CN112056508B - Grain carbohydrate matrix for special medical food and preparation method thereof - Google Patents

Abstract

The invention discloses a preparation method of a cereal carbohydrate matrix, which comprises the following steps: (1) crushing grains to a grain powder raw material; (2) Adding 3-5% soybean protein isolate and 50-60mL/kg high temperature alpha amylase solution with concentration of 8000-10000U/mL into cereal powder, and mixing well. (3) Performing steam enzymolysis and tempering treatment on a grain powder raw material, (4) extruding and puffing the grain powder subjected to the steam enzymolysis and tempering treatment, wherein the extrusion temperature is 110-130 ℃, and the screw rotation speed is 150-250r/min; (4) Drying and crushing the extrudate to obtain the carbohydrate matrix powder. The method adopts the steps of grain crushing, soybean protein adding, steam enzymolysis tempering and extrusion puffing treatment to prepare the grain carbohydrate matrix powder with low viscosity, good reconstitution property and rich food flavor, and is suitable for preparing special medical food.

Description

A kind of grain carbohydrate substrate for special medical food and its preparation method

technical field

The invention relates to the preparation technology of special nutritional food for special populations, in particular to a grain carbohydrate matrix used for special medical food and a preparation method thereof.

Background technique

Formula food for special medical purposes, hereinafter referred to as food for special medical purpose, is a formula food specially processed and formulated to meet the special needs of nutrients or diet for people with food restriction, digestion and absorption disorders, and metabolic disorders. This type of food has a significant effect in improving the nutritional status of patients and reducing the medical costs of hospitalized patients.

In recent years, the special medical food industry has shown a good development trend in the world. The global market size of special medical food is about 56 billion to 64 billion yuan per year, and it continues to increase at an average annual growth rate of 6%. Compared with developed countries such as Europe and the United States, the research and application of special medical food in my country is obviously lagging behind, but the demand has grown very rapidly in recent years, and the average annual growth rate of the market has reached 37%. However, at present, most of the FSMPs currently used clinically in my country are foreign brand products, and the three energy-supplying substances of carbohydrates, proteins and fats in existing products are mainly composed of protein powder, dextrin or starch, edible oil or special fat, etc. Nutrient raw materials are compounded, and carbohydrates are mainly provided by dextrin. Although this formula principle has obvious advantages in accurately controlling the composition and content of various nutrients and ensuring that the product has better brewing characteristics, the products generally lack food flavor, high osmotic pressure, and gastrointestinal tolerance. Poor issues. For people who rely on special medical food as their main or sole source of nutrition for a long time, the above problems will directly affect consumers' compliance with taking food, which is not conducive to the exertion of nutritional support. Therefore, the flavor and taste of FSMP are still the restrictive factors affecting its clinical use, and it is also an issue that requires special attention in the development of new products of FSMP.

Cereals are the most important staple food in people's daily diet, and they are also an important source of dietary carbohydrates. The unique flavor brought by grains as a carbohydrate matrix to food is unmatched by single nutrients such as dextrin and starch. Using grains as the carbohydrate matrix, according to the nutritional needs of specific groups of people, fortifying and processing special medical food with nutritional ingredients will help to improve the flavor and taste of the product and improve the patient's compliance with taking it. However, due to the high starch content, grain-based carbohydrate-based processed special medical food has problems such as high product viscosity, poor preparation dispersion and poor tube feeding fluidity. Tube feeding is a common dietary intake route for special medical food, and the tube feeding fluidity of the product is an important factor affecting the incidence of nutritional tube blockage. Therefore, indicators such as viscosity, brewing dispersibility and fluidity of tube feeding have become the main issues affecting the processing of special medical food with grain as carbohydrate matrix. How to improve the starch predigestibility of cereal carbohydrate matrix and improve the brewing characteristics of powder is an important technical bottleneck in the development of special medical food with cereal carbohydrate matrix.

Aiming at improving the predigestibility and brewing dispersibility of cereal powder, relevant researches have been carried out. The study found that adding high-temperature α-amylase to the grain can partially hydrolyze the grain starch and reduce the viscosity of the powder by using the high temperature in the puffing cavity during the extrusion process. However, since the extrusion process takes only about 20s, the enzyme and the substrate cannot fully interact, and the enzymolysis effect is relatively limited. At the same time, the flavor quality of the powder needs to be further improved. In view of the above problems, the present invention creates a grain carbohydrate matrix preparation technology based on the addition of an appropriate amount of soybean protein, which is based on raw material crushing-steam enzymolysis conditioning-extrusion puffing, which promotes the gelatinization and degradation of grain starch, and at the same time controls protein-reduction The degree of Maillard reaction between sugars further improves the flavor quality and brewing characteristics of the base powder.

Contents of the invention

The first object of the present invention is to provide a method for preparing a cereal carbohydrate matrix used in food for special medical purposes, which can improve the predigestibility of corn starch and the brewing characteristics of powder, and at the same time improve the flavor quality of the matrix.

The second object of the present invention is to provide a cereal carbohydrate matrix prepared by the above-mentioned preparation method, which has the characteristics of low viscosity, good tube feeding fluidity, and good food flavor, and can replace other carbohydrate raw materials for special use. Raw materials for medical food development.

The first purpose of the present invention is achieved through the following technical solutions:

A method for preparing a grain carbohydrate matrix used in food for special medical treatment, the processing flow is:

Grain crushing→addition of soybean protein isolate→steam enzymatic hydrolysis and conditioning→extrusion and puffing→drying→crushing

Specifically include the following steps:

(1) Pulverizing the grain to obtain the grain flour raw material;

(2) Add the grain powder raw material into the raw material mixing tank, add soybean protein isolate with a weight percentage of 3-5%, and add a high-temperature α-amylase solution with a concentration of 8000-10000U/mL through a spraying device, and the addition amount is 50 -60mL/kg, mix the enzyme solution, grain powder and protein evenly through the stirring device;

(3) sending the mixed mixture into a conditioner to carry out steam enzymatic conditioning treatment;

(4) Send the grain powder after steam enzymatic hydrolysis and tempering to an extrusion extruder through a screw conveyor for extrusion and expansion, the extrusion temperature is 110-130° C., and the screw speed is 150-250 r/min.

(5) Drying the extruded product, and then pulverizing to obtain cereal carbohydrate matrix powder.

The present invention establishes a preparation method of raw material crushing-protein addition-steam enzymatic hydrolysis-conditioning-extrusion puffing carbohydrate matrix for special medical food, specifically:

The present invention adds a certain amount of soybean protein isolate to the grain powder, and the reducing sugars such as dextrin generated in the process of steam enzymatic hydrolysis and extruding and puffing undergo moderate Maillard reaction with the protein, which can improve the flavor quality of the powder , together with further melting, shearing and other effects in the extrusion process, can promote the degradation of protein and improve the predigestibility of protein. Through the analysis of flavor evaluation, it was found that when the amount of soybean protein isolate was 3-5%, and the extrusion temperature was controlled at 110-130°C, the extrudate had a more obvious roasted aroma, and the sensory score reached the highest level.

The concentration and addition amount of the enzyme liquid in the present invention affect the dosage of the enzyme, and when the dosage of the enzyme is 400-600U/g, the brewing dispersibility of the obtained matrix is the best. On the premise that the amount of enzyme added is determined, the determination of the concentration of the enzyme solution is to control the amount of water added during the process of adding the enzyme solution. Since the steam enzymatic conditioning process will further increase the moisture content in the grain flour raw material, and the enzymatic hydrolysis will decompose the starch into dextrin and oligosaccharides, the result of the above comprehensive effects will lead to shearing of the material during the extrusion process. The force is reduced, which significantly reduces the puffing effect of the grain and affects the gelatinization and degradation of the remaining starch. Therefore, in order to ensure that the moisture content in the grain flour raw material is controlled at a certain level during extrusion and puffing, and to achieve the ideal puffing effect, the above-mentioned settings are made for the concentration and addition amount of the enzyme solution and the amount of steam.

Optimally, the present invention also transports the material treated by enzymatic hydrolysis conditioning to the high-temperature-resistant storage silo through a screw conveyor, accumulates and stores it for 10-20 minutes, and then performs extrusion and puffing. Adding α-amylase during puffing treatment can reduce the caking rate and viscosity of puffed grain powder to a certain extent, and improve its water solubility. However, due to the short action time, amylase can only play a very limited role. Amylase reacts with the substrate at high temperature through steam enzymatic hydrolysis and conditioning treatment, and then transfers the conditioned material to the storage bin to allow the enzyme to continue to function for 10-20 minutes, prolonging the The enzymatic hydrolysis reaction time allows the corn starch to be fully enzymatically hydrolyzed. When the standing reaction time in the storage bin is less than 10 minutes, the degree of pre-enzymolysis of starch is not enough, and the viscosity of the obtained grain matrix powder is high, but when the reaction time is too long (>20min), due to excessive enzymolysis of starch, subsequent The puffing of extruded extrudates is too low, and the degree of gelatinization of residual starch decreases.

Optimally, the steam enzymatic hydrolysis conditioning parameters in step (3) of the present invention are controlled as follows: the steam conditioning time is 1.5-2.5min, the saturated steam pressure is 0.2-0.3MPa, and the total steam volume is controlled at 7-7% of the weight of the conditioning material. 9%.

Optimally, the particle size of the grain flour in step (1) of the present invention is between 10-20 mesh. By comparing the brewability of extrudates obtained from grain flours with different particle sizes under the same processing conditions, it was found that either too large or too small a particle size would have a negative impact on the brewability of the extrudates. When the grain granules are small, the enzyme can fully interact with the starch granules, and the enzymatic hydrolysis effect is better, but in the process of steam conditioning, if the granules are too small, the viscosity of the grain flour will increase under the action of steam and enzyme, and the powder fluidity will be serious Reduced, the interaction with steam is insufficient, and at the same time affects the conveying efficiency of raw materials in the conditioner, and the small grain particles increase the moisture content of raw materials due to excessive water absorption, resulting in a decrease in shear force during the extrusion process.

Optimally, hot air or heat pump drying is used in the drying treatment in step (5), so that the moisture content of the extrudate is below 7%.

Optimally, the particle size of the carbohydrate matrix powder obtained by pulverizing in step (5) is between 60-100 mesh.

A grain carbohydrate matrix used for food for special medical treatment is prepared by the above-mentioned preparation method.

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

(1) The present invention can further improve the flavor of the extrudate by adding a certain proportion of soybean protein isolate to the pulverized grain raw material to control the degree of Maillard reaction in the steam conditioning and extruding puffing and other heat-and-moisture processes. Makes the extrudate have a distinct roasted aroma. At the same time, under the action of high heat and mechanical shear in the above treatment process, the hydrogen bonds and disulfide bonds between protein molecules are broken, resulting in protein degradation, and the content of soluble protein increases, which is beneficial to the digestion and utilization of protein.

(2) The present invention utilizes the characteristic that α-amylase can degrade starch to generate dextrin and oligosaccharide at high temperature, thereby reducing the viscosity of starch, and continuously feeds steam through a steam conditioner to ensure that the material is maintained at a higher temperature, and then steam The processed grain powder is transferred to the high temperature resistant storage bin for heat preservation for a certain period of time, so as to fully enzymatically hydrolyze the grain starch. In the subsequent extrusion and puffing process, under the action of further enzymatic hydrolysis by amylase and the mechanical shear generated by the puffing machine, the starch in the grain is further degraded and destroyed, and a large amount of small molecular carbohydrates are generated. Moreover, by increasing the number of storage bins, the time difference between the steam pre-enzymatic hydrolysis conditioning and the extrusion process can be eliminated, and continuous production can be realized.

(3) The cereal carbohydrate base powder developed by the present invention not only has good brewing characteristics and fluidity of nasal feeding tube, and can meet the basic needs of special medical food preparation, but more importantly, the present invention selects grains with a flavor and taste more suitable for Chinese people. As raw materials, the prepared carbohydrate matrix powder has a strong food flavor. Compared with dextrin and other nutrients as the matrix, it can provide the product with a significant roasted grain aroma, thereby improving the flavor quality of the product and helping to ensure the compliance of long-term consumers.

Detailed ways

The present invention will be further described below in conjunction with specific examples, so that those skilled in the art can better understand and implement the technical solutions of the present invention.

Example 1

A method for preparing a grain carbohydrate matrix for special medical food, comprising the following steps:

(1) By adjusting the grinding time of the grain grinder, the diameter of the sieve, and the clearance of the hammer sieve, the grain powder raw material with a particle size of 10-20 mesh is obtained by grinding.

(2) Add 5% soy protein isolate to the pulverized cereal flour.

(3) Prepare a high-temperature α-amylase solution with distilled water so that the enzyme concentration is 10000 U/mL, control the addition amount of the high-temperature α-amylase solution to 50 mL/kg, and mix well.

(4) Transfer the grain raw material powder mixed with enzyme into the conditioner for steam enzymatic conditioning treatment, set the steam conditioning time to 2min, the saturated steam pressure to 0.25MPa, and the total steam volume to be controlled at 8% of the material weight.

(5) The grain powder after the steam enzymatic hydrolysis and tempering treatment is transported by the screw conveyor and transferred to the storage bin for accumulation and standing for 20 minutes, and then sent to the extrusion extruder by the screw conveyor for expansion. The extrusion temperature is 125°C. The screw speed is 150r/min.

(6) The extrudate is dried by hot air or heat pump, so that the moisture content of the extrudate reaches below 7%. And the dried extrudate is crushed into a powder with a particle size of 60-100 mesh to obtain carbohydrate matrix powder.

Example 2

A method for preparing a grain carbohydrate matrix for special medical food, comprising the following steps:

(1) By adjusting the grinding time of the grain grinder, the diameter of the sieve, and the clearance of the hammer sieve, the grain powder raw material with a particle size of 10-20 mesh is obtained by grinding.

(2) Add 3% soy protein isolate to the pulverized cereal flour.

(3) Prepare a high-temperature α-amylase solution with distilled water so that the enzyme concentration is 10000 U/mL, and control the addition rate of the high-temperature α-amylase solution to 60 mL/kg.

(4) Transfer the grain raw material powder mixed with enzyme into the conditioner for steam enzymolysis conditioning treatment, set the steam conditioning time to 2.5min, the saturated steam pressure to 0.3MPa, and the total steam volume to be controlled at 9% of the weight of raw materials.

(5) The grain powder after the steam enzymatic hydrolysis and tempering treatment is transported by the screw conveyor and transferred to the storage bin for accumulation and standing for 10 minutes, and then sent to the extrusion extruder by the screw conveyor for expansion. The extrusion temperature is 130°C. The screw speed is 250r/min.

(6) The extrudate is dried by hot air or heat pump, so that the moisture content of the extrudate reaches below 7%. And the dried extrudate is crushed into a powder with a particle size of 60-100 mesh to obtain carbohydrate matrix powder.

Example 3

A method for preparing a grain carbohydrate matrix for special medical food, comprising the following steps:

(1) By adjusting the grinding time of the grain grinder, the diameter of the sieve, and the clearance of the hammer sieve, the grain powder raw material with a particle size of 10-20 mesh is obtained by grinding.

(2) Add 4% soy protein isolate to the pulverized cereal flour.

(3) Prepare a high-temperature α-amylase solution with distilled water so that the enzyme concentration is 8000 U/mL, and control the addition amount of the high-temperature α-amylase solution to 50 mL/kg.

(4) Transfer the grain raw material powder mixed with enzyme into the conditioner for steam enzymatic conditioning treatment, set the steam conditioning time to 1.5min, the saturated steam pressure to 0.2MPa, and the total steam volume to be controlled at 7% of the weight of raw materials.

(5) The grain powder after the steam enzymatic hydrolysis and tempering treatment is transported by the screw conveyor and transferred to the storage bin for accumulation and standing for 15 minutes, and then sent to the extrusion extruder by the screw conveyor for expansion. The extrusion temperature is 110°C. The screw speed is 200r/min.

(5) The extrudate is dried by hot air or heat pump, so that the moisture content of the extrudate reaches below 7%. And the dried extrudate is crushed into a powder with a particle size of 60-100 mesh to obtain carbohydrate matrix powder.

The comparative analysis result of substrate made by the present invention is as follows:

(1) Analysis of carbohydrate matrix powder prepared by different treatment processes

Using rice as raw material, the performance test of cereal carbohydrate matrix powder includes matrix powder brewing characteristics, flavor quality and nutritional content. The experimental group carried out relevant performance analysis with the carbohydrate base powder prepared in Example 1. Extrusion puffing and enzyme extrusion puffing were used as controls. The processing conditions of extrusion expansion are the same as in Example 1: crush the rice to 10-20 mesh, add soybean protein isolate powder with a weight ratio of 5%, add water to adjust the moisture content of the raw material to about 20%, and the extrusion temperature is 125°C. The screw speed is 150r/min. Enzyme extrusion is to adjust the water content of rice flour to about 20% by adding 400U/g high-temperature α-amylase solution, and the other is the same as direct extrusion. The specific test results are shown in Table 1 and Table 2.

Table 1: Effects of different processing techniques on the brewing properties and flavor scores of base powder

Note: When the letters next to the values in the same column are different, it means that the difference has reached a significant level, p<0.05

The water solubility index is used to measure the degradation degree of starch in the powder, which is related to the amount of soluble small molecules generated by the degradation of starch. Due to the action of high-temperature α-amylase, the starch structure in the powder is destroyed, a large amount of soluble sugars are released, its water solubility index increases, and the fluidity of the powder increases, so the caking rate and dispersion time during the brewing process have been significantly reduced. Although the matrix powder treated by direct extrusion and extrusion with enzymes also has a certain roasted aroma, it can be seen from the sensory score analysis that the roasted aroma of the matrix powder prepared by the technology of the present invention is more obvious than the former two, which can significantly improve the flavor of the powder. sensory qualities of the body.

Table 2: Effects of different treatment processes on the nutritional components of matrix powder

Note: When the letters next to the values in the same column are different, it means that the difference has reached a significant level, p<0.05

As can be seen from Table 2, the reducing sugar and soluble protein content of the rice flour treated by the method of the present invention is significantly higher than that of direct enzyme extrusion extrusion, and the starch content is significantly reduced, which is also the reason why the method can obviously improve the powder Important reason for brewing characteristics.

(2) Performance test of FSMP full nutritional formula powder prepared from grain carbohydrate matrix obtained by different processing techniques

The principle of preparing full nutritional formula powder for special medical food is to use rice as raw material, use cereal carbohydrate base powder prepared by different processing techniques to replace dextrin and starch carbohydrates in full nutritional formula powder for special medical food, and according to the base powder Other components such as protein and fat contained in the formula powder were fine-tuned to the amount of protein and fat added in the formula powder, and the special medical food full-nutrition formula powder with different processed rice as the carbohydrate matrix was prepared. The specific formula is shown in Table 3.

Table 3 Formula composition of main nutritional components of special medical food with different carbohydrate sources (/100g)

Formula Description: The non-substitute formula in the above table represents the basic formula composition of the FSMP full nutritional formula powder commonly used in the market at present. The powder oil contains about 50% vegetable oil, and its packaging materials are mainly carbohydrate ingredients and A small amount of protein. The rice flour prepared by different processing techniques in 3 substitute formulas was used as the carbohydrate matrix to replace the maltodextrin in the non-substitute formula. The rice raw material contained about 8% protein, and 5% soybean protein isolate was further added in the preparation of the matrix powder. , so the amount of casein added in the formula is reduced by 5g accordingly.

The experimental group used the carbohydrate base powder prepared in Example 1 to prepare the full nutritional formula powder of special medical food. The control group adopts the carbohydrate base powder prepared by other processing techniques, including extrusion puffing and enzyme extrusion puffing, and the processing parameters of other groups are the same as those in Example 1.

The performance test of the above FSMP nutritional formula powder includes brewing characteristics and sensory evaluation:

(a) Determination of viscosity

Weigh 5.00g of sample in the special aluminum cylinder of the RVA analyzer, add 20mL of distilled water, put it into the rotating blade, insert the aluminum cylinder into the measuring tank, start the measurement program, and measure the viscosity. The measurement procedure is: keep at 38°C for 13 minutes, the rotation speed is 960r/min for the first 10s, and the rotation speed is maintained at 160r/min throughout the entire measurement process thereafter.

(b) Determination of residual rate of nasal feeding tube

Weigh 40.00g of the sample into a 500mL beaker, add 65°C water to prepare 200mL of nutrient solution, stir evenly and transfer it into an infusion bottle, after cooling to room temperature, use a disposable infusion set to simulate the gravity drip method of clinical enteral nutrition support Carry out instillation, and the flow rate is controlled at 100-150mL/h. After all the infusion of the nutrient solution is completed, the weight of the adherents on the inner wall of the nasal feeding tube is weighed to calculate the residual rate of the nutrient solution.

(c) Sensory evaluation

25 healthy volunteers were recruited to conduct sensory evaluation on the powder and prepared nutrient solution. Place the sample in a clean white porcelain dish, and observe the color of the powder visually in a well-lit and soft environment. In addition, pour 20.00g of the sample into a transparent container, add 80mL of water at 65°C to prepare a nutrient solution, stir well, smell its smell, observe its brewability, taste its taste, etc. The samples are randomly coded and evaluated at room temperature. After each evaluation of a sample, you need to rinse your mouth with pure water before proceeding to the evaluation of the next sample. The sensory evaluation table is formulated with reference to the QB 4221-2011 standard, as shown in Table 4, and the total evaluation score is calculated by the cumulative sum of the four items.

Table 4 Sensory Evaluation Criteria for Teyi Complete Nutritional Formula Powder

(3) Test results and analysis

See Table 5 and Table 6 for specific performance test results of FSMP full nutritional formula powder prepared by different processing techniques:

Table 5: Ease of use evaluation of different FSMP nutritional formula powders

Table 6: Sensory evaluation results of different FSMP nutritional formula powders

According to the patient's disease type and pathophysiological state, clinical patients can take FSMP nutritional formula powder in two ways: direct oral administration, nasogastric feeding tube or gastroenterostomy tube feeding. On the premise of ensuring sufficient and balanced nutrition of the product, the taste and flavor of the product and the convenience of preparation and use are important factors affecting its clinical application. Therefore, the present invention screens the representative indicators that affect the preparation convenience of the formula powder: water solubility index, viscosity and nasal feeding tube residual rate, and analyzes the preparation convenience of the special medical food full nutrition formula powder prepared from different carbohydrate substrates , and the results are shown in Table 5.

It can be seen from Table 5 that the water solubility index, viscosity, and the residual amount in the nutrition tube of the simulated nasal feeding tube feeding process of the FSMP complete nutritional formula powder prepared by replacing maltodextrin with the carbohydrate matrix prepared in Example 1 Both were equivalent to the conventional special medical food full-nutrition formula powder with maltodextrin as the carbohydrate matrix, and compared with the formula powder prepared by direct extrusion or extrusion extrusion with enzyme as the carbohydrate matrix instead of dextrin, the water-soluble The viscosity index of the product is significantly improved, and the viscosity of the product and the residual rate of the nasal feeding tube are significantly reduced, which shows that the convenience of use of the special medical food complete nutritional formula powder prepared with the carbohydrate matrix prepared by the present invention is comparable to that of the conventional formula with maltodextrin as the carbohydrate. The effect of the product is equivalent, which is obviously better than that of direct extrusion expansion and enzyme extrusion expansion technology.

As mentioned above, in addition to brewing and dispersing flavor quality and other sensory qualities are also an important factor affecting the clinical use of special medical food, therefore, using the sensory evaluation criteria listed in Table 4, the special The medical food complete nutrition formula powder was comprehensively evaluated from the four aspects of structure, smell, taste and reconstitution, and the results are shown in Table 6. Although the full nutritional formula powder of special medical food prepared by extruding and extruding with enzymes as the carbohydrate matrix is better than the non-substitute conventional formula in terms of smell and taste, its reconstitution score is much lower than that of conventional formula. Lower than the latter, resulting in a comprehensive evaluation result score significantly lower than that of the conventional formula without substitution. The smell and taste of the special medical food full nutritional formula powder prepared with the carbohydrate matrix prepared by the present invention are further improved compared with direct extrusion puffing and enzyme extrusion puffing. At a comparable level, therefore, the composite evaluation score was significantly higher than that of the conventional formulation without substitution and the carbohydrate matrix substitution formulation prepared by the other two techniques.

The above experiments were measured with rice, but wheat flour, corn flour, and millet flour, or mixtures thereof, had similar effects.

The above implementation examples have described in detail the different implementation processes of the present invention, and the substrates obtained in other embodiments can also obtain approximate test data results, which are not listed one by one; the implementation methods of the present invention are not limited thereto, and ordinary skills in the technical field Personnel can realize the purpose of the present invention according to the content disclosed in the present invention, and any improvement and deformation made on the basis of the concept of the present invention all fall within the protection scope of the present invention, and the specific protection scope is described in the claims. prevail.

Claims (4)

1. A method of preparing a cereal carbohydrate matrix for use in a medical speciality food, comprising the steps of:

(1) Crushing grains to obtain a grain powder raw material;

(2) Adding 3-5 wt% of soybean protein isolate into the cereal flour, adding 50-60mL/kg of high-temperature alpha amylase solution with the concentration of 8000-10000U/mL, and stirring uniformly;

(3) Feeding the uniformly mixed grain powder raw material into a conditioner for steam enzymolysis conditioning treatment;

(4) Extruding and puffing the grain powder subjected to steam conditioning treatment, wherein the extrusion temperature is 110-130 ℃, and the screw rotation speed is 150-250r/min;

(5) Drying the extrudate, and then crushing to obtain carbohydrate matrix powder;

in the step (1), the granularity of the grain powder raw material is 10-20 meshes;

the parameters of the steam enzymolysis tempering treatment in the step (3) are controlled as follows: the steam hardening and tempering time is 1.5-2.5min, the saturated steam pressure is 0.2-0.3MPa, and the total steam quantity is controlled to be 7-9% of the weight of the hardened and tempered material;

and (4) conveying the material subjected to steam enzymolysis and tempering treatment to a high-temperature-resistant storage bin through a screw conveyor, stacking and storing for 10-20min, and then extruding and puffing.

2. The method for preparing a grain carbohydrate matrix for a special medical food according to claim 1, wherein the drying process in the step (5) is performed by hot air or heat pump so that the moisture content of the extrudate is 7% or less.

3. The method for preparing a cereal carbohydrate base for medical speciality foods according to claim 1, wherein the carbohydrate base powder obtained by the pulverization in the step (5) has a particle size of 60 to 100 mesh.

4. A cereal carbohydrate matrix for use in specialist food products, characterised in that it is produced by a process according to any one of claims 1 to 3.