Preparation method of novel chitosan-containing low-sodium high-salt salty agent

Abstract

The invention discloses a preparation method of a novel chitosan-containing low-sodium high-salt salty agent, and belongs to the technical field of food processing. Citric acid and chitosan are used as base materials, the cross-linked chitosan salt microspheres are prepared with the assistance of an ultrasonic technology, salt can be stably wrapped in the microspheres through the cross-linked structure of the microspheres, a better embedding effect is achieved, polysaccharide microspheres swell along with chewing of an eater in the mouth, salt is released, the salty utilization rate is increased, and the taste of the eater is improved. The solubility and hygroscopicity of the salt microspheres are improved; by controlling the cross-linked structure and the microscopic particle size in the microspheres, the continuity and the strength of the salty taste are enhanced while the total salt content used for product production is obviously reduced. According to the requirements of market development and the trend of modern food development, the product provides a new thought for developing low-sodium high-salt reagents.

Description

Technical Field

[0001] The invention relates to a method for preparing a low-sodium high-salt salty flavor enhancer, in particular to a method for preparing a low-sodium high-salt salty flavor enhancer containing chitosan assisted by ultrasound. Background Art

[0002] Salt is one of the electrolytes necessary for the human body. It helps maintain normal acid-base balance and water balance, and can also extend the shelf life of food and improve the taste. Our human body must take in a certain amount of salt every day to ensure sufficient sodium content in order to maintain the balance of substances in the body. However, if you take in too much, it will break the body's balance and cause harm to the body. As people's health awareness continues to increase, the wave of "low-salt life" has gradually emerged, and people are paying more and more attention to the "salt reduction" action. Therefore, it is urgent to develop a product that can ensure people's health while not losing flavor. At present, in the medical field, people have examined the performance of drug sustained release by encapsulating drugs in gel microspheres with core-shell structures. This product applies this property to the food field. Citric acid and chitosan are used as the base materials, and cross-linked chitosan salt microspheres are prepared with the assistance of ultrasonic technology. The cross-linked structure of the microspheres can stably wrap the salt inside, achieving a better embedding effect. As the consumer chews in the mouth, the polysaccharide microspheres swell and the salt is released, which increases the utilization rate of the salty taste and improves the solubility and hygroscopicity of the salt microspheres. By controlling the cross-linked structure and microscopic particle size inside the microspheres, the total salt used in the production of the product is significantly reduced, while the persistence and intensity of the salty taste are enhanced. Summary of the invention

[0003] In view of the above problems, the present invention provides a method for preparing a low-sodium, high-salt salt flavor enhancer. The cross-linked chitosan salt microspheres are prepared with the assistance of ultrasonic technology, providing an innovative strategy for preparing low-sodium, high-salt agents. The release of salt is regulated based on the structure of the salt microspheres, and the total salt used in product production is significantly reduced while enhancing the persistence and intensity of the salty taste. It will effectively improve phenomena such as excessive salt intake or the inability to correctly select low-salt products, and can effectively reduce health risks associated with high-salt intake, maintain a healthy lifestyle, and prevent chronic diseases. At the same time, it improves the quality of low-salt products and meets the dual needs of consumers for health and taste buds, which also conforms to the development trend of improving health awareness, scientific and technological progress, and sustainable development.

[0004] In order to achieve the above effect, the technical solution adopted by the present invention is as follows:

[0005] The first object of the present invention is to provide a method for preparing cross-linked chitosan, comprising the following steps:

[0006] 1.0 g chitosan was dissolved in 2 M citric acid solution at 80-90 °C for 1-4 h. After cooling the solution, the pH was adjusted to 2-5 with 4 M sodium hydroxide. The solution was allowed to stand for 1 h and then centrifuged at 8000 × g for 15 min at 4 °C. The obtained sediment was washed with distilled water until pH = 7 to obtain the sample. The sample was freeze-dried for 14 h to obtain citric acid cross-linked chitosan, and the product was named CsC-RF.

[0007] Preferably, the preparation process is as follows: 1.0 g of chitosan is dissolved in a 2 M citric acid solution at 80-90 °C for 1-4 h under an ultrasonic frequency of 50 W, an amplitude of 40%, and a radio frequency treatment of 15 min. After cooling the solution, the pH value is adjusted to 2-5 with 4 M sodium hydroxide.

[0008] Preferably, the preparation process is as follows: 1.0 g of chitosan is dissolved in a 2 M citric acid solution at 80-90 °C for 1-4 h under an ultrasonic frequency of 100 W, an amplitude of 40%, and a radio frequency treatment of 15 min. After cooling the solution, the pH value is adjusted to 2-5 with 4 M sodium hydroxide.

[0009] Preferably, the preparation process is as follows: 1.0 g of chitosan is dissolved in a 2 M citric acid solution at 80-90 °C for 1-4 hours under an ultrasonic frequency of 200 W, an amplitude of 40%, and a radio frequency treatment of 15 min. After cooling the solution, the pH value is adjusted to 2-5 with 4 M sodium hydroxide.

[0010] The second object of the present invention is to provide a method for preparing cross-linked chitosan salt microspheres, comprising the following steps:

[0011] Under the same conditions as CsC-RF, 100 mL of 2 M citric acid solution was treated for 6 h at 80-90 °C using a WS constant temperature water bath shaker, and then the pH of the solution was adjusted to 4.0 with 4 M sodium hydroxide. After centrifugation at 8000 × g for 15 min, the precipitate was washed and freeze-dried, named CsC-WB, and CsC-RF and NaCl were dissolved in 50 mL of distilled water at a ratio of 1:1, 1:2, 1:3, 2:1 or 3:1, and the pH of the solution was adjusted to 2-5. After 3 h, the solution was freeze-dried to obtain CsC salt microspheres, and the product was labeled as CsC-RF-NaCl.

[0012] Preferably, the preparation process is: CsC-RF and NaCl are dissolved in 50 mL of distilled water at a ratio of 1:1, and the pH value of the solution is adjusted to 2-5. After 3 h, the solution is freeze-dried to obtain CsC salt microspheres, and the product is labeled as CsC-RF-NaCl-Ⅰ.

[0013] Preferably, the preparation process is: CsC-RF and NaCl are dissolved in 50 mL of distilled water at a ratio of 1:2, and the pH value of the solution is adjusted to 2-5. After 3 h, the solution is freeze-dried to obtain CsC salt microspheres, and the product is labeled as CsC-RF-NaCl-Ⅱ.

[0014] Preferably, the preparation process is: dissolve CsC-RF and NaCl in 50 mL of distilled water at a ratio of 1:3, and adjust the pH value of the solution to 2-5. After 3 h, freeze-dry the solution to obtain CsC salt microspheres, and label the product as CsC-RF-NaCl-Ⅲ.

[0015] Preferably, the preparation process is: CSC-RF and NaCl are dissolved in 50 mL of distilled water at a ratio of 2:1, and the pH value of the solution is adjusted to 2-5. After 3 h, the solution is freeze-dried to obtain CsC salt microspheres, and the product is labeled as CsC-RF-NaCl-IV.

[0016] Preferably, the preparation process is: dissolve CsC-RF and NaCl in 50 mL of distilled water at a ratio of 3:1, and adjust the pH value of the solution to 2-5. After 3 h, freeze-dry the solution to obtain CsC salt microspheres, and label the product as CsC-RF-NaCl-V.

[0017] The cross-linked chitosan salt microspheres prepared by the method of the present invention have high stability and Na + With Cl - The Na+ content of the salt microspheres is also evenly distributed in the microspheres, which shows excellent hygroscopicity and solubility. Similarly, this shows that the product can dissolve quickly in the saliva of the mouth and produce a salty taste. + The content is lower than that of NaCl, and these salt microsphere particles show obvious utilization potential in the preparation of low-salt foods. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Flow chart for the preparation of salt microspheres

[0019] Figure 2 Solubility observation diagram of ultrasound-assisted preparation of cross-linked chitosan

[0020] Figure 3 Sensory evaluation results of cross-linked chitosan salt microspheres

[0021] Figure 4 Microscopic morphology observation diagram of Experimental Example 6 DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below in conjunction with the embodiments of the present invention. The described embodiments are used to explain the present invention but do not limit the present invention:

[0023] Example 1

[0024] 1.0 g chitosan was dissolved in 2 M citric acid solution at 80-90 °C for 1-4 h under 50 W ultrasonic frequency, 40% amplitude, and 15 min radio frequency treatment. After cooling the solution, the pH value was adjusted to 2-5 with 4 M sodium hydroxide.

[0025] Example 2

[0026] 1.0 g chitosan was dissolved in 2 M citric acid solution at 80-90 °C for 1-4 h under 50 W ultrasonic frequency, 40% amplitude, and 15 min radio frequency treatment. After cooling the solution, the pH value was adjusted to 2-5 with 4 M sodium hydroxide.

[0027] Example 3

[0028] 1.0 g chitosan was dissolved in 2 M citric acid solution at 80-90 °C for 1-4 h under 50 W ultrasonic frequency, 40% amplitude, and 15 min radio frequency treatment. After cooling the solution, the pH value was adjusted to 2-5 with 4 M sodium hydroxide.

[0029] The sample solutions prepared in Examples 1 to 3 of the present invention were allowed to stand for 1 h, and then centrifuged at 8000×g for 15 min at 4°C. The obtained sediment was washed with distilled water until pH=7 to obtain a sample. The sample was freeze-dried for 14 h to obtain CsC-RF. CsC-RF and NaCl were dissolved in 50 ml of distilled water at a ratio of 1:1.

[0030] In this process, if Figure 2 As shown, from data analysis and state comparison (sample in the middle position), we found that the salt microsphere dissolution effect was best when ultrasonicated at a frequency of 150 W for 15 min.

[0031] Example 4

[0032] CsC-RF and NaCl were dissolved in 50 mL of distilled water at a ratio of 1:1, and the pH of the solution was adjusted to 2-5. After 3 h, the solution was freeze-dried to obtain CsC salt microspheres, and the product was labeled as CsC-RF-NaCl-Ⅰ.

[0033] Example 5

[0034] CSC-RF and NaCl were dissolved in 50 mL of distilled water at a ratio of 1:2, and the pH of the solution was adjusted to 2-5. After 3 h, the solution was freeze-dried to obtain CsC salt microspheres, and the product was labeled as CsC-RF-NaCl-Ⅱ.

[0035] Example 6

[0036] CSC-RF and NaCl were dissolved in 50 mL of distilled water at a ratio of 1:3, and the pH of the solution was adjusted to 2-5. After 3 h, the solution was freeze-dried to obtain CsC salt microspheres, and the product was labeled as CsC-RF-NaCl-Ⅲ.

[0037] Example 7

[0038] CSC-RF and NaCl were dissolved in 50 mL of distilled water at a ratio of 2:1, and the pH of the solution was adjusted to 2-5. After 3 h, the solution was freeze-dried to obtain CsC salt microspheres, and the product was labeled as CsC-RF-NaCl-Ⅳ.

[0039] Example 8

[0040] CSC-RF and NaCl were dissolved in 50 mL of distilled water at a ratio of 3:1, and the pH of the solution was adjusted to 2-5. After 3 h, the solution was freeze-dried to obtain CsC salt microspheres, and the product was labeled as CsC-RF-NaCl-V.

[0041] Sensory evaluation was performed on Examples 4 to 5 of the present invention to evaluate the persistence and intensity of their saltiness. All sensory evaluations were conducted in a sensory evaluation room, and each experiment was repeated three times. In the comparative evaluation of saltiness, the evaluation members were not trained, but were informed of the purpose of the test. The members consisted of 6 student volunteers, including 4 girls and 2 boys, aged between 18 and 22 years old. The volunteers had no history of taste or smell disorders and agreed to the standard sample evaluation procedure (ISO 8586) before participating. The volunteers participated in the evaluation test of the saltiness comparison of different salt solutions. Salt microspheres were added to the salt solution (about 50 mM) at a concentration of 0.1 wt%. The panelists gave each volunteer 5 mL of Cs salt solution and asked them to hold the solution in their mouths for 10 s and then spit it out. The volunteers then evaluated the relative saltiness of the samples based on a 50 mM NaCl solution. Between tasting the samples twice, the panelists were required to rinse their mouths thoroughly with water for 2 min before the next evaluation. The relative saltiness of the sample is expressed as:

[0042] Among them, -, no difference in saltiness or slightly lighter; +, slightly salty; + +, relatively salty; +++, very salty. From the evaluation results, it can be concluded that the ratio of 1:3 in Example 6 can best achieve the expected best effect.

[0043] Table 1 Sensory evaluation results of CsC salt microspheres

[0044]

[0045] like Figure 3As shown in Table 1, 6 sensory evaluation panel members conducted sensory evaluation and comparison according to the cross-linked salt microspheres obtained in Examples 4 to 8. Example 6 had a moderate salty taste and a good flavor score. As shown in Table 2, Example 6 had a 20% and 10% improvement in color compared to Example 4 and Example 5, respectively, and the color was uniform and nearly transparent. The microscopic morphology of the salt microspheres of Experimental Example 6 was observed using a scanning electron microscope at a magnification of 10,000 times and at 15 kV, as shown in FIG. Figure 4 As shown, the microspheres were observed to be irregular spherical, rounded and with small pore sizes, which further indicated that the ratio of Example 6 was the best ratio.

[0046] Table 2 Sensory evaluation results of CsC salt solution

[0047]

[0048] Finally, it should be noted that the above embodiments are only used to help understand the technical solutions and core ideas of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein, and these modifications or replacements also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a low-sodium high-salt salty flavor enhancer, characterized in that: The preparation method is as follows: (1) 1.0 g chitosan was treated at an ultrasonic frequency of 150 W and an amplitude of 40% for 15 min, dissolved in a 2 M citric acid solution in a water bath at 80-90 °C for 1-4 h, and after cooling the solution, the pH value was adjusted to 2-5 with 4 M sodium hydroxide; (2) The solution was allowed to stand for 1 h and then centrifuged at 8000 × g for 15 min at 4 °C. The sediment was washed with distilled water until pH = 7 to obtain a sample. The sample was freeze-dried for 14 h to obtain citric acid cross-linked chitosan, which was named CsC-RF. (3) Under the same conditions as CsC-RF, 100 mL of 2 M citric acid solution was treated at 80-90 °C using a WS constant temperature water bath shaker for 6 h, and then the pH of the solution was adjusted to 4.0 with 4 M sodium hydroxide; (4) After centrifugation at 8000 × g for 15 min, the precipitate was washed and freeze-dried and named CsC-WB. CsC-RF and NaCl were dissolved in 50 mL of distilled water at different ratios and the pH value of the solution was adjusted to 2-5. After 3 h, the solution was freeze-dried to obtain CsC salt microspheres, which were labeled as CsC-RF-NaCl.

2. The preparation method according to claim 1, characterized in that: The ultrasonic conditions in step (1) are as follows: ultrasonic frequency 150W, 15min, water bath temperature 80-90°C, water bath time 1-4h, and the solution pH is adjusted to 2-5.

3. The preparation method according to claim 1, characterized in that: In step (2), the centrifugal force is 8000×g, the centrifugal time is 15 min, and the pH of the sediment is adjusted to 7.

4. The preparation method according to claim 1, characterized in that: In step (3), the water bath temperature is 80-90° C. for 6 hours, and the pH of the solution is adjusted to 4.

0.

5. The preparation method according to claim 1, characterized in that: In step (4), the centrifugal force is 8000×g, the centrifugal time is 15 min, and the pH of the sediment is adjusted to 2-5.

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