Preparation method of modified composite protein powder, texture-stable high-satiation protein bar containing the same, and preparation method thereof

Abstract

The invention discloses a preparation method of a modified composite protein powder, a high-satiation protein bar with stable texture containing the same and a preparation method, and relates to the technical field of food preparation. The preparation method of the modified composite protein powder comprises: adding the composite protein powder into a sodium chloride solution, stirring evenly, standing at low temperature and separating to obtain the composite protein powder modified by sodium chloride; mixing a polyphosphate aqueous solution with the obtained composite protein powder modified by sodium chloride, stirring evenly, heating, and separating after the treatment to obtain the composite protein powder modified by polyphosphate; mixing a glutamine aminotransferase aqueous solution with the obtained composite protein powder modified by polyphosphate, heating for cross-linking reaction, and separating after the reaction to obtain the modified composite protein powder. The invention ensures the texture stability of the protein bar and improves the problem of easy hardening of the protein bar during storage by modifying the formula components and designing the preparation process.

Description

Technical Field

[0001] The invention provides a preparation method of a modified composite protein powder, a texture-stable high-satiety protein bar containing the modified composite protein powder, and a preparation method thereof, and relates to the technical field of food preparation. Background Art

[0002] Protein bars are nutritionally comprehensive, rich in high protein, suitable for replacing regular meals and easy to carry. They are especially popular among women aged 18-40 who need to manage their body shape. By replacing regular meals or high-calorie snacks, calorie intake can be reduced to achieve the goal of maintaining body shape. There are many kinds of meal replacement products on the market, but products that can achieve a comprehensive nutritional structure and are low in calories and fullness are relatively scarce. An imperfect nutritional structure may lead to extra energy intake or lack of nutrients, which in turn causes health problems and cannot meet the needs of controlling energy intake by replacing regular meals or high-calorie snacks.

[0003] Some protein bars are made of single or compound proteins. The biological value and applicability of proteins are ignored in the formula design, making it difficult to meet the exercise needs of fitness people. At the same time, the emphasis on high protein content ignores the balanced nutritional ratio and insufficient satiety, which cannot achieve the purpose of energy control, fat reduction and balanced nutrition. Some products also add a lot of sugar to improve the taste, resulting in high calories.

[0004] Most powdered protein bars have the problem of unstable product quality. As the storage time increases, the product hardness increases and the quality deteriorates. Ready-to-eat bars are typical multi-domain foods. There is a significant difference in water activity between syrup and protein. During storage, water migrates from syrup with high water activity to protein with low water activity. After the syrup loses water, it is easy to crystallize, resulting in increased hardness. The selection of raw materials with different water activities, the moisturizing or emulsification treatment of the main raw materials, etc. are important factors affecting water migration. Summary of the invention

[0005] In order to solve the above problems, the present invention designs a protein bar specifically for female groups with body management needs. The product has the characteristics of high satiety, good taste and stable quality, and is designed according to the "Dietary Guidelines for Chinese Residents" and the balanced dietary nutrition structure needs of fitness people. The specific solution is as follows:

[0006] First, the present invention provides a method for preparing a modified composite protein powder, comprising the following steps:

[0007] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 0-4°C, and the time of the low temperature standing is 2-3h;

[0008] S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder;

[0009] S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0010] Preferably, in S1, the composite protein powder includes soy protein isolate powder, and also includes one or more of pea protein powder, rice protein powder, yeast protein powder, instant soy powder, oat protein powder, soy peptide powder and almond powder.

[0011] Preferably, the concentration of the sodium chloride solution in distilled water in S1 is 2-3% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15-20wt%.

[0012] Preferably, in S2, the polyphosphate includes sodium pyrophosphate or sodium tripolyphosphate; the concentration of the polyphosphate aqueous solution is 0.5-1.0% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15-20wt%.

[0013] Preferably, in S2, the temperature of the heating treatment is 50-55°C, and the time of the heating treatment is 1.0-1.5h.

[0014] Preferably, in S3, the concentration of the glutamine aminotransferase aqueous solution is 1.0-1.5% (w / v); the mass percentage of the polyphosphate-modified composite protein powder in the third protein suspension is 10-12wt%.

[0015] Preferably, in S3, the temperature of the cross-linking reaction is 37°C, and the cross-linking reaction time is 2-3h; the enzyme inactivation treatment comprises heating the obtained cross-linking mixture to 80-85°C and maintaining it for 10-15min, and then naturally cooling it to room temperature.

[0016] Preferably, the separation in any of the steps S1, S2 and S3 adopts dialysis, wherein the molecular weight cutoff of the dialysis bag is 400-600Da, the dialysate is distilled water, the dialysis temperature is 4-10°C, the dialysis time is 18-24h, the dialysate is replaced every 4-6h during the dialysis, and a dialysis product is obtained after the dialysis is completed; and after the dialysis is completed, the obtained dialysis product is centrifuged, the precipitate is collected and dried; the centrifugation conditions are 3500-4000rpm, 10-15min.

[0017] Second, the present invention provides a high-satiety protein bar with stable texture, comprising modified composite protein powder, polydextrose, maltitol liquid and phospholipids; wherein the modified composite protein powder is prepared by any of the aforementioned preparation methods of the modified composite protein powder.

[0018] Preferably, the components included in the texture-stable high-satiety protein bar are as follows, by mass: 18-26 parts of the modified composite protein powder, 10-12 parts of the polydextrose, 23-25 ​​parts of the maltitol liquid and 0.3-0.5 parts of the phospholipids.

[0019] Thirdly, the present invention provides a method for preparing the above-mentioned high-satiety protein bar with stable texture, comprising the following steps:

[0020] (1) adding polydextrose and water into a sugar boiling pot and mixing them evenly to obtain a polydextrose solution, heating and boiling the obtained polydextrose solution until boiling, stirring the obtained polydextrose solution while boiling, and stopping heating when it is detected that the solid content in the polydextrose solution reaches a set value, and cooling the polydextrose solution to obtain a polydextrose solution for use;

[0021] (2) pouring the modified composite protein powder and other components in the high-satiety protein bar with stable texture and the polydextrose solution into a mixing container, stirring and mixing to obtain a mixed material;

[0022] (3) extruding, cutting and packaging the obtained mixed material to obtain a high-satiation protein bar with stable texture;

[0023] Wherein, in the step (1), the content of polydextrose in the polydextrose solution is 50-60%; the heating temperature is 100-110° C., the set value is 74-75%; and the cooling is cooling to below 35° C.

[0024] Preferably, the step (2) comprises: pouring the polydextrose solution into the mixing container, adding the maltitol solution into the polydextrose solution and stirring for 1-2 minutes; continuing to add the composite protein powder and stirring for 2-3 minutes; continuing to add the remaining components included in the high-satiety protein bar with stable texture, and performing multiple forward and reverse stirring for 3-5 minutes to achieve uniformity.

[0025] Beneficial effects:

[0026] The method provided by the present invention prepares modified composite protein powder, and the cross-linking modification of the composite protein powder is used to form stable covalent bonds between protein molecules, thereby enhancing the structural stability and water holding capacity of the protein, so that the protein bar maintains a soft and stable texture during storage. In the sugar boiling process, polydextrose is used to boil syrup to maintain a uniform distribution of water, which is matched with the modified composite protein powder with high water holding capacity to prevent water migration from causing the hardening of the protein bar. The reasonable combination of multiple ingredients such as modified composite protein powder and polydextrose liquid ensures a high satiety of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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 are briefly introduced below.

[0028] Figure 1 This is a photo of the mixed material obtained in step (2) of Example 1;

[0029] Figure 2 This is a photo of a portion of the semi-finished product after extrusion molding in step (3) of Example 1;

[0030] Figure 3 This is a photo of part of the sample after cutting in step (3) of Example 1. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0033] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified.

[0034] The following specific embodiments are used to illustrate the implementation of the present invention. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0035] In a first aspect, the present invention provides a method for preparing a modified composite protein powder, comprising the following steps:

[0036] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 0-4°C, and the time of the low temperature standing is 2-3h;

[0037] S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder;

[0038] S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0039] In some embodiments, the temperature of the low temperature standing can be 0°C, 1°C, 2°C, 3°C, 4°C. The temperature of the low temperature standing is preferably 4°C. The time of the low temperature standing can be 2h, 2.3h, 2.5h, 2.8h, 3h. Within the range of the standing temperature and the standing time, the purpose of sodium chloride modification can be achieved, and within this range, the change of temperature and time will not have a significant effect on the modified composite protein powder; according to common sense in the art, the standing temperature should not be lower than 0°C. Within the range of 0-4°C, the protein molecules can maintain a relatively stable state, which is conducive to the subsequent separation and modification process; selecting a standing time of 2-3 hours can ensure that the reaction and precipitation are fully carried out, and will not excessively extend the production cycle, thereby improving the operating efficiency, and can also avoid excessive processing; the standing temperature and time changes within the above range will not cause a significant difference in the performance of the modified composite protein powder.

[0040] In some embodiments, in the S1, the composite protein powder includes soy protein isolate powder, and may also include one or more of pea protein powder, rice protein powder, yeast protein powder, instant bean powder, oat protein powder, soy peptide powder, and almond powder. Exemplarily, in the S1, the composite protein powder may include soy protein isolate powder and pea protein powder, the composite protein powder may include soy protein isolate powder, pea protein powder and rice protein powder, the composite protein powder may include soy protein isolate powder, pea protein powder, rice protein powder and yeast protein powder, the composite protein powder may include soy protein isolate powder, instant bean powder, oat protein powder and pea protein powder, the composite protein powder may include soy protein isolate powder, instant bean powder, oat protein powder, pea protein powder and yeast protein powder, the composite protein powder may include soy protein isolate powder, instant bean powder, oat protein powder, pea protein powder and yeast protein powder, the composite protein powder may include soy protein isolate powder, instant bean powder, soy peptide powder, almond powder, pea protein powder and oat protein powder, the composite protein powder may include soy protein isolate powder, instant bean powder, pea protein powder, oat protein powder and soy peptide powder.

[0041] In some embodiments, the concentration of the sodium chloride solution in distilled water in S1 is 2-3% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15-20wt%. The concentration of the sodium chloride solution in distilled water in S1 can be set to 2% (w / v), 2.2% (w / v), 2.5% (w / v), 2.8% (w / v), 3% (w / v); the mass percentage of the composite protein powder in the first protein suspension can be set to 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%.

[0042] In some embodiments, in S2, the polyphosphate includes sodium pyrophosphate or sodium tripolyphosphate; the concentration of the polyphosphate aqueous solution is 0.5-1.0% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15-20wt%. In S2, the concentration of the polyphosphate aqueous solution can be 0.5% (w / v), 0.6% (w / v), 0.7% (w / v), 0.8% (w / v), 0.9% (w / v), 1.0% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension can be 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%.

[0043] In some embodiments, in S3, the concentration of the aqueous solution of transglutaminase is 1.0-1.5% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the third protein suspension is 10-12wt%. In S3, the concentration of the aqueous solution of transglutaminase can be 1.0% (w / v), 1.1% (w / v), 1.2% (w / v), 1.3% (w / v), 1.4% (w / v), 1.5% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the third protein suspension can be 10wt%, 10.5wt%, 11wt%, 11.5wt%, 12wt%.

[0044] When the concentrations of the sodium chloride, polyphosphate and glutamine transaminase are within the above range, under the premise that other conditions remain unchanged, the concentration of any one of the three is increased respectively, and the water holding capacity of the obtained modified composite protein powder is improved accordingly. When the concentrations of the three are lower than the above lower limit, the corresponding modification step loses its effect. When the concentrations of the three are higher than the above upper limit, the properties of the obtained modified composite protein powder no longer change significantly.

[0045] In some embodiments, in S2, the temperature of the heating treatment is 50-55°C, and the time of the heating treatment is 1.0-1.5h. The temperature of the heating treatment can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, and the time of the heating treatment can be 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h. When the above parameters vary within the range, the modified composite protein powder obtained has a higher water holding capacity; when the heating treatment temperature is not within the above parameter range, the water holding capacity of the modified protein powder obtained is reduced, and when the heating treatment time is higher than 1.5h, the water holding capacity of the protein powder will not increase, and more unnecessary energy consumption will occur.

[0046] In some embodiments, in S3, the temperature of the cross-linking reaction is 37°C, and the cross-linking reaction time is 2-3h; the enzyme inactivation treatment includes heating the obtained cross-linked mixture to 80-85°C and maintaining it for 10-15min, and then naturally cooling it to room temperature. The cross-linking reaction time can be 2h, 2.3h, 2.5h, 2.8h, 3h. The enzyme inactivation treatment includes heating the obtained cross-linked mixture to a certain temperature and maintaining it for a certain time. The temperature can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, and the time can be 10min, 11min, 12min, 13min, 14min, 15min, and then naturally cooling it to room temperature. The cross-linking reaction takes a certain amount of time to reach equilibrium, and a reaction time of 2-3 hours is sufficient for sufficient cross-linking reaction between protein molecules; selecting a temperature range of 80-85°C can ensure that the enzyme is completely inactivated, thereby stopping the cross-linking reaction, and maintaining it for 10-15min is sufficient to completely inactivate the enzyme.

[0047] In some embodiments, the separation in any of the steps S1, S2, and S3 is performed by dialysis, wherein the dialysis bag has a molecular weight cutoff of 400 to 600 Da, the dialysate is distilled water, the dialysis temperature is 4-10° C., the dialysis time is 18-24 h, the dialysate is replaced every 4-6 h during the dialysis, and a dialysis product is obtained after the dialysis is completed; and after the dialysis is completed, the obtained dialysis product is centrifuged, the precipitate is collected and dried; and the centrifugation conditions are 3500-4000 rpm, 10-15 min. The molecular weight cutoff of the dialysis bag can be 400Da, 500Da, 600Da, preferably 500Da; the dialysis temperature can be 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C; the dialysis time can be 18h, 20h, 21h, 22h, 24h; during the dialysis, the dialysate can be replaced every 4h, 4.5h, 5h, 5.5h, 6h; the centrifugation condition can be 3500rpm, 3600rpm, 3700rpm, 3800rpm, 3900rpm, 4000rpm, and the centrifugation time can be 10min, 11min, 12min, 13min, 14min, 15min. The parameters in the separation step adopt conventional parameters in the art. When the parameters are within the above range, the properties of the modified composite protein powder obtained are not significantly affected.

[0048] In a second aspect, the present invention provides a high-satiety protein bar with a stable texture, comprising a modified composite protein powder, polydextrose, maltitol liquid and phospholipids; wherein the modified composite protein powder is prepared by the preparation method of the modified composite protein powder in the above embodiment. When other conditions are exactly the same, the water holding capacity of the modified composite protein powder directly affects the texture stability of the protein bar. When the water holding capacity of the modified composite protein powder increases, the texture stability of the protein bar also increases.

[0049] In some embodiments, the components included in the high satiety protein bar with stable texture are calculated by mass: 18-26 parts of the modified composite protein powder, 10-12 parts of the polydextrose, 23-25 ​​parts of the maltitol liquid and 0.3-0.5 parts of the phospholipids. The modified composite protein powder can be 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, the polydextrose can be 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, the maltitol liquid can be 23 parts, 23.5 parts, 24 parts, 24.5 parts, 25 parts, and the phospholipids can be 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts. The mass fractions of the above components within the specified range can ensure that the protein bar has the characteristics of high protein and good taste.

[0050] In some embodiments, the texture-stable high-satiation protein bar further comprises: one or more of instant bean powder, sorbitol liquid, glycerol, coconut oil, resistant dextrin, enzymatic oatmeal powder, oatmeal powder, purple potato powder, chia seeds, rice flour, soy milk powder, whole milk powder, and oligomaltosaccharide powder. In a specific embodiment of this embodiment, the components included in the texture-stable high-satiation protein bar are calculated by mass: 18 parts of modified composite protein powder, 12 parts of polydextrose, 25 parts of maltitol liquid, 5 parts of sorbitol liquid, 12 parts of soy milk powder, 8 parts of oatmeal powder, 8 parts of instant bean powder, 3 parts of rice flour, and 0.5 parts of phospholipids.

[0051] In a third aspect, the present invention provides a method for preparing the high-satiety protein bar with stable texture as described in the above embodiment, comprising the following steps:

[0052] (1) adding polydextrose and water into a sugar boiling pot and mixing them evenly to obtain a polydextrose solution, heating and boiling the obtained polydextrose solution until boiling, stirring the obtained polydextrose solution while boiling, and stopping heating when it is detected that the solid content in the polydextrose solution reaches a set value, and cooling the polydextrose solution to obtain a polydextrose solution for use;

[0053] (2) pouring the modified composite protein powder and other components in the high-satiety protein bar with stable texture and the polydextrose solution into a mixing container, stirring and mixing to obtain a mixed material;

[0054] (3) extruding, cutting and packaging the obtained mixed material to obtain a high-satiation protein bar with stable texture;

[0055] In some embodiments, in the step (1), the content of polydextrose in the polydextrose solution is 50-60%; the heating temperature is 100-110°C, and the set value is 74-75%; the cooling is cooling to below 35°C. The content of polydextrose in the polydextrose solution can be 50%, 52%, 55%, 57%, 60%; the heating temperature can be 100°C, 103°C, 105°C, 108°C, 110°C, and the set value can be 74%, 74.2%, 74.5%, 74.8%, 75%.

[0056] In some embodiments, step (2) includes: pouring the polydextrose solution into the mixing container, adding the maltitol solution to the polydextrose solution and stirring for 1-2 minutes; continuing to add the composite protein powder and stirring for 2-3 minutes; continuing to add the remaining components included in the high-satiety protein bar with stable texture, and performing multiple forward and reverse stirring for 3-5 minutes to make it uniform. Wherein, the maltitol solution is added to the polydextrose solution and stirred, and the stirring time can be 1 minute, 1.5 minutes, and 2 minutes; continuing to add the composite protein powder and stirring, and the stirring time can be 2 minutes, 2.5 minutes, and 3 minutes; the forward and reverse stirring time can be 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, and 5 minutes.

[0057] When the above parameter settings change within the range, the properties of the product protein bar will not be significantly affected; the parameters within the above range can ensure the sugar boiling efficiency and overall production efficiency while avoiding chemical reactions caused by excessively high temperatures or waste of energy.

[0058] The technical solution of the present invention is described in detail below through specific embodiments.

[0059] Preparation Example 1 Preparation of modified composite protein powder:

[0060] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 4° C., and the time of the low temperature standing is 2 h;

[0061] S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder;

[0062] S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0063] In S1, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of sodium chloride in distilled water in S1 is 2% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%;

[0064] In S2, the polyphosphate includes sodium pyrophosphate; the concentration of the polyphosphate aqueous solution is 0.5% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15wt%; the heating treatment is performed at a temperature of 50°C for 1.5h;

[0065] In S3, the concentration of the glutamine aminotransferase aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the third protein suspension is 10wt%; the cross-linking reaction is carried out at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature;

[0066] The separation in steps S1, S2 and S3 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation condition is 3500rpm, 15min.

[0067] Preparation Example 2 Preparation of modified composite protein powder (the difference from Preparation Example 1 is that the amount of sodium chloride is increased):

[0068] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 4° C., and the time of the low temperature standing is 2 h;

[0069] S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder;

[0070] S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0071] In S1, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of sodium chloride in distilled water in S1 is 3% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%;

[0072] In S2, the polyphosphate includes sodium pyrophosphate; the concentration of the polyphosphate aqueous solution is 0.5% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15wt%; the heating treatment is performed at a temperature of 50°C for 1.5h;

[0073] In S3, the concentration of the glutamine aminotransferase aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the third protein suspension is 10wt%; the cross-linking reaction is carried out at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature;

[0074] The separation in steps S1, S2 and S3 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation condition is 3500rpm, 15min.

[0075] Preparation Example 3 Preparation of modified composite protein powder (the difference from Preparation Example 1 is that the amount of polyphosphate is increased):

[0076] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 4° C., and the time of the low temperature standing is 2 h;

[0077] S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder;

[0078] S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0079] In S1, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of sodium chloride in distilled water in S1 is 2% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%;

[0080] In S2, the polyphosphate includes sodium pyrophosphate; the concentration of the polyphosphate aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15wt%; the heating treatment is performed at a temperature of 50°C for 1.5h;

[0081] In S3, the concentration of the glutamine aminotransferase aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the third protein suspension is 10wt%; the cross-linking reaction is carried out at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature;

[0082] The separation in steps S1, S2 and S3 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation condition is 3500rpm, 15min.

[0083] Preparation Example 4 Preparation of modified composite protein powder (the difference from Preparation Example 1 is that the amount of glutamine transaminase is increased):

[0084] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 4° C., and the time of the low temperature standing is 2 h;

[0085] S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder;

[0086] S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0087] In S1, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of sodium chloride in distilled water in S1 is 2% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%;

[0088] In S2, the polyphosphate includes sodium pyrophosphate; the concentration of the polyphosphate aqueous solution is 0.5% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15wt%; the heating treatment is performed at a temperature of 50°C for 1.5h;

[0089] In S3, the concentration of the glutamine aminotransferase aqueous solution is 1.5% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the third protein suspension is 10wt%; the cross-linking reaction is carried out at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature;

[0090] The separation in steps S1, S2 and S3 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation condition is 3500rpm, 15min.

[0091] Preparation Example 5 Preparation of modified composite protein powder (the difference from Preparation Example 1 is that the composite protein powder components in S1 are different, and the polyphosphate in S2 is different):

[0092] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 4° C., and the time of the low temperature standing is 2 h;

[0093] S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder;

[0094] S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0095] In S1, the composite protein powder includes soy protein isolate powder and soy peptide powder, and the mass ratio of the two is 8:1; the concentration of sodium chloride in distilled water in S1 is 2% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%;

[0096] In S2, the polyphosphate includes sodium tripolyphosphate; the concentration of the polyphosphate aqueous solution is 0.5% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15wt%; the heating treatment is performed at a temperature of 50°C for 1.5h;

[0097] In S3, the concentration of the glutamine aminotransferase aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the third protein suspension is 10wt%; the cross-linking reaction is carried out at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature;

[0098] The separation in steps S1, S2 and S3 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation condition is 3500rpm, 15min.

[0099] Preparation of modified composite protein powder in comparative preparation example 1 (the difference from preparation example 1 is that sodium chloride treatment is not used):

[0100] S1, preparing a polyphosphate aqueous solution, adding a composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a first protein suspension, heating the first protein suspension, and separating the mixture obtained after the heating treatment to obtain a composite protein powder modified by polyphosphate;

[0101] S2, preparing an aqueous solution of transglutaminase, adding the composite protein powder modified by polyphosphate to the aqueous solution of transglutaminase and stirring evenly to obtain a second protein suspension, heating the second protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0102] In S1, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the polyphosphate includes sodium pyrophosphate; the concentration of the polyphosphate aqueous solution is 0.5% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%; the heating treatment is performed at a temperature of 50°C and a time of 1.5h;

[0103] In S2, the concentration of the glutamine aminotransferase aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder modified by polyphosphate in the second protein suspension is 10wt%; the cross-linking reaction is carried out at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature;

[0104] The separation in steps S1 and S2 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation conditions are 3500rpm, 15min.

[0105] Preparation of modified composite protein powder in comparative preparation example 2 (the difference from preparation example 1 is that polyphosphate treatment is not used):

[0106] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 4° C., and the time of the low temperature standing is 2 h;

[0107] S2, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by sodium chloride to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a second protein suspension, heating the second protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

[0108] In S1, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of sodium chloride in distilled water in S1 is 2% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%;

[0109] In S2, the concentration of the glutamine aminotransferase aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 10wt%; the cross-linking reaction is carried out at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature;

[0110] The separation in steps S1 and S2 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation conditions are 3500rpm, 15min.

[0111] Preparation of modified composite protein powder in comparative preparation example 3 (the difference from preparation example 1 is that glutamine aminotransferase treatment is not used):

[0112] S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 4° C., and the time of the low temperature standing is 2 h;

[0113] S2, preparing a polyphosphate aqueous solution, adding the composite protein powder modified by sodium chloride to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a modified composite protein powder;

[0114] In S1, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of sodium chloride in distilled water in S1 is 2% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15wt%;

[0115] In S2, the polyphosphate includes sodium pyrophosphate; the concentration of the polyphosphate aqueous solution is 0.5% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15wt%; the heating treatment is performed at a temperature of 50°C for 1.5h;

[0116] The separation in steps S1, S2 and S3 is carried out by dialysis, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysate is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysate is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation condition is 3500rpm, 15min.

[0117] Preparation of modified composite protein powder in comparative preparation example 4 (the difference from preparation example 1 is that only sodium chloride treatment is used):

[0118] Sodium chloride is dissolved in distilled water to obtain a sodium chloride solution, and the composite protein powder is added to the sodium chloride solution and stirred evenly to obtain a protein suspension, and the protein suspension is placed at low temperature and separated to obtain a modified composite protein powder. The temperature of the low temperature placement is 4°C, and the time of the low temperature placement is 2 hours; the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of sodium chloride in distilled water is 2% (w / v); the mass percentage of the composite protein powder in the protein suspension is 15wt%.

[0119] The separation adopts dialysis method, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysis fluid is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysis fluid is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation conditions are 3500rpm, 15min.

[0120] Preparation of modified composite protein powder in comparative preparation example 5 (the difference from preparation example 1 is that only polyphosphate treatment is used):

[0121] Prepare a polyphosphate aqueous solution, add a composite protein powder to the polyphosphate aqueous solution and stir evenly to obtain a protein suspension, heat the protein suspension, separate the mixture obtained after the heating treatment, and obtain a modified composite protein powder. The composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the polyphosphate includes sodium pyrophosphate; the concentration of the polyphosphate aqueous solution is 0.5% (w / v); the mass percentage of the composite protein powder in the protein suspension is 15wt%; the heating treatment is at a temperature of 50°C and a time of 1.5h.

[0122] The separation adopts dialysis method, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysis fluid is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysis fluid is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation conditions are 3500rpm, 15min.

[0123] Preparation of modified composite protein powder in comparative preparation example 6 (the difference from preparation example 1 is that only glutamine aminotransferase treatment is used):

[0124] Prepare a transglutaminase aqueous solution, add a composite protein powder to the transglutaminase aqueous solution and stir evenly to obtain a protein suspension, heat the protein suspension for a cross-linking reaction, obtain a cross-linked mixture after the cross-linking reaction is completed, inactivate the cross-linked mixture to obtain an enzyme-inactivated mixture, and separate the enzyme-inactivated mixture to obtain a modified composite protein powder. Wherein, the composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1; the concentration of the transglutaminase aqueous solution is 1.0% (w / v); the mass percentage of the composite protein powder in the protein suspension is 10wt%; the cross-linking reaction is at a temperature of 37°C and a time of 2h; after the cross-linking reaction is completed, the system is heated to 80°C and maintained for 15min, and then naturally cooled to room temperature.

[0125] The separation adopts dialysis method, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysis fluid is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysis fluid is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation conditions are 3500rpm, 15min.

[0126] Comparative Preparation Example 7

[0127] A mixed solution containing polyphosphate, sodium chloride and transglutaminase is prepared with distilled water so that the concentration of sodium chloride in the mixed solution is 2% (w / v), the concentration of polyphosphate is 0.5% (w / v), and the concentration of transglutaminase is 1.0% (w / v). The obtained mixed solution is mixed with a composite protein powder, and the obtained mixture is reacted at 37°C for 2h, then warmed to 50°C, treated for 1.5h, and then continued to warm to 80°C for 15min, cooled naturally to room temperature, and separated to obtain a treated powdered product. The composite protein powder includes soy protein isolate powder, soy peptide powder, oat protein powder, and pea protein powder, and the mass ratio of the four is 10:1:1:1. The polyphosphate includes sodium pyrophosphate. The mass percentage of the composite protein powder in the obtained mixture is 15wt%. The separation adopts dialysis method, wherein the molecular weight cutoff of the dialysis bag is 500Da, the dialysis fluid is distilled water, the dialysis temperature is 4°C, the dialysis time is 18h, the dialysis fluid is replaced every 6h, and after the dialysis is completed, the precipitate is collected by centrifugation and dried; the centrifugation conditions are 3500rpm, 15min.

[0128] Example 1 Preparation of high satiety protein bars with stable texture:

[0129] Formula: 22 parts of modified composite protein powder (Preparation Example 1), 12 parts of polydextrose, 25 parts of maltitol liquid, and 0.5 parts of phospholipids.

[0130] (1) adding polydextrose and water into a sugar boiling pot and mixing them evenly to obtain a polydextrose solution, heating and boiling the obtained polydextrose solution until boiling, stirring the obtained polydextrose solution while boiling, and stopping heating when it is detected that the solid content in the polydextrose solution reaches a set value, and cooling the polydextrose solution to obtain a polydextrose solution for use;

[0131] (2) pouring the modified composite protein powder and other components in the high-satiety protein bar with stable texture and the polydextrose solution into a mixing container, stirring and mixing to obtain a mixed material;

[0132] (3) extruding, cutting and packaging the obtained mixed material to obtain a high-satiation protein bar with stable texture;

[0133] Wherein, in the step (1), the content of polydextrose in the polydextrose solution is 60%; the heating temperature is 100° C., the set value is 75%; and the cooling is cooling to below 35° C.

[0134] The step (2) comprises: pouring the polydextrose solution into the mixing container, adding the maltitol solution into the polydextrose solution and stirring for 2 minutes; continuing to add the compound protein powder and stirring for 2 minutes; continuing to add the remaining components included in the high-satiety protein bar with stable texture, and performing multiple forward and reverse stirring for 5 minutes to achieve uniformity.

[0135] The thickness of the product obtained by molding in step (3) is controlled to be 14 mm.

[0136] Example 2 Preparation of high satiety protein bars with stable texture (the difference from Example 1 is that the preparation process parameters are different):

[0137] Formula: 22 parts of modified composite protein powder (Preparation Example 1), 12 parts of polydextrose, 25 parts of maltitol liquid, and 0.5 parts of phospholipids.

[0138] (1) adding polydextrose and water into a sugar boiling pot and mixing them evenly to obtain a polydextrose solution, heating and boiling the obtained polydextrose solution until boiling, stirring the obtained polydextrose solution while boiling, and stopping heating when it is detected that the solid content in the polydextrose solution reaches a set value, and cooling the polydextrose solution to obtain a polydextrose solution for use;

[0139] (2) pouring the modified composite protein powder and other components in the high-satiety protein bar with stable texture and the polydextrose solution into a mixing container, stirring and mixing to obtain a mixed material;

[0140] (3) extruding, cutting and packaging the obtained mixed material to obtain a high-satiation protein bar with stable texture;

[0141] Wherein, in the step (1), the content of polydextrose in the polydextrose solution is 50%; the heating temperature is 110° C., the set value is 74%; and the cooling is cooling to below 35° C.

[0142] The step (2) comprises: pouring the polydextrose solution into the mixing container, adding the maltitol solution into the polydextrose solution and stirring for 1 minute; continuing to add the compound protein powder and stirring for 3 minutes; continuing to add the remaining components included in the high-satiety protein bar with stable texture, and performing multiple forward and reverse stirring for 5 minutes to achieve uniformity.

[0143] The thickness of the product obtained by molding in step (3) is controlled to be 14 mm.

[0144] Example 3 Preparation of high-satiety protein bars with stable texture (the difference from Example 1 is that the proportion of modified composite protein powder in the formula is increased, and the other aspects remain unchanged).

[0145] Formula: 26 parts of modified composite protein powder (Preparation Example 1), 12 parts of polydextrose, 25 parts of maltitol liquid, and 0.5 parts of phospholipids.

[0146] The difference between Example 4 and Example 1 is that the modified composite protein powder prepared in Preparation Example 2 is used.

[0147] The difference between Example 5 and Example 1 is that the modified composite protein powder prepared in Preparation Example 3 is used.

[0148] The difference between Example 6 and Example 1 is that the modified composite protein powder prepared in Preparation Example 4 is used.

[0149] The difference between Example 7 and Example 1 is that the modified composite protein powder prepared in Preparation Example 5 is used.

[0150] The difference between Comparative Example 1 and Example 1 is that the modified composite protein powder prepared in Comparative Preparation Example 1 is used.

[0151] The difference between Comparative Example 2 and Example 1 is that the modified composite protein powder prepared in Comparative Preparation Example 2 is used.

[0152] The difference between Comparative Example 3 and Example 1 is that the modified composite protein powder prepared in Comparative Preparation Example 3 is used.

[0153] The difference between Comparative Example 4 and Example 1 is that the modified composite protein powder prepared in Comparative Preparation Example 4 is used.

[0154] The difference between Comparative Example 5 and Example 1 is that the modified composite protein powder prepared in Comparative Preparation Example 5 is used.

[0155] The difference between Comparative Example 6 and Example 1 is that the modified composite protein powder prepared in Comparative Preparation Example 6 is used.

[0156] The difference between Comparative Example 7 and Example 1 is that the modified composite protein powder prepared in Comparative Preparation Example 7 is used.

[0157] The difference between Comparative Example 8 and Example 1 is that the composite protein powder is not subjected to any modification treatment.

[0158] The difference between Comparative Example 9 and Example 1 is that the polydextrose is replaced by an equal amount of maltitol, and the other step parameters remain unchanged.

[0159] Water holding capacity test:

[0160] Sample preparation for measurement: Weigh 1 gram of the composite protein powder sample prepared in the preparation example or the comparative preparation example, and use the untreated composite protein powder as the control sample (including soy protein isolate powder, soy peptide powder, oat protein powder, pea protein powder, the mass ratio of the four is 10:1:1:1), use a precision electronic balance to ensure that the weighing is accurate to 0.001 grams, and the sample is placed in a 50mL pre-weighed centrifuge tube. Add 10 milliliters of distilled water to the centrifuge tube. A pipette or a measuring cylinder can be used to accurately measure the volume of water. The ratio of water to protein powder is 10:1 (v / w). Oscillate the sample with a vortex shaker to ensure that the protein powder and water are fully mixed to form a uniform suspension. Let the mixed sample stand at room temperature for 30 minutes to allow the protein powder to fully absorb water. Place the centrifuge tube in a centrifuge and centrifuge at 2000g for 10 minutes. After centrifugation, carefully pour out the supernatant to avoid pouring out the precipitate.

[0161] Measurements and calculations: Weigh the centrifuge tube containing the pellet, record the total weight and calculate the water holding capacity. Record the results in Table 1.

[0162] The calculation formula for water holding capacity is: The unit is g / g, which means the number of grams of water held by each gram of protein powder.

[0163] Table 1 Calculation results of water holding capacity measurement

[0164] sample Water holding capacity g / g sample Water holding capacity g / g Preparation Example 1 6.24 Comparative Preparation Example 3 4.59 Preparation Example 2 6.89 Comparative Preparation Example 4 4.56 Preparation Example 3 7.36 Comparative Preparation Example 5 4.42 Preparation Example 4 7.12 Comparative Preparation Example 6 4.39 Preparation Example 5 6.35 Comparative Preparation Example 7 4.17 Comparative Preparation Example 1 4.41 Control samples 3.86 Comparative Preparation Example 2 4.56

[0165] Hardness change detection:

[0166] Texture analysis method: The texture analyzer squeezes the sample through the probe and measures the change in hardness of the sample.

[0167] step:

[0168] All the above samples were cut into the same size and stored at the same room temperature. The hardness changes of the samples were measured at preset time intervals (such as 0 days, 7 days, 14 days, 21 days, and 28 days). A texture analyzer was used with a cylindrical probe.

[0169] Set the test parameters:

[0170] Compression speed: 1mm / s

[0171] Compression depth: 50% of sample thickness

[0172] Trigger force: 0.5N

[0173] Test temperature: room temperature (about 20-25℃)

[0174] After calibrating the instrument, place the sample on the test platform of the texture analyzer. Start the texture analyzer and record the hardness value of the sample at each time point - the maximum compression force (N). Repeat the test 5 times and take the average value to get the result. The results are shown in Table 2.

[0175] Table 2 Hardness change test results

[0176]

[0177]

[0178] According to the above test results, it can be seen from the embodiments that the ratio of each component in the composite protein powder has no significant effect on the texture stability of the protein bar of the present invention, and the amount of each reagent in the modification step of the composite protein powder of the present invention changes within the range selected by the embodiment, which has a smaller effect on the hardness change rate of the protein bar, and the obtained protein bar has a smaller hardness change rate, reflecting better texture stability. It can be seen from the embodiments and comparative examples that the modified composite protein powder plays a key role in maintaining texture stability in the protein bar, and the three-step modification of the present invention is indispensable, and the three do not act alone but synergistically act on the composite protein powder. In addition, the present invention uses polydextrose as the main adhesive and also contributes to texture stability.

[0179] Sodium chloride pretreatment: Sodium chloride may enhance the ionic strength of protein by binding to protein molecules, thereby improving water holding capacity. Polyphosphate treatment: Polyphosphate may further improve its water holding capacity by changing the rheological properties of thermally induced gels of proteins. Glutamine transaminase cross-linking: It may form stable covalent bonds with protein molecules through cross-linking reactions, thereby increasing the molecular weight and water holding capacity of proteins. Through the above research, it can be seen that the above three-step modification alone has a certain effect on the modified composite protein powder, but the effect is not significant. We speculate that based on the complex structure of protein molecules, the combination of these three steps of modification may have a synergistic effect, resulting in better results, which is ultimately reflected in the protein bar, giving the protein bar better texture stability. From the comparative preparation example 7, it can be known that the modification order of the protein affects the properties of the protein and the texture stability of the prepared protein bar, and the reason may be: the scheme of the preparation example and the embodiment of the present invention modifies the composite protein powder by sodium chloride, which may change the surface charge, solubility and aggregation state of the protein, and lays the foundation for the subsequent modification of polyphosphate and transglutaminase; then, the composite protein powder modified by sodium chloride is modified using polyphosphate, and polyphosphate may further enhance the water holding capacity and stability of the protein through its special structure and function; finally, the protein is cross-linked by transglutaminase, which may improve the functional properties of the protein, such as thermal stability, water retention and gel ability. And the composite protein powder is directly mixed with polyphosphate aqueous solution, sodium chloride solution and transglutaminase aqueous solution, and the method of adding three kinds of modifying agents to process the composite protein powder at the same time may destroy the synergistic effect of protein modification, and different modifiers may have different effects on the protein in different orders, and may even produce the effect of offsetting each other; the structure of the protein has a crucial influence on its functional properties. In Preparation Example 1, the structure of the protein may have undergone orderly and beneficial changes through a step-by-step modification process, thereby improving its water-holding capacity and other functional properties; whereas in Comparative Preparation Example 7, due to inappropriate modification sequence and conditions, the protein structure may have undergone disordered or adverse changes, thereby failing to achieve the intended purpose.

[0180] Satiety test:

[0181] 80 healthy women aged 25-30 years old, 155-165 cm in height and 50-60 kg in weight were randomly divided into 8 groups, 10 people in each group. The experimental group ate the protein bar samples described in Examples 1-6 once at breakfast time, one portion (25 g) each time. The control group 1 took commercially available protein bar sample A (25 g) for breakfast, and the control group 2 took normal meals for breakfast. All participants did not take any medication during the experiment, had a normal dinner the day before the experiment, and did not eat after 22:00. The blood sugar increase ratios at different time periods after meals and the postprandial time when obvious hunger appeared were measured (all data were taken as the average of 10 people in each group). The results are shown in Table 3.

[0182] Table 3 Product satiety feedback results

[0183]

[0184] It can be seen that the protein bar prepared by the present invention has good sugar control effect and strong satiety.

[0185] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0186] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a modified composite protein powder, characterized in that: The following steps are involved: S1, dissolving sodium chloride in distilled water to obtain a sodium chloride solution, adding the composite protein powder to the sodium chloride solution and stirring evenly to obtain a first protein suspension, and separating the first protein suspension after standing at low temperature to obtain a composite protein powder modified by sodium chloride, wherein the temperature of the low temperature standing is 0-4°C, and the time of the low temperature standing is 2-3h; S2, preparing a polyphosphate aqueous solution, adding the sodium chloride-modified composite protein powder to the polyphosphate aqueous solution and stirring evenly to obtain a second protein suspension, heating the second protein suspension, and separating the mixture obtained after the heating treatment to obtain a polyphosphate-modified composite protein powder; S3, preparing an aqueous solution of glutamine aminotransferase, adding the composite protein powder modified by polyphosphate to the aqueous solution of glutamine aminotransferase and stirring evenly to obtain a third protein suspension, heating the third protein suspension to perform a cross-linking reaction, obtaining a cross-linked mixture after the cross-linking reaction is completed, performing an enzyme inactivation treatment on the cross-linked mixture to obtain an enzyme inactivation mixture, and separating the enzyme inactivation mixture to obtain a modified composite protein powder.

2. The method for preparing the modified composite protein powder according to claim 1, characterized in that: In S1, the composite protein powder includes soy protein isolate powder, and also includes one or more of pea protein powder, rice protein powder, yeast protein powder, instant soy powder, oat protein powder, soy peptide powder, and almond powder.

3. The method for preparing the modified composite protein powder according to claim 1, characterized in that: The concentration of the sodium chloride solution in distilled water in S1 is 2-3% (w / v); the mass percentage of the composite protein powder in the first protein suspension is 15-20wt%.

4. The method for preparing the modified composite protein powder according to claim 1, characterized in that: In S2, the polyphosphate includes sodium pyrophosphate or sodium tripolyphosphate; the concentration of the polyphosphate aqueous solution is 0.5-1.0% (w / v); the mass percentage of the composite protein powder modified by sodium chloride in the second protein suspension is 15-20wt%.

5. The method for preparing the modified composite protein powder according to claim 1, characterized in that: In S2, the temperature of the heating treatment is 50-55°C, and the time of the heating treatment is 1.0-1.5h.

6. The method for preparing the modified composite protein powder according to claim 1, characterized in that: In S3, the concentration of the glutamine aminotransferase aqueous solution is 1.0-1.5% (w / v); the mass percentage of the polyphosphate-modified composite protein powder in the third protein suspension is 10-12wt%.

7. The method for preparing the modified composite protein powder according to claim 1, characterized in that: In S3, the temperature of the cross-linking reaction is 37° C., and the cross-linking reaction time is 2-3 hours; the enzyme inactivation treatment includes heating the obtained cross-linking mixture to 80-85° C., maintaining it for 10-15 minutes, and then naturally cooling it to room temperature.

8. The method for preparing the modified composite protein powder according to claim 1, characterized in that: The separation in any of the steps S1, S2 and S3 adopts dialysis, wherein the molecular weight cutoff of the dialysis bag is 400-600Da, the dialysis fluid is distilled water, the dialysis temperature is 4-10°C, the dialysis time is 18-24h, the dialysis fluid is replaced every 4-6h during the dialysis, and a dialysis product is obtained after the dialysis is completed; and after the dialysis is completed, the obtained dialysis product is centrifuged, and the precipitate is collected and dried; the centrifugation conditions are 3500-4000rpm, 10-15min.

9. A high-satiation protein bar with stable texture, comprising modified composite protein powder, polydextrose, maltitol liquid and phospholipids; characterized in that: in, The modified composite protein powder is prepared by the method according to any one of claims 1 to 8.

10. The high satiety protein bar with stable texture according to claim 9, characterized in that: The components included in the high-satiety protein bar with stable texture are as follows, by mass: 18-26 parts of the modified composite protein powder, 10-12 parts of the polydextrose, 23-25 ​​parts of the maltitol liquid and 0.3-0.5 parts of the phospholipid.

11. A method for preparing the high-satiation protein bar with stable texture as claimed in claim 9, characterized in that: The following steps are involved: (1) adding polydextrose and water into a sugar boiling pot and mixing them evenly to obtain a polydextrose solution, heating and boiling the obtained polydextrose solution until boiling, stirring the obtained polydextrose solution while boiling, and stopping heating when it is detected that the solid content in the polydextrose solution reaches a set value, and cooling the polydextrose solution to obtain a polydextrose solution for use; (2) pouring the modified composite protein powder and other components in the high-satiety protein bar with stable texture and the polydextrose solution into a mixing container, stirring and mixing to obtain a mixed material; (3) extruding, cutting and packaging the obtained mixed material to obtain a high-satiation protein bar with stable texture; Wherein, in the step (1), the content of polydextrose in the polydextrose solution is 50-60%; the heating temperature is 100-110° C., the set value is 74-75%; and the cooling is cooling to below 35° C.

12. The method for preparing a high-satiation protein bar with a stable texture according to claim 11, characterized in that: The step (2) comprises: pouring the polydextrose solution into the mixing container, adding the maltitol solution into the polydextrose solution and stirring for 1-2 minutes; continuing to add the compound protein powder and stirring for 2-3 minutes; continuing to add the remaining components included in the high-satiety protein bar with stable texture, and performing multiple forward and reverse stirring for 3-5 minutes to achieve uniformity.

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