阅读说明：本技术 一种具有核壳结构的营养盐及其结晶制备方法 (Nutrient salt with core-shell structure and crystallization preparation method thereof ) 是由 龚俊波 陈明洋 王显军 黄孟阳 余畅游 刘烨 王烁 张明宇 王静康 荀春 尹秋响 于 2020-05-18 设计创作，主要内容包括：本发明公开了一种以氯化钠为核心的核壳结构营养盐及其制备方法,将氯化钠加入55～80℃水中,配成饱和溶液；加入相对于氯化钠质量的3％～20％的一种或多种壳结构物质,恒温悬浮搅拌5～30分钟,搅拌速率为300～700转/分钟；减压蒸发,蒸发速率相对于初始总水量为1％～10％/h,时间为5～60h；蒸发总量不超60％；维持搅拌速率,恢复常压并恒温悬浮搅拌0.5～2h；经过滤、干燥,得到具有核壳结构的营养盐。壳结构质量占总质量的1％～10％。营养盐颗粒的平均圆度值在0.7以上,粒度范围100～1000微米,休止角为25°以下。实现在氯化钠粒子表面大剂量添加营养物质,工艺简单,成本低廉,易于工业化生产。(The invention discloses a core-shell structure nutrient salt taking sodium chloride as a core and a preparation method thereof, wherein the sodium chloride is added into water with the temperature of 55-80 ℃ to prepare a saturated solution; adding one or more shell structure substances accounting for 3-20% of the mass of the sodium chloride, and carrying out constant-temperature suspension stirring for 5-30 minutes at a stirring speed of 300-700 revolutions per minute; carrying out reduced pressure evaporation, wherein the evaporation rate is 1-10%/h relative to the initial total water amount, and the time is 5-60 h; the total evaporation amount is not more than 60%; maintaining the stirring speed, recovering the normal pressure, and carrying out constant-temperature suspension stirring for 0.5-2 h; filtering and drying to obtain the nutritive salt with the core-shell structure. The mass of the shell structure accounts for 1-10% of the total mass. The average circularity value of the nutrient salt particles is more than 0.7, the particle size range is 100-1000 microns, and the angle of repose is less than 25 degrees. Realizes the addition of nutrient substances on the surface of the sodium chloride particles in large dose, has simple process and low cost, and is easy for industrial production.)

1. A nutritive salt with a core-shell structure is characterized in that the core structure of particles is sodium chloride, the shell structure is a nutrient component, and the mass of the shell structure accounts for 1-10% of the total mass; the average circularity value of the nutrient salt particles is more than 0.7, the average particle size is 100-1000 microns, and the angle of repose is less than 25 degrees.

2. The nutritive salt according to claim 1, wherein the nutritive component of the shell structure is one or more of hawthorn extract, white kidney bean extract, pea protein powder, almond protein powder, rice protein powder, corn protein powder, soybean protein powder, vitamin a, vitamin D, aspartic acid, tryptophan, phenylalanine, glutamic acid, cystine, or tyrosine; there is no proportionality requirement for the various blends.

3. The method for preparing the crystals of the nutrient salt with the core-shell structure according to claim 1, which is characterized by comprising the following steps:

1) adding sodium chloride into water at the temperature of 55-80 ℃ to prepare a saturated solution;

2) adding one or more shell structure substances accounting for 3-20% of the mass of the sodium chloride, and carrying out constant-temperature suspension stirring for 5-30 minutes at a stirring speed of 300-700 revolutions per minute;

3) maintaining the stirring speed in the step 2), and carrying out reduced pressure evaporation, wherein the evaporation speed is 1-10% per hour relative to the initial total water amount, and the evaporation duration is 5-60 hours; the total evaporation amount is not more than 60% of the initial total water amount;

4) maintaining the stirring speed in the step 3), recovering the normal pressure, and carrying out constant-temperature suspension stirring for 0.5-2 h;

5) filtering and drying to obtain the nutritive salt with the core-shell structure.

4. The method of claim 2, further comprising: the drying temperature is 30-60 ℃, and the drying time is 4-12 hours under the normal pressure condition.

Technical Field

The invention belongs to the technical field of chemical engineering industrial crystallization, and particularly relates to a nutrient salt with a core-shell structure and a crystallization preparation method thereof.

Background

Sodium chloride (Sodium chloride), an ionic compound, is usually colorless cubic crystal or fine crystal powder, and is a seasoning which is widely used in the food field, commonly called as salt. The price of salt is set in China from 1 month and 1 day in 2017, and the special operation of salt is cancelled. This means that the competition of the salt market will be increasingly intense, and the development and refining of high-end salt is an effective way to improve the competitiveness of products, which is also a strong demand for improving the living standard of people in China. The salt particles are used as carriers, and various nutrient substances such as protein, vitamins, amino acid and the like are added, so that the salt with various nutrient functions is formed, has higher nutrient value than common salt, and becomes a development trend of high-end salt. The salt is an indispensable seasoning for daily diet, so compared with special taking of nutritional supplements, the mode of adding nutrients on the salt for intake is simpler and more efficient, the complex operation brought by special taking of various nutritional supplements is avoided, and the purpose of long-term stable intake of nutrients is easier to achieve. The mode of supplementing nutrient substances by utilizing nutrient salt is favored by people who live at a fast pace and need to supplement various nutrient substances.

An important technical index for developing the multifunctional nutritive salt is that the nutritive substance can be added in large dose. This is because the daily intake of salt is low, and the prerequisite for achieving a sufficient nutrient intake by attaching common nutrients such as proteins, vitamins, amino acids to salt is to increase the ratio of nutrients in each salt particle. This requirement has led to great difficulties in the development of multifunctional nutritive salts: the molecular structure of nutrients such as protein, vitamin, amino acid and the like is too different from sodium chloride, crystal particles in forms of eutectic crystal and the like cannot be formed, only a physical coating form can be adopted, the traditional granulation coating obviously improves the process difficulty and the manufacturing cost, and is not practical for products with lower selling price such as salt; meanwhile, nutrients such as protein, vitamins, amino acid and the like are easy to adhere, so that the salt is seriously caked, the particle size difference is large, the particle shape is ugly and irregular, the distribution of the nutrients is extremely uneven, and the preparation failure is finally caused in the granulation process. Due to the difficulties, the high-end salt in the market is mainly 'sea salt' containing trace elements, which greatly limits the deep development and variety diversification of the high-end salt category 'nutrient salt'.

Therefore, there is a need to develop a new technology for preparing a salt product capable of attaching large amounts of nutrients such as proteins, vitamins, amino acids, etc., achieving uniform particle size and regular particle shape, and having simple process, low cost and easy industrial production.

Disclosure of Invention

In order to overcome the defect that the conventional salt is difficult to add nutrients in a large amount and fill up the technical blank, the invention provides a nutrient salt with a core-shell structure and a crystal preparation method thereof. The nutritive salt is characterized in that the core structure of the granule is sodium chloride, the shell structure is a nutrient component, and the mass of the shell structure accounts for 1-10% of the total mass; the average circularity value of the nutrient salt particles is more than 0.7, the average particle size is 100-1000 microns, and the angle of repose is less than 25 degrees.

The shell structure contains one or more of fructus crataegi extract, white kidney bean extract, semen Pisi Sativi protein powder, semen Armeniacae amarum protein powder, rice protein powder, semen Maydis protein powder, soybean protein powder, vitamin A, vitamin D, aspartic acid, tryptophan, phenylalanine, glutamic acid, cystine, and tyrosine; there is no proportionality requirement for the various blends.

The preparation method of the nutrient salt crystal with the core-shell structure comprises the following steps:

1) adding sodium chloride into water at the temperature of 55-80 ℃ to prepare a saturated solution;

2) adding one or more shell structure substances accounting for 3-20% of the mass of the sodium chloride, and carrying out constant-temperature suspension stirring for 5-30 minutes at a stirring speed of 300-700 revolutions per minute;

3) maintaining the stirring speed in the step 2), and performing reduced pressure evaporation, wherein the evaporation speed is 1-10% per hour relative to the initial total water amount, the evaporation duration is 5-60 hours, and the total evaporation amount is not more than 60% of the initial total water amount;

4) maintaining the stirring speed in the step 3, recovering the normal pressure, and carrying out constant-temperature suspension stirring for 0.5-2 h;

5) filtering and drying to obtain the nutritive salt with the core-shell structure.

Wherein the drying condition is that the temperature is 30-60 ℃ and the drying condition is 4-12 h under the normal pressure condition.

The invention provides a nutrient salt with a core-shell structure and a crystal preparation method thereof, and creativity of the nutrient salt is as follows:

(1) realize the large-dose addition of nutrient substances on the surface of the sodium chloride particles. The key point is that in the crystallization process, the evaporation rate is controlled to be maintained in a specific supersaturation degree interval, so that an unstable interface is generated between the surface of the sodium chloride crystal and a solvent, and a large amount of nutrient substances can be firmly adhered to the surface of the sodium chloride crystal to form an obvious core-shell structure. As shown in figure 1, the core structure is sodium chloride, and the shell structure is nutrient. This supersaturation interval needs to be determined by the nucleation and growth kinetics of sodium chloride crystals. In sodium chloride crystallization, when the supersaturation degree is low, the nucleation rate and the growth rate are both slow, and the growth rate is dominant; as the supersaturation increases, the rates of both increase, with the nucleation rate increasing faster than the growth rate, and therefore after some critical point of supersaturation, the nucleation rate dominates. Under such a rule, the upper limit of the supersaturation interval of the unstable interface is the critical point of supersaturation at which the nucleation rate is transformed into the predominant rate, and the lower limit needs to be examined through a large number of experiments. Finally, the supersaturation degree control operation in the technical scheme is determined as reduced pressure evaporation, the evaporation rate is 1% -10%/h (relative to the initial total water amount), and the evaporation duration is 5-60 h (the total evaporation amount does not exceed 60% of the initial total water amount).

(2) Simple process, low cost and easy industrial production. The technical scheme can be realized by only adjusting the original sodium chloride crystallization process parameters without an additional granulating device. This advantage ensures the industrial feasibility of the technology.

(3) The shell structure may contain one or more nutrients to achieve a single or complex nutritional function. The protein extract, the vitamins and the amino acid listed in the technical method can be singly attached or uniformly mixed and then attached to the surface of the sodium chloride particles, so that a multi-category and multi-nutrition functional nutrient salt product can be realized.

(4) The nutrient salt particles are spherical particles, see figure 2, so that particle bonding in the crystallization process and caking in the later storage, transportation and sale processes are avoided, and an anti-caking agent is not required to be added. The sodium chloride in the technical scheme can form a spherical shape in the crystallization process, and because the contact area between spherical particles is extremely small, a large amount of negative agglomeration of common cubic salt under the high viscosity of nutrient substances can be avoided.

For the temperature, the evaporation rate, the stirring control and the nutrient addition amount in the method, if the temperature, the evaporation rate, the stirring control and the nutrient addition amount exceed the parameter setting range, namely, the temperature is too high or too low, the evaporation rate is too high or too low, and the stirring is too weak or too strong, the problems of supersaturation degree interval of an unstable interface of sodium chloride crystals, unqualified sphericity, preparation failure caused by the fact that a large amount of nutrient substances adhere to the crystals and the like cannot be met, and the target coating amount, granularity and sphericity cannot be obtained through preparation. The temperature, evaporation rate, stirring control and nutrient addition amount adopted in the method are optimized schemes comprehensively considering nutrient addition amount, granularity and particle shape control, production efficiency and economic efficiency.

Drawings

FIG. 1: electron microscope photo of cross section of core-shell structure nutritive salt;

FIG. 2: electron microscope photographs of the appearance of the core-shell structure nutritive salt particles;

FIG. 3: photograph of core-shell structure nutritive salt particle pile.

Detailed Description

The present invention will be described in further detail with reference to the following examples. It should not be understood that the scope of the above-described subject matter of the present invention is limited to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention.