Anti-aging method for fresh-keeping wet noodles based on heat-moisture treatment

Abstract

The invention discloses a fresh-keeping wet noodle anti-aging method based on heat-moisture treatment, and belongs to the technical field of noodle food. According to the anti-aging method of the fresh-keeping wet noodles, the flour needs to be subjected to heat-moisture treatment in advance, the treated flour and the untreated flour are compounded, and then the compounded flour is prepared by adopting a conventional wet noodle preparation method. Wherein the flour subjected to heat-moisture treatment and the untreated flour are compounded, so that not only can the formation of a gluten network structure be facilitated, but also the internal structure of the starch can be improved, the gelatinization degree of the starch is improved, the recrystallization ability is weakened, and a certain anti-aging effect is achieved. The fresh-keeping wet noodles obtained by the method are good in anti-aging effect, low in cost, non-toxic and harmless, and the eating quality can be improved; and the method is simple, energy-saving and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of noodle food, and specifically provides a method for preserving wet noodles and resisting aging based on moist heat treatment. Background Art

[0002] As one of the staple foods, noodles are very popular among people. Noodles are mainly made of wheat flour as the main raw material. According to statistics, more than 40% of the total wheat flour in Asia is used to make wheat noodles. There are many kinds of noodles in life. According to the moisture content, dry noodles are less than 20%, semi-dry noodles are 20-26%, fresh noodles are 28-32%, and cooked noodles are more than 45%. Among them, instant noodles and dried noodles are more consumed. They are dry noodles, but they take a long time to re-cook, and are made by high temperature and dehydration. They have high calories and low nutritional value.

[0003] There are two main types of cooked wet noodles: frozen cooked noodles and fresh wet noodles. Frozen cooked noodles are fresh noodles that are quickly frozen after being cooked and stored at -18℃. They only need to be reheated for a short time when eaten. They are generally used exclusively for catering and can be served quickly, but they must be frozen and sealed and transported through the cold chain. In addition, ice crystal growth and water migration during storage will cause the quality of frozen cooked noodles to decline and the taste to deteriorate, affecting the quality of noodles and consumer acceptance. Fresh wet noodles are called long life noodles in English, also known as LL noodles, instant wet noodles, convenient wet noodles and wet instant noodles. They can be stored at room temperature. They are boiled instant noodles that are not fried, steamed, and then packaged and sterilized. They are nutritious, hygienic, non-dehydrated, smooth in taste, no preservatives added, and easy to eat and carry. The moisture content of this product is as high as 65%, and it only needs to be reheated for a short time when eaten. However, due to the high water content and high water activity of wet noodles, microorganisms can easily grow and reproduce, resulting in a relatively short shelf life of noodles. In addition, starch aging is the main factor leading to the deterioration of noodle quality. The starch molecular chains will migrate and re-form an ordered crystalline structure, which increases the hardness and stickiness of the noodles and makes them lose their tough and chewy taste.

[0004] In recent years, the technology of keeping wet noodles fresh and anti-aging has made some progress. At present, the research is mainly focused on delaying aging by adding hydrophilic polysaccharides, emulsifiers, enzyme preparations, modified starch and other ingredients. In addition, microwave treatment, irradiation treatment, ozone preservation and other technologies have also been applied to the anti-aging research of keeping wet noodles fresh. However, there are still some problems, such as the optimization of the compounding of improvers and the synergistic mechanism are still unclear, and a single preservation technology is difficult to meet the needs, and some technologies require large-scale equipment and consume more resources. Summary of the invention

[0005] In view of the defects and shortcomings of the prior art, the purpose of the present invention is to provide a method for preserving wet noodles and resisting aging based on moist heat treatment. The processing method is relatively simple, low-cost, and safe to operate. The fresh wet noodles prepared by the processing method have good anti-aging properties and only need to be reheated for a short time when eaten.

[0006] In order to achieve the above purpose, the technical solutions provided are as follows:

[0007] The present invention provides a method for preserving wet noodles and resisting aging based on moist heat treatment, comprising the following steps:

[0008] (1) Flour heat treatment

[0009] Weigh the flour and add distilled water in a spray form to adjust the moisture content to 15-25g / 100g. After crushing, spread it on a tray, wrap it completely with tin foil, and place it in a blast drying oven for wet heat treatment. After treatment, cool it to room temperature, dry it to a moisture content of less than 10g / 100g, and then crush it and sieve it. The temperature of the wet heat treatment is 90°C to 130°C and the time is 60min.

[0010] (2) Flour compounding

[0011] The flour subjected to the wet heat treatment in step (1) is compounded with untreated flour at a ratio of 10 to 50 wt %;

[0012] (3) Production of fresh wet noodles

[0013] The flour compounded in step (2) is prepared according to a conventional wet noodle making method.

[0014] In one embodiment, the flour in step (1) is any one or more of wheat flour (wheat flour), rye flour, corn flour, buckwheat flour, millet flour, and miscellaneous grain flour; wherein the miscellaneous grain flour includes one or more of castanopsis serrata flour, mung bean flour, red bean flour, and coix seed flour.

[0015] In one embodiment, the flour in step (1) is wheat flour, wherein the moisture content of the wheat flour is 9.20 g / 100 g, the protein content is 15.19%, the wet gluten content is 36.20%, and the total starch content is 72.42%, which is a high-quality wheat flour.

[0016] In one embodiment, the temperature of the wet heat treatment in step (1) is 90° C. and the time is 60 min; and the moisture content is adjusted to 15 g / 100 g.

[0017] In one embodiment, the temperature of the wet heat treatment in step (1) is 110° C. and the time is 60 min; and the moisture content is adjusted to 20 g / 100 g.

[0018] In one embodiment, the temperature of the wet heat treatment in step (1) is 130° C. and the time is 60 min; and the moisture content is adjusted to 25 g / 100 g.

[0019] In one embodiment, the temperature of the wet heat treatment in step (1) is 90-110° C., and the time is 60 min; and the moisture content is adjusted to 15-20 g / 100 g.

[0020] In one embodiment, the flour after the wet heat treatment in step (2) is compounded with the untreated flour in a ratio of 12.5 to 50 wt %; preferably 35 to 50 wt %; more preferably 50 wt %.

[0021] In one embodiment, the wet noodle making method in step (3) comprises: kneading dough → fermenting the dough → rolling → cutting into strips → boiling → washing → acid soaking → packaging → sterilization → cold air cooling → finished product.

[0022] In one embodiment, the dough kneading comprises: weighing the compound flour into a dough mixer, weighing salt and dissolving it in water, and adding the salt water into the wheat flour in small amounts and multiple times; wherein the mass of the salt is 1-2% of the mass of the flour.

[0023] In one embodiment, the dough is proofed: the kneaded dough is poured into a stainless steel basin, covered with plastic wrap, and placed in a constant temperature and humidity incubator at 25 to 30° C. for 10 to 15 minutes; the purpose is to allow water to evenly penetrate into the flour, and after the gluten protein fully absorbs water, a good gluten network is formed, so that the dough has good stretchability and extensibility.

[0024] In one embodiment, the rolling and cutting are as follows: kneading the fermented dough into dough, placing the dough between the rollers of a noodle machine, and rolling it three times at roller intervals of 3.0 mm and 2.0 mm, respectively; cutting the rolled dough into strips with a slitting knife (with an interval of 2 mm) and cutting it into a suitable length.

[0025] In one embodiment, the cooking process comprises adding water into a pot, adding fresh noodles after the water boils, and cooking for 3 to 5 minutes.

[0026] In one embodiment, the water washing time is controlled at 30 to 60 seconds. Washing with cold water can remove surface adhesives such as starch paste to prevent noodles from sticking together; at the same time, it can cool and shrink the surface of the noodles to enhance the strength of the surface.

[0027] In one embodiment, the acid soaking is as follows: the surface water of the washed noodles is roughly drained and then immersed in a lactic acid-sodium lactate buffer solution with a pH of 4.0 to 4.5 for 60 to 90 seconds, which can inhibit the growth of microorganisms and extend the shelf life of the product while minimizing the effect of the sour taste of the noodles caused by the acid soaking.

[0028] In one embodiment, the packaging and sterilization: packaging in a high temperature sterilization bag, and then sterilizing at 90-100° C. for 10-15 minutes, thereby further extending the shelf life of the noodles.

[0029] The invention also provides fresh-keeping wet noodles obtained by the method.

[0030] The invention also provides application of the method in the field of food processing.

[0031] Beneficial Effects

[0032] The present invention discloses a method for keeping fresh wet noodles and resisting aging based on wet heat treatment, wherein the wet heat treatment can not only improve the internal structure of starch, increase the gelatinization degree of starch, weaken the recrystallization ability, and play a certain anti-aging role, but also denature the protein, destroy the structure of gluten protein, and lead to the decline of noodle quality; by compounding the wet heat treated flour and the untreated flour, the problem of protein quality decline can be effectively overcome, and the problem of easy aging of the fresh wet noodles can also be solved;

[0033] (1) By controlling the parameters such as the temperature of the wet heat treatment and the water content of the system, the problem of increased hardness of the noodles due to starch aging during the storage process can be better solved. When the wet heat treatment temperature is 90°C and the water content is 15g / 100g, the wheat flour obtained by the treatment is mixed with the untreated wheat flour at a ratio of 50%. The hardness increase of the noodles prepared in this way can be controlled at 123.41g, and the noodles have good tensile properties. The hardness increase is lower than that of the noodles prepared by other wet heat treatment methods, and the anti-aging effect is the best.

[0034] (2) In addition, this method is easy to operate, low-cost, energy-saving and environmentally friendly, and has a large processing capacity. It is easy to promote and apply in existing production processes and can be widely used in the food processing industry, providing a better solution for wet noodle production companies. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0036] Example

[0037] A method for preserving wet noodles and resisting aging based on moist heat treatment comprises the following steps:

[0038] (1) Heat and moisture treatment of wheat

[0039] Weigh 150g of wheat flour sample, add a certain amount of distilled water in a spraying manner while stirring, adjust to the required moisture content (see Table 1), spread it on a tray after crushing, wrap it completely with tin foil, place it in a blast drying oven at a certain temperature (see Table 1) for wet heat treatment for 60min, wait for the sample to cool to room temperature, place it in a blast drying oven at 45℃ to dry until the moisture content is less than 10g / 100g, then crush it, pass it through a 100-mesh standard sieve, seal it and store it for later use;

[0040] (2) According to the proportions in Table 1, the wheat flour subjected to the wet heat treatment in step (2) is mixed with the untreated wheat flour to prepare noodles;

[0041] (3) Production of fresh wet noodles

[0042] Mixing the dough: Weigh 100g of mixed wheat flour in a dough mixer, measure a certain amount of deionized water (65% water absorption measured by Mixolab), weigh salt (1.5% of the mass of wheat flour) and dissolve it in deionized water, then add the well-mixed salt water to the wheat flour in small amounts and multiple times;

[0043] Proofing: Pour the kneaded dough into a stainless steel basin, cover it with plastic wrap, and place it in a constant temperature and humidity incubator at 25°C for 15 minutes;

[0044] Rolling and cutting: knead the fermented dough into dough, place the dough between the rollers of the noodle machine, and roll it three times at roller spacings of 3.0 mm and 2.0 mm respectively; cut the rolled dough into strips with a shredder (spacing 2 mm) and cut into 20 cm long noodles for later use, with the size of the noodles being 20 cm×0.20 cm×0.20 cm;

[0045] Pre-cooking: Add 1000mL of water to a pot, add fresh noodles after the water boils, and cook for 3 minutes;

[0046] Washing: Wash the pre-cooked noodles with cold water for 60 seconds;

[0047] Acid soaking: After washing, drain the surface water of the noodles and soak them in pH 4.2 lactic acid-sodium lactate buffer for 90 seconds;

[0048] Packaging and sterilization: Pack the acid-soaked noodles in a high-temperature sterilization bag, and then sterilize them at 95°C for 15 minutes.

[0049] Table 1 Sample No.

[0050]

[0051]

[0052] Blank Group

[0053] The only difference from Example 1 is that only untreated wheat flour is used to prepare fresh wet noodles, and other parameters and conditions are the same as those in Example 1.

[0054] Comparative Example 1

[0055] A method for preserving wet noodles and resisting aging based on moist heat treatment comprises the following steps:

[0056] (1) Heat and moisture treatment of wheat

[0057] Weigh 150g of wheat flour sample, add distilled water in a spraying manner while stirring, adjust the moisture content to 15g / 100g, crush and seal in a pressure-resistant bottle, place the sealed pressure-resistant bottle in a 90℃ forced air drying oven for wet heat treatment for 60min, take out after cooling, spread on a tray and place in a 45℃ forced air drying oven to dry until the moisture content is less than 10g / 100g, then crush, pass through a 100-mesh standard sieve, seal and store for later use;

[0058] (2) mixing with untreated wheat flour at a ratio of 50% to further prepare fresh wet noodles;

[0059] (3) The preparation process of fresh-keeping wet noodles is consistent with that of the embodiment.

[0060] Comparative Example 2

[0061] A method for preserving wet noodles and resisting aging based on moist heat treatment comprises the following steps:

[0062] (1) Heat and moisture treatment of wheat

[0063] Weigh 150g of wheat flour sample, add distilled water in a spraying state while stirring, adjust the moisture content to 15g / 100g, crush and place in a hydrothermal reactor, set the reactor to 90°C, react for 60min, take out the sample and cool it to room temperature, then place it in a 45°C forced air drying oven to dry it to a moisture content of less than 10g / 100g, then crush it, pass it through a 100-mesh standard sieve, seal it and store it for later use;

[0064] (2) mixing with untreated wheat flour at a ratio of 50% to further prepare fresh wet noodles;

[0065] (3) The preparation process of fresh-keeping wet noodles is consistent with that of the embodiment.

[0066] Results Analysis

[0067] 1. The wet gluten content of the flour mixed with wheat flour treated with different moisture and heat treatments and untreated wheat flour was determined according to the GB / T 5506.1-2008 method. The results are shown in Table 2:

[0068] Table 2 Blank Example and Wet Gluten Content of Examples 1 to 12

[0069] serial number Wet gluten content (%) Blank example <![CDATA[36.20±0.20 a ]]> Example 1 <![CDATA[30.06±0.07 b ]]> Example 2 <![CDATA[26.39±0.43 e ]]> Example 3 <![CDATA[23.81±0.21 h ]]> Example 4 <![CDATA[20.78±0.12 j ]]> Example 5 <![CDATA[28.54±0.16 d ]]> Example 6 <![CDATA[24.97±0.34 g ]]> Example 7 <![CDATA[21.68±0.28 i ]]> Example 8 <![CDATA[18.68±0.15 l ]]> Example 9 <![CDATA[29.30±0.27 c ]]> Example 10 <![CDATA[25.32±0.14 f ]]> Embodiment 11 <![CDATA[19.75±0.35 k ]]> Example 12 <![CDATA[16.68±0.16 m ]]> Comparative Example 1 <![CDATA[26.52±0.23 e ]]> Comparative Example 2 <![CDATA[17.02±0.35 m ]]>

[0070] As shown in Table 2, compared with the blank example, the wet gluten content of the embodiments is reduced, and when the same heat-treated wheat flour is added, the wet gluten content is significantly reduced as the amount of addition increases, which indicates that the protein of the wheat flour is denatured during the heat-treatment process, and the gluten protein is destroyed, resulting in a reduction in the wet gluten content. In addition, preliminary experiments have shown that when the wet gluten content is less than 20%, the noodles made from the three raw material flours in Examples 8, 11, 12 and Comparative Example 2 are loose and porous, and cannot form a dense and orderly network structure. The breaking rate of the noodles after cutting is high, and they cannot be used to measure the tensile properties of noodles. In particular, Example 12 has the lowest wet gluten content, and the network structure of the prepared noodles is the most severely damaged, and it is basically impossible to form, and it cannot be used to measure the texture characteristics of noodles.

[0071] 2. The wet noodles prepared in the embodiment and the comparative example were placed in a refrigerator at 4°C and the hardness of the noodles was measured after 1 day and 7 days of storage. The measurement method was as follows: the noodles were boiled for 30 seconds and then taken out, cooled to room temperature, the surface moisture of the noodles was absorbed with filter paper, and the measurement was completed within 15 minutes. Each sample was tested 10 times in parallel, and the average value was calculated after removing the maximum and minimum values. The texture analyzer was calibrated for mass and height before use. The TPA probe model was P / 36R. The parameters were set as pre-test rate: 5.0 mm / s; test rate: 1.0 mm / s; post-test rate: 1.0 mm / s; compression degree: 70%; test force: 5.0 g; time interval between two compressions: 1.0 s; the measurement results are shown in Table 3:

[0072] Table 3 Texture characteristics of the fresh-keeping wet noodles obtained in the blank examples and Examples 1 to 11

[0073] serial number 1st d hardness / g 7d hardness / g Increase in hardness / g Blank example 3369.66±291.46 4191.50±201.99 821.84 Example 1 3182.89±246.22 3785.75±162.75 602.86 Example 2 3186.60±270.24 3365.27±45.48 178.66 Example 3 3244.84±323.73 3399.89±272.49 155.06 Example 4 3712.52±273.34 3835.93±251.34 123.41 Example 5 3557.65±278.16 3738.59±92.73 180.94 Example 6 2851.33±302.66 3212.29±159.14 360.96 Example 7 2862.51±201.98 3245.39±140.57 382.88 Example 8 2888.95±225.93 3109.66±425.01 220.71 Example 9 3115.76±209.41 3876.77±272.65 761.02 Example 10 3182.37±199.40 3334.58±335.21 152.21 Embodiment 11 3248.13±28.19 3422.56±251.88 174.42 Comparative Example 1 3174.27±139.80 3362.66±170.32 188.39 Comparative Example 2 3295.52±209.97 3571.01±307.01 275.49

[0074] As shown in Table 3, compared with the blank example, the hardness of the noodles in Examples 1 to 11 decreased, and the hardness of the noodles increased with the extension of storage time. However, after adding the wet heat treated wheat flour, the increase in noodle hardness decreased, which can play a certain anti-aging role. In particular, the addition effect of Examples 1 to 4 is relatively good, and as the addition amount increases, the increase in noodle hardness is also continuously decreasing. The increase in noodle hardness in Example 4 is the least, and the anti-aging ability is relatively good. This may be because during the wet heat treatment process, the starch is pre-gelatinized, the degree of gelatinization increases, the expansion ability of the starch granules is weakened, and the recrystallization ability is weakened during the cooling and storage process, thereby delaying the aging of the noodles.

[0075] According to the temperature and moisture content of the wet heat treatment of wheat flour in Example 4, and mixed with untreated wheat flour in the same proportion, the wet heat treatment method is changed, that is, Comparative Examples 1 and 2. It can be found that the anti-aging effect of Comparative Example 1 is better than that of Comparative Example 2, but both are not as good as the effect of Example 4. This may be because the reaction kettle has an impact on the starch during the heating process, and the wheat flour in the pressure-resistant bottle is easy to aggregate, the heat conduction effect is different, and the processing amount of the sample is limited. If the wheat flour is wrapped in tin foil, the wheat flour is more evenly distributed, and the operation is simple, energy-saving and environmentally friendly.

[0076] 3. The wet noodles prepared in the embodiment and the comparative example were placed in a refrigerator at 4°C to accelerate the aging process. The tensile properties of the noodles were measured after storage for 1 day and 7 days. The measurement method was as follows: the noodles were re-boiled for 30 seconds, then taken out, cooled to room temperature, the surface moisture of the noodles was absorbed with filter paper, and the measurement was completed within 15 minutes. Each sample was tested 10 times in parallel, and the average value was calculated after removing the maximum and minimum values. An A / SPR model probe was used, the calibration distance was 40mm, the speeds before, during, and after the test were 2mm / s, 2mm / s, and 10mm / s, respectively. The calibration distance was 40mm, the stretching distance was 90mm, and the trigger force was 5g. The maximum stretching distance and the starting distance were 140mm and 20mm, respectively. The measurement results are shown in Table 4:

[0077] Table 4 Tensile properties of the fresh wet noodles obtained in the blank examples and Examples 1 to 7, 9, and 10

[0078] serial number 1st day tensile force / g Tensile force at 7d / g Blank example 33.90±1.52 32.19±2.01 Example 1 31.53±1.48 26.28±1.93 Example 2 31.40±1.78 27.85±3.45 Example 3 30.21±2.17 26.63±3.77 Example 4 28.46±1.78 25.94±2.53 Example 5 28.69±2.66 25.08±2.28 Example 6 24.66±2.32 22.95±2.38 Example 7 22.69±1.23 18.90±1.55 Example 9 26.43±1.64 22.38±5.83 Example 10 23.45±1.60 21.67±1.39 Comparative Example 1 30.81±1.91 27.31±2.09

[0079] It can be seen from the results in the table that compared with the fresh-keeping wet noodles prepared in the blank example, the tensile force of the fresh-keeping wet noodles obtained in Examples 1 to 7, 9, 10 and Comparative Example 1 is reduced, and with the increase in the amount of the same kind of wet-heat treated wheat flour added, the tensile force of the noodles is constantly decreasing, which is related to the reduction in the wet gluten content. During the wet-heat treatment process, the protein is partially denatured, the gluten network structure is destroyed, and the combination of starch and protein is also affected. Compared with other examples, the network structure of the two noodles obtained in Example 1 and Example 2 is less damaged, and the tensile performance is better.

[0080] In summary, the fresh-keeping wet noodles prepared by the method of the present invention can delay the aging of the fresh-keeping wet noodles and maintain good edible quality.

[0081] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preserving wet noodles and resisting aging based on moist heat treatment, characterized in that: The steps include: (1) Flour heat treatment Weigh the flour and add distilled water in a spray form to adjust the moisture content to 15-25g / 100g. After crushing, spread it on a tray, wrap it completely with tin foil, and place it in a blast drying oven for wet heat treatment. After treatment, cool it to room temperature, dry it until the moisture content is less than 10g / 100g, and then crush it and sieve it. The temperature of the wet heat treatment is 90°C to 130°C and the time is 60min. (2) Flour compounding The flour subjected to the wet heat treatment in step (1) is compounded with untreated flour at a ratio of 10 to 50 wt %; (3) Production of fresh wet noodles The flour compounded in step (2) is prepared according to a conventional wet noodle making method.

2. The method according to claim 1, characterized in that The flour in step (1) is any one or more of wheat flour, rye flour, corn flour, buckwheat flour, millet flour, and miscellaneous grain flour.

3. The method according to claim 1, characterized in that The temperature of the wet heat treatment in step (1) is 90° C. and the time is 60 min; the moisture content is adjusted to 15 g / 100 g.

4. The method according to claim 1, characterized in that: The temperature of the wet heat treatment in step (1) is 110° C. and the time is 60 min; the moisture content is adjusted to 20 g / 100 g.

5. The method according to claim 1, characterized in that The temperature of the wet heat treatment in step (1) is 130° C. and the time is 60 min; the moisture content is adjusted to 25 g / 100 g.

6. The method according to claim 1, characterized in that The temperature of the wet heat treatment in step (1) is 90-110° C. and the time is 60 min; the moisture content is adjusted to 15-20 g / 100 g.

7. The method according to claim 1, characterized in that The flour after the wet heat treatment in step (2) is compounded with the untreated flour at a ratio of 12.5 to 50 wt%.

8. The method according to claim 1, characterized in that The wet noodle making method in step (3) comprises: kneading the dough → fermenting the dough → rolling → cutting into strips → boiling → washing → acid soaking → packaging → sterilization → cold air cooling → finished product.

9. Fresh noodles obtained by the method according to any one of claims 1 to 8.

10. Use of the method according to any one of claims 1 to 8 or the fresh-keeping wet noodles according to claim 9 in the field of food processing.

Images