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CN-121986901-A - Pure highland barley powder extrusion puffing process optimization method

CN121986901ACN 121986901 ACN121986901 ACN 121986901ACN-121986901-A

Abstract

The invention discloses an optimization method of a pure highland barley powder extrusion and puffing process, and belongs to the technical field of food extrusion processing. The method solves the technical problems that high-fiber highland barley powder is easy to have insufficient puffing, hard texture, low retention rate of thermosensitive functional components such as beta-glucan and the like in the extrusion process. The method comprises the steps of optimizing technological parameters based on a multi-target response surface method, determining the water content of materials, the temperatures of a first area, a second area, a third area and a fourth area of a machine barrel, and the rotating speed of a screw, carrying out low-temperature superfine grinding on highland barley powder, adding a composite emulsifier and edible sodium bicarbonate during tempering, and controlling the temperature gradient between the third area and the fourth area to be less than or equal to 20 ℃ and the gradient between the fourth area and a die head to be less than or equal to 10 ℃ during extrusion. The method is mainly used for producing high-quality pure highland barley puffed food, can synergistically improve the puffing rate and the beta-glucan retention rate of the product, effectively control the hardness of the product, and improve the edible quality and the nutritional value.

Inventors

  • WANG FUQING
  • XU QINGDONG
  • Dawageji

Assignees

  • 西藏天虹科技股份有限责任公司

Dates

Publication Date
20260508
Application Date
20260128

Claims (10)

  1. 1. The method for optimizing the extrusion and puffing process of the pure highland barley powder is characterized by comprising the following steps of: The method comprises the steps of S1, optimizing process parameters based on multi-objective response, namely adopting a three-factor three-level Box-Behnken experimental design, taking the highest temperature of a material water content, a cylinder fourth area and a screw rotating speed as independent variables, taking the expansion rate, the hardness and the beta-glucan retention rate of a product as parallel response indexes, establishing three quadratic polynomial prediction models by utilizing multiple regression fitting, calculating P values of factors and interaction items by using variance analysis, and screening the items with obvious influence by taking the P values smaller than 0.05 as a standard, and obtaining the optimal process parameter combination capable of simultaneously realizing high expansion rate, low hardness and high functional ingredient retention rate by solving a satisfaction degree function of the prediction models, wherein the optimal process parameter combination is that the material water content is 20-24%, the cylinder temperature control interval is one area 70-85 ℃, two area 110-130 ℃, three area 135-155 ℃ and four area 145-165 ℃, and the screw rotating speed is 180-250r/min; S2, raw material pretreatment, namely carrying out low-temperature ultrafine grinding on pure highland barley powder until the granularity passes through a 200-mesh sieve, wherein D90 is less than or equal to 75 mu m; S3, tempering, namely adding a compound emulsifier accounting for 1.5% -2.5% of the total mass of the pre-treated highland barley powder and 1% -3% of edible sodium bicarbonate into the pre-treated highland barley powder, wherein the compound emulsifier is formed by compounding glycerol monostearate and sucrose ester according to the mass ratio of 1:1; And S4, extruding and puffing, namely feeding the quenched and tempered materials into a double-screw extruding and puffing machine, and controlling a machine set to operate according to the barrel temperature and the screw rotating speed obtained by the response surface method in S1, wherein the temperature gradient between the third area and the fourth area of the machine barrel is controlled to be less than or equal to 20 ℃, the temperature gradient between the fourth area and a die head is controlled to be less than or equal to 10 ℃, and extruding and puffing are carried out, so that a high-quality puffed product can be obtained.
  2. 2. The method for optimizing the extrusion puffing process of pure highland barley powder according to claim 1, wherein microcrystalline cellulose accounting for 0.5% -1% of the total mass of the highland barley powder is further added as a fiber network modifier in the tempering treatment of the step S3.
  3. 3. The method for optimizing the extrusion process of pure highland barley powder according to claim 1, wherein the temperature change tempering treatment is performed on the product after the extrusion in the step S4, wherein the temperature change tempering treatment is performed for 10min at 60-70 ℃ and then for 20min at 35-45 ℃.
  4. 4. The method for optimizing the extrusion and puffing process of pure highland barley powder according to claim 1, wherein natural vitamin E accounting for 0.1% -0.5% of the total mass of the highland barley powder is also added as a thermal protective agent in the tempering treatment of the step S3.
  5. 5. The method for optimizing the extrusion process of pure highland barley flour according to claim 1, wherein the multi-objective response optimizing method in step S1 further comprises: converting the multiple response indexes into a single comprehensive satisfaction value by adopting a satisfaction function, wherein the satisfaction function of each response index is respectively that a large-scale function is adopted for the puffing rate and the beta-glucan retention rate, and a small-scale function is adopted for the hardness; integrating the satisfaction degree of each response by a weighted geometric average method, wherein the weight is set to be 0.4 according to the product requirement, the hardness weight is 0.3, and the retention weight of beta-glucan is 0.3; searching the maximum value of comprehensive satisfaction in a parameter feasible domain by using an optimization algorithm, and verifying that the prediction confidence of the obtained parameter combination is higher than 95%; The final determined technological parameter combination needs to meet the conditions that the puffing rate is more than or equal to 350 percent, the hardness is less than or equal to 3.5N, the beta-glucan retention rate is more than or equal to 85 percent, and the comprehensive satisfaction value of the three indexes is not lower than 0.85.
  6. 6. The method for optimizing the extrusion and puffing process of pure highland barley powder according to claim 1, wherein the screw elements of the twin-screw extrusion and puffing machine are provided with three groups of 60-degree staggered angle kneading blocks and reverse screw elements in a melting section, and a shallow groove forward screw element and two groups of 90-degree staggered angle kneading blocks in a homogenizing section.
  7. 7. The optimization method of the pure highland barley powder extrusion process according to claim 1, wherein trehalose accounting for 1% -2% of the total mass of the highland barley powder is also added as a moisture regulator in the tempering treatment of the step S3.
  8. 8. The method for optimizing the extrusion puffing process of pure highland barley powder according to claim 1, wherein after the puffed product is obtained in the step S4, the method further comprises the coating treatment of carrying out fluidized bed spray coating by using a mixed coating agent consisting of sodium alginate solution and monoglyceride emulsion, wherein the weight of the coating is increased by 2% -5%, and finally the coating is dried until the moisture content is lower than 5%.
  9. 9. The method for optimizing the extrusion puffing process of pure highland barley powder according to claim 1, wherein after the puffed product is obtained in the step S4, the method further comprises the steps of carrying out structural characterization and component analysis on the product, analyzing the crystallinity of starch by adopting X-ray diffraction, observing a micro-porous structure by adopting a scanning electron microscope, and detecting the retention rate of gamma-aminobutyric acid, wherein the method is used for evaluating the structure and the nutrition quality of the product.
  10. 10. The method for optimizing the extrusion puffing process of pure highland barley flour according to claim 1, further comprising the step of establishing a quantitative relation model between texture parameters of the puffed product and sensory scores, wherein the texture parameters comprise hardness, brittleness, chewiness and elasticity, the sensory scores comprise mouthfeel, flavor and overall acceptability, and the quantitative relation model is realized by the following steps: S110, performing texture measurement, namely performing full texture analysis and test on the puffed product by adopting a texture analyzer, measuring hardness, brittleness, chewiness and elasticity parameters, repeatedly measuring each sample for at least ten times, and taking an average value; S120, performing sensory evaluation, and comprehensively evaluating crispness, mouth-dissolving property, highland barley fragrance, peculiar smell, color, shape and overall acceptance of the puffed product by adopting a nine-ingredient taste evaluation method; S130, carrying out data preprocessing, and carrying out standardization processing on texture parameters and sensory score data so as to eliminate dimension influence and improve model stability; S140, establishing a prediction model, and constructing a mathematical relationship model by adopting a partial least square regression or multiple linear regression method and taking a texture parameter as an independent variable and a sensory score or a comprehensive sensory score as a dependent variable; s150, optimizing and verifying the model, screening key texture parameters according to the variable importance projection values and regression coefficients, and simplifying the model structure, wherein the model is externally verified by utilizing an independent verification set, and the prediction performance of the model needs to meet two indexes simultaneously, namely, the prediction root mean square error of the model is not more than 20% of the sensory scoring standard deviation, and the correlation coefficient between the model prediction value and the actual measurement value is more than or equal to 0.7; S160, applying the established model to a process control system, predicting the sensory acceptability of the puffed product by monitoring the texture parameters of the puffed product in real time, and reversely regulating and controlling the water content, the barrel temperature and the screw rotating speed process parameters to realize closed-loop control and continuous optimization of the product quality.

Description

Pure highland barley powder extrusion puffing process optimization method Technical Field The invention belongs to the technical field of food extrusion processing, and particularly relates to an optimization method of a pure highland barley powder extrusion and puffing process. Background Highland barley is used as a cereal with high dietary fiber and high beta-glucan content, and has wide application potential in the field of health foods. Extrusion puffing technology is commonly used for grain processing to increase the puffing degree and improve the taste of the product, but a plurality of technical difficulties still exist in the application of pure highland barley flour. Because the highland barley powder has high fiber content and special starch and protein composition, the highland barley powder is easy to have the problems of insufficient puffing or over-hard texture in the extrusion process. The high fiber content prevents the starch from being fully gelatinized and uniformly puffed, so that the puffing rate of the product is low, and the water retention and structural characteristics of the fiber also easily cause high hardness of the product, thereby influencing the edible quality. On the other hand, the functional components such as beta-glucan in highland barley belong to heat-sensitive substances, and are easy to degrade or change in structure in the high-temperature and high-pressure extrusion process, so that the retention rate is reduced, and the nutritional value of the product is reduced. In the aspect of process parameter regulation, key variables such as material water content, barrel temperature, screw speed and the like have remarkable influence on puffing effect, texture and nutrient component retention, but the response indexes often have a constraint relation. For example, increasing temperature or increasing mechanical shear may improve the overrun, but may result in increased beta glucan loss, and decreasing processing strength helps to retain functional ingredients, but may result in decreased overrun and increased hardness. This trade-off relationship between multiple objectives increases the complexity of process optimization. In the prior researches, the extrusion process is optimized by adopting methods such as single factor or simple orthogonal experiments, and the system strategy for optimizing multiple response indexes simultaneously is lacking, so that the synergistic improvement of the puffing rate, the hardness and the ingredient retention rate is difficult to realize. In addition, the highland barley materials are easy to be subjected to phenomena of water precipitation, fiber aggregation and the like in the tempering and extrusion processes, the flowability and the molding stability of the materials are affected, and the difficulty of continuous production is increased. Therefore, a finer raw material pretreatment and parameter cooperative control method needs to be explored, and the unique nutritional ingredients of highland barley are reserved to the maximum extent while a good puffing structure and texture are realized. Disclosure of Invention The invention provides an optimization method of an extrusion puffing process of pure highland barley powder, which can synergistically improve the puffing rate and the beta-glucan retention rate of a product, effectively control the hardness of the product and improve the formability and stability of a high-fiber material in extrusion processing. To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the present invention provides a method for optimizing an extrusion process of pure highland barley flour, comprising the steps of: The method comprises the steps of S1, optimizing process parameters based on multi-objective response, namely adopting a three-factor three-level Box-Behnken experimental design, taking the highest temperature of a material water content, a cylinder fourth area and a screw rotating speed as independent variables, taking the expansion rate, the hardness and the beta-glucan retention rate of a product as parallel response indexes, establishing three quadratic polynomial prediction models by utilizing multiple regression fitting, calculating P values of factors and interaction items by using variance analysis, and screening the items with obvious influence by taking the P values smaller than 0.05 as a standard, and obtaining the optimal process parameter combination capable of simultaneously realizing high expansion rate, low hardness and high functional ingredient retention rate by solving a satisfaction degree function of the prediction models, wherein the optimal process parameter combination is that the material water content is 20-24%, the cylinder temperature control interval is one area 70-85 ℃, two area 110-130 ℃, three area 135-155 ℃ and four area 145-165 ℃, and the screw rotating speed is 180-250r/min; S2,