Making method of corn-wheat composite noodles added with arachin

Abstract

The invention discloses a making method of corn-wheat composite noodles added with arachin, and belongs to the field of food processing. The corn-wheat composite noodles are prepared from the following raw materials in percentage by mass: 70-76% of wheat flour, 21-25% of corn flour, 1-4% of arachin, 1-2% of table salt and 0.1-0.5% of dietary alkali. When the corn-wheat composite noodles are prepared, the overall quality of the corn noodles is improved in a mode of adding the arachin, the internal network structure of the noodles is more uniform, the quality is better, the requirements of zero food additives are met, and the addition amount of the corn flour is also increased.

Description

Technical Field

[0001] The invention belongs to the field of food processing, and in particular relates to a method for preparing corn-wheat composite noodles added with peanut globulin. Background Art

[0002] Corn is an important food crop in my country, and has a long history of cultivation in my country. It is also called corn and corn cobs. Corn not only has antibacterial, bactericidal, hypoglycemic, anti-tumor and antioxidant effects, but also can enhance immunity, has high nutritional value (corn kernels contain about 70%-75% starch, about 10% protein, about 4% fat, and about 2% vitamins, and are also rich in dietary fiber, phytosterols and complex carbohydrates), and has excellent characteristics of resistance to barrenness, cold and drought, strong ability to adapt to the environment, easy to plant, rich resources and easy to harvest, so it has broad prospects for development and application.

[0003] Although there are many products made from corn flour on the market, such as corn buns, corn noodles, corn bread, corn tortillas, etc., since corn flour does not contain gluten protein, adding too much corn flour will cause corn processed products to have quality problems such as volume shrinkage and poor palatability. To solve the above quality deterioration problems, additives such as gluten powder and guar gum are generally added to optimize the quality. However, given that consumers generally tend to choose foods with natural ingredients and are cautious about food additives, a corn noodle with zero food additives is a direction with market prospects and is also in line with consumers' pursuit of natural green food.

[0004] At present, the amount of corn flour added to corn noodles without adding improvers generally does not exceed 20%. For example, the corn flavored noodles of the Chen Keming brand sold on the market have a corn addition amount of 20wt%. In addition, in the "Effect of Corn Flour Ratio on the Quality of Corn-Wheat Mixed Flour Noodles", corn flour and wheat flour were selected for the preparation of noodles. It was found that the corn flour addition amount was the highest when it was 15wt%, and the overall noodle score would decrease if the corn flour addition amount was increased. Therefore, it is necessary to explore how to increase the amount of corn flour added without using additives and reducing the quality of corn noodles. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing corn-wheat composite noodles with added peanut globulin, which utilizes the functional properties of peanut globulin such as water absorption and gelation to form a protein network structure in corn dough, thereby increasing the amount of corn flour added and improving the quality problems of corn noodles such as easy breakage, difficulty in forming, and poor viscoelasticity. The corn flour content in the prepared product is 21-25%, which is higher than the 20% content range of commercially available corn-wheat composite noodles, and the internal pore structure of the noodles is more uniform, and the quality of the corn noodles is better.

[0006] In order to achieve the above object, the present invention provides a corn-wheat composite noodle, wherein the corn-wheat composite noodle is prepared from the following raw materials by mass fraction:

[0007] Wheat flour 70-76%, corn flour 21-25%, peanut globulin 1-4%, salt 1-2%, edible alkali 0.1-0.5%.

[0008] Furthermore, the wheat flour includes high-gluten wheat flour.

[0009] Furthermore, the added amount of the peanut globulin is 2%.

[0010] Furthermore, the preparation method of the peanut globulin is as follows: defatted peanut powder is dissolved in a phosphate buffer with a pH of 7.5 to 8 at a ratio of 1:20 to 30 (w / v), stirred for 1 to 2 hours, and then the supernatant is collected by centrifugation, and ammonium sulfate in an amount of 20 to 25 wt% of the mass of the supernatant is added to the supernatant, and the mixture is allowed to stand for 3 to 5 hours, and then the precipitate is collected by centrifugation, and the precipitate is dissolved in a phosphate buffer with a pH of 7.5 to 8, and finally the mixture is dialyzed with stirring for 24 to 48 hours, and the solution after the dialysis is freeze-dried to obtain peanut globulin.

[0011] The present invention also provides a method for preparing corn-wheat composite noodles, the preparation method comprising the following steps:

[0012] S1. Raw material pretreatment: crush the raw corn kernels and pass them through a 80-100 mesh sieve to obtain corn flour;

[0013] S2, preparing corn-wheat composite flour: mixing the corn flour and wheat flour described in step S1 to obtain corn-wheat composite flour A;

[0014] S3, preparing corn-wheat composite dough: mixing the corn-wheat composite flour A, peanut globulin, salt, edible alkali and water described in step S2 and kneading the dough to obtain corn-wheat composite dough B;

[0015] S4, proofing the corn-wheat composite dough: proofing the corn-wheat composite dough B described in step S3 to obtain corn-wheat composite dough C;

[0016] S5, extrusion of corn-wheat composite noodles: the corn-wheat composite powder C in step S4 is extruded through an extruder to obtain corn-wheat composite noodles.

[0017] In one embodiment of the present invention, the amount of water added in step S3 is 40-60 wt % of the mass of the corn-wheat composite flour A.

[0018] In one embodiment of the present invention, the proofing in step S4 is as follows: proofing the corn-wheat composite dough B at 25-40° C. for 30-50 minutes in a one-time proofing manner.

[0019] In one embodiment of the present invention, the diameter of the corn-wheat composite noodles in step S5 is 2 to 3 mm.

[0020] Beneficial effects of the present invention:

[0021] 1. The amount of corn flour used in the corn-wheat composite noodles with added peanut globulin of the present invention is higher than that of the commercially available corn-wheat composite noodles, and the amount of corn flour added can be increased to 25wt% while ensuring excellent quality, and having good hardness, elasticity, aspect ratio, appearance structure and other characteristics.

[0022] 2. The present invention analyzes texture characteristics, colorimetric analysis, microstructure, and cooking characteristics, and finds that peanut globulin has a better improvement effect on noodles than peanut protein. At the same time, when the addition amount of peanut globulin is 2%, the noodles have better hardness and elasticity, suitable color, better cooking characteristics, more uniform internal pore structure, and better appearance and quality characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The microstructure of corn noodles with different contents of peanut globulin added according to the present invention (magnified 2000 times and 500 times);

[0024] Figure 2 : is the water absorption rate of corn noodles with different contents of peanut globulin added according to the present invention, and different letters in the figure indicate significant differences (p<0.05);

[0025] Figure 3 : is the cooking loss rate of corn noodles with different contents of peanut globulin added according to the present invention, and different letters in the figure indicate significant differences (p<0.05);

[0026] Figure 4 : is the moisture content of corn noodles with different amounts of peanut globulin added according to the present invention, and different letters in the figure indicate significant differences (p<0.05);

[0027] Figure 5 Graphs 1 and 2 show the breaking rates of corn noodles with different amounts of peanut globulin added thereto according to the present invention. Different letters in the graph indicate significant differences (p<0.05). DETAILED DESCRIPTION

[0028] The present invention will be further described below through specific implementation examples.

[0029] Source of raw materials

[0030] The corn variety was Xianyu 335, purchased from Dandong Honglong Corn Planting Professional Cooperative; high-gluten wheat flour was purchased from Xinxiang Xinliang Grain and Oil Processing Co., Ltd.; defatted peanut protein was purchased from Henan Liangjian Technology Co., Ltd.; edible salt was purchased from China Salt Industry Group Co., Ltd.; and edible alkali was purchased from Angel Yeast Co., Ltd.

[0031] Preparation process of peanut globulin used in the embodiment: defatted peanut protein is dissolved in 0.05 mol / L, pH=7.9 phosphate buffer at a ratio of 1:20-30 (w / v), stirred with a magnetic stirrer at room temperature for 1-2 hours, the completely dissolved solution is divided into centrifuge bottles and centrifuged at 5000-8000 rpm, 14°C for 20-30 minutes, the supernatant after centrifugation is collected, ammonium sulfate powder is added to 24% of the supernatant and stirred to completely dissolve, and the solution is The mixture was allowed to stand in a 4°C refrigerator for 3-4 hours. The solution was centrifuged in a high-speed refrigerated centrifuge at 4°C and 5000-8000 rpm for 20-30 minutes. The precipitate was collected and dissolved in the above-mentioned phosphate buffer solution. The peanut globulin solution dissolved in the phosphate buffer solution was put into a dialysis bag and dialyzed for 48 hours in a 4°C chromatography cabinet while stirring to remove salt ions. Finally, the peanut globulin solution after dialysis was freeze-dried to obtain peanut globulin powder, which was stored in a cool, dry and sealed condition.

[0032] Testing process

[0033] 1. Whiteness value: The colorimetry of the corn-wheat composite noodles after cooling for 1 h was measured using a colorimeter (Ultra Scan Pro, Hunter Lab, USA), and the L*, a*, and b* values ​​were recorded.

[0034] 2. Hardness and elasticity: Take the center part of the corn noodles after cooling for 2 hours, cut into 1 cm long, place three sections in parallel, and measure its texture parameters using a texture analyzer (Stable Micro System, UK, TA-XTPLUSZ). The texture analyzer setting parameters are: TPA mode, test probe P50, pre-test rate 2.0 mm / s, test rate 0.8 mm / s, and post-test rate 1.0 mm / s, compression ratio 70%, induction force 5g, compression interval 1s. Get the hardness and elasticity of the sample.

[0035] 3. Microstructure: The cooked corn noodles were freeze-dried in vacuum and then observed under an electron microscope. Measurement conditions: voltage 15kV, gold spraying 90s, and electron microscope images with magnifications of 500x and 2000x were selected. The internal network of corn-wheat composite noodles with peanut globulin was observed.

[0036] 4. Determination of cooking characteristics of noodles:

[0037] (1) Determination of water absorption: 20 g of fresh corn noodles were dried in an oven at 45°C for 2 h to obtain dry noodles (m0, g). The noodles were placed in 500 mL of boiling water and boiled for 5 min. After being taken out, they were rinsed with cold water for 30 s and allowed to cool completely. The surface moisture was wiped dry with kitchen paper and weighed (m1, g). The water absorption rate of the noodles (A) was calculated as follows: A (%) = [(m1-m0) / m0] × 100.

[0038] (2) Determination of cooking loss rate: evaporate the noodle soup to a certain volume, place it in a weighing box (m2, g), and dry it in an oven at 105°C to constant weight, recorded as m3 (g), and the weight gain of the weighing box is m3-m2 (g); the calculation formula for the noodle cooking loss rate (B) is: B (%) = [(m3-m2) / m0] × 100.

[0039] (3) Determination of moisture content: Take 10g of fresh noodles, chop them into small pieces, and dry them at 105℃ until constant weight. Y is the moisture content (g / 100g), m4 is the mass of the weighing bottle and sample (g), m5 is the mass of the weighing bottle and sample after drying (g), and m6 is the mass of the weighing bottle (g); the calculation formula for the moisture content of noodles is: Y = [(m4-m5) / (m4-m6)] × 100.

[0040] (4) Determination of broken noodle rate: Take 20 corn noodles with a length of 20 cm, boil them in 500 mL of boiling water for 5 min, then take them out and count the number of broken noodles X; the calculation formula for the broken noodle rate is: C (%) = (X / 20) × 100.

[0041] Example 1

[0042] S1. Raw material pretreatment: crush raw corn kernels and pass through a 100-mesh sieve to obtain corn flour;

[0043] S2, preparation of corn-wheat composite flour: compounding the corn flour and wheat flour in step S1 according to a certain proportion to obtain corn-wheat composite flour A; wherein the total content of corn flour in the composite flour A is 22.5%, and the type of wheat flour is high-gluten wheat flour;

[0044] S3, preparation of corn-wheat composite dough: adding peanut globulin to corn-wheat composite flour A in an amount of 1% by weight of the composite flour A, adding salt to corn-wheat composite flour A in an amount of 1.5% by weight of the composite flour A, adding edible alkali to corn-wheat composite flour A in an amount of 0.38% by weight of the composite flour A, putting into a dough mixer, adding water to corn-wheat composite flour A in an amount of 52% by weight of the composite flour A, adding water and kneading to obtain corn-wheat composite dough B;

[0045] S4, proofing the corn-wheat composite dough: using a one-time proofing method, wrapping the corn-wheat composite dough B with plastic wrap, and proofing it at 25° C. for 30 min to obtain the corn-wheat composite dough C;

[0046] S5, extrusion of corn-wheat composite noodles: extruding the corn-wheat composite dough C in step S4 through an extruder to form strips with a diameter of 2.5 mm, thereby obtaining corn-wheat composite noodles D;

[0047] S6. Steaming corn-wheat composite noodles: Cook the corn-wheat composite dough D in step S4 at 100° C. for 5 min to obtain corn-wheat composite noodles.

[0048] Example 2

[0049] The specific operation steps are the same as those in Example 1, except that the amount of peanut globulin added in S3 is 2% of the mass of the composite powder A.

[0050] Example 3

[0051] The specific operation steps are the same as those in Example 1, except that the amount of peanut globulin added in S3 is 3% of the mass of the composite powder A.

[0052] Example 4

[0053] The specific operation steps are the same as those in Example 1, except that the amount of peanut globulin added in S3 is 4% of the mass of the composite powder A.

[0054] Comparative Example 1

[0055] The specific operation steps are the same as those in Example 1, except that the amount of peanut globulin added in S3 is 0% of the mass of the composite powder A.

[0056] Comparative Example 2

[0057] The specific operation steps are the same as those in Example 1, except that defatted peanut protein is used instead of peanut globulin in S3, and the amount of peanut protein added is 2% of the mass of the composite powder A.

[0058] Comparative Example 3

[0059] The specific operation steps are the same as those in Example 1, except that defatted peanut protein is used instead of peanut globulin in S3, and the amount of peanut protein added is 4% of the mass of the composite powder A.

[0060] Comparative Example 4

[0061] The specific operation steps are the same as those in Example 1, except that the total content of corn flour in the composite flour A is adjusted to 27%.

[0062] After the corn-wheat composite noodles prepared in this comparative example were cooked, it was found that the noodles were obviously broken and had poor edible quality.

[0063] Results

[0064] 1. Chromaticity analysis: Table 1 shows the effect of different amounts of peanut globulin added on the color of corn noodles. L* represents brightness, a* represents red, and b* represents yellow. The brightness increases significantly with the increase in the amount of peanut globulin added, and the red color also increases with the increase in the amount of peanut globulin added, but the trend of change is not significant; there is no significant correlation between the yellow color and the amount of peanut globulin added. The increase in the brightness of corn noodles is due to the white color of peanut globulin. With the addition of peanut globulin, the internal structure of corn noodles is denser and more regular, so its surface is smoother and has a better light reflection effect. In addition, compared with the same amount of peanut protein added, the brightness of corn noodles with peanut globulin added is significantly increased. In summary, peanut globulin can increase the brightness and redness of corn noodles and improve the color.

[0065] Table 1 Chroma of corn noodles with different peanut globulins added

[0066]

[0067] Table 1

[0068]

[0069] Note: Different letters indicate significant differences (p<0.05).

[0070] 2. Texture analysis: Texture characteristics play an important role in the quality and taste of noodles, and are also an important reference indicator for consumers to buy noodles. As shown in Table 2, the TPA of cooked noodles changes significantly with the increase of peanut globulin. Compared with the control group, the hardness, cohesion, chewiness, and resilience of corn noodles with added peanut globulin show an upward trend with the increase of the added amount. This is because peanut globulin forms a protein network structure inside the corn noodles, but the elasticity of corn noodles decreases with the increase of the added amount of peanut globulin. In addition, compared with the same amount of peanut protein, the hardness, cohesion, chewiness, and resilience of corn noodles with added peanut globulin are better improved. Considering the above factors, when the addition of peanut globulin is 2%, corn noodles have the best texture characteristics.

[0071] Table 2 Texture characteristics of corn noodles with different peanut globulins added

[0072]

[0073] Note: Different letters indicate significant differences (p<0.05).

[0074] 3. Scanning electron microscope (SEM) analysis: The electron microscope images of corn noodles with different peanut globulins added are as follows Figure 1 (magnified 2000 times, magnified 500 times) as shown, the structures of Example 1, Example 2, and Example 3 are more orderly than Comparative Example 1, and the internal structure of Comparative Example 1 is relatively rough and loose, with more holes. The structure of Example 2 shows a dense network of protein and starch interaction, with relatively fewer internal pores, a relatively uniform gluten network structure, a thicker fiber network, and a network structure of Example 2 that is better than Comparative Example 2. The structure of Example 4 is relatively disordered because the amount of peanut globulin added is too high, which affects the construction of the interpenetrating network. Figure 1 It can be seen that the addition of an appropriate amount of peanut globulin is beneficial to the construction of the internal network structure of noodles, but when the added amount is too high, the construction of the network will be affected, thereby affecting the quality of the noodles.

[0075] 4. Cooking characteristics:

[0076] (1) Water absorption analysis: An important manifestation of the hydration degree of noodles is the water absorption rate of noodles. The hydration degree directly affects the taste and quality of noodles and is an important indicator in the noodle evaluation system. The water absorption rate of noodles is affected by various factors, such as the quality of flour, additives added to the dough to improve the dough, and the gluten network structure, protein network structure, etc. Generally speaking, high-quality noodles tend to have a high water absorption rate. Figure 2 Effect of different amounts of peanut globulin added on the water absorption rate of corn noodles. The experimental results show that the water absorption rate of noodles continues to increase with the increase of the amount of peanut globulin added. This is because the protein network structure formed by peanut globulin in the dough makes the dough structure more orderly, and the tightly ordered network structure has a better water storage effect. However, with the increase in the amount of peanut globulin added, the trend of increasing water absorption rate becomes more and more gentle. That is, when the amount of peanut globulin added reaches a certain level, it has little effect on the construction of the gluten network in the noodles, that is, the water absorption rate of the noodles does not change significantly. In addition, adding peanut protein can also increase the water absorption rate of noodles, but at the same dose as peanut globulin, the effect is not as obvious.

[0077] (2) Analysis of cooking loss rate: The cooking loss rate of noodles refers to the loss of the quality of noodles caused by the separation of the materials on the noodles from the noodles and entering the cooking water during the cooking process. A low cooking loss rate means that corn noodles have better quality. Figure 3The cooking loss rate of corn noodles is affected by the addition of different amounts of peanut globulin. As can be seen from the figure, when peanut protein is added, the cooking loss rate of noodles decreases, but when the same concentration of peanut globulin is added, the cooking loss rate of noodles decreases more significantly, among which the cooking loss rate of corn noodles in Example 4 is the smallest. Peanut globulin forms a dense gluten network structure between the corn noodles and the flour, more tightly combining starch molecules, reducing the starch dissolution rate of corn noodles, and making the structure of noodles more stable, thereby reducing the cooking loss of noodles.

[0078] (3) Moisture content analysis: The moisture content of noodles is an important indicator to measure the cooking characteristics of noodles. The taste and quality of corn noodles are closely related to the moisture content of corn noodles. Figure 4 The figure shows the effect of different amounts of peanut globulin added on the moisture content of noodles. As can be seen from the figure, the moisture content of corn noodles shows a trend of first decreasing and then increasing with the increase in the amount of peanut globulin added. The moisture content of the noodles in Example 3 is the lowest. The protein network formed by peanut globulin and the gluten network form a network interpenetrating structure. The dense network structure not only increases the content of strongly bound water but also hinders the entry of water molecules, thereby reducing its moisture content. The moisture content of the corn noodles in Example 4 actually increases. This is because when the peanut globulin content is too high, it will affect the construction of the gluten network, causing its orderliness to decrease. As shown in Figure 1 As shown, the network structure of the corn noodles in Example 4 is rougher and more disordered.

[0079] (4) Analysis of broken strip rate: Figure 5 The effect of different addition amounts of peanut globulin on the breaking rate of corn noodles is shown. The breaking rate of Example 2 is the lowest, but there is no significant difference in the breaking rate of each group. Therefore, the addition of peanut globulin has little effect on the breaking rate of corn noodles.

[0080] In summary, the addition of peanut globulin to corn-wheat composite noodles can significantly improve the texture, color, microstructure, cooking characteristics, etc. of noodles, and the quality is better. The optimal addition amount of peanut globulin in corn noodles is 2%.

[0081] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A corn-wheat composite noodle, characterized in that: The corn-wheat composite noodles are prepared from the following raw materials by mass fraction: Wheat flour 70-76%, corn flour 21-25%, peanut globulin 1-4%, salt 1-2%, edible alkali 0.1-0.5%.

2. The corn-wheat composite noodles according to claim 1, characterized in that: The added amount of the peanut globulin is 2%.

3. The corn-wheat composite noodles according to claim 1 or 2, characterized in that: The preparation method of peanut globulin is as follows: defatted peanut powder is dissolved in a phosphate buffer with a pH value of 7.5 to 8 at a ratio of 1:20 to 30, w / v, and stirred for 1 to 2 hours, then the supernatant is collected by centrifugation, ammonium sulfate in an amount of 20 to 25 wt% of the mass of the supernatant is added to the supernatant, and the mixture is allowed to stand for 3 to 5 hours, then the precipitate is collected by centrifugation, and the precipitate is dissolved in a phosphate buffer with a pH value of 7.5 to 8, and finally the mixture is stirred and dialyzed for 24 to 48 hours, and the solution after the dialysis is freeze-dried to obtain peanut globulin.

4. A method for making corn-wheat composite noodles according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: S1. Raw material pretreatment: crush the raw corn kernels and pass them through a 80-100 mesh sieve to obtain corn flour; S2, preparing corn-wheat composite flour: mixing the corn flour and wheat flour described in step S1 to obtain corn-wheat composite flour A; S3, preparing corn-wheat composite dough: mixing the corn-wheat composite flour A, peanut globulin, salt, edible alkali and water described in step S2 and kneading the dough to obtain corn-wheat composite dough B; S4, proofing the corn-wheat composite dough: proofing the corn-wheat composite dough B described in step S3 to obtain corn-wheat composite dough C; S5, extrusion of corn-wheat composite noodles: the corn-wheat composite powder C in step S4 is extruded through an extruder to obtain corn-wheat composite noodles.

5. The method according to claim 4, characterized in that: The amount of water added in step S3 is 40-60 wt % of the mass of the corn-wheat composite flour A.

6. The method according to claim 4, characterized in that: The proofing in step S4 is as follows: proofing the corn-wheat composite dough B at 25-40° C. for 30-50 minutes in a one-time proofing manner.

7. The method according to claim 4, characterized in that: The diameter of the corn-wheat composite noodles in step S5 is 2 to 3 mm.

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