阅读说明：本技术 功能性食用淀粉的制备方法 (Preparation method of functional edible starch ) 是由 佟毅 王灿 代建军 田颖 许克家 吕哲 田博 于 2020-11-20 设计创作，主要内容包括：本发明涉及食品加工领域,具体涉及一种制备功能性食用淀粉的方法,该方法包括以下步骤：(1)将淀粉原料与醇混合配制成淀粉乳,向淀粉乳中加入碱金属盐的醇溶液以调节pH为碱性；(2)对步骤(1)所得产物依次进行浓缩和分散；(3)采用逐步升温干燥法对分散的产物进行干燥。该方法具有操作较为简单安全,并且采用该方法制备的功能性食用淀粉具有品质高、质量稳定且食用安全性高等优点。(The invention relates to the field of food processing, in particular to a method for preparing functional edible starch, which comprises the following steps: (1) mixing a starch raw material with alcohol to prepare starch milk, and adding an alkali metal salt alcohol solution into the starch milk to adjust the pH to be alkaline; (2) sequentially concentrating and dispersing the product obtained in the step (1); (3) drying the dispersed product by a gradual heating drying method. The method is simple and safe to operate, and the functional edible starch prepared by the method has the advantages of high quality, stable quality, high edible safety and the like.)

1. A method for preparing functional edible starch, which is characterized by comprising the following steps:

(1) mixing a starch raw material with alcohol to prepare starch milk, and adding an alkali metal salt alcohol solution into the starch milk to adjust the pH to be alkaline;

(2) sequentially concentrating and dispersing the product obtained in the step (1);

(3) drying the dispersed product by a gradual heating drying method.

2. The process of claim 1, wherein the starch feedstock in step (1) has a moisture content of 10-20 wt.%;

and/or, the dry content of the starch milk in the step (1) is 30-40 wt%.

3. The process according to claim 1, wherein the alcohol in step (1) is selected from ethanol and/or propanol;

and/or, in the step (1), the alkali metal salt is selected from at least one of sodium carbonate, potassium carbonate and sodium bicarbonate.

4. The process according to claim 1, wherein the pH of the starch milk in step (1) is adjusted to 9-9.5;

and/or the alcoholic solution of the alkali metal salt is an ethanol solution with the alkali metal salt concentration of 1-10 wt%;

preferably, the alcoholic solution of alkali metal salt is an ethanol solution with a sodium carbonate concentration of 1-10 wt%.

5. The method according to claim 1, wherein the concentration in the step (2) is carried out under the condition that the dry content in the concentrated starch milk is more than 40 wt%, preferably 50-60 wt%;

and/or, the dispersing conditions in step (2) are such that the particle size of the resulting product is in the range of 0.1 to 1 mm.

6. The method of claim 1, wherein the gradual temperature rise drying method in step (3) comprises a primary drying, a secondary drying and a tertiary drying in sequence, wherein the primary drying is performed under conditions such that the moisture content in the primary dried product is 5-10 wt%;

and/or the conditions of the secondary drying are such that the moisture content in the secondary dried product is less than 5% by weight and more than 3% by weight;

and/or, the conditions of the third drying are such that the moisture content in the third dried product is less than 3 wt%.

7. The method of claim 6, wherein the temperature of the secondary drying is 60-80 ℃ higher than the temperature of the primary drying;

and/or the temperature of the third drying is 20-40 ℃ higher than that of the second drying.

8. The method of claim 1 or 6, wherein the temperature-gradual drying method in step (3) comprises the steps of:

A. drying the dispersed product at 40-50 deg.C for 2-10 h;

B. carrying out secondary drying on the primary dried product at the temperature of 110-130 ℃ for 1-2 h;

C. the secondary dried product is dried for three times at the temperature of 150 ℃ and 170 ℃ for 1-3 h.

9. The method according to claim 1, wherein the method further comprises adjusting the pH of the dried product to 4-6 with an acid, and then washing, drying, pulverizing and sieving the obtained product in order to obtain functional edible starch;

preferably, the acid is selected from citric acid and/or hydrochloric acid.

10. The method of claim 9, wherein the manner of washing comprises: at least one of leaching, dissolving and swirling washing;

and/or, the drying mode is at least one of vacuum drying, oven drying and boiling drying;

and/or the crushing mode is selected from grinding and/or extrusion.

Technical Field

The invention relates to the field of food processing, in particular to a preparation method of functional edible starch.

Background

Modified starch is obtained by physically, chemically or biologically modifying the granular structure of starch on the basis of native starch, thereby imparting properties which are not possessed by native starch, such as slowing down retrogradation, improving cooking characteristics, increasing the freeze-thaw stability of starch paste, improving the transparency and gloss of starch paste and gel, improving the processability and tolerability of the product, and making it suitable for a particular use. The modified starch is widely applied to the food industry, and can be used as a plurality of functional additives to improve the food quality or develop new varieties, reduce the production cost and optimize the production process.

The physical method will become a hot point for developing starch modification technology in the future due to the unique advantages of the technology and related products. Firstly, the physically modified starch has the properties of nature, no chemical addition and the like, has the application characteristics superior to those of natural starch, and meets the requirements of consumers on safety, health and high quality of processed foods; secondly, the physical method greatly enriches the current modification means mainly based on the chemical method, provides more possibilities for the compound modification of starch, and meets the requirements of food enterprises on the multifunction and differentiation of modified starch; finally, the physical method has no waste water and byproducts in the production process, has high added value of products, and meets the requirements of the industry and government on green and efficient growth of food industry. In conclusion, physical denaturation becomes an important development trend of starch denaturation in the future, and the progress of the process and application technology of the physical denaturation continuously pushes the healthy and rapid forward development of the modified starch industry.

CN107383219A discloses a method for preparing modified starch by kneading starch and an aqueous solution of an alkali metal salt in a kneader, drying, crushing and sieving, performing heat treatment in a pressure-resistant closed container and an ethyl acetate medium, filtering and recovering a solvent, then performing water washing and pH adjustment, drying, crushing and sieving. However, the kneader cannot mix the starch and the alkali metal aqueous solution uniformly, which affects the quality stability of the product. In addition, the method adopts the ethyl acetate medium to carry out thermal reaction in a high-temperature pressure container, so that the safety is not high, and the method is not beneficial to large-scale industrial production.

Disclosure of Invention

The invention aims to solve the problems of insufficient quality stability and low safety in the production process of modified starch in the prior art, and provides a preparation method of functional edible starch. The method has the characteristics of simple operation, high safety and good product quality.

In order to achieve the above object, the present invention provides a method for preparing functional edible starch, comprising the steps of:

(1) mixing a starch raw material with alcohol to prepare starch milk, and adding an alkali metal salt alcohol solution into the starch milk to adjust the pH to be alkaline;

(2) sequentially concentrating and dispersing the product obtained in the step (1);

(3) drying the dispersed product by a gradual heating drying method.

Through the technical scheme, the preparation of the high-quality functional edible starch can be carried out by adopting a simpler and safer mode, and the industrial large-scale production of the modified starch with stable quality and high safety is favorably realized.

Detailed Description

It is to be understood that the following detailed description is intended only to further illustrate and explain the present invention, and is not intended to limit the present invention.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a method for preparing functional edible starch, which comprises the following steps:

(1) mixing a starch raw material with alcohol to prepare starch milk, and adding an alkali metal salt alcohol solution into the starch milk to adjust the pH to be alkaline;

(2) sequentially concentrating and dispersing the product obtained in the step (1);

(3) drying the dispersed product by a gradual heating drying method.

Any starch feedstock available in the art may be suitable for use in the process provided herein. For example, the starch material may be selected from at least one of wheat starch, corn starch, tapioca starch, potato starch, and rice starch.

According to a preferred embodiment of the present invention, wherein the moisture content of the starch feedstock in step (1) is 10-20% by weight. Preferably 10-14 wt%.

According to a preferred embodiment of the present invention, the alcohol in step (1) may be any alcohol available in the art for food processing, as long as the purpose of removing water is achieved.

Preferably, the alcohol in step (1) is at least one of ethanol, methanol and propanol. In view of food safety, ethanol and/or propanol are preferred, and ethanol is more preferred.

According to a preferred embodiment of the present invention, wherein the dry content of the starch milk in step (1) is 30-40 wt%. The dry matter content refers to the percentage of the dry basis of the starch in the starch milk to the total weight of the starch milk.

The inventor of the invention skillfully discovers that the alcoholic solution of the alkali metal salt has the characteristic of easily dissolving starch in the process of research. The preparation of modified starch by using alcoholic solution of alkali metal salt can realize the purposes of easily dissolving starch and ensuring no browning in the starch modification process. Any alcoholic solution of an alkali metal salt having the above characteristics may be suitable for use in the method of the present invention.

According to a preferred embodiment of the present invention, wherein the alcoholic solution of alkali metal salt in step (1) is an alcoholic solution of alkali metal salt with a concentration of 1 to 10% by weight. Ethanol solutions with alkali metal salts concentrations of 3 to 5% by weight are preferred.

Preferably, the alcoholic solution of alkali metal salt is an ethanol solution with a sodium carbonate concentration of 1-10 wt%. Preferably an ethanol solution with a sodium carbonate concentration of 3-5% by weight.

According to a preferred embodiment of the present invention, wherein the pH of the starch milk in step (1) is adjusted to alkaline for the purpose of avoiding high temperature degradation of starch. The method provided by the present invention can be applied as long as the adjusted pH value can achieve the object.

Preferably, the pH of the starch milk is adjusted to 9-9.5.

According to a preferred embodiment of the present invention, the step (1) further comprises stirring the starch milk after adjusting the pH of the starch milk to mix the starch milk uniformly.

Preferably, the conditions of the stirring include: time 5-20min, speed 200-.

According to the invention, the concentration in step (2) is aimed at removing the alcoholic solution of alkali metal salts in the starch milk. Any means of concentration known in the art may be suitable for use in the methods provided herein.

Preferably, for the purpose of improving the production efficiency and rapidly realizing the drying condition, the concentration can be carried out by selecting a suction filtration mode and/or a plate-and-frame filtration mode.

Preferably, the concentration conditions are such that the dry content of the starch milk is above 40 wt%, preferably 50-60 wt%.

According to the invention, in the step (2), the purpose of dispersing is to make the particle size of the concentrated starch uniform, so as to avoid the problems of uneven heating in the subsequent drying process and the like. Any dispersion means known in the art may be suitable for use in the methods provided herein.

Preferably, the dispersion may be at least one of pulverized, disintegrated, and ground.

More preferably, the dispersing conditions are such that the particle size of the resulting product is in the range of 0.1 to 1 mm. Preferably in the range of 0.2-0.5 mm.

The inventor of the invention skillfully discovers that when the modified starch is prepared, the problem of local gelatinization of the starch caused by excessive temperature rise in the temperature rise process at one time can be effectively avoided by adopting a gradual temperature rise drying method, and the product quality can be further improved.

According to a preferred embodiment of the present invention, the gradual temperature-rising drying method in the step (3) includes sequentially performing primary drying, secondary drying, and tertiary drying. Wherein:

the primary drying conditions are such that the moisture content in the primary dried product is 5 to 10% by weight.

The secondary drying conditions are such that the moisture content in the secondary dried product is less than 5% by weight and 3% by weight or more.

The conditions of the tertiary drying are such that the moisture content in the tertiary dried product is less than 3% by weight.

According to a preferred embodiment of the present invention, wherein the temperature of the secondary drying is 60 to 80 ℃ higher than the temperature of the primary drying.

Decomposing a preferred embodiment of the present invention, wherein the temperature of the third drying is 20 to 40 ℃ higher than the temperature of the second drying.

According to the preferred embodiment of the present invention, the operation is efficient and reliable according to actual production conditions. Wherein, the gradual temperature rising drying method in the step (3) may include the following steps:

A. drying the dispersed product at 40-50 deg.C for 2-10 h.

B. The primary dried product is dried for the second time at the temperature of 110-130 ℃ for 1-2 h.

C. The secondary dried product is dried for three times at the temperature of 150 ℃ and 170 ℃ for 1-3 h.

According to a preferred embodiment of the present invention, wherein the method further comprises adjusting the pH of the dried product to 4-6 with an acid. And then washing, drying, crushing and sieving the obtained product in sequence to obtain the functional edible starch.

According to the present invention, the acid may be any acid currently available in the art for pH adjustment in the food industry. Preferably, the acid may be citric acid and/or hydrochloric acid.

More preferably, the acid is an aqueous solution having a concentration of 3 to 5% by weight.

According to a preferred embodiment of the present invention, the dried product needs to be washed after its pH is adjusted for the purpose of reducing the content of impurities and improving the quality of the product. The washing means may be any washing means commonly used in the art.

Preferably, the washing manner may be selected from at least one of rinsing, dissolving and whirling washing.

According to a preferred embodiment of the invention, the process further comprises drying the washed product. The drying may be by any means known in the art.

Preferably, the drying manner may be at least one selected from vacuum drying, oven drying, and boiling drying.

More preferably, the drying conditions include: the time is 2-10h, and the temperature is 40-50 ℃.

Further preferably, the drying conditions are such that the moisture content in the obtained dried product is between 10 and 14 wt.%.

According to a preferred embodiment of the present invention, the method further comprises pulverizing the dried product after drying. The pulverization can adopt any conventional pulverization mode in the field.

Preferably, the means of comminution may be selected from milling and/or extrusion.

More preferably, the pulverization conditions are such that the particle size of the obtained pulverized product is in the range of 80 to 100 mesh. That is, the pulverized product can pass through a 80-100 mesh sieve.

According to a preferred embodiment of the present invention, the brabender viscosity of the functional edible starch prepared by the method provided by the present invention is: c point 600 BU 900BU, E point 900BU 1200 BU. The pH is 4.5-6.5. The conductivity was 100-. The water content is 12-14 wt%.

The present invention will be described in detail below by way of examples. It should be understood that the following examples are only intended to further illustrate and explain the present invention, and are not intended to limit the present invention.

In the following examples and comparative examples, the viscosity of starch was measured by: brabender viscometry (measured using a Brabender viscometer model E from Brabender). The conductivity test method comprises the following steps: conductivity method (measured by a conductivity meter model number FiveEasy Plus from Mettler). The determination mode of the moisture content in the starch is as follows: rapid moisture meter method (using Merterla HG63 model rapid moisture meter detection). Drying was carried out using a high temperature oven model DKM610C from yamadoto corporation. The concentrated (filtered) material is crushed by a 2500Y high-speed crusher of the West kitchen company.

In the following examples and comparative examples, the starch material used was, without specific reference, a waxy corn starch product purchased from Huanglong food industry Co., Ltd, which had a water content of 13. + -. 1% by weight.

Example 1

(1) 500g of starch raw material and 960g of ethanol are mixed to prepare starch milk, and the dry matter content is 30 weight percent. To the starch milk was added 20g of an ethanol solution of sodium carbonate (concentration 3% by weight), the pH was adjusted to 9, and the mixture was stirred at 200rpm for 5 min.

(2) And (2) carrying out suction filtration on the product obtained in the step (1) until the dry basis content of the starch is 50 wt%, and crushing the suction-filtered material to the particle size of about 0.5mm by adopting a high-speed crusher.

(3) Drying the crushed product at 50 ℃ for 2h for one time; carrying out secondary drying on the primary dried product at 130 ℃ for 1 h; the secondary dried product was dried three times at 160 ℃ for 3 hours. The moisture content of the product after each drying is detailed in table 1.

(4) The dried product was adjusted to pH 4 with 150g of 3% strength by weight aqueous citric acid solution and stirred for 10 min.

(5) The stirred product was filtered to a water content of 40% by weight and washed with tap water until the filtrate was clear.

(6) The washed product was dried to a moisture content of 14 wt%. Further pulverizing to particle size of about 0.18mm, sieving with 80 mesh sieve, and collecting the undersize product. Obtaining the functional edible starch A1.

Example 2

(1) 500g of starch raw material and 750g of ethanol are mixed to prepare starch milk, and the dry matter content is 35 percent by weight. To the starch milk was added 18g of an ethanol solution of sodium carbonate (concentration 4% by weight), the pH was adjusted to 9.3, and the mixture was stirred at 300rpm for 10 min.

(2) And (2) carrying out suction filtration on the product obtained in the step (1) until the dry basis content of the starch is 55 weight percent, and crushing the suction-filtered material to the particle size of about 0.4mm by adopting a high-speed crusher.

(3) Drying the crushed product at 50 ℃ for 2h for one time; carrying out secondary drying on the primary dried product at 130 ℃ for 1 h; the secondary dried product was dried three times at 160 ℃ for 3 hours. The moisture content of the product after each drying is detailed in table 1.

(4) The dried product was adjusted to pH 4 with 120g of 4% strength by weight citric acid and stirred for 10 min.

(5) The stirred product was filtered to a water content of 40% by weight and washed with tap water until the filtrate was clear.

(6) The washed product was dried to have a moisture content of 13 wt%. Further pulverizing to particle size of about 0.18mm, sieving with 80 mesh sieve, and collecting the undersize product. Obtaining the functional edible starch A2.

Example 3

(1) 500g of starch raw material and 600g of ethanol are mixed to prepare starch milk, and the dry matter content is 40 weight percent. To the starch milk was added 16g of an ethanol solution of sodium carbonate (concentration 5% by weight), the pH was adjusted to 9.5, and the mixture was stirred at 400rpm for 20 min.

(2) And (2) carrying out suction filtration on the product obtained in the step (1) until the dry basis content of the starch is 60 wt%, and crushing the suction-filtered material to the particle size of about 0.2mm by adopting a high-speed crusher.

(3) Drying the crushed product at 50 ℃ for 2h for one time; carrying out secondary drying on the primary dried product at 130 ℃ for 1 h; the secondary dried product was dried three times at 160 ℃ for 3 hours. The moisture content of the product after each drying is detailed in table 1.

(4) The dried product was adjusted to pH 4 with 100g of 5% strength by weight citric acid and stirred for 10 min.

(5) The stirred product was filtered to a water content of 40% by weight and washed with tap water until the filtrate was clear.

(6) The washed product was dried to have a content of 12% by weight. Further pulverizing to particle size of about 0.15mm, sieving with 100 mesh sieve, and collecting the undersize product. Obtaining the functional edible starch A3.

Example 4

Waxy corn starch having a moisture content of 15% by weight was used as the starting material. 500g of starch raw material and 960g of ethanol are mixed to prepare starch milk, and the dry matter content is 29 percent by weight. To the starch milk was added 20g of an ethanol solution of sodium carbonate (concentration 3% by weight), the pH was adjusted to 9, and the mixture was stirred at 200rpm for 5 min. The remaining steps and methods were the same as in example 1. The moisture content of the product after each drying is detailed in table 1. Obtaining the functional edible starch A4.

Example 5

The method of example 1 was used except that the dry content of the starch milk prepared in step (1) was 50% by weight. The moisture content of the product after each drying is detailed in table 1. Obtaining the functional edible starch A5.

Example 6

The method of example 1 was used except that the time for primary drying in step (3) was 1 hour, the time for secondary drying was 0.5 hour, and the time for tertiary drying was 0.5 hour. The moisture content of the product after each drying is detailed in table 1. Obtaining the functional edible starch A6.

Example 7

The method of example 1 was used except that the temperature for the primary drying in step (3) was 40 ℃, the temperature for the secondary drying was 130 ℃ and the temperature for the tertiary drying was 140 ℃. The moisture content of the product after each drying is detailed in table 1. Obtaining the functional edible starch A7.

Example 8

The method of example 1 was used except that the pulverized product was dried by a two-stage heating method, specifically, the pulverized product was dried at 50 ℃ for 3 hours for one time; the primary dried product was dried twice at 160 ℃ for 4 h. The moisture content of the product after each drying is detailed in table 1. Obtaining the functional edible starch A8.

Comparative example 1

The procedure of example 1 was followed except that the ethanol solution of sodium carbonate was replaced with an aqueous solution of sodium carbonate of the same concentration. The moisture content of the product after each drying is detailed in table 1. Obtaining functional edible starch D1.

Comparative example 2

The procedure of example 1 was followed except that in step (3), the temperature was once raised to 160 ℃ and the drying was carried out for 6 hours. The moisture content of the dried product is detailed in table 1. Obtaining functional edible starch D2.

TABLE 1 moisture content in starch (% by weight)

	Primary drying	Secondary drying	Three times of drying
				Example 1	7.1	4.9	2.9
Example 2	6.4	4.1	2.1
				Example 3	5.2	3.7	1.6
Example 4	7.8	5.9	4.1
				Example 5	7.5	5.6	3.8
Example 6	11.4	8.5	4.9
				Example 7	8.6	6.5	3.7
Example 8	7.1	2.9	/
				Comparative example 1	7.9	5.2	3.4
Comparative example 2	3.2	/	/

Test example 1

The functional food starches obtained in the above examples and comparative examples were subjected to an appearance rating and a performance test, and the appearance rating criteria are detailed in table 2. The results are shown in tables 3 and 4, respectively.

TABLE 2 appearance rating Standard of functional edible starch

Here, the foreign matter refers to particles produced by gelatinization of starch under a high temperature state, and the color thereof is brown or black.

TABLE 3 appearance rating of functional edible starch

Starch numbering	Colour(s)	Degree of gelatinization
			A1	1	1
A2	1	1
			A3	1	1
A4	2	2
			A5	2	2
A6	3	3
			A7	3	3
A8	3	3
			D1	4	4
D2	5	5

As is evident from the contents of Table 3, when the functional food starch is prepared by the preferred method and conditions of the present invention, the obtained product can reach a high quality level in terms of color and gelatinization degree. When the conditions are changed, the obtained product shows a tendency of decreasing the apparent evaluation level, for example, the sample is caked, the color is yellowish, the gelatinization occurs, and the like.

TABLE 4 functional edible starch Properties

As can be seen from the comparison of starches A1-A8 and D1 in Table 2, the use of alcoholic solutions leads to functional food starches which have a higher viscosity and a higher viscosity stability than when aqueous solutions of sodium carbonate are used.

As can be seen by comparing starch A1-A8 with D2, the viscosity and viscosity stability of the sample can be improved by adopting the gradual heating drying method.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.