Low-digestibility animal protein-wheat flour composite noodles and preparation method thereof

Abstract

The invention discloses low-digestibility animal protein-wheat flour composite noodles and a preparation method thereof, and belongs to the technical field of food processing. Wheat flour and exogenous animal protein are used as main raw materials, whey protein isolate, silkworm pupa protein, egg white protein and fish protein are selected, and the addition amount is 15% of the mass of the wheat flour. Through multi-index comprehensive screening, the silkworm pupa protein and whey protein isolate have better market development potential. By utilizing the synergistic effect of the exogenous animal protein and the wheat starch, the content of fast digestible starch (RDS) of the noodles can be remarkably reduced, the ratio of slow digestible starch (SDS) to resistant starch (RS) is increased, and the GI value of the noodles is lower than 70; meanwhile, cooking and texture characteristics are optimized, the cooking loss rate is smaller than or equal to 8%, and the breaking rate is smaller than or equal to 0.3%. The noodles have the characteristics of low glycemic content and high-quality eating taste, are balanced in nutrition, are suitable for diabetics to eat, can also be used as daily staple food of healthy people, and are simple and convenient in preparation process, easy to industrially produce and wide in market application prospect.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a method for reducing starch digestibility by adding exogenous animal protein and its application in noodles, and particularly to a low glycemic index noodle preparation technology that regulates the digestibility of wheat starch through exogenous animal protein. Background Technology

[0002] Noodles are a traditional staple food in my country, playing a vital role in people's daily diet due to their ease of processing, unique taste, and strong satiating effect. However, traditional wheat noodles, made primarily of wheat, contain rapidly digestible starch (RDS) accounting for over 79%, which can easily cause a rapid rise in postprandial blood sugar. Long-term excessive intake is detrimental to blood sugar stability and is particularly unsuitable for diabetic patients and obese individuals. Statistics show that the prevalence of type 2 diabetes among adults in my country has reached 12.8%, and long-term consumption of high-GI staple foods is a significant risk factor for this disease.

[0003] To address the high glycemic index (GI) of traditional wheat noodles, existing technologies often employ methods such as adding dietary fiber, plant protein, or modified starch to regulate starch digestibility. However, these methods can easily lead to problems like deteriorated noodle texture and reduced cooking quality, such as increased breakage rate and cooking losses. For instance, excessive addition of dietary fiber can result in a rough noodle texture and reduced stickiness; plant proteins like soy protein have poor compatibility with wheat flour, easily damaging the gluten network structure and affecting noodle quality. Exogenous animal protein, as a high-quality protein source with a balanced amino acid composition, can regulate starch digestibility through interaction. However, there is currently a lack of mature and systematic technical solutions regarding the precise application of exogenous animal protein in low-GI noodles, such as optimal addition ratios, mechanisms of action, and synergistic quality optimization, limiting its industrial application in functional noodles. Therefore, researching methods for reducing starch digestibility by adding exogenous animal protein and its application in noodles has significant practical value, providing feasible reference ideas and technical directions for solving this common industry problem. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a method for reducing the GI value and its application in noodles. By screening suitable exogenous animal proteins and the optimal addition ratio, the GI value of noodles is reduced while ensuring their good eating quality and processing characteristics, providing technical support for the development of functional staple foods.

[0005] To achieve the above objectives, the present invention provides the following technical method:

[0006] A method for reducing starch digestibility by adding exogenous animal protein and its application in noodles, comprising the following steps:

[0007] (1) Raw material pretreatment: Wheat flour and exogenous animal protein are mixed evenly at a ratio of 1:0.15 to obtain mixed powder;

[0008] (2) Dough preparation: Add 80% of the mass of the mixed powder to the mixed powder, stir until it forms flocculent, let it rise at a constant temperature of 25℃ for 15 minutes, and knead until the dough surface is smooth and uniform.

[0009] (3) Noodle shaping: The dough is placed in a dough press and pressed into a uniform sheet with a thickness of 2mm. The sheet is then cut into noodle blanks with a width of 2-3mm and a length of 20-25cm by a strip cutting device.

[0010] (4) Finished product processing: The noodle blank is packaged to obtain functional wheat noodles with reduced GI value; if dried noodles are to be prepared, the noodle blank needs to be dried at 35°C and 60% relative humidity until the moisture content is ≤12% before packaging.

[0011] Preferably, the raw materials include, by weight, 100 g of wheat flour and 15 g of exogenous animal protein.

[0012] Preferably, the exogenous animal protein is one or more of whey protein isolate, silkworm pupa protein, egg white protein, and fish protein.

[0013] Preferably, the wheat noodles have a GI value ≤70, a rapidly digestible starch (RDS) content ≤65%, and a total content of slowly digestible starch (SDS) and resistant starch (RS) ≥35%.

[0014] Preferably, the wheat flour is medium-gluten wheat flour with a starch content of 70-75% and a gluten protein content of 9-11%.

[0015] Preferably, the noodles have a cooking loss rate of ≤8%, a breakage rate of ≤0.3%, a water absorption rate of ≤70%, a hardness of 1200-1650g, and an elasticity of ≥0.68.

[0016] Preferably, the purity of exogenous animal protein is ≥90%, and it is odorless and free of lumps.

[0017] Preferably, the dough is pressed 3-5 times with the dough press, and then left to stand for 2 minutes after each pressing to ensure that the dough sheet has a uniform structure.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The wheat noodles of the present invention significantly optimize starch digestibility by adding 15% exogenous animal protein (whey protein isolate and silkworm pupa protein), reducing the GI value to 70 and 64.5 respectively, with a fast-digesting starch content ≤65% and a total content of slow-digesting starch and resistant starch ≥35%, which can effectively delay the rise in postprandial blood sugar and is suitable for consumption by diabetic patients and healthy people.

[0020] 2. The selected exogenous animal protein has good compatibility with wheat flour, and the noodles prepared have excellent cooking quality, with a cooking loss rate of ≤8%, a breakage rate of ≤0.3%, a water absorption rate of ≤70%, and excellent textural properties (hardness 1200-1650g, elasticity ≥0.68). They have a chewy and smooth texture, no off-flavors, and high market acceptance.

[0021] 3. The addition of exogenous animal protein enriches the types and content of protein in noodles, makes up for the deficiency of lysine in wheat flour, and achieves the dual goals of "reduced GI" and "high nutrition". The protein content is 15-20% higher than that of traditional noodles.

[0022] 4. The preparation process is simple, requires no special equipment, the raw materials are readily available, the production cost is controllable, and it can realize the industrial production of various product forms such as fresh noodles, dried noodles, and frozen noodles, with a wide range of applications. Attached Figure Description

[0023] This invention appendix Figure 8 , of which:

[0024] Figure 1 Digestive properties of wheat starch with added proteins;

[0025] Figure 2 Texture properties of dough with different added proteins;

[0026] Figure 3 The cooking loss rate of noodles with different added proteins;

[0027] Figure 4 The water absorption rate of noodles with different added proteins;

[0028] Figure 5 Breakage rate of noodles with different protein additions;

[0029] Figure 6 Texture of noodles with different added proteins;

[0030] Figure 7 Digestibility of noodles with different added proteins;

[0031] Figure 8 The GI values ​​for noodles with different added proteins. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the embodiments. Unless otherwise specified, all reagents used in the embodiments are commercially available. The embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0033] Example 1: Screening of protein concentration

[0034] 1) Digestibility characteristics of wheat starch with added proteins

[0035] The mass ratios of wheat starch and protein in the system were 1:0, 1:0.05, 1:0.15, 1:0.25, 1:0.35, and 1:0.45, respectively. First, 0.5 g of starch was dispersed in 5 mL of deionized water. Then, protein was added to the solution according to the ratio, and the mixture was stirred evenly at room temperature for 20 min. The mixture was then gelatinized at 95°C for 20 min on a temperature-controlled magnetic stirrer, and finally transferred to a constant temperature of 37°C and magnetically stirred for 15 min. The mixture was then ready for use.

[0036] The digestion experiment was performed according to the in vitro simulation method established by Englyst et al. First, 5 mL of pepsin solution (7 mg / mL, enzyme activity 2000 U / mg, prepared with 0.5 M, pH 1.5 hydrochloric acid-potassium chloride solution) was added, and the mixture was stirred in a 37°C water bath for 60 min. At 0, 30, and 60 min, 0.1 mL samples were taken and incubated in a boiling water bath to inactivate the enzyme. Then, a mixed enzyme solution of α-amylase and α-glucosidase was added, prepared with 0.5 M, pH 5.2 acetate-sodium acetate buffer solution, and the mixture was stirred in a 37°C water bath. At 0, 10, 20, 60, 90, 120, and 180 min, 0.2 mL samples were taken into centrifuge tubes containing 1.8 mL of anhydrous ethanol. After vortexing, the tubes were centrifuged at 10000 r / min for 5 min, and the supernatant was collected. The glucose content was determined using a glucose kit (glucose oxidase-peroxidase method). Starch digestibility is the ratio of glucose production at a specific time point multiplied by a coefficient of 0.9 to the total starch content in the original sample. The contents of rapidly digestible starch (RDS) and slowly digestible starch (SDS) are starch digested within 20 min and 20-120 min, respectively, while the contents of resistant starch (RS) are starch that has not been digested after 120 min.

[0037] RDS(%)=(G 20 -G o )×0.9 / S×100 (1-1)

[0038] SDS(%)=(G 120 -G 20 )×0.9 / S×100 (1-2)

[0039] RS(%) = (1 - RDS - SDS) × 100 (1-3)

[0040] In the formula:

[0041] G0 - Amount of free glucose before enzymatic hydrolysis, mg;

[0042] G 20 - The amount of glucose produced after 20 min of enzymatic hydrolysis, in mg;

[0043] G 120 - The amount of glucose produced after 120 min of enzymatic hydrolysis, in mg;

[0044] S - Total starch content in the sample, mg.

[0045] Figure 1 A, B, C, and D represent the digestibility of wheat starch systems supplemented with whey protein, silkworm pupa protein, egg white protein, and fish protein, respectively. Figure 1 It was found that all four exogenous animal proteins significantly affected the contents of RDS, SDS, and RS, but the effects varied. All four exogenous animal proteins reduced RDS content, with a significant decrease in RDS content as protein concentration increased. Silkworm pupa protein had the greatest impact on RDS, decreasing it from 79.05±0.82% to 59.63±0.70% when added at 45% concentration; whey protein isolate followed, decreasing RDS from 79.05±0.82% to 62.78±0.42%. SDS content increased with the addition of the four exogenous animal proteins, but the trend was not entirely consistent with the increase in protein concentration. Furthermore, all four exogenous animal proteins increased RS content, but this was not directly proportional to concentration. Silkworm pupa protein had the greatest impact on RS content, increasing it from 6.92±0.44% to 23.47±0.38% when added at 45% concentration. In summary, the inhibitory effects are ranked as follows: silkworm pupa protein > whey protein isolate > egg white protein > fish protein.

[0046] 2) Texture properties of wheat dough with different proportions of added protein

[0047] Four exogenous animal proteins were mixed with wheat flour (WF) at proportions of 5%, 15%, 15%, 22%, 35%, and 45% to prepare a mixed powder. Water with an absorption rate of 80% was added to the mixed powder, and the mixture was stirred until it formed a flocculent state. The mixture was then proofed in a 25°C incubator for 15 minutes. The cotton fibers were then kneaded into a dough. The dough was then formed into cylindrical samples with a diameter of 25 mm × 10 mm (height), wrapped in plastic film, and allowed to stand for 10 minutes. The textural properties of the dough were measured using a physical property analyzer (TPA mode). The experimental parameters were: probe model P / 3 6R, probe speed before test 1.0 mm / s, probe speed during test 1.0 mm / s, probe speed after test 10.0 mm / s, test time 5 s, strain 50%, and trigger force 10 g. The textural property test was repeated 6 times.

[0048] Figure 2 In the figures, A, B, C, and D represent the textural properties of doughs containing whey protein, silkworm pupa protein, egg white protein, and fish protein, respectively. Figure 2 Experimental results showed that with the increase of exogenous animal protein concentration, the overall hardness and chewiness of the dough gradually increased. This trend indicates that the addition of exogenous protein effectively enhanced the dough's toughness and structural strength, optimized its cohesion, and made it more compact and chewy during processing and consumption. However, textural properties must also consider palatability: excessive hardness and chewiness will lead to difficulty in chewing, a tough and rough texture, and deviate from the quality requirements of high-quality noodles. Meanwhile, viscosity is another important indicator for judging noodle quality. For noodles, moderate viscosity helps improve texture, but excessive viscosity will cause the noodles to stick together during steaming or boiling, resulting in a sticky texture and clogging of processing equipment—a typical characteristic of inferior noodles. Experimental results showed that with the increase of protein addition, dough viscosity increased, which will significantly reduce the dough's processing adaptability and the final noodle quality. Considering both textural quality (palatability) and digestibility, this study ultimately determined the optimal addition ratio of exogenous animal protein to be 15%. At this ratio, the dough's hardness and chewiness are within a reasonable range, ensuring that the noodles have ideal toughness and texture while avoiding a decrease in palatability due to excessively high quality parameters. More importantly, this amount can significantly reduce starch digestibility, achieving the dual goals of excellent noodle taste and health benefits, and providing a scientific basis for subsequent production processes and product design.

[0049] Example 2: Application of exogenous animal protein in noodles

[0050] Four types of exogenous animal proteins were mixed with wheat flour (WF) at a ratio of 15% to prepare a mixed powder. Water with an absorption rate of 80% was added to the mixed powder and stirred into a flocculent state. The mixture was then proofed in a constant temperature oven at 25°C for 15 minutes. Subsequently, the cotton fibers were kneaded into a dough. The dough was placed in a pasta machine and pressed into a sheet of uniform thickness. A strip-cutting device was installed on the pasta machine to cut the sheet into noodles of uniform length and width. The noodles were then placed in resealable bags for later use. A total of five processing groups were set up.

[0051] 1) Cooking loss rate of wheat noodles with different added proteins

[0052] Take an appropriate amount of prepared noodles, put them into 500 mL of boiling water and boil for 5 minutes. Quickly remove them and rinse them with 200 mL of cold water. Pour the rinsing liquid into a pot. Pour the remaining noodle soup into a beaker that has been heated to constant weight and place it in an oven at 105℃ to reach constant weight again. The cooking loss rate of the noodles is calculated using formula 4-1:

[0053] Cooking loss rate (%) = (1-4)

[0054] In the formula: m2 is the sum of the dried beaker and the dry matter, g; ml is the constant weight of the beaker, g; mo is the weight of the noodles, g.

[0055] Cooking loss rate refers to the proportion of soluble substances (such as starch and protein) lost by noodles during the cooking process. See [link to noodle cooking loss rate section]. Figure 3 Adding whey protein isolate, silkworm pupa protein, and egg white protein did not significantly change the cooking loss rate of the noodles. However, adding fish protein gradually increased the cooking loss rate. This may be because, under heating conditions, the proteins in the fish protein affect the starch, causing them to interact and form a looser structure, resulting in greater loss of soluble components from the noodles. Therefore, noodles with added silkworm pupa protein and whey protein exhibit excellent cooking quality.

[0056] 2) Breakage rate of wheat noodles with different added proteins

[0057] According to SB / T 10137-93 standard, the noodles were boiled for 5 minutes and then quickly removed. 30 noodles of uniform length 20 cm were taken from the noodles prepared in 4.3.5 and boiled in boiling water. The noodle breakage rate was calculated based on the number of noodles that had broken (less than 12 cm in length).

[0058] like Figure 4The addition of whey protein isolate and silkworm pupa protein slightly reduced the noodle breakage rate. This is likely because the proteins interact with the gluten in wheat flour, enhancing the elastic network structure of the dough and increasing the tensile strength of the noodles. Therefore, the noodles are less prone to breakage during cooking, maintaining a low breakage rate. Adding egg white protein did not change the breakage rate, while adding fish protein increased it, which is related to the reduced cohesiveness of the noodles after protein addition. Therefore, noodles with added silkworm pupa protein and whey protein have better steaming and cooking quality.

[0059] 3) Water absorption rate of wheat noodles with added proteins

[0060] Take an appropriate amount of the prepared noodles, put them into boiling water and boil for 5 minutes. Remove them and pat dry. The water absorption rate of the noodles is calculated using formula 1-5.

[0061] Water absorption rate (%) = (1-5)

[0062] In the formula: m2 is the mass of the noodles after cooking, in grams; m l The mass of the noodles before cooking is in grams.

[0063] Water absorption rate refers to the amount of water absorbed by noodles during the steaming or cooking process, and is typically used to assess the softness and texture of noodles. For example... Figure 5 As shown, the addition of protein reduces the water absorption rate of noodles. Specifically, the addition of whey protein isolate slightly reduces the water absorption rate, but not significantly; while the addition of silkworm pupa protein, egg white protein, and fish protein significantly reduces the water absorption rate. This is likely because the increase in moisture during heating mainly comes from the hydration of starch during gelatinization, and compared to starch, protein has a poorer water absorption capacity. Therefore, the addition of protein reduces the overall water absorption rate.

[0064] 4) Texture properties of wheat noodles with added proteins

[0065] The prepared noodles were cooked, cooled, and then arranged into a square. The experimental parameters were as follows: probe model P / 36R, speed before test 1.0 mm / s, speed during test 0.15 mm / s, speed after test 2.0 mm / s, time 5s, strain 50%, and trigger force 5 g.

[0066] The effect of exogenous animal protein on the textural properties of noodles, such as Figure 6 As shown. Hardness is a core indicator characterizing the structural strength and toughness of noodles, directly affecting their chewing texture. High-quality noodles need to have moderate hardness; too high a hardness makes them difficult to chew, while too low a hardness makes them prone to breakage and lacking in toughness. Figure 6It was found that the four exogenous animal proteins had significant differences in their regulatory effects on noodle hardness (P<0.05): Among them, the noodles with added egg white protein (EWPN) had the highest hardness, at 1636.50±99.33g, which was significantly higher than the blank control group, indicating that the addition of egg white protein could significantly enhance the structural strength and toughness of the noodles; the noodles with added whey protein isolate (WPIN) and silkworm pupa protein (SPPN) had hardnesses of 1240.20±75.48g and 1241.40±94.05g, respectively, which were slightly higher than the blank control group, but there was no significant difference among the three (P>0.05), indicating that whey protein isolate and silkworm pupa protein could slightly increase the hardness of the noodles and enhance their structural stability; unlike the above three proteins, the noodles with added fish protein (FPN) had a hardness of 977.28±62.46g, which was significantly lower than the blank control group, indicating that the addition of fish protein would reduce the structural strength and toughness of the noodles, making the noodles softer.

[0067] Elasticity reflects the ability of noodles to recover their original shape after being squeezed by external force, and is an important indicator affecting the palatability of noodles. Noodles with moderate elasticity have a more elastic texture and are neither hard nor mushy. Experimental results showed that different exogenous animal proteins had significantly different effects on noodle elasticity (P<0.05): the elasticity of noodles in the blank control group (WFN) was 0.74±0.02, while the elasticity of noodles with added egg white protein (EWPN) was 0.72±0.03, with no significant difference between the two (P>0.05), indicating that the addition of egg white protein had virtually no effect on noodle elasticity; the elasticity of noodles with added whey protein isolate (WPIN) and silkworm pupa protein (SPPN) were 0.68±0.03 and 0.68±0.03, respectively. The elasticity of the noodles was 0.01, slightly lower than that of the blank control group, but the difference was not significant (P>0.05). It is speculated that the two proteins may slightly affect the formation of the gluten network during the interaction with gluten protein, resulting in a slight reduction in noodle elasticity, but without a significant negative impact on palatability. The noodles with added fish protein (FPN) had the lowest elasticity, at 0.58±0.03, which was significantly lower than that of the blank control group (P<0.05). This indicates that the addition of fish protein will significantly reduce the elasticity of the noodles, making them lack a chewy texture and have a soft and mushy taste.

[0068] Stickiness is a negative indicator for evaluating the texture of noodles. Excessive stickiness will cause the noodles to stick together when steaming or boiling and stick to the mouth when chewing, significantly reducing the eating experience. High-quality noodles need to have low stickiness. Table 4.3 shows that the four exogenous animal proteins had significant differences in their effects on the viscosity of noodles (P<0.05): the noodles with added whey protein isolate (WPIN) had the lowest viscosity (0.10±0.02), significantly lower than the blank control group (0.24±0.06), indicating that whey protein isolate can effectively reduce noodle viscosity and improve the problem of noodle stickiness; the noodles with added egg white protein (EWPN) had a viscosity of 0.14±0.03, also significantly lower than the blank control group, which can effectively optimize the noodle texture; the noodles with added silkworm pupa protein (SPPN) had a viscosity of 0.21±0.02, which was not significantly different from the blank control group (P>0.05), indicating that the addition of silkworm pupa protein basically did not change the noodle viscosity and would not cause the problem of stickiness; the noodles with added fish protein (FPN) had the highest viscosity (0.28±0.05), significantly higher than the blank control group, indicating that the addition of fish protein would increase the viscosity of noodles, which may cause the noodles to stick to the teeth when eaten, affecting palatability.

[0069] Based on the three core textural indicators of hardness, elasticity, and stickiness, combined with auxiliary analyses of chewiness and cohesion (high-quality noodles need to meet the characteristics of high hardness, high chewiness, moderate elasticity, and low stickiness), the optimization effect of four exogenous animal proteins on the textural properties of noodles can be ranked as follows: egg white protein (EWPN) > whey protein isolate (WPIN) ≈ silkworm pupa protein (SPPN) > fish protein (FPN). Among them, noodles with added egg white protein performed best: the hardness was significantly higher than that of the blank control group, enhancing the structural strength and toughness of the noodles; the elasticity was not significantly different from that of the blank control group, maintaining a good chewy texture; the stickiness was significantly lower than that of the blank control group, avoiding the problems of sticking and sticking to teeth; at the same time, its chewiness was the highest (705.90±20.13g), significantly higher than that of the other groups, giving the noodles an ideal chewy feel, fully meeting the textural requirements of high-quality noodles.

[0070] The texture properties of noodles with added whey protein isolate and silkworm pupa protein were similar. Both slightly increased noodle firmness and reduced stickiness (whey protein isolate had a more significant effect). Elasticity decreased slightly but not significantly, and overall, the noodle texture quality was not reduced, making them potential candidates for noodle texture improvement. However, the texture properties of noodles with added fish protein were the worst. Their firmness, elasticity, and chewiness were significantly lower than the control group, and their stickiness increased significantly, failing to meet the texture requirements of high-quality noodles. Further optimization and improvement are needed to address their negative impact on noodle texture.

[0071] 5) Sensory evaluation of wheat noodles with added proteins

[0072] The noodle samples to be tested were placed in a temperature-controlled, odorless sensory evaluation room. An evaluation team of 10 people with basic food sensory evaluation skills was formed. Evaluators were required to avoid consuming tobacco, alcohol, spicy, or strongly flavored foods within 10 hours prior to the evaluation. Samples were presented using a random coding method, and evaluators completed the tasting independently, with no communication allowed throughout the process. After evaluating each sample, evaluators were required to rinse their mouths with tasteless purified water and wait 5 minutes before evaluating the next sample to avoid cross-contamination. Sensory evaluation criteria are shown in Table 1.

[0073] Table 1 Sensory Evaluation Criteria for Protein Noodles

[0074]

[0075] Table 2 Sensory evaluation scores for different proteins added below.

[0076]

[0077] The addition of protein alters the texture, mouthfeel, and appearance of noodles. The table shows the sensory evaluation indicators for different noodles. Overall, the addition of protein leads to a lower score, but the overall score is close to that of traditional wheat noodles, indicating higher market acceptance.

[0078] 6) Digestibility characteristics of wheat noodles with added proteins

[0079] Depend on Figure 7 As can be seen, compared with the blank control group (WFN), noodles with the addition of four exogenous animal proteins all showed significantly reduced RDS content and increased SDS and RS content, indicating that exogenous animal proteins can effectively inhibit the starch digestibility of noodles and delay the starch digestion and absorption process. In terms of regulatory effects, there were significant differences among the four proteins. Noodles with added silkworm pupa protein (SPPN) had the lowest RDS content and the highest RS content, indicating that it had the most significant inhibitory effect on starch digestion. Next were whey protein isolate (WPIN) and egg white protein (EWPN), both of which had similar regulatory effects on starch components, effectively reducing RDS and increasing RS content. Fish protein (FPN) had a relatively weak regulatory effect on starch components, with higher RDS content than the other three protein groups and lower RS ​​content than the other three groups, indicating that its ability to inhibit starch digestion was relatively limited.

[0080] Depend on Figure 8The glycemic index (GI) of the blank control group (WFN) was 78.85, classifying it as a high-GI food (GI>70). Its C∞, K, and HI values ​​were the highest among all groups, indicating that pure wheat flour noodles have a rapid and high degree of starch digestion, easily leading to a rapid rise in postprandial blood glucose. After adding four exogenous animal proteins, all hydrolysis parameters of the noodles showed varying degrees of reduction, with the GI values ​​significantly lower than those of the blank control group. This indicates that all four proteins effectively reduced the glycemic index of the noodles and improved their glycemic response characteristics, which is completely consistent with the changes in starch content.

[0081] In terms of specific parameters, the silkworm pupa protein supplementation group performed best: its GI value was 64.51, falling into the medium GI food range (55≤GI≤70), a decrease of 14.34 compared to the blank control group; indicating that silkworm pupa protein can significantly reduce the maximum degree and rate of starch hydrolysis, thereby effectively inhibiting starch digestion and improving postprandial blood glucose. The whey protein isolate (WPIN) supplementation group had a GI value of 70.04, close to the medium GI food threshold, and its inhibitory effect was second only to silkworm pupa protein.

[0082] In summary, whey protein isolate and silkworm pupa protein can comprehensively guarantee the sensory quality of noodles, improve the health problems of high blood sugar and digestion, and maintain the inherent basic quality of the product. Moreover, the two have balanced performance and flexible selection, providing reliable support for the stable and consistent sensory quality in the large-scale production of healthy noodles.

Claims

1. A method for preparing low-digestible animal protein-wheat flour composite noodles, characterized in that, Includes the following steps: (1) Raw material pretreatment: Wheat flour and exogenous animal protein are mixed evenly at a ratio of 1:0.15 to obtain mixed powder; (2) Dough preparation: Add 80% of the mass of the mixed powder to the mixed powder, stir until it forms flocculent, let it rise at a constant temperature of 25℃ for 15 minutes, and knead until the dough surface is smooth and uniform. (3) Noodle shaping: The dough is placed in a dough press and pressed into a uniform sheet with a thickness of 2mm. The sheet is then cut into noodle blanks with a width of 2-3mm and a length of 20-25cm by a strip cutting device. (4) Finished product processing: The noodle blank is packaged to obtain functional wheat noodles with reduced GI value; if dried noodles are to be prepared, the noodle blank needs to be dried at 35°C and 60% relative humidity until the moisture content is ≤12% before packaging.

2. The preparation method according to claim 1, characterized in that, The ingredients, by weight, include: 100g wheat flour and 15g exogenous animal protein.

3. The preparation method according to claim 1, characterized in that, The exogenous animal protein is one or more of whey protein isolate, silkworm pupa protein, egg white protein, and fish protein.

4. The preparation method according to claim 1, characterized in that, The wheat noodles have a GI value ≤70, a rapidly digestible starch (RDS) content ≤65%, and a total content of slowly digestible starch (SDS) and resistant starch (RS) ≥35%.

5. The preparation method according to claim 1, characterized in that, The wheat flour is medium-gluten wheat flour, with a starch content of 70-75% and a gluten protein content of 9-11%.

6. The preparation method according to claim 1, characterized in that, The noodles have a cooking loss rate of ≤8%, a breakage rate of ≤0.3%, a water absorption rate of ≤70%, a hardness of 1200-1650g, and an elasticity of ≥0.

68.

7. The preparation method according to claim 1, characterized in that, The purity of exogenous animal protein is ≥90%, with no off-odor or clumping.

8. The preparation method according to claim 1, characterized in that, The dough is rolled 3-5 times with the dough press, and left to rest for 2 minutes after each roll to ensure a uniform dough structure.

9. A low-digestible animal protein-wheat flour composite noodle, characterized in that, The noodles prepared according to any one of claims 1-8 are low-glycemic staple foods and can be used in the daily diet of diabetic patients, obese people and healthy people.

10. A low-digestibility animal protein-wheat flour composite noodle according to claim 9, characterized in that, The noodles are further processed into fresh wet noodles, dried noodles, frozen noodles, or ready-to-eat noodle products.

Images