Psicose fatty acid ester as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of saccharide derivatives, and discloses psicose fatty acid ester and a preparation method and application thereof.The preparation method comprises the steps that 1, an alkane solvent, psicose crystals and fatty acid ester are evenly mixed and then react for 2-4 h at normal pressure under the weak base condition; (2) after the reaction in the step (1) is finished, adjusting the pH value to 6.5-7.0 to terminate the reaction, cooling, adding water, standing to obtain an organic layer, and carrying out reduced pressure distillation on the organic layer to obtain a psicose fatty acid ester crude product; and (3) extracting the psicose fatty acid ester crude product, and drying to obtain the psicose fatty acid ester. The psicose fatty acid ester with high monoester content is obtained by using psicose to replace sucrose in a substrate to perform esterification reaction with fatty acid ester, so that the requirement of food processing stability can be met, a low-calorie healthy life style can be realized, the operation is simple and convenient, the production cost is low, the method is widely applied to the field of food, and the market requirement is met.

Description

Technical Field

[0001] The invention belongs to the technical field of sugar derivatives, and particularly relates to a psicose fatty acid ester and a preparation method and application thereof. Background Art

[0002] At present, sucrose fatty acid esters are mainly used as emulsifiers and stabilizers in artificial dairy products as food additives. With the gradual increase in quality requirements, the impurities in sucrose fatty acid esters are too high, and sucrose monoesters, sucrose diesters, and sucrose polyesters need to be evenly distributed within a certain range to meet the use effect.

[0003] At present, the production method of sucrose fatty acid esters is mainly carried out through high-temperature vacuum esterification reaction. After the ester exchange reaction is completed, the organic phase solution is extracted by high-temperature vacuum distillation, and the finished product is obtained after purification and vacuum drying. However, the high-temperature vacuum and solvent removal process consumes a lot of energy, and long-term high-temperature distillation may cause the sucrose ester product to degrade. The purification steps are cumbersome, the industrial product has an irregular shape, and the uniformity is difficult to guarantee, which is difficult to meet market demand.

[0004] Allulose is a rare six-carbon ketose and is considered to be the most promising sucrose substitute. Since the metabolic pathway of allulose in the human body is different from that of ordinary sugars, moderate intake of allulose by the human body will not cause fluctuations in blood sugar and insulin levels, so allulose is superior to traditional sugars such as glucose and sucrose to a certain extent. At present, there is no academic report on allulose fatty acid esters, which has great practical potential, and its synthesis and use will also attract greater attention.

[0005] Therefore, being able to provide a D-psicose fatty acid ester and a preparation method thereof is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a D-psicose fatty acid ester and a preparation method and application thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A method for preparing psicose fatty acid ester comprises the following specific steps:

[0009] (1) mixing an alkane solvent, psicose crystals and fatty acid ester uniformly and reacting them under weak alkaline conditions at normal pressure for 2-4 hours;

[0010] (2) After the reaction in step (1) is completed, the pH value is adjusted to 6.5-7.0 to terminate the reaction, the temperature is lowered, water is added, and the mixture is allowed to stand to obtain an organic layer, and the organic layer is distilled under reduced pressure to obtain a crude product of psicose fatty acid ester;

[0011] (3) Extracting and drying the crude psicose fatty acid ester to obtain psicose fatty acid ester.

[0012] In the present invention, psicose is used to replace sucrose in a substrate to carry out esterification reaction with fatty acid esters. The raw materials are natural and psicose fatty acid esters with a high monoester content can be obtained.

[0013] Preferably, in step (1), the mass ratio of the alkane solvent, the psicose crystals and the fatty acid ester is 2.0-4.0:1.0:1.0-2.0;

[0014] The pH value of the weak alkaline condition is 8.0-9.0;

[0015] The reaction temperature is 50°C-60°C;

[0016] The weak alkaline condition is adjusted by sodium hydroxide.

[0017] According to the synthesis conditions and stability characteristics of the sugar fatty acid ester, the present invention ensures that the reaction conditions are in an optimal state by adjusting the reaction pH value to maintain at 8.0-9.0, which is beneficial to the forward progress of the reaction, improves the reaction efficiency, and ensures the stability of the allulose fatty acid ester.

[0018] Preferably, the sodium hydroxide is 3% sodium hydroxide, and the addition amount is 1.0-2.0wt% of the reaction system.

[0019] The present invention uses hydrogen hydroxide to adjust the pH value of the reaction. Under the same concentration, sodium hydroxide can increase the pH value of the solution more quickly, and a relatively small amount of addition can meet the required pH index requirements, thereby accelerating the reaction rate.

[0020] Preferably, the allulose crystals in step (1) are ground before mixing, the grinding medium diameter is 1-3 mm, the grinding speed is 1000-2000 r / min, and the grinding time is 10-30 min.

[0021] Preferably, the grinding medium is zirconia beads.

[0022] The present invention grinds the psicose crystals to reduce the particle size of the material, increase the contact area of ​​the reaction molecules, increase the active sites of the sugars involved in the reaction, and improve the yield of the psicose fatty acid ester.

[0023] Preferably, the reaction temperature in step (1) is 50-60°C.

[0024] Preferably, the alkane solvent in step (1) is at least one of n-hexane, n-heptane and isooctane;

[0025] The fatty acid ester is at least one of methyl stearate, ethyl stearate, ethyl laurate and methyl laurate.

[0026] Preferably, the alkane solvent is n-hexane, and the fatty acid ester is methyl stearate.

[0027] Preferably, hydrochloric acid is used to adjust the pH value in step (2);

[0028] The cooling is to cool to 25-30°C at a cooling rate of 5°C / h;

[0029] The adding of water is adding warm water at 25-30° C., and the amount of water added is 10-20 wt % of the psicose crystals;

[0030] The parameters of the reduced pressure distillation are: temperature of 70-100° C. and pressure of 0.09 MPa.

[0031] Preferably, the amount of warm water added is 15 wt % of the psicose crystals, and the temperature of the warm water is 25° C.

[0032] Preferably, the hydrochloric acid is 3% hydrochloric acid, and the added amount is 0.5-1.0wt% of the reaction system.

[0033] Preferably, the pressure of the extraction reactor in step (3) is 25-35 MPa, the temperature is 40-50°C, the extraction time is 1-3h, and the supercritical CO2 flow rate is 1-2L / min;

[0034] The extracted extract enters a separation kettle for separation, and the pressure of the separation kettle is 8-10 MPa and the temperature is 25-35°C.

[0035] The psicose fatty acid ester obtained according to the above-mentioned preparation method.

[0036] Application of the psicose fatty acid ester obtained according to the preparation method described above in food.

[0037] The finished product of allulose fatty acid ester prepared by the present invention has a single high-purity characteristic, has excellent emulsification, wetting, viscosity adjustment, dispersion, anti-aging, antibacterial and other functions, has stable quality and can be used for large-scale production.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention provides a psicose fatty acid ester and a preparation method and application thereof. In the present invention, psicose is used to replace sucrose in a substrate and conducts an esterification reaction with a fatty acid ester to obtain a psicose fatty acid ester with a high monoester content. The psicose fatty acid ester can meet the requirements of food processing stability and realize a healthy lifestyle with high stability and low calories. The operation is simple and the production cost is low. The ester is widely used in the food field to meet the market demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0041] Figure 1 This is a high performance liquid chromatogram of psicose and fatty acid ester before reaction in Example 1 of the present invention;

[0042] Figure 2 This is a high performance liquid chromatogram of the psicose fatty acid ester product of Example 1 of the present invention. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] A method for preparing psicose fatty acid ester comprises the following specific steps:

[0046] (1) placing 100 g of allulose crystals and 1 mm zirconium oxide beads into a sand mill at a stirring speed of 1500 r / min for a grinding time of 20 min;

[0047] (2) adding 31 g of the D-psicose crystals obtained in step (1) and 93 g of n-hexane solvent to a 250 mL reaction container, adding 46.5 g of methyl stearate while stirring, heating to 55° C., adding 3% sodium hydroxide to adjust the pH to 8.5, and reacting at normal pressure for 4 h;

[0048] (3) After the reaction is completed, the pH value is adjusted to 6.5 with 3% hydrochloric acid to terminate the reaction, and the temperature is slowly cooled to 25° C. at a cooling rate of 5° C. / h. 25° C. warm water is added under stirring in an amount of 15 wt % of the psicose crystals. After stirring for 3 min, the mixture is allowed to stand and separate to obtain an organic layer. The organic layer is subjected to reduced pressure distillation (70° C., 0.09 MPa) to remove the organic solvent, and the mixture is dried with air to obtain a crude psicose fatty acid ester.

[0049] (4) The crude product of allulose fatty acid ester is placed in an extractor, and supercritical CO2 fluid is introduced. The supercritical CO2 flow rate is 2 L / min, the pressure of the extraction reactor is 35 MPa, the temperature is 45° C., and the extraction time is 3 h. The obtained extract is placed in a separation reactor for separation. The pressure of the separation reactor is 8 MPa, and the temperature is 25° C. After the extract product is dried, allulose fatty acid ester is obtained, and the yield is about 91%.

[0050] Among them, Figure 1 is the HPLC chromatogram of Psicose and fatty acid ester before reaction. Figure 2 This is the HPLC chromatogram of the allulose fatty acid ester product. It can be seen from the figure that in the UV liquid phase spectrum, the retention time of the allulose absorption peak is 5.685min, and the retention time of the fatty acid ester absorption peak is 20.695min. After the reaction is completed, the absorption peak at 5.685min is significantly reduced, there is no absorption peak at 20.695min, and a new substance absorption peak appears at 23.98min, indicating that the esterification reaction between allulose and fatty acid ester occurs to produce allulose fatty acid ester.

[0051] Example 2

[0052] A method for preparing psicose fatty acid ester comprises the following specific steps:

[0053] (1) placing 100 g of allulose crystals and 2 mm zirconium oxide beads into a sand mill at a stirring speed of 1000 r / min for a grinding time of 30 min;

[0054] (2) adding 25 g of the D-psicose crystals obtained in step (1) and 50 g of n-heptane solvent to a 250 mL reaction container, adding 50 g of ethyl stearate while stirring, heating to 50° C., adding 3% sodium hydroxide to adjust the pH value to 9, and reacting at normal pressure for 3 h;

[0055] (3) After the reaction is completed, the pH value is adjusted to 6.8 with 3% hydrochloric acid to terminate the reaction, and the temperature is slowly cooled to 30° C. at a cooling rate of 5° C. / h. 30° C. warm water is added under stirring in an amount of 10 wt % of the psicose crystals. After stirring for 3 min, the mixture is allowed to stand and separate to obtain an organic layer. The organic layer is subjected to reduced pressure distillation (100° C., 0.09 MPa) to remove the organic solvent, and the mixture is dried with air to obtain a crude psicose fatty acid ester.

[0056] (4) The crude product of allulose fatty acid ester is placed in an extractor, and supercritical CO2 fluid is introduced. The supercritical CO2 flow rate is 1.5 L / min, the pressure of the extraction reactor is 30 MPa, the temperature is 45° C., and the extraction time is 2 h. The obtained extract is placed in a separation reactor for separation. The pressure of the separation reactor is 10 MPa and the temperature is 25° C. After the extract product is dried, allulose fatty acid ester is obtained, and the yield is about 89%.

[0057] Example 3

[0058] A method for preparing psicose fatty acid ester comprises the following specific steps:

[0059] (1) placing 100 g of allulose crystals and 3 mm zirconium oxide beads into a sand mill at a stirring speed of 2000 r / min for a grinding time of 10 min;

[0060] (2) Add 12 g of the D-psicose crystals obtained in step (1) and 48 g of isooctane solvent to a 250 mL reaction container, add 12 g of methyl laurate while stirring, heat to 60° C., add 3% sodium hydroxide to adjust the pH to 8.0, and react at normal pressure for 2 h;

[0061] (3) After the reaction is completed, the pH value is adjusted to 7.0 with 3% hydrochloric acid to terminate the reaction, and the temperature is slowly cooled to 30° C. at a cooling rate of 5° C. / h. 30° C. warm water is added under stirring in an amount of 20 wt % of the psicose crystals. After stirring for 5 min, the mixture is allowed to stand and separate to obtain an organic layer. The organic layer is subjected to reduced pressure distillation (100° C., 0.09 MPa) to remove the organic solvent, and the crude psicose fatty acid ester is obtained by air drying.

[0062] (4) The crude product of allulose fatty acid ester is placed in an extractor, and supercritical CO2 fluid is introduced. The supercritical CO2 flow rate is 1 L / min, the pressure of the extraction reactor is 25 MPa, the temperature is 40° C., and the extraction time is 2 h. The obtained extract is placed in a separation reactor for separation. The pressure of the separation reactor is 10 MPa and the temperature is 30° C. After the extract product is dried, allulose fatty acid ester is obtained, and the yield is about 85%.

[0063] Example 4

[0064] A method for preparing psicose fatty acid ester comprises the following specific steps:

[0065] (1) placing 100 g of allulose crystals and 1 mm zirconium oxide beads into a sand mill at a stirring speed of 1500 r / min for a grinding time of 20 min;

[0066] (2) adding 20 g of the D-psicose crystals obtained in step (1) and 60 g of n-hexane solvent to a 250 mL reaction container, adding 40 g of ethyl laurate while stirring, heating to 55° C., adding 3% sodium hydroxide to adjust the pH value to 8.5, and reacting at normal pressure for 3 h;

[0067] (3) After the reaction is completed, the pH value is adjusted to 6.8 with 3% hydrochloric acid to terminate the reaction, and the temperature is slowly cooled to 25° C. at a cooling rate of 5° C. / h. 25° C. warm water is added under stirring in an amount of 20 wt % of the psicose crystals. After stirring for 4 min, the mixture is allowed to stand and separate to obtain an organic layer. The organic layer is subjected to reduced pressure distillation (70° C., 0.09 MPa) to remove the organic solvent, and the crude psicose fatty acid ester is obtained by air drying.

[0068] (4) The crude product of allulose fatty acid ester is placed in an extractor, and supercritical CO2 fluid is introduced. The supercritical CO2 flow rate is 1.5 L / min, the pressure of the extraction reactor is 30 MPa, the temperature is 40° C., and the extraction time is 3 h. The obtained extract is placed in a separation reactor for separation. The pressure of the separation reactor is 8 MPa, and the temperature is 25° C. After the extract product is dried, allulose fatty acid ester is obtained, and the yield is about 87%.

[0069] Comparative Example 1

[0070] D-psicose fatty acid ester was prepared according to the method of Example 1. The difference from Example 1 was that a sand mill was not used to grind D-psicose. The other steps and operations were the same as those of Example 1. The product yield was about 65%.

[0071] Comparative Example 2

[0072] D-psicose fatty acid ester was prepared according to the method of Example 2, except that the temperature was raised to 80° C., and the other steps and operations were the same as those of Example 2. The product yield was about 50%.

[0073] Comparative Example 3

[0074] D-psicose fatty acid ester was prepared according to the method of Example 3, except that the reaction pH was adjusted to 7.0. The other steps and operations were the same as those of Example 3, and the product yield was about 46%.

[0075] The various embodiments are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to in detail.

[0076] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing psicose fatty acid ester, It is characterized in that The specific steps include: (1) mixing an alkane solvent, psicose crystals and fatty acid ester uniformly and reacting them under weak alkaline conditions at normal pressure for 2-4 hours; (2) After the reaction in step (1) is completed, the pH value is adjusted to 6.5-7.0 to terminate the reaction, the temperature is lowered, water is added, and the mixture is allowed to stand to obtain an organic layer, and the organic layer is distilled under reduced pressure to obtain a crude product of psicose fatty acid ester; (3) Extracting and drying the crude psicose fatty acid ester to obtain psicose fatty acid ester.

2. The method for preparing a psicose fatty acid ester according to claim 1, It is characterized in that In step (1), the mass ratio of the alkane solvent, the psicose crystals and the fatty acid ester is 2.0-4.0:1.0:1.0-2.0; The pH value of the weak alkaline condition is 8.0-9.0; The reaction temperature is 50-60°C; The weak alkaline condition is adjusted by sodium hydroxide.

3. The method for preparing a psicose fatty acid ester according to claim 2, It is characterized in that The sodium hydroxide is 3% sodium hydroxide, and the added amount is 1.0-2.0wt% of the reaction system.

4. The method for preparing a psicose fatty acid ester according to claim 1, It is characterized in that In step (1), the allulose crystals are ground before mixing, the grinding medium diameter is 1-3 mm, the grinding speed is 1000-2000 r / min, and the grinding time is 10-30 min.

5. The method for preparing a psicose fatty acid ester according to claim 1, It is characterized in that The alkane solvent in step (1) is at least one of n-hexane, n-heptane and isooctane; The fatty acid ester is at least one of methyl stearate, ethyl stearate, ethyl laurate and methyl laurate.

6. The method for preparing a psicose fatty acid ester according to claim 1, It is characterized in that In step (2), the pH value is adjusted using hydrochloric acid; The cooling is to cool to 25-30°C at a cooling rate of 5°C / h; The adding of water is adding warm water at 25-30° C., and the amount of water added is 10-20 wt % of the psicose crystals; The parameters of the reduced pressure distillation are: temperature of 70-100° C. and pressure of 0.09 MPa.

7. The method for preparing a psicose fatty acid ester according to claim 6, It is characterized in that The hydrochloric acid is 3% hydrochloric acid, and the added amount is 0.5-1.0wt% of the reaction system.

8. The method for preparing a psicose fatty acid ester according to claim 1, It is characterized in that The extraction reactor pressure in step (3) is 25-35 MPa, the temperature is 40-50°C, the extraction time is 1-3h, and the supercritical CO 2 Flow rate is 1-2L / min; The extracted extract enters a separation kettle for separation, and the pressure of the separation kettle is 8-10 MPa and the temperature is 25-35°C.

9. The psicose fatty acid ester obtained according to the preparation method according to any one of claims 1 to 8.

10. Use of the psicose fatty acid ester obtained by the preparation method according to any one of claims 1 to 8 in food.

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