Preparation and application of octenylsuccinate cyclodextrin ester-allicin inclusion complex

Abstract

The present invention belongs to the technical field of emulsion preparation, and specifically relates to an ultrasound-assisted preparation of an octenylsuccinic acid cyclodextrin ester-allicin inclusion complex and its application in the preparation of a high internal phase Pickering emulsion. Under the condition of pH 8.0, octenylsuccinic anhydride is added to a β-cyclodextrin solution, and modified OS-β-CD particles are obtained after ultrasonic treatment. The obtained particles are embedded with allicin to obtain an OS-β-CD-allicin inclusion complex. The OS-β-CD-allicin inclusion complex obtained by the present invention has good emulsifying properties and antibacterial properties, and the prepared high internal phase Pickering emulsion can significantly improve the quality and shelf life of meat products.

Description

Technical Field

[0001] The invention belongs to the technical field of emulsion preparation, and particularly relates to an ultrasound-assisted prepared octenyl succinate cyclodextrin ester-allicin inclusion complex (OS-β-CD-allicin inclusion complex) and application of the OS-β-CD-allicin inclusion complex in the preparation of a high internal phase Pickering emulsion. Background Art

[0002] Meat and meat products are widely loved by consumers. With the continuous improvement of consumers' awareness of healthy diet and consumption level, the enthusiasm for consuming meat products with high animal fat content has been declining. The large amount of cholesterol contained in fat can induce many chronic diseases including obesity, which seriously affects human health. However, when the fat content is reduced, the emulsification stability of meat products will be reduced, the flavor will be poor, and the product quality will be reduced. Therefore, low-fat emulsified meat products are the development trend of the current food industry. High internal phase Pickering emulsions have semi-solid characteristics. Due to their unique properties, high internal phase Pickering emulsions are increasingly used to replace animal fat in meat products, thereby improving their taste and nutritional content.

[0003] High internal phase Pickering emulsion is a type of ultra-concentrated emulsion with a dispersed phase of more than 74%, where droplets accumulate and deform into a polyhedral geometric shape. It is usually called an ultra-concentrated emulsion or gel emulsion, and has potential applications in functional health foods, cosmetics, scaffolds, and porous polymer templates. Due to its low water content, it can effectively prevent the growth of microorganisms and has a longer shelf life than other emulsion systems.

[0004] At present, most of the high internal phase Pickering emulsions are prepared by protein particles. The high internal phase Pickering emulsion prepared by protein particles has good stability, but it cannot form a stable high internal phase Pickering emulsion when the pH is close to the isoelectric point of the protein, while β-cyclodextrin (β-CD) will not be affected. β-CD is an oligosaccharide composed of 7 glucose molecules connected by α-1,4 glycosidic bonds. Because of its good emulsification and low production cost, it has become one of the commonly used emulsifiers, but it cannot prepare a stable high internal phase Pickering emulsion. Studies have shown that the introduction of OSA hydrophobic long chains can effectively improve the hydrophilic and lipophilic properties of β-CD, thereby improving its emulsification ability. The prepared OS-β-CD is a high-quality emulsifier for preparing stable high internal phase Pickering emulsions. However, the high internal phase Pickering emulsion stabilized by OS-β-CD will also be affected by the growth of microorganisms during storage and will be stratified. Therefore, it is necessary to inhibit the growth and reproduction of microorganisms by appropriate means.

[0005] Research has shown that there are many antibacterial substances, but they are generally chemically unstable and easily decomposed, such as allicin.

[0006] Therefore, how to use antibacterial substances to further enhance the stability of high internal phase Pickering emulsions is an urgent problem to be solved at this stage. Summary of the invention

[0007] The invention makes up for the deficiencies of the prior art and provides an octenylsuccinic acid cyclodextrin ester-allicin inclusion complex (OS-β-CD-allicin inclusion complex) and a preparation method thereof.

[0008] Another object of the present invention is to provide a method for preparing a high internal phase Pickering emulsion stabilized by an OS-β-CD-allicin inclusion complex.

[0009] Another object of the present invention is to provide an application of the high internal phase Pickering emulsion prepared by the above method in low-fat meat products to increase the shelf life of the meat products.

[0010] To achieve the above purpose, the present invention adopts the following technical solution:

[0011] A method for preparing an octenylsuccinic acid cyclodextrin ester-allicin inclusion complex comprises the following steps: adding octenylsuccinic anhydride (OSA) to a β-cyclodextrin solution at a pH of 8.0, obtaining modified OS-β-CD particles after ultrasonic treatment, and embedding the obtained particles with allicin to obtain the OS-β-CD-allicin inclusion complex.

[0012] Furthermore, under the condition of pH 8.0, OSA was added to the β-cyclodextrin solution, and the reaction system was ultrasonically treated after thorough mixing. After washing and drying, modified OS-β-CD particles were obtained; allicin was encapsulated with OS-β-CD to obtain OS-β-CD-allicin inclusion complex; wherein, the amount of OSA added was 3% of the mass of β-cyclodextrin; the ultrasonic time was 10-35min, and the power was 150-450W.

[0013] The ultrasonic treatment conditions are: frequency 30 kHz, temperature 35° C., working 4 s, rest 2 s, and then ultrasonic treatment 10-30 min.

[0014] The ultrasonic time is 25-35 minutes, and the power is 200-300W.

[0015] The modified OS-β-CD particles are dissolved in water to obtain a saturated OS-β-CD solution, which is then added to allicin dissolved in anhydrous ethanol, and then ultrasonically mixed and embedded to obtain an OS-β-CD-allicin inclusion complex; wherein the core-to-wall ratio (W / W) of allicin and OS-β-CD solution is 1:5-1:9, the power of the ultrasonic reaction is 150-450W, and the reaction time is 5-25min. wherein the mass ratio of garlic oil to anhydrous ethanol is 1:1.

[0016] The OS-β-CD saturated solution contains 1.8%-2.6% of modified OS-β-CD particles; wherein the OS-β-CD saturated solution is prepared by adding the modified OS-β-CD particles into water under a 40-50° C. water bath condition and stirring and heating until the modified OS-β-CD particles are completely dissolved to obtain a saturated solution.

[0017] An octenyl succinate cyclodextrin ester-allicin inclusion compound is prepared according to the method.

[0018] Application of the inclusion compound, and application of the inclusion compound in preparing a high internal phase Pickering emulsion.

[0019] A high internal phase Pickering emulsion contains the octenylsuccinate cyclodextrin ester-allicin inclusion complex.

[0020] The emulsion is composed of an oil phase and the octenyl succinate cyclodextrin ester-allicin inclusion compound according to claim 7, wherein the oil phase accounts for 60% to 80% of the volume of the emulsion.

[0021] Application of high internal phase Pickering emulsion and application of said emulsion in preparing lipid substitutes.

[0022] Preparation of specific low-fat meatballs

[0023] The lean pork and back fat were separated and cut into small pieces, and then minced for 30 seconds using a meat grinder. Ingredients were added in proportion, and part of the fat in the meatballs was replaced by the high internal phase Pickering emulsion stabilized by the embedded OS-β-CD-allicin inclusion complex. After mixing, the meatballs were quickly chopped for 3 minutes and processed into meatballs with a diameter of about 2.5 mm. The formed meatballs were cooked separately, cooled and stored in a cold storage at 4°C.

[0024] The emulsion replaces pig back fat in a ratio of 25% to 100%.

[0025] The cooking time is 10 minutes.

[0026] The principle of the present invention is:

[0027] The present invention utilizes β-cyclodextrin with natural hydrophilic properties, and introduces hydrophobic groups by esterification reaction with octenyl succinic anhydride with good hydrophobicity under weak alkaline conditions, so that OS-β-CD contains both hydrophobic -C=C- double bonds and hydrophilic carboxyl groups (-COOH), and a certain influence is exerted on the internal structure of the particles by specific ultrasonic treatment, so that the reaction with octenyl succinic anhydride is accelerated, and the hydrophilic and lipophilic properties are improved, thereby improving its emulsification ability. When stabilizing the oil-in-water emulsion, the hydrophilic carboxyl group penetrates into the water phase, and the lipophilic alkenyl long chain penetrates into the oil phase, so that OS-β-CD forms a very dense film at the oil-water interface, thereby preventing the emulsion droplets from aggregating with each other to maintain the high stability of the emulsion. When OS-β-CD forms a physical barrier film on the surface of allicin (fat-soluble), the stability of allicin can be improved and its odor can be buried. In addition, the obtained OS-β-CD–allicin inclusion complex is also a solid particle with good emulsification properties, which can be used to prepare high internal phase Pickering emulsions and further applications.

[0028] The preparation method of the present invention and the obtained product have the following advantages and beneficial effects:

[0029] 1. The present invention uses ultrasound technology to assist in the preparation of OS-β-CD particles to enhance the hydrophobicity of β-cyclodextrin, which is a combination of physical and chemical modifications, is pollution-free, and the preparation process is green and environmentally friendly.

[0030] 2. The ultrasound-assisted reaction process is simple, fast and efficient, reducing the reaction time from tens of hours in traditional methods to tens of minutes, greatly shortening the reaction cycle and improving efficiency.

[0031] 3. The present invention can provide a highly stable environment for the embedded active substances (such as allicin) for carrying or protecting the active substances; it can also improve the bioavailability of the active substances and minimize the impact on the sensory properties of the product.

[0032] 4. The high internal phase Pickering emulsion prepared by the present invention has high stability, can partially replace fat, and has good application prospects in the processing of low-fat emulsified minced meat. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram showing the effect of different ultrasonic powers on the degree of substitution of OS-β-CD particles provided in Example 1 of the present invention.

[0034] Figure 2 This is a diagram showing the effect of different ultrasonic powers on the particle size and potential of OS-β-CD particles provided in Example 1 of the present invention.

[0035] Figure 3This is a graph showing the effect of different ultrasonic powers on the activation index of OS-β-CD particles provided in Example 1 of the present invention.

[0036] Figure 4 This is a diagram showing the effect of different ultrasonic times on the degree of substitution of OS-β-CD particles provided in Example 2 of the present invention.

[0037] Figure 5 This is a diagram showing the effect of different ultrasonic times on the particle size and potential of OS-β-CD particles provided in Example 2 of the present invention.

[0038] Figure 6 This is a graph showing the effect of different ultrasound times on the activation index of OS-β-CD particles provided in Example 2 of the present invention.

[0039] Figure 7 This is a laser confocal microscopy image of the OS-β-CD-allicin inclusion complex provided in Example 3 of the present invention.

[0040] Figure 8 This is a graph showing the effect of 2.5% OS-β-CD-allicin inclusion compound dispersion on the storage stability of high internal phase Pickering emulsion under different oil phase ratios provided in Example 3 of the present invention.

[0041] Fig. 9 This is an influence diagram of the storage stability of a 2.5% OS-β-CD-allicin inclusion compound dispersion and a high internal phase Pickering emulsion with an oil phase volume of 80% provided in Example 3 of the present invention.

[0042] Fig.10 Laser confocal microscopy image of the high internal phase Pickering emulsion stabilized by the OS-β-CD-allicin inclusion complex provided in Example 3 of the present invention

[0043] Fig.11 This is a graph showing the effect of different high internal phase Pickering emulsion replacement amounts on the cooking loss of low-fat meatballs provided in Example 3 of the present invention.

[0044] Fig.12 This is a graph showing the effect of different high internal phase Pickering emulsion replacement amounts on the color difference of low-fat meatballs during different storage periods provided in Example 3 of the present invention.

[0045] Fig.13 This is a graph showing the effect of different amounts of high internal phase Pickering emulsion replacement on the texture of low-fat meatballs during different storage periods provided in Example 3 of the present invention.

[0046] Fig.14 This is a graph showing the effect of different amounts of high internal phase Pickering emulsion replacement on the pH of low-fat meatballs during different storage periods, as provided in Example 3 of the present invention.

[0047] Fig.15 This is a graph showing the effect of different high internal phase Pickering emulsion replacement amounts on low-fat meatballs TVB-N during different storage periods provided in Example 3 of the present invention.

[0048] Fig.16 This is a graph showing the effect of different high internal phase Pickering emulsion replacement amounts on the TBARS of low-fat meatballs during different storage periods provided in Example 3 of the present invention.

[0049] Fig.17 For the present invention comparative case Figure 1 The effect of 2.5% β-cyclodextrin-allicin inclusion complex dispersion on the storage stability of Pickering emulsion under different oil phase ratio conditions is provided.

[0050] Fig.18 For the present invention comparative case Figure 2 A graph showing the effect of 2.5% non-sonicated OS-β-CD–allicin inclusion complex dispersion on the storage stability of Pickering emulsions at different oil phase ratios is provided. DETAILED DESCRIPTION

[0051] In view of the technical problems existing in the prior art, after a lot of practice, the experimental scheme of the present invention is proposed. The following is a further description of the specific implementation of the present invention in combination with examples. It should be noted that the specific implementation described here is only for the purpose of illustrating and explaining the present invention, and is not limited to the present invention.

[0052] The present invention adds OSA to a β-cyclodextrin solution under the condition of pH 8.0, and after sufficient mixing, ultrasonic treatment is performed on the reaction system, and modified OS-β-CD particles are obtained after washing and drying. Allicin is embedded in OS-β-CD to obtain an OS-β-CD-allicin inclusion complex, and the OS-β-CD-allicin inclusion complex is mixed with corn oil, and a high internal phase Pickering emulsion is obtained after homogenization, and the emulsion is used to replace fat in low-fat meat products. The present invention partially or completely embeds allicin molecules into the OS-β-CD cavity, which not only reduces the contact of allicin molecules with the surrounding environment, but also increases its stability, thereby better exerting its antibacterial effect, so that the obtained OS-β-CD-allicin inclusion complex has good emulsifying properties and antibacterial properties, and the prepared high internal phase Pickering emulsion can significantly improve the quality and shelf life of meat products.

[0053] Example 1

[0054] Weigh 30g of β-cyclodextrin and dissolve it in distilled water to prepare a 35% β-cyclodextrin suspension. Stir it with a magnetic stirrer for 20 minutes. Adjust the β-cyclodextrin suspension to 8.0 with 3% NaOH solution. Slowly add 16.67% OSA ethanol solution at 35°C, based on octenyl succinic anhydride accounting for 3% of the total cyclodextrin. Stir continuously with a constant temperature magnetic stirrer. During the addition of OSA solution, continue to add 3% NaOH solution to maintain the pH of the reaction system at 8.0.

[0055] The mixed solution after adding OSA solution was placed in an ultrasonic cell disruptor. The ultrasonic treatment conditions were: frequency 30kHz, temperature 35℃, working 4s, rest 2s, ultrasonic power 150-450W, ultrasonic reaction 15min. After the reaction, the solution was adjusted to 6-7 with 0.1mol / LHCl, centrifuged at 6000r / min for 10min, the supernatant was discarded, the precipitate was washed twice with deionized water, and then washed twice with 70% ethanol solution by volume, dried at 40℃ for 2h, and crushed through a 100-mesh sieve.

[0056] The degree of substitution, particle size, potential and activation index of the OS-β-CD particles obtained by the above modification were then tested (see Figure 1-3 ),Depend on Figure 1 It can be seen that with the increase of ultrasonic power, the effect on the degree of substitution of OS-β-CD first increases and then decreases; when the ultrasonic power reaches 225W, the degree of substitution of OS-β-CD reaches the maximum value; when the ultrasonic power continues to increase, the degree of substitution continues to decrease. Figure 2 It can be seen that the effect of ultrasonic power on the particle size of OS-β-CD also shows a trend of first increasing and then decreasing, and the absolute value of the potential is the largest at 225W. Figure 3 It can be seen that the particle activation index reaches its maximum value at 225 W, and the higher the activation index, the higher the hydrophobicity.

[0057] From the above data, it can be seen that the optimal ultrasonic power is 225W.

[0058] Example 2

[0059] Weigh 30g of β-cyclodextrin and dissolve it in distilled water to prepare a 35% β-cyclodextrin suspension. Stir it with a magnetic stirrer for 20 minutes. Adjust the β-cyclodextrin suspension to 8.0 with 3% NaOH solution. Add octenyl succinic anhydride in an amount of 3% of the total β-cyclodextrin. Slowly add 16.67% OSA ethanol solution at 35°C. Stir continuously with a constant temperature magnetic stirrer. During the addition of OSA solution, continue to add 3% NaOH solution to maintain the pH of the reaction system at 8.0.

[0060] The mixed solution after adding OSA solution was placed in a cell disruptor, and the conditions for ultrasonic treatment were: frequency 30kHz, temperature 35℃, working 4s, rest 2s, ultrasonic power 225W, ultrasonic reaction 0-35min. After the reaction, the solution was adjusted to 6-7 with 0.1mol / L HCl, centrifuged at 6000r / min for 10min, the supernatant was discarded, the precipitate was washed twice with 70% volume fraction ethanol solution, washed twice with deionized water, dried at 40℃ for 2h, and crushed through a 100-mesh sieve.

[0061] The degree of substitution, particle size, potential and activation index of the OS-β-CD particles obtained by the above modification were then tested (see Figure 4-6 ),

[0062] Depend on Figure 4 It can be seen that when the ultrasonic reaction is between 0 and 15 minutes, the degree of substitution of OS-β-CD increases with the increase of reaction time; when the ultrasonic reaction reaches 20 minutes, the degree of substitution decreases instead; then, as the reaction time increases, the degree of substitution increases again, reaching the maximum value at 30 minutes of ultrasonic reaction, and when the ultrasonic reaction continues, that is, at 35 minutes of ultrasonic reaction, the degree of substitution decreases slightly. Figure 5 It can be seen that the effect of ultrasound time on OS-β-CD particle size reaches its maximum value at 30 min, and the absolute value of potential is also the largest, which corresponds to the particle substitution degree. Figure 6 It can be seen that the activation index also corresponds to the degree of substitution and reaches the maximum at 30 min, which indicates that after OSA modification of β-CD, its hydrophobicity increases with the increase of the degree of substitution.

[0063] Based on the above data, it can be seen that the optimal ultrasonic time is 30 minutes, that is, when the ultrasonic power is 225W and the ultrasonic reaction is 30 minutes, the prepared octenyl succinic acid cyclodextrin anhydride has the largest degree of substitution and the best hydrophobicity.

[0064] Example 3

[0065] 2.4 g of the modified OS-β-CD particles obtained under the conditions of ultrasonic power of 225 W and ultrasonic reaction for 30 min were weighed and dissolved in distilled water, and allicin was weighed according to the core-wall ratio of 1:8 (W / W), and 50% allicin ethanol solution was slowly added to the 2.4% OS-β-CD saturated solution, and after being fully stirred, the particles were embedded for 5 min under ultrasonic conditions of 225 W. After the embedding reaction was completed, the particles were centrifuged, and the allicin not embedded on the surface of the particles was washed with ethanol, and dried to obtain the OS-β-CD-allicin inclusion complex.

[0066] The OS-β-CD–allicin inclusion complex obtained above was dissolved in distilled water to form a 2.5% saturated solution and mixed with an oil phase. The volume fraction of the vegetable oil used was 60%–80%. A high-speed homogenizer was used to homogenize the mixture at 13,000 rpm for 2 minutes to obtain a stable high internal phase Pickering emulsion of the OS-β-CD–allicin inclusion complex.

[0067] Figure 7 This is a laser confocal microscope image of the OS-β-CD-allicin inclusion complex. As can be seen from the figure, OS-β-CD appears red when excited at a wavelength of 633nm after being stained with Nile blue (Figure a), and allicin appears green when excited at 488nm after being stained with Nile red (Figure b). In the combined image, the green allicin is wrapped by the red OS-β-CD (Figure c), which shows that OS-β-CD and allicin have a complex reaction, and allicin enters the cavity of OS-β-CD.

[0068] Figure 8 The appearance of Pickering emulsions with different oil-water ratios stabilized by OS-β-CD-allicin inclusion complex after 1d, 7d and 41d. The emulsions with a particle concentration of 2.5% and an oil phase ratio of 60%-80% can form stable emulsions when they are just prepared. After 7d of storage, the emulsions have different degrees of creaming. When the added oil phase volume is 60%-70%, the stratification phenomenon of the emulsion is more obvious. The emulsions with an oil phase volume of 75%-80% are stable and no stratification occurs. After 41d of storage, the emulsions with an oil phase volume of 75%-80% are still stable and no stratification occurs.

[0069] Fig. 9 The appearance of 2.5% OS-β-CD–allicin inclusion compound dispersion and 80% oil phase volume high internal phase Pickering emulsion after 1d, 30d, 60d, 90d, 120d and 147d. The high internal phase Pickering emulsion has good stability within 1-120d and no stratification has occurred; at the 147th day, the emulsion stratified. This shows that the OS-β-CD–allicin inclusion compound prepared after ultrasonic modification has good stability, and the storage time of its stable emulsion is 3.5 times that of the OS-β-CD–allicin inclusion compound stable emulsion without ultrasonic modification.

[0070] Fig.10The laser confocal microscopy images of the high internal phase Pickering emulsion stabilized by OS-β-CD-allicin inclusion complex. As shown in Figure (a), corn oil is excited to green at 488nm after being stained with Nile red, while the OS-β-CD-allicin inclusion complex in Figure (b) is excited to red at 633nm after being stained with Nile blue. The bright green areas and the red scattered around them in the combined image (c) indicate that the high internal phase Pickering emulsion stabilized by OS-β-CD-allicin inclusion complex is a typical O / W emulsion. In addition, it can be seen from the figure that the oil droplets are evenly and tightly distributed in the continuous phase containing the OS-β-CD-allicin inclusion complex, which makes the high internal phase Pickering emulsion have good stability.

[0071] Example 4

[0072] The high internal phase Pickering emulsion with an oil phase ratio of 80% obtained in the above embodiment is used to prepare a low-fat product:

[0073] Remove visible fascia, separate the lean meat and back fat, cut into small pieces, grind them with a meat grinder for 30 seconds respectively, add ingredients according to the proportions recorded in the following table, replace different proportions of back fat with high internal phase Pickering emulsion stabilized by OS-β-CD-allicin inclusion complex, mix well and quickly chop for 3 minutes, process into meatballs with a diameter of about 2.5 mm, cook the formed meatballs separately, take out the meatballs, cool them to room temperature, and store them at 4°C.

[0074] The formulas of low-fat meatballs made by replacing pork back fat with high internal phase Pickering emulsion in different experimental groups are shown in Table 1, and low-fat meatballs without adding high internal phase Pickering emulsion are used as controls.

[0075] Table 1 Formula for making low-fat meatballs using high internal phase Pickering emulsion to replace pork back fat

[0076]

[0077] The optimal high internal phase Pickering emulsion replacement amount was obtained for the different low-fat meatballs obtained above through cooking loss, texture, sensory evaluation and later storage conditions.

[0078] 1) Cooking loss rate is an important indicator for evaluating the degree of weight loss of meat products during the cooking process. The cooking loss rate of low-fat meatballs is calculated by measuring the weight change of meatballs before and after cooking. Fig.11As shown in the figure, as the amount of fat replacement increases, the cooking loss rate of low-fat meatballs decreases. This may be because after adding the high internal phase Pickering emulsion, the interaction between the emulsion OS-β-CD-allicin inclusion complex and the protein in the minced meat is enhanced, forming a more stable and elastic network structure, enhancing its ability to bind water, improving water holding capacity, and improving process quality. Therefore, the cooking loss rate of low-fat meatballs is reduced.

[0079] 2) Sensory evaluation has a key influence on the determination of food quality. According to the requirements of GB / T2210-2008, sensory assessors should score the organizational state, taste, color, etc. of meatballs. As can be seen from Table 2, compared with the control group (meatballs without emulsion replacing fat), the sensory scores of the organizational state and taste of low-fat meatballs increased with the increase of fat replacement, but as the fat replacement continued to increase, its score showed a downward trend. The amount of emulsion added had little effect on the color of low-fat meatballs, but when the amount of emulsion added exceeded 75%, the meatballs emitted a faint garlic smell. When the amount of high internal phase Pickering emulsion added was 50%, the sensory scores of meatballs were all very high, and the acceptance of meatballs was the highest. At this time, the interaction between the minced meat proteins was enhanced, forming a more stable and elastic network structure than the control group, and the taste was also improved.

[0080] Table 2 Sensory evaluation results of different emulsion replacement ratios

[0081]

[0082] 3) Product color is an important indicator for evaluating meat products. Appropriate meat product color can increase consumers' preference for the product and stimulate consumers to consume. The L value, a value, and b value of low-fat meatballs were measured using a colorimeter. Fig.12 The figure shows the effect of different fat replacement amounts on the color difference of low-fat meatballs. As can be seen from the figure, as the amount of fat replaced by the emulsion increases, the L value of the meatballs increases and is greater than that of the control group, while the a value and b value decrease with the amount of fat replacement. During storage, the L value of different fat replacement amounts increases with the extension of storage time, while the a value and b value decrease with the extension of storage time.

[0083] 4) The amount of fat added can significantly affect the texture and taste of meat products. The hardness, elasticity and chewiness of low-fat meatballs were measured using a texture analyzer. Fig.13It can be seen that compared with the control group, the hardness and chewiness of the meatballs increased significantly with the continuous increase in the amount of fat replacement, while the elasticity of the meatballs did not change significantly. This may be because with the increase in the amount of fat replacement, the interaction between the minced meat proteins increased, forming a more stable and elastic network structure than the control group, thereby enhancing some of the texture quality indicators of the meatballs. During the entire storage process, the hardness and chewiness of the meatballs increased with the extension of storage time, while the elasticity decreased with the extension of storage time. The change in hardness may be because the meatballs have better water retention in the early stage of storage, and the hardness of the meatballs is relatively small. As the storage time goes by, the meatballs lose water and the hardness increases accordingly.

[0084] 5) Microbial contamination is one of the main factors leading to food spoilage, which can reflect the degree of spoilage of meat products. The total colony count of low-fat meatballs was determined with reference to GB 4789.2-2016 "National Food Safety Standard for Microbiological Examination of Food Colony Count Determination". Table 3 shows the effect of different fat replacement ratios on the total colony count of low-fat meatballs during storage. It can be seen that on the 0th day, the total colony count of samples with different fat replacement amounts was not significantly different from that of the control group. As the storage time increased, the total colony count of samples with different fat replacement amounts was significantly less than that of the control group (P < 0.05). The greater the fat replacement ratio, the less contamination of the meatballs. The total colony count of the meatballs in the control group reached 9.67×10 5 , began to spoil, while the meatballs with 100% fat replacement began to spoil on the 15th day. This may be because the unstable allicin is embedded in the high internal phase Pickering emulsion used to replace fat, and allicin has a good inhibitory effect on microorganisms. As the storage time goes by, allicin is slowly released, thereby inhibiting the growth and reproduction of microorganisms in the meatballs to a certain extent.

[0085] Table 3 Total colony count results for different fat replacement ratios

[0086]

[0087] 6) pH can be used as an important indicator to examine the freshness of meat products. The pH value of low-fat meatballs was measured with reference to GB51009.237-2016 "Determination of pH value of food". Fig.14It can be seen that with the increase of storage period, the pH value of each group of samples showed a trend of first decreasing and then increasing. The pH value of the control group reached the lowest on the 3rd day, while the pH value of the experimental group (25%-100%) reached the lowest on the 6th day. On the 0th day, there was no significant difference in the pH value between the control group and the experimental group. This is because meat products, as a good buffer system, have a good buffering effect on the added emulsion and can maintain the pH value of the meatballs. With the extension of storage period, the pH value first decreased, which may be because the decomposition of glycogen and adenosine triphosphate in the meatballs produced lactic acid and phosphoric acid, respectively, resulting in a decrease in the pH value of the meatballs; then the pH value gradually increased, which may be because the number of microorganisms continued to increase. Under the action of microorganisms, protein decomposition produced alkaline substances such as ammonia and amines, causing the pH value of the meatballs to increase. And during the entire storage period, the fat replacement group mostly showed a lower pH value than the control group. The pH value of low-fat meatballs with different fat replacement ratios changed at different amplitudes. The pH value of the control group decreased the fastest, while the pH value of 100% replacement changed the slowest. This may be because the less fat the low-fat meatballs have, the slower they may spoil, and allicin has an inhibitory effect on microorganisms. Judging from the results of the total colony count at different emulsion replacement ratios, the total colony count decreased significantly with the increase in fat replacement, indicating that the emulsion does have an inhibitory effect on the growth and reproduction of microorganisms, thereby slowing down the rate of pH increase.

[0088] 7) Volatile basic nitrogen (TVB-N) is also an important evaluation index for the freshness of meat products. Its change is related to the utilization of protein by microorganisms and enzymes in meat products. The lower the TVB-N value, the higher the freshness of the meat product. The TVB-N of low-fat meatballs was measured with reference to GB5009.228-2016 "Determination of Volatile Basic Nitrogen". Fig.15 The figure shows the changes of TVB-N values ​​of low-fat meatballs with different fat replacement during storage. On the 0th day, the TVB-N values ​​of low-fat meatballs with 25% and 50% fat replacement were not much different from those of the control group. As the fat replacement degree continued to increase, the TVB-N value of the meatballs decreased significantly (P < 0.05). As the storage time increased, the TVB-N values ​​of the experimental groups with different fat replacement amounts were basically significantly less than those of the control group (P < 0.05). This may be because allicin is embedded in the high internal phase Pickering emulsion. As the fat replacement ratio increases, the antibacterial effect of allicin is better, which can inhibit the generation of TVB-N in meatballs, which is consistent with the change trend of pH and total colony count of meatballs.

[0089] 8) Thiobarbituric acid value (TBARS value) is an important indicator to measure the degree of fat oxidation in meat products. It is the result of the reaction of 2-thiobarbituric acid (TBA) with the derivatives produced by oxidative decomposition in meat products. The higher the TBARS value, the higher the degree of oxidation. The TBARS value of low-fat meatballs is calculated by measuring the absorbance value at 532nm. Fig.16 The figure shows the changes of TBARS values ​​of low-fat meatballs with different fat replacement amounts during storage. On the 0th day, the TBARS values ​​of low-fat meatballs with different fat replacement amounts were significantly lower than those of the control group (P < 0.05). This may be because the fat added to the control group was not well wrapped, and the degree of fat oxidation during the operation was high. The reduction of the amount of fat added to the meatballs can also lead to a decrease in the TBARS value. With the extension of storage time, the TBARS values ​​of the experimental groups with different fat replacement amounts were significantly lower than those of the control group (P < 0.05). The greater the fat replacement ratio, the lighter the degree of fat oxidation of the meatballs. This may be because the solid particles of the emulsion have an insulating effect. When preparing the high internal phase Pickering emulsion, the OS-β-CD-allicin inclusion complex wraps the corn germ oil inside. With the increase of the amount of high internal phase Pickering emulsion added, the minced meat forms a denser gel network structure, which reduces the contact between corn germ oil and fat and oxygen, thereby inhibiting fat oxidation. In addition, the reduction of the amount of fat added to the meatballs also leads to a decrease in the TBARS value.

[0090] Comparative Example 1

[0091] Weigh 2.4g of unmodified β-cyclodextrin particles and dissolve them in distilled water to form a 2.4% particle dispersion. Weigh allicin at a core-wall ratio of 1:8 (W / W). Mix 50% allicin ethanol solution with OS-β-CD solution and stir thoroughly. Then embed for 5 minutes under ultrasonic conditions at 225W. After the embedding reaction is completed, centrifuge, wash off the unembedded allicin on the surface of the particles with ethanol, and dry to obtain the β-cyclodextrin-allicin inclusion complex.

[0092] The β-cyclodextrin-allicin inclusion complex obtained above was dissolved in distilled water to form a 2.5% saturated solution and mixed with corn oil with a volume fraction of 60%-80%. The mixed solution was homogenized at 13000 rpm for 2 minutes using a high-speed homogenizer to obtain a stable emulsion of the β-cyclodextrin-allicin inclusion complex.

[0093] The storage stability of the emulsion obtained above was tested, see Fig.17The appearance of Pickering emulsions with different oil-water ratios stabilized by β-cyclodextrin-allicin inclusion complex after 1d, 7d, and 41d. Emulsions with a particle concentration of 2.5% and an oil phase ratio of 60%-70% can form stable emulsions when they are just prepared, but cannot form stable emulsions at 75-80%; after 7d of storage, the emulsions have different degrees of creaming. When the added oil phase volume is 60%-70%, the stratification phenomenon of the emulsion is more obvious, and the oil-water phase separation of the emulsion at 75-80% indicates that the unmodified β-cyclodextrin-allicin inclusion complex cannot prepare stable high internal phase Pickering emulsions.

[0094] Comparative Example 2

[0095] Weigh 30g of β-cyclodextrin and dissolve it in distilled water to prepare a 35% cyclodextrin suspension. Stir it with a magnetic stirrer for 20 minutes. Adjust the cyclodextrin suspension to 8.0 with a 3% NaOH solution. Slowly drop a 16.67% OSA ethanol solution at 35°C. Continue to drop 3% NaOH solution during the addition of OSA solution to maintain the pH of the reaction system. Stir continuously for 4 hours with a constant temperature magnetic stirrer. After the reaction, adjust the solution to 6–7 with 0.1mol / L HCl, centrifuge at 6000r / min for 10 minutes, discard the supernatant, wash the precipitate twice with a 70% ethanol solution by volume, wash it twice with deionized water, dry it at 40°C for 2 hours, and crush it through a 100-mesh sieve.

[0096] Weigh 2.4g of the modified OS-β-CD obtained after magnetic stirring and dissolve it in distilled water to form a 2.4% particle dispersion. Weigh allicin according to the core-wall ratio of 1:8 (W / W). Mix the 50% allicin ethanol solution with the OS-β-CD solution and stir well. Then embed it under ultrasonic conditions of 225W for 5min. After the embedding reaction is completed, centrifuge, wash the allicin not embedded on the surface of the particles with ethanol, and dry to obtain the OS-β-CD-allicin inclusion complex.

[0097] The OS-β-CD–allicin inclusion complex was dissolved in distilled water to form a 2.5% saturated solution and mixed with an oil phase. The volume fraction of the vegetable oil used was 60%–80%. A high-speed homogenizer was used to homogenize the mixed solution at 13,000 rpm for 2 minutes to obtain a stable high internal phase Pickering emulsion of the OS-β-CD–allicin inclusion complex.

[0098] Table 4 Different indicators of β-cyclodextrin, OS-β-CD without ultrasound, and OS-β-CD under optimal conditions

[0099]

[0100] As shown in Table 4, after modification by OSA, the particle size of β-cyclodextrin becomes smaller, the absolute value of potential becomes larger, and the hydrophobicity is also enhanced. The degree of substitution of OS-β-CD prepared at an ultrasonic power of 225W and an ultrasonic time of 30min is 0.0296, which is 2.1 times that of the sample without ultrasonic treatment. The particle size of OS-β-CD prepared under the optimal conditions is 1111.83nm, the potential is -17.83mV, and the activation index is 93.22%, which enhances the hydrophobicity of OS-β-CD and improves its emulsification ability.

[0101] Fig.18 The appearance of Pickering emulsions with different oil-water ratios stabilized by OS-β-CD-allicin inclusion complex after 1d, 7d and 41d. When the concentration of OS-β-CD-allicin inclusion complex without ultrasonic modification was 2.5%, the emulsions with oil phase ratio of 60%-75% could form stable emulsions when they were just prepared. Although stable emulsions could be formed at 80%, a small amount of oil precipitated immediately. After 7d of storage, the emulsions had different degrees of creaming. When the volume of added oil phase was 60%-70%, the stratification of the emulsions was more obvious, while the emulsions with oil phase ratio of 75%-80% did not stratify. After 41d of storage, the emulsions with oil phase ratio of 75%-80% began to stratify, while the high internal phase Pickering emulsion prepared by ultrasonic modified OS-β-CD-allicin inclusion complex still did not stratify at 41d, and stratification occurred at 147d.

[0102] In summary, compared with unmodified β-cyclodextrin and unultrasonic modified OS-β-CD, ultrasound-assisted OS-β-CD has better surface hydrophobicity and improves the emulsification ability of β-cyclodextrin. Moreover, compared with unmodified β-cyclodextrin-allicin inclusion complex and unultrasonic modified OS-β-CD-allicin inclusion complex, the high internal phase Pickering emulsion prepared by ultrasound-modified OS-β-CD-allicin inclusion complex has excellent storage stability. And the high internal phase Pickering emulsion can be used to replace fat in meat products, thereby improving the quality of meat products and extending the shelf life of meat products.

Claims

1. A method for preparing an octenylsuccinic acid cyclodextrin ester-allicin inclusion complex, characterized in that: Under the condition of pH 8.0, OSA was added to the β-cyclodextrin solution, and the reaction system was ultrasonically treated after being fully mixed. After washing and drying, the modified OS-β-CD particles were obtained, wherein the ultrasonic conditions were: power 225W, frequency 30kHz, temperature 35°C, working 4s, rest 2s, ultrasonic time 30min, the mass fraction of β-CD dextrin emulsion was 35%, and the addition amount of OSA was 3% of the mass of β-cyclodextrin; The modified OS-β-CD particles were dissolved in water to obtain a saturated OS-β-CD solution, which was then added to allicin dissolved in anhydrous ethanol. After addition, ultrasonic mixing and encapsulation were performed to obtain an OS-β-CD-allicin inclusion complex. The core-to-wall ratio (W / W) of allicin and OS-β-CD solution was 1:

8. The ultrasonic conditions were: power 225 W, reaction time 5 min.

2. The method for preparing the octenylsuccinate cyclodextrin ester-allicin inclusion complex according to claim 1, characterized in that: The OS-β-CD saturated solution contains 1.8%-2.6% of modified OS-β-CD particles; wherein the OS-β-CD saturated solution is prepared by adding the modified OS-β-CD particles into water under a 40-50° C. water bath condition and stirring and heating until the modified OS-β-CD particles are completely dissolved to obtain a saturated solution.

3. An octenylsuccinate cyclodextrin ester-allicin inclusion complex prepared by the method of claim 1, characterized in that: The octenyl succinate cyclodextrin ester-allicin inclusion complex is prepared according to the method described in claim 1.

4. The use of the inclusion compound according to claim 1, characterized in that: The inclusion compound is used in preparing a high internal phase Pickering emulsion.

5. A high internal phase Pickering emulsion, characterized in that: Containing the octenylsuccinate cyclodextrin ester-allicin inclusion compound as claimed in claim 1.

6. The high internal phase Pickering emulsion according to claim 5, characterized in that: The emulsion is composed of an oil phase and the octenyl succinate cyclodextrin ester-allicin inclusion compound according to claim 3, wherein the oil phase accounts for 75% to 80% of the volume of the emulsion.

7. The use of the high internal phase Pickering emulsion according to claim 5, characterized in that: Application of the emulsion in preparing lipid substitutes.

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