the filtrate is adjusted to 4, and the precipitate is collected after centrifugation (3500r / min for 10 min) again. The precipitate is desalted in a dialysis bag in deionized water. After dialysis, the dialysis bag is placed on filter paper, and the water is absorbed with water-absorbing paper. The water content of the obtained chilli meal protein is 20%.

[0060] The chilli meal protein is mixed with deionized water, and papain, chymotrypsin and trypsin are added for enzymolysis. The supernatant is collected after centrifugation (3500r / min for 10 min) again after the enzymolysis is completed. The chilli protein nanoparticles are obtained after vacuum freeze-drying. The conditions for vacuum freeze-drying are as follows: pre-cooling time of 6h, pre-cooling temperature of-50℃, sublimation temperature of 5℃, freeze-drying time of 30h, and vacuum degree of 20Pa.

[0061] The weight ratio of the chilli meal protein, deionized water, papain, chymotrypsin and trypsin is 1:4:0.01:0.01:0.01. The enzymolysis time is 5h, the pH value of the enzymolysis is 6-7, and the enzymolysis temperature is 45℃.

[0062] Comparative Example 1

[0063] A kind of capsicum seed oil microcapsule, its preparation method is different from example 2, different from example 2 is that the wall material of capsicum protein nanoparticles is replaced by commercially available soy protein isolate, and the emulsifier is replaced by glycerol monostearate, and the rest is the same as example 2.Specifically: soy protein isolate and malt dextrin are used as wall material, the weight ratio of soy protein isolate and malt dextrin in wall material is 1:1, without capsicum protein nanoparticle preparation step;Glycerol monostearate is added to capsicum seed oil, and stirred in 65℃ water bath to completely dissolve to prepare oil phase.

[0064] Comparative example 2

[0065] A kind of capsicum seed oil microcapsule, its preparation method is different from example 2, different from example 2 is that the vacuum program freeze drying is different, and the rest is the same as example 2.Different specifically: 20Pa vacuum program freeze drying 22h (-50℃ 3h, -30℃ 3h, -10℃ 4h, 10℃ 2h, 30℃ 3h, 50℃ 7h).

[0066] Comparative example 3

[0067] A kind of capsicum seed oil microcapsule, its preparation method is different from example 2, different from example 2 is that the vacuum program freeze drying is different, and the rest is the same as example 2.Different specifically: 20Pa vacuum program freeze drying 22h (-50℃ 3h, -10℃ 5h, 30℃ 7h, 50℃ 7h).

[0068] Comparative example 4

[0069] A kind of capsicum seed oil microcapsule, its preparation method is different from example 2, different from example 2 is that the emulsifier is different, and the rest is the same as example 2, different specifically: the emulsifier is obtained by mixing glycerol monostearate, sucrose ester and tri-glycerol monostearate in a weight ratio of 1:0.2:3.

[0070] Comparative example 5

[0071] A kind of capsicum seed oil microcapsule, its preparation method is different from example 2, different from example 2 is that the emulsifier is different, and the rest is the same as example 2, different specifically: the emulsifier is obtained by mixing propylene glycol fatty acid ester, octenyl succinate starch and glycerol monostearate in a weight ratio of 1:0.2:3.

[0072] In order to show the technical effect of the preparation of capsicum seed oil microcapsule of the application, the capsicum seed oil microcapsules prepared in examples 1-5 and comparative examples 1-5 are divided into ten groups, and their embedding rate, moisture content, storage stability, oil loading and surface oil content are determined, and the test results are shown in table 1 and table 2, all data are repeated three times and averaged.

[0073] The test is determined by the following method:

[0074] 1.1 Determination of microcapsule embedding rate

[0075] 1.1.1 Determination of total oil mass in microcapsules

[0076] Accurately weigh 2g of chili seed oil microcapsules into a filter paper tube, and add 70mL of petroleum ether (30-60℃) to a round-bottom flask dried to constant weight. Extract using a fat analyzer for 3 hours. After extraction, dry the round-bottom flask to constant weight. The difference in mass before and after extraction is the total oil content (M1) of the chili seed oil microcapsules.

[0077] 1.1.2 Determination of surface oil content of microcapsules

[0078] Add 2g of chili seed oil microcapsules to 20mL of petroleum ether, shake thoroughly, and extract for 1 minute. Filter, place the filtrate in a constant-weight round-bottom flask, evaporate the petroleum ether using a rotary evaporator, and recover it. Then dry the round-bottom flask in an oven at 105℃ until constant weight. The difference in mass before and after drying the round-bottom flask is the surface content (M2) of the chili seed oil microcapsules.

[0079] 1.1.3 Determination of embedding rate

[0080]

[0081] Where: M1—total oil mass of microcapsules, g;

[0082] M2 — Mass of surface oil on microcapsules, g.

[0083] 2.1 Determination of moisture content in microcapsules

[0084] 2.1.2 Moisture content determination

[0085] The moisture content of chili seed oil microcapsules was determined using a halogen moisture analyzer. 2.5g of chili seed oil microcapsules were accurately weighed and evenly spread on an aluminum pan. The heating temperature was set to 105℃, and the aluminum pan was placed inside the instrument for heating. Heating continued until the instrument automatically stopped, indicating that the moisture in the sample had been completely removed. The moisture content displayed on the instrument screen was recorded.

[0086] 3.1 Storage stability test

[0087] Accurately weigh 70g of chili seed oil and 70g of chili seed oil microcapsule product for ten groups, accurate to 0.01g, and place them simultaneously in an oven at (63±1)℃ for accelerated oxidation testing. At the initial stage and on days 6, 12, and 18, appropriate amounts of oil and microcapsules were taken to determine their peroxide value, following the method specified in GB / T 5009.227-2016 "National Food Safety Standard - Determination of Peroxide Value in Food".

[0088] 4.1 Oil Load Measurement

[0089] The 2 g of chilli seed oil microcapsule powder was added to 20 mL of 2 mol / L HC1 solution and stirred with a magnetic stirrer for 30 min to break the capsule wall. 80 mL of chloroform and 20 mL of methanol were added and the mixture was stirred for 30 min to extract the oil. The suspension was centrifuged at a speed of 10000 rpm / min for 10 min, the organic phase was collected and placed in an oven at 60°C until the solvent completely evaporated, the remaining oil was weighed and the oil loading was calculated as follows:

[0090]

[0091] 5.1 Surface oil content determination

[0092] The 2 g of chilli seed oil microcapsule powder was added to 30 ml of petroleum ether and stirred gently for 1 min. The mixture was then filtered through a quick filter paper and the residue was washed again with 20 ml of petroleum ether. The filtrate was combined and placed in an oven at 60°C until the solvent completely evaporated, then the residual oil was collected and weighed and the surface oil content was calculated as follows:

[0093]

[0094] The results of the test are as follows:

[0095] Table 1:

[0096] Oil loading (%) Surface oil content (%) Embedding rate (%) Moisture content (%) Example 1 42.21 7.11 80.23 3.52 Example 2 45.89 6.02 85.04 3.67 Example 3 48.94 4.35 91.35 3.40 Example 4 37.87 8.01 88.01 3.84 Example 5 36.08 9.15 85.64 3.73 Comparative Example 1 37.86 13.98 68.12 4.56 Comparative Example 2 38.75 15.72 71.19 3.41 Comparative Example 3 35.11 17.53 69.24 3.33 Comparative Example 4 39.91 15.37 75.56 3.97 Comparative Example 5 36.77 16.12 73.43 3.85

[0097] Table 2:

[0098]

[0099]

[0100] From Table 1 and Table 2, it can be seen that the embedding material of Example 1, which is prepared by vacuum program freeze-drying with chilli protein nanoparticles and malt dextrin as wall materials and complex emulsifiers, is obviously beneficial to improve the embedding rate, reduce the water content, and slow down the increase of peroxide value, and can realize the extension of the storage period of chilli seed oil microcapsules. Compared with Example 1, the embedding rate of Example 2 is higher, which may be due to the fact that the chilli meal powder is extracted by soaking and beating liquid, and the chilli meal protein is obtained by dialysis bag concentration method, and then the chilli protein nanoparticles are obtained by enzyme hydrolysis with papain, chymotrypsin and trypsin, so that the ingredients with better directionality to chilli seed oil are obtained, which is beneficial to the embedding of chilli seed oil. Compared with Example 2, the embedding rate of Comparative Examples 1-3 decreases significantly, and the peroxide value increases significantly, which may be due to the fact that the freeze-drying process is not conducive to the water vapor penetration of the embedding layer, resulting in the increase or rupture of the pores on the surface of the microcapsule structure. Compared with Example 2, the embedding rate of Comparative Examples 4-5 is lower than that of Example 2, which may be due to the fact that different complex emulsifiers form different skeletons for oil particle condensation, and the adsorption of proteins on the oil-water interface and the film forming effect are different. Compared with Example 2, the embedding rate of Example 3 is significantly improved, and the water content is slightly reduced, which may be due to the fact that the combination of collagen peptide and chilli protein nanoparticles is beneficial to the adsorption of wall materials on the surface of chilli seed oil molecules, film forming, and the use of vacuum program freeze-drying is beneficial to the water vapor penetration of the embedding layer formed by chilli protein nanoparticles and collagen peptide and malt dextrin, which is beneficial to the sublimation of water and the reduction of pore generation on the surface of the microcapsule structure, thereby improving the embedding rate and reducing the water content, and facilitating storage.

[0101] The number of devices and the scale of processing described herein is intended to exemplify the invention. Applications, modifications and variations of the application will be apparent to those skilled in the art without departing from the general concept of the application.

[0102] While embodiments of the application have been disclosed in connection with the specified embodiments, as illustrated and described, it will be readily apparent to those skilled in the art that various modifications can be made to the application without departing from the spirit and scope of the application as set forth in the claims and equivalents thereof.

Claims

1. A method for preparing chili seed oil microcapsules, characterized in that, The wall material includes capsicum protein nanoparticles, maltodextrin, and collagen peptides. The capsicum protein nanoparticles, maltodextrin, and collagen peptides are completely dissolved in distilled water to form an aqueous phase. The core material is chili seed oil: the emulsifier is completely dissolved in the chili seed oil to form an oil phase; wherein, the emulsifier is obtained by mixing propylene glycol fatty acid ester, sucrose ester and soybean lecithin in a weight ratio of (1~2):0.2:3, and the emulsifier content is 1.5~2%; The aqueous phase and oil phase are mixed and stirred evenly to form a mixed emulsion, which is then homogenized, pre-frozen, and subjected to vacuum programmed freeze-drying to obtain chili seed oil microcapsules; wherein the weight ratio of chili seed oil to wall material is (0.8~1):

1. The capsicum protein nanoparticles are prepared by the following method: Chili meal and deionized water were soaked at a weight ratio of (5~10):2 for 50~90 minutes, then blended into a slurry. Two to three times the weight of the slurry of deionized water and a 0.2~3M NaOH solution were added and mixed thoroughly. The pH of the mixture was adjusted to 8~9. Extraction was carried out at 40~55℃, with an ultrasonic frequency of 20~30KHz and an ultrasonic power of 100~200W for 2~3 hours. The mixture was then centrifuged at 2500~3500r / min for 10~20 minutes, and the filtrate was collected. The pH of the filtrate was adjusted to 4~5, and the mixture was allowed to stand for 10~20 minutes before centrifugation again. The precipitate was collected and desalted in deionized water using a dialysis bag. After dialysis, the dialysis bag was placed on filter paper, and the water was absorbed with absorbent paper to obtain chili meal protein with a water content of 20~50%. The chili protein was mixed with deionized water, and a complex protease was added for enzymatic hydrolysis. After the enzymatic hydrolysis was completed, the mixture was centrifuged again, and the supernatant was collected and freeze-dried under vacuum to obtain chili protein nanoparticles. The complex protease was papain, chymotrypsin and trypsin. The weight ratio of chili meal protein: deionized water: papain: chymotrypsin: trypsin is 1:(4~8):0.01:0.01:0.01, the enzymatic hydrolysis time is 5~6h, the enzymatic hydrolysis pH is 6~7, and the enzymatic hydrolysis temperature is 45~55℃. The wall material is composed of capsicum protein nanoparticles, maltodextrin, and collagen peptides in a weight ratio of 1:1:0.

2. In the aqueous phase, the soluble starch content of the solids is 5-10%. Furthermore, the vacuum programmed freeze drying process involves gradually increasing the temperature from -50℃ to 50℃, with a temperature difference of 10℃ between adjacent stages. Each stage is treated at a constant temperature for 1 to 4 hours, specifically under a 20Pa vacuum: -50℃ for 3 hours, -40℃ for 2 hours, -30℃ for 1 hour, -20℃ for 1 hour, -10℃ for 1 hour, 0℃ for 1 hour, 10℃ for 1 hour, 20℃ for 1 hour, 30℃ for 2 hours, 40℃ for 3 hours, and 50℃ for 4 hours.

2. The method for preparing chili seed oil microcapsules as described in claim 1, characterized in that, The aqueous phase preparation specifically involves adding capsicum protein nanoparticles, collagen peptides, and maltodextrin to distilled water and stirring in a 60°C water bath until completely dissolved. The oil phase preparation specifically involves stirring emulsifier and chili seed oil in a 65°C water bath until completely dissolved.

3. The method for preparing chili seed oil microcapsules as described in claim 2, characterized in that, The formation of the mixed emulsion and homogenization are specifically as follows: stirring with a constant temperature magnetic stirrer for 30 min, passing through a colloid mill 3 times to form a mixed emulsion, and homogenizing 3 times under a high pressure homogenizer at 30 MPa.

4. The method for preparing chili seed oil microcapsules as described in claim 3, characterized in that, Chili seed oil: wall material weight ratio = 1:1, emulsifier content is 2%.

5. Chili seed oil microcapsules, characterized in that, Prepared according to the method according to any one of claims 1 to 4.

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