阅读说明：本技术 一种香芹酚微胶囊及其制备方法 (Carvacrol microcapsule and preparation method thereof ) 是由 李才明 刘彤晖 李兆丰 顾正彪 李泽西 班宵逢 洪雁 程力 于 2019-10-31 设计创作，主要内容包括：本发明公开了一种香芹酚微胶囊及其制备方法,属于油脂微胶囊化技术领域。采用淀粉基复合型壁材包被香芹酚,淀粉基壁材是由CGT酶作用于淀粉或麦芽糊精而得,包括环糊精、糊精以及多种葡聚糖。本发明中香芹酚微胶囊制备方法具体包括：使用CGT酶作用于淀粉制备环糊精,先对淀粉进行液化糊化预处理,再加入CGT酶和香芹酚,反应完成后添加乳化剂,对乳状液进行剪切和均质,喷雾干燥得到香芹酚微胶囊。本发明在纯β-环糊精/香芹酚包合物的基础上进行了改进,香芹酚微胶囊在稳定性、溶解性以及负载量等都具有明显优势。本发明成本低廉、操作方便、绿色环保,生产工艺简单,适合实际生产中大规模的推广应用。(The invention discloses a carvacrol microcapsule and a preparation method thereof, belonging to the technical field of oil microencapsulation.A starch-based composite wall material is adopted to coat carvacrol, the starch-based wall material is obtained by the action of CGT enzyme on starch or maltodextrin and comprises cyclodextrin, dextrin and a plurality of glucans.)

1. A preparation method of carvacrol microcapsules is characterized by comprising the following steps:

(1) taking starch milk or maltodextrin solution as a raw material, adding CGT enzyme for liquefaction, and simultaneously heating and gelatinizing to prepare starch or maltodextrin gelatinizing solution;

(2) adding CGTase and carvacrol into the gelatinized liquid obtained in the step (1) under stirring, and stirring for reaction;

(3) adding an emulsifier into the reaction liquid in the step (2), and stirring for reaction;

(4) and (4) shearing the reaction liquid in the step (3), homogenizing, and carrying out spray drying to obtain the carvacrol microcapsules.

2. The preparation method of carvacrol microcapsules according to claim 1, wherein the starch in step (1) is one or more of tapioca starch, corn starch, waxy corn starch, potato starch, rice starch and wheat starch, and the maltodextrin is maltodextrin derived from the starch and having a DE value of 5-25.

3. The preparation method of the carvacrol microcapsules according to claim 1 or 2, wherein the CGTase is added in the step (1) in an amount of 1-4U/g of starch or maltodextrin wet base, the gelatinization temperature is 80-90 ℃, the CGTase is continuously stirred for 30-60 min at the gelatinization temperature until the gelatinization is complete, and the temperature is reduced to 50 ℃.

4. The preparation method of the carvacrol microcapsules according to claim 1, wherein the addition amount of the CGTase in the step (2) is 2U/g of starch or maltodextrin wet base, and the mass ratio of carvacrol to starch or maltodextrin is 1 (4-10).

5. A preparation method of carvacrol microcapsules according to claim 1 or 4, characterized in that the continuous stirring reaction time of the step (2) at 50 ℃ is 4-12 hours.

6. The method for preparing carvacrol microcapsules according to claim 1, wherein the emulsifier in step (3) is one or more of tween, sucrose ester, span, xanthan gum, arabic gum and the like, and the mass ratio of the emulsifier to starch or maltodextrin is 1: 20.

7. The preparation method of carvacrol microcapsules according to claim 1, wherein in the step (4), the shearing speed is 9000-12000 rpm, the shearing time is 2-5 min, and the batch time is 5s every 30 s; the homogenizing pressure is 20-50 MPa, and the homogenizing times are 2-3 times.

8. Carvacrol microcapsules obtainable by a process according to any one of claims 1 to 7.

9. An alternative to an antibiotic feed additive comprising carvacrol microcapsules as claimed in claim 7.

10. Use of carvacrol microcapsules according to claim 8 for the preparation of a substitute for antibiotic additives for feed.

Technical Field

The invention relates to a carvacrol microcapsule and a preparation method thereof, belonging to the technical field of oil microencapsulation.

Background

Carvacrol (isothymol, C)₁₀H₁₄O) is a phenolic monoterpene compound extracted from essential oil of origanum vulgaris leaves, thyme, bergamot and other plants, has strong bacteriostasis and oxidation resistance, and has more broad-spectrum bacteriostasis than other volatile essential oil due to the existence of free hydroxyl and phenolic groups in carvacrol. The carvacrol has the functions of strong antibacterial activity, small required dosage, environmental protection, safe use, no side effect and the like, and is considered as a potential substitute of the antibiotic feed additive. However, carvacrol is insoluble in water, has poor stability, is easy to volatilize and oxidize, and has special smell which is not easy to accept, so that the practical application is difficult.

Cyclodextrin is a closed cyclic molecule formed by hydrolyzing and cyclizing starch, glycogen, glucan polymer and the like under the catalysis of cyclodextrin glucosyltransferase (CGTase), and is formed by connecting 6 or more than 6D-glucopyranoses through α -1, 4-glycosidic bonds, the most common and industrially most widely applied cyclodextrins are α, β and gamma-cyclodextrin, respectively comprise 6, 7 and 8 glucose residues, and the glucose residues are acid-resistant, heat-resistant, alkali-resistant, non-hygroscopic, free of fixed melting point and good in thermal stability.

The carvacrol has good potential application value due to broad-spectrum antibacterial activity, but has the problems of easy volatilization and easy oxidation, and the cyclodextrin is acted on the carvacrol to form an inclusion compound by utilizing the special structure of the cyclodextrin which is externally hydrophilic and internally hydrophobic, so that the volatility and the easy oxidation of the cyclodextrin can be effectively improved, the special smell can be masked, and the storage life can be prolonged. If the cyclodextrin product is directly used as a wall material to perform inclusion on carvacrol, the defects of high cost, low loading capacity, poor solubility and the like exist, and the preparation of the carvacrol inclusion compound by combining the cyclodextrin production process is not reported.

Disclosure of Invention

The invention provides a method for clathrating carvacrol by an enzyme method, which combines the processes of synthesizing cyclodextrin by the enzyme method and clathrating carvacrol by the cyclodextrin, and comprises the steps of preparing cyclodextrin by a CGT enzyme method, adding carvacrol in the preparation process, adding an emulsifier after reaction, homogenizing, and carrying out spray drying, thereby reducing the cost.

The first purpose of the invention is to provide a preparation method of carvacrol microcapsules.

The preparation method of the carvacrol microcapsule comprises the following steps: CGTase acts on starch to prepare cyclodextrin, the starch is subjected to liquefaction and gelatinization pretreatment, the CGTase and carvacrol are added, an emulsifier is added after the reaction is finished, the emulsion is sheared and homogenized, and the carvacrol microcapsule is obtained by spray drying.

The preparation method of the carvacrol microcapsule comprises the following steps:

(1) taking starch milk or maltodextrin solution as a raw material, adding CGT enzyme for liquefaction, and simultaneously heating and gelatinizing to prepare starch or maltodextrin gelatinizing solution;

(2) adding CGTase and carvacrol into the gelatinized liquid obtained in the step (1) under stirring, and stirring for reaction;

(3) adding an emulsifier into the reaction liquid in the step (2), and stirring for reaction;

(4) and (4) shearing the reaction liquid in the step (3), homogenizing, and carrying out spray drying to obtain the carvacrol microcapsules.

In one embodiment of the invention, the starch in the step (1) is one or more of tapioca starch, corn starch, waxy corn starch, potato starch, rice starch and wheat starch, and the maltodextrin is maltodextrin derived from the starch and has a DE value of 5-25.

In one embodiment of the invention, the addition amount of the liquefied CGTase in the step (1) is 1-4U/(g of starch or maltodextrin wet base), the gelatinization temperature is 80-90 ℃, the mixture is continuously stirred for 30-60 min at the gelatinization temperature until the gelatinization is complete, and the temperature is reduced to 50 ℃.

In one embodiment of the invention, the addition amount of the CGTase in the step (2) is 2U/(g of starch or maltodextrin wet base), and the mass ratio of carvacrol to starch or maltodextrin is 1 (4-10).

In one embodiment of the present invention, the reaction time of the continuous stirring at 50 ℃ in the step (2) is 4 to 12 hours.

In one embodiment of the invention, the emulsifier in step (3) is one or more of tween, sucrose ester, span, xanthan gum, arabic gum and the like, and the mass ratio of the emulsifier to the starch or maltodextrin is 1: 20.

In one embodiment of the present invention, the continuous stirring time at 50 ℃ in step (3) is 20 min.

In one embodiment of the invention, in the step (4), the shearing speed is 9000-12000 rpm, the shearing time is 2-5 min, the shearing is performed once every 30s, and the intermittent time is 5 s; the homogenizing pressure is 30-40 MPa, and the homogenizing times are 2-3 times.

In one embodiment of the present invention, the spray drying conditions in step (4) are: the air inlet temperature is 180-185 ℃, the air outlet temperature is 85-95 ℃, and the feeding flow is 20-22 mL/min.

The invention has the beneficial effects that:

(1) according to the invention, based on the process of synthesizing cyclodextrin by using an enzyme method, carvacrol is added in the process of preparing cyclodextrin, the carvacrol can not only remove the product inhibition phenomenon of cyclodextrin to a certain extent, but also can be complexed with the product cyclodextrin to form a more stable inclusion compound, and a compound organic solvent is not required to be used, so that the cost is greatly saved.

(2) When the CGTase acts on starch, besides cyclodextrin, dextrin, glucan and other substances are generated, the dextrin, the glucan and other substances can be compounded with cyclodextrin components in the microcapsule for use to form a compound microcapsule, and compared with a pure cyclodextrin/carvacrol clathrate compound, the solubility and the carvacrol carrying capacity are both obviously increased.

(3) The wall material of the carvacrol microcapsule prepared by the invention is CGT enzyme zymolyte of starch or maltodextrin, and the microcapsule structure is formed by utilizing the spontaneous coupling effect of carvacrol and a reaction system, so that the separation and purification are not needed, and the cost is greatly reduced.

(4) The implementation method is simple and convenient, is suitable for industrial production and has low cost. The carvacrol microcapsule prepared by the invention has good embedding effect, can better improve the solubility and instability of carvacrol, prolongs the storage period and ensures the quality of products.

Drawings

FIG. 1 effect of different liquefaction enzyme addition amounts on cyclodextrin production.

FIG. 2 shows the change of the cyclodextrin production at different reaction times.

Detailed Description

1. The content of α -cyclodextrin, β -cyclodextrin and gamma-cyclodextrin in the reaction emulsion is measured according to the following method:

(1) adding 1-2 mL of emulsion into about 30mL of boiled 10mM phosphate buffer (pH 6.5), breaking the inclusion structure of carvacrol/cyclodextrin in boiling water bath for 10min, diluting to 50-100 mL with the same phosphate buffer, mixing uniformly, centrifuging (8000rpm, 10min), and taking the supernatant to be tested.

(2) α -determination of cyclodextrin content, taking the solution to be tested treated in step (1), adding 1.0mL of 1.0M hydrochloric acid solution, adding 1.0mL of 0.1mM methyl orange solution prepared by 10mM phosphate buffer solution, standing at room temperature for 20min to ensure color stability, and determining absorbance at 505nm, taking the buffer solution as a blank group, establishing a standard curve by using α -cyclodextrin standard solution, calculating the concentration of α -cyclodextrin in the solution to be tested, and multiplying the concentration by the corresponding volume to obtain α -cyclodextrin content.

(3) β -determination of cyclodextrin content by adding 3.5mL of 30mM NaOH into the solution to be tested treated in step (1), and then adding0.5mL of 5mM Na was added₂CO₃And (3) placing 0.02% (w/v) phenolphthalein solution prepared from the solution at room temperature for 20min to ensure stable color development, measuring the absorbance at 550nm, establishing a standard curve by using β -cyclodextrin standard solution by using a buffer solution as a blank group, calculating the concentration of β -cyclodextrin in the solution to be measured, and multiplying the concentration by the corresponding volume to obtain the β -cyclodextrin content.

(4) Determination of the content of gamma-cyclodextrin: taking the solution to be tested treated in the step (1), adding 50 mu L of 1.0M hydrochloric acid solution, then adding 2mL of 0.2M, pH 4.2.2 citric acid buffer solution and 100 mu L of 5mM bromocresol green solution, standing at room temperature for 20min until color development is stable, and measuring the absorbance at 630 nm. And (3) taking the buffer solution as a blank group, establishing a standard curve by using the gamma-cyclodextrin standard solution, calculating the concentration of the gamma-cyclodextrin in the solution to be detected, and multiplying the concentration by the corresponding volume to obtain the content of the gamma-cyclodextrin.

2. The determination of the carvacrol content in the emulsion or powder product adopts an ultraviolet-spectrophotometer method:

putting 0.1g of sample into a centrifuge tube, adding 10mL of absolute ethyl alcohol, oscillating for 1min, carrying out ultrasonic treatment for 10min, and standing for 12h to fully extract carvacrol by the ethyl alcohol. Centrifuging at 3500rpm for 15min, collecting supernatant 1mL, diluting 10-20 times, measuring light absorption value at 270nm, establishing standard curve with carvacrol standard solution, and calculating carvacrol content.

The invention is further illustrated by the following examples.