Method for delaying aging of starchy food

Abstract

The invention discloses a method for delaying aging of starchy food, and belongs to the technical field of food processing. The method comprises the following steps that 1, starchy food is packaged with a polyethylene bag and then subjected to electron beam irradiation treatment, the electron beam irradiation power is 150 kW, and the irradiation dose is 3-12 kGy; and step 2, storing the irradiated starchy food at the temperature of 4 DEG C for 1-12 days to obtain the anti-aging starchy food. Wherein the starchy food is steamed bun, bread or starch gel. According to the method provided by the invention, the anti-aging starchy food is prepared under the assistance of electron beam irradiation for the first time, so that the aging rate of the starchy food is obviously delayed, the quality of the starchy food is improved, and the industrial production of the starchy food is promoted. The method has the advantages of greenness, safety, simplicity in operation, low cost and the like, the shelf life of the food is greatly prolonged, and the prepared starchy food is low in aging degree and moderate in viscoelasticity in the shelf life.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for delaying the aging of starchy foods. Background Art

[0002] Starchy foods (such as steamed bread, bread, cold noodles, and jelly) occupy a crucial position in the diet. During storage, starchy foods are prone to quality deterioration, including dehydration and condensation, hardening, loss of elasticity, and a rough texture. This deterioration hinders the rapid development of the starchy food industry. This phenomenon is primarily due to starch retrogradation, a process in which gelatinized starch molecules recombine, rearrange, and aggregate through intramolecular and intermolecular hydrogen bonds, forming an ordered, aggregated structure. Industrially, methods to slow the retrogradation of starchy foods include manipulating raw material composition, adding exogenous additives, controlling storage conditions, and optimizing processing techniques. Exogenous additives are the most widely used. However, the inhibitory effect of exogenous additives is limited by factors such as food type, processing conditions, and the molecular structure and dosage of the additive. Furthermore, the inhibitory effect of a single additive is limited, making it difficult to achieve long-term aging delay and shelf life extension. Therefore, exploring and developing more effective, safe, and rapid technologies to delay the retrogradation of starchy foods is crucial for improving their edible quality and extending their shelf life.

[0003] Electron beam irradiation is a new, green, physical, cold sterilization technology. It utilizes an electron beam generated by an electron accelerator to irradiate food, causing a series of physical, chemical, or biological effects. This kills insect eggs and microorganisms, extending the shelf life of food. It can also treat foods of varying packaging, shapes, and structures. The electron beam can penetrate food packaging and enter the food interior, thoroughly sterilizing it and avoiding secondary contamination during food processing. Compared to traditional high-temperature sterilization methods, electron beam irradiation technology offers highly efficient sterilization without compromising the original quality of the food. It offers advantages such as safety, high efficiency, low energy consumption, ease of operation, strong penetrating power, and the absence of residual radioactivity.

[0004] This invention utilizes a novel cold sterilization technology—electron beam irradiation—to control the quality of starchy foods. It demonstrates for the first time that electron beam irradiation can reduce the hardness, gel strength, and water loss of starchy foods during storage, thereby reducing aging and slowing the rate of aging, thereby extending the shelf life of the products. This invention ensures the hygienic safety of starchy foods while maintaining optimal edible quality and extending their shelf life. This not only safeguards food safety and reduces food waste, but also further promotes the industrialization of starchy foods. Summary of the Invention

[0005] Technical problems to be solved: In view of the technical problems in existing anti-aging technologies for starchy foods, such as the fact that the inhibitory effect is limited by factors such as the type of food, processing conditions, and the molecular structure and addition amount of additives, and that the inhibitory effect of a single additive is limited, and that it cannot achieve long-term aging delay and shelf life extension, the present invention provides a method for delaying aging of starchy foods. The method has the advantages of being green and safe, simple to operate, low cost, and free from secondary pollution. The prepared starchy food has a low degree of aging and moderate viscoelasticity during the shelf life.

[0006] Technical solution: The first object of the present invention is to provide a method for delaying the aging of starchy foods, comprising the following steps:

[0007] Step 1: The starchy food is packaged in a polyethylene bag and then subjected to electron beam irradiation treatment, with an electron beam irradiation power of 150 kW and an irradiation dose of 3 to 12 kGy;

[0008] Step 2: Storing the irradiated starchy food to obtain the anti-aging starchy food at a storage temperature of 4° C. for 1 to 12 days;

[0009] Wherein, the starchy food is steamed bun, bread or starch gel.

[0010] Preferably, when the starchy food is a starch gel (such as jelly), the preparation method of the starch gel is as follows: starch and distilled water are mixed to form starch milk, which is heated in a boiling water bath while stirring while heating, and then the transparent starch slurry is poured into a mold and naturally cooled to obtain starch gel, wherein the ratio of starch to distilled water is 1:10 to 15 (w / v).

[0011] Preferably, the starch is at least one of corn starch, wheat starch, sweet potato starch, potato starch and mung bean starch.

[0012] Preferably, the heating time in the boiling water bath is 20 to 30 minutes, and the cooling time is 1 to 3 hours.

[0013] Preferably, the accelerator used for the electron beam irradiation treatment in step 1 is an electron linear accelerator with an energy of 10.0 MeV.

[0014] Preferably, the specification of the polyethylene bag in step 1 is 240 mm×340 mm.

[0015] Preferably, in step 2, when the starchy food is starch gel, the starchy food is wrapped with plastic wrap during storage, and the plastic wrap is replaced every day to remove the emitted moisture; when the starchy food is steamed buns or bread, it is sealed and stored.

[0016] Preferably, the irradiation dose in step 1 is 4 to 8 kGy.

[0017] The second object of the present invention is to provide an anti-aging starchy food prepared based on the above method.

[0018] Beneficial effects:

[0019] 1. The present invention proposes for the first time the anti-aging effect of electron beam irradiation on starch gel. The electron beam irradiation technology used is safe, easy to operate, economical, short in action time, does not introduce any additives, has no radioactive residues, does not cause food to heat up, and is suitable for large-scale industrial production.

[0020] 2. The present invention optimizes the preparation parameters of starchy foods and adjusts the electron beam irradiation dose to obtain starchy foods with moderate viscoelasticity and good anti-aging effects. Experiments have shown that under the conditions of an electron beam irradiation power of 150kW and an irradiation dose of 3-12kGy, the purpose of delaying aging can be achieved, with an irradiation dose of 4-6kGy having the best effect. The storage time of starchy foods after electron beam irradiation can be increased from 1-3 days to 12 days. The hardness, gel strength, and water loss rate of starchy foods during storage can also be reduced, reducing the degree of aging, slowing the aging rate of starchy foods, and greatly extending the storage time of the products. While ensuring the hygienic safety of starchy foods, the best edible quality of foods is maintained and the shelf life of foods is extended, promoting the industrial development of starchy foods. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the hardness of starch gel during storage;

[0022] Figure 2 is the gel strength of starch gel during storage;

[0023] Figure 3 is the water loss rate of starch gel during storage;

[0024] Figure 4 This is a real shot of the starch gel sample during storage;

[0025] Figure 5 is the degree of aging of starch gel during storage;

[0026] Figure 6 is the crystallinity of starch gel during storage;

[0027] Figure 7 is the short-range molecular order of starch gel during storage;

[0028] Figure 8 It is the degree of aging of steamed buns during storage;

[0029] Figure 9 It is the degree of aging of bread during storage. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] The starch used in the examples of this specification is mung bean starch, purchased from Xinxiang Liangrun Whole Grain Food Co., Ltd., and the starch mesh size is 100 mesh.

[0032] The accelerator used for electron beam irradiation treatment is an electron linear accelerator with an energy of 10.0 MeV.

[0033] Example 1

[0034] In the present embodiment, the starchy food is starch gel (jelly).

[0035] This embodiment provides a method for delaying the aging of starchy foods, and the specific steps are as follows:

[0036] Starch and distilled water were mixed at a ratio of 1:12.5 (w / v) to produce a starch emulsion. The mixture was heated in a boiling water bath for 30 minutes with constant stirring. The transparent starch slurry was then poured into a circular mold (15 mm high and 150 mm in diameter) and shaken to remove all air trapped in the mold until the mold was flat and free of bubbles. The mixture was then allowed to cool naturally for 2 hours to produce a starch gel. The starch gel was placed in a polyethylene bag (240 mm × 340 mm) and transported on a conveyor belt to an electron beam irradiation station. The electron beam energy was 10.0 MeV and the power was 150 kW. The irradiation doses were set at 4, 6, 8, 10, and 12 kGy, respectively. The irradiated starch gels were stored at 4°C for 1, 6, and 12 days. During storage, the starchy food was wrapped in plastic wrap, which was changed daily to remove any moisture.

[0037] Example 2

[0038] In the present embodiment, the starchy food is starch gel (jelly).

[0039] This embodiment provides a method for delaying the aging of starchy foods, and the specific steps are as follows:

[0040] Starch and distilled water were mixed at a ratio of 1:10 (w / v) to produce a starch emulsion. The mixture was heated in a boiling water bath for 20 minutes with constant stirring. The transparent starch slurry was then poured into a circular mold (15 mm high and 150 mm in diameter) and shaken to remove all air trapped in the mold until the mold was flat and free of bubbles. The mold was then allowed to cool naturally for 1 hour to produce a starch gel. The starch gel was placed in a polyethylene bag (240 mm × 340 mm) and transported on a conveyor belt to an electron beam irradiation station. The electron beam energy was 10.0 MeV and the power was 150 kW. The irradiation doses were set at 4, 6, 8, 10, and 12 kGy, respectively. The irradiated starch gel was stored at 4°C for 1, 6, and 12 days. During storage, the starchy food was wrapped in plastic wrap, which was changed daily to remove any moisture.

[0041] Example 3

[0042] In the present embodiment, the starchy food is starch gel (jelly).

[0043] This embodiment provides a method for delaying the aging of starchy foods, and the specific steps are as follows:

[0044] Starch and distilled water were mixed at a ratio of 1:15 (w / v) to produce a starch emulsion. The mixture was heated in a boiling water bath for 30 minutes with constant stirring. The transparent starch slurry was then poured into a circular mold (15 mm high and 150 mm in diameter) and shaken to remove all air trapped in the mold until the mold was flat and free of bubbles. The mixture was then allowed to cool naturally for 3 hours to produce a starch gel. The starch gel was placed in a polyethylene bag (240 mm × 340 mm) and transported on a conveyor belt to an electron beam irradiation station. The electron beam energy was 10.0 MeV and the power was 150 kW. The irradiation doses were set at 4, 6, 8, 10, and 12 kGy, respectively. The irradiated starch gel was stored at 4°C for 1, 6, and 12 days. During storage, the starchy food was wrapped in plastic wrap, which was changed daily to remove any moisture.

[0045] Example 4

[0046] In this embodiment, the starchy food is steamed bread.

[0047] This embodiment provides a method for delaying the aging of starchy foods, and the specific steps are as follows:

[0048] Dissolve 1% (by weight of flour) instant active dry yeast in distilled water (30°C). Let stand for 10 minutes, then mix thoroughly with all-purpose wheat flour at a flour-to-water ratio of 2:1 (w / v). Pour the mixture into a multi-purpose dough mixer and mix at medium speed for 10 minutes. Next, roll the dough 25 times on a dough sheeter before cutting and shaping (60g per portion). Place the kneaded dough in a proofer and let it rise for 30 minutes at 30°C and 80% relative humidity (RH). Prepare boiling water in a steamer in advance. Steam the fermented dough in a stainless steel steamer for 20 minutes. After steaming, turn off the steamer and allow the steamed buns to equilibrate in the steamer for 5 minutes to prevent them from collapsing. Remove the steamed buns and cool them at room temperature (25±2°C). The steamed buns were placed in polyethylene bags (240 mm x 340 mm) and placed on a conveyor belt to the electron beam irradiation site. The electron beam energy was 10.0 MeV, the power was 150 kW, and the irradiation dose was set at 3, 6, 9, and 12 kGy. After irradiation, the buns were sealed and stored at room temperature (25 ± 2°C).

[0049] Example 5

[0050] In this embodiment, the starchy food is bread.

[0051] This embodiment provides a method for delaying the aging of starchy foods, and the specific steps are as follows:

[0052] The bread is made using a single-fermentation method. High-gluten wheat flour (1000g), sucrose (60g), yeast (18g), and table salt (12g) are mixed in a dough mixer. Water (600g) is then added and stirred slowly, then rapidly, until the gluten is essentially formed, allowing it to be pulled into a thin film with a jagged edge. Butter (60g) is then added and stirred slowly, then rapidly, until the dough forms a uniform, transparent film with no jagged edges when broken. The dough is then removed and allowed to rest at room temperature (25±2°C) for 30 minutes. The dough is then divided into several 150g balls, rolled into balls, and allowed to rest for 15 minutes before being shaped into molds. The molds are then placed in a proofing oven (humidity 80±5%, temperature 36±2°C). After proofing for 60 minutes, the bread is baked in an electric oven at 180°C (top heat) and 200°C (bottom heat) for 25 minutes. After baking, the bread is removed, cooled to room temperature (25±2°C), and packaged in polyethylene bags (240mm x 340mm). The packaged bread was placed on a conveyor belt and transported to the electron beam irradiation site. The electron beam energy was 10.0 MeV, the power was 150 kW, and the irradiation dose was set to 3, 6, 9, and 12 kGy. The irradiated bread was stored in a sealed container at room temperature (25 ± 2°C).

[0053] Comparative Example 1

[0054] The same as Example 1, except that the starch gel is not subjected to electron beam irradiation. The specific steps are as follows:

[0055] Starch and distilled water were mixed at a ratio of 1:12.5 (w / v) to produce a starch emulsion. The mixture was heated in a boiling water bath for 30 minutes with constant stirring. The transparent starch slurry was then poured into a circular mold (15 mm high and 150 mm in diameter). The mold was shaken to remove all air trapped in the mold until it was flat and free of bubbles. The mixture was then allowed to cool naturally for 2 hours to produce a starch gel. The starch gel was stored at 4°C for 1, 6, and 12 days. During storage, the starchy food was wrapped in plastic wrap, which was changed daily to remove any excess moisture.

[0056] Comparative Example 2

[0057] The same as Example 1, except that the dose of electron beam irradiation is different. The specific steps are as follows:

[0058] Starch and distilled water were mixed at a ratio of 1:12.5 (w / v) to produce a starch emulsion. The mixture was heated in a boiling water bath for 30 minutes with constant stirring. The transparent starch slurry was then poured into a circular mold (15 mm high and 150 mm in diameter) and shaken to remove all air trapped in the mold until the mold was flat and free of bubbles. The mixture was then allowed to cool naturally for 2 hours to produce a starch gel. The starch gel was placed in a polyethylene bag (240 mm × 340 mm) and transported on a conveyor belt to an electron beam irradiation station. The electron beam energy was 10.0 MeV, the power was 150 kW, and the irradiation dose was set at 15 kGy. The irradiated starch gel was stored at 4°C for 1, 6, and 12 days. During storage, the starchy food was wrapped in plastic wrap, which was changed daily to remove any moisture.

[0059] Comparative Example 3

[0060] Same as Example 4, except that the yeast steamed buns are not subjected to electron beam irradiation. The specific steps are as follows:

[0061] Dissolve 1% (by weight of flour) instant active dry yeast in distilled water (30°C). Let it sit for 10 minutes, then mix it with all-purpose wheat flour at a flour-to-water ratio of 2:1 (w / v). Pour the mixture into a multi-purpose dough mixer and mix at medium speed for 10 minutes. Next, roll the dough 25 times on a dough sheeter before cutting and shaping (60g per portion). Place the kneaded dough in a proofer and let it rise for 30 minutes at 30°C and 80% relative humidity (RH). Prepare boiling water in a steamer in advance. Steam the fermented dough in a stainless steel steamer for 20 minutes. After steaming, turn off the steamer and allow the steamed buns to equilibrate in the steamer for 5 minutes to prevent them from collapsing. Remove the steamed buns and cool them at room temperature (25±2°C). Store the buns in sealed polyethylene bags (240mm×340mm) at room temperature (25±2°C).

[0062] Comparative Example 4

[0063] Same as Example 5, except that the bread is not subjected to electron beam irradiation. The specific steps are as follows:

[0064] The bread is made using a single fermentation method. High-gluten wheat flour (1000g), sucrose (60g), yeast (18g) and table salt (12g) are placed in a dough mixer and mixed well. Then water (600g) is added and stirred slowly at first and then quickly until the gluten is basically formed, that is, a thin film can be pulled out, and the break is jagged. Then butter (60g) is added and stirred slowly at first and then quickly until the dough can present a uniform and transparent thin film, and there is no jagged when it breaks. The dough is then taken out and placed at room temperature (25±2℃) for 30 minutes. It is divided into several 150g dough balls and rolled into balls. After relaxing for 15 minutes, it is shaped into molds and then placed in a proofing box (humidity 80±5%, temperature 36±2℃). After proofing for 60 minutes, it is baked in an electric oven with an upper fire of 180℃ and a lower fire of 200℃ for 25 minutes. After baking, take out the bread, cool it to room temperature (25±2°C), and then pack it in polyethylene bags (240mm×340mm) and store it in a sealed container at room temperature (25±2°C).

[0065] The products prepared in Examples 1, 4 and 5 and the comparative example were tested for hardness, gel strength, water loss rate and aging characteristics. The test methods are as follows:

[0066] Hardness test: The hardness of starch gel was determined using a texture analyzer. The starch gel was cut into a cuboid with a length and width of 2.5 cm and a height of 1.5 cm and placed on a test bench. The test was performed using a P / 50 probe. The pre-test speed was 2 mm / s, the test and post-test speeds were both 1 mm / s, and the compression ratio was 30%.

[0067] Gel strength test: The strength of starch gel was determined using a texture analyzer. The starch gel was cut into a rectangular block with a length and width of 2.5 cm and a height of 1.5 cm and placed on the test bench. The test was performed using a P / 0.5 probe. The speed before, during, and after the test was 1 mm / s, and the compression height was 6 mm.

[0068] Water loss test: Weigh and record the weight of fresh unirradiated and irradiated starch gels. Then store the gels at 4°C for 1, 6, and 12 days and record the weight of the starch gels. Calculate the water loss rate using the following formula:

[0069]

[0070] Ageing test: Accurately weigh 3mg of raw starch and 9μL of deionized water in an aluminum crucible, equilibrate at 4℃ for 12h, and then test in a differential scanning calorimeter (DSC) at a temperature range of 20-120℃ and a heating rate of 10℃ / min to obtain the gelatinization enthalpy of starch (ΔHg). Starch gels (steamed bread / bread) stored for different times are freeze-dried and ground into powder. The freeze-dried gel powder is subjected to a DSC test under the same test conditions to obtain the ageing enthalpy of starch (ΔHr). The ageing degree of starch is calculated using the following formula:

[0071]

[0072] Crystal structure testing: The crystal structure was determined using an X-ray diffractometer using the step-scan method. The measurement conditions were: tube voltage 40 kV, current 40 mA, scan range 4°-50° (2θ), scan speed 5° / min, and step size 0.02°.

[0073] Short-range ordered structure test: freeze-dried starch gel sample was mixed with potassium bromide in a ratio of 1:100 (w / w), ground evenly and pressed into thin slices in a vacuum tablet press. The thin slice sample was placed in a Fourier transform infrared spectrometer at 4 cm -1 The resolution is 4000-400cm -1 A total of 64 scans were performed within the range, with air as the background during the scanning test.

[0074] The test results are as follows Figures 1 to 9 shown.

[0075] from Figure 1 and Figure 2 As can be seen, the hardness and gel strength of the starch gels increased with increasing storage days, indicating that the starch gels had aged. However, the increases in hardness and strength of the irradiated gels were smaller than those of the unirradiated (0 kGy) gels. After 12 days of storage, the hardness and strength of the 0 kGy gels increased by 1325.19 g and 339.14 g, respectively; the hardness and strength of the 6 kGy gels increased by 769.86 g and 104.58 g, respectively; while the gels irradiated with a dose of 12 kGy only increased by 319.57 g and 65.57 g. The hardness and gel strength of the electron beam irradiated gels were lower than those of the unirradiated (0 kGy) gels at all storage days, indicating that electron beam irradiation effectively slowed the aging of the starch gels. However, the gel strength of the starch gels irradiated with a dose of 10 kGy and 12 kGy was very low at 0 days of storage, indicating deterioration in starch gel quality. The starch gels did not rebound under compression at a 40% compression ratio, making textural properties unavailable for determination. The starch gel irradiated with a dose of 15 kGy in Comparative Example 2 could not rebound under compression at a compression ratio of 30%, and the texture properties could not be measured, indicating that high-dose electron beam irradiation would reduce the quality of the starch gel and was not suitable for consumption by consumers.

[0076] The water loss rate is measured by measuring the difference in mass of the gel sample before and after storage, reflecting the ability of the components in the gel to bind easily flowing water. The smaller the water loss rate of the gel after storage, the better the water holding capacity. Figure 3 It can be seen that as the storage days increase, the water loss rate of the starch gel increases and the gel becomes harder, indicating that the starch gel has aged. Moreover, when the storage time is extended from 1 day to 6 days, the water loss rate of the gel increases rapidly. When the storage time is further extended to 12 days, the water loss rate of the gel slows down, indicating that the starch gel ages faster in the early stages of storage. Under the same storage days, the water loss rate of the starch gel irradiated by electron beam is significantly lower than that of the unirradiated (0 kGy) starch gel, indicating that electron beam irradiation effectively slows the water loss of the starch gel and delays the aging of the starch gel.

[0077] from Figure 4 The starch gel photos clearly show the water loss of the gel. As the storage days increase, the unirradiated (0 kGy) starch gel undergoes obvious dehydration and condensation, which is consistent with the water loss data. However, the dehydration and condensation phenomenon of the irradiated starch gel is not obvious, indicating that electron beam irradiation can slow down the water loss of starch gel.

[0078] Retrogradation is an indicator used to quantify the degree of retrogradation of starch during storage. The enthalpy change (ΔH) of crystallization and melting during starch retrogradation is measured by differential scanning calorimetry. The ratio of retrogradation enthalpy (ΔHr) to initial gelatinization enthalpy (ΔHg) can be used to characterize the retrogradation degree. Figure 5 As shown in the results, the aging degree of the gel irradiated by electron beam is lower than that of the unirradiated (0 kGy) starch gel at any storage day, and decreases with the increase of irradiation dose. For example, at 0 days of storage, the aging degree of the starch gel irradiated with an electron beam dose of 6 kGy is 23.75% lower than that of the starch gel irradiated with 0 kGy; the aging degree of the starch gel irradiated with an electron beam dose of 12 kGy is 36.81% lower than that of the starch gel irradiated with 0 kGy, indicating that the degree of recrystallization of starch in the gel system is reduced after electron beam irradiation, proving that electron beam irradiation can delay the aging of starch gel. The aging degree of all samples increases with the extension of storage time, indicating that the degree of aging of starch gel deepens during storage.

[0079] X-ray diffraction (XRD) can reflect the aging degree of starch gel by detecting the formation and changes of crystalline regions in starch gel. Figure 6The relative crystallinity of starch gels irradiated with different electron beam doses after storage for 0 and 6 days is shown. With the extension of storage time (from 0 to 6 days), the relative crystallinity of all starch gels increased significantly, indicating that the degree of aging of starch gels deepened during storage. Compared with the unirradiated starch gel (0 kGy), the relative crystallinity of irradiated starch gel was significantly reduced, and decreased with the increase of irradiation dose. Starch aging is mainly due to the reduction of the degree of free movement of starch molecules under low temperature conditions, and the rearrangement to form crystalline regions. The starch molecules gradually recover through hydrogen bonds to form dense and ordered crystalline bundles. The inhibition of starch recrystallization by electron beam irradiation may be related to the destruction of the three-dimensional network structure of starch gel by high-energy electron beam flow. The higher the irradiation dose received by the starch gel, the lower its relative crystallinity. This may be related to the energy generated by the electron beam. The higher the irradiation dose, the more energy the starch gel absorbs. The energy generated by the electron beam can affect the hydrogen bonds between starch molecules, making it difficult for the hydrogen bonds between adjacent starch molecules to combine, and reducing the orderly rearrangement of starch molecules, thereby interfering with the formation of hydrogen bonds in the microcrystal bundles of starch molecules and further delaying the aging of starch.

[0080] 1047 cm in infrared spectrum -1 The absorption band at 1022 cm is closely related to the short-range ordered structure of the double helix, while the absorption band at 1022 cm -1 The absorption band at 1047 / 1022 cm is related to the amorphous structure of starch. -1 The ratio of is used to evaluate the short-range molecular order of the sample. Figure 7 It can be seen that with the extension of storage time, the 1047 / 1022cm -1 The value shows a significant increasing trend. This indicates that the degree of starch gel retrogradation intensifies during storage and the order of starch molecules increases. This is mainly because the enhanced interaction between starch molecules during storage leads to the rearrangement of starch molecules, the gradual recovery of hydrogen bonds, and the re-formation of the double helix structure of starch molecules. Compared with the unirradiated starch gel (0kGy), the 1047 / 1022cm -1 The values decreased and showed a decreasing trend with the increase of irradiation dose. On the 0th and 6th day, the starch gel irradiated with a dose of 12 kGy had a 1047 / 1022 cm2 / cm3 value compared with the unirradiated gel (0 kGy). -1 The values decreased by 0.13 and 0.14, respectively. The late stage of aging is primarily the result of amylopectin recrystallization. This experimental phenomenon demonstrates that electron beam irradiation can effectively control the recrystallization process of amylopectin during long-term aging. This suggests that electron beam irradiation has a positive effect on delaying the aging of starchy foods.

[0081] In summary, electron beam irradiation can significantly delay the aging of starch gels during storage. Combined with the hardness and gel strength data of fresh starch gels (storage day 0), the gel strength of starch gels irradiated with doses of 10 kGy and 12 kGy was very low at storage day 0, indicating that the quality of the starch gels deteriorated. This indicates that high-dose electron beam irradiation can reduce the quality of starch gels and make them unsuitable for consumer consumption. Therefore, the appropriate irradiation dose for delaying starch gel aging is 4 to 6 kGy.

[0082] Figure 8 The aging degree of steamed buns during storage is shown in Figure 1. The aging degree of steamed buns increases significantly from 6 to 12 days of storage. At the same storage time, the aging degree of irradiated buns is significantly lower than that of unirradiated buns (0 kGy). Furthermore, the aging degree decreases with increasing irradiation dose, indicating that electron beam irradiation can delay steamed bun aging. Furthermore, electron beam irradiation has the effect of sterilizing and extending the shelf life of food. Unirradiated (0 kGy) steamed buns (sealed) can only be stored for 4 days at room temperature (25 ± 2°C); however, irradiated buns can be stored for 12 days under the same packaging and storage conditions. Figure 9 The change in bread staling during storage. Bread staling increases with storage time, indicating increased starch recrystallization in the bread system during storage. For the same storage time, bread staling is inversely proportional to the irradiation dose; a higher irradiation dose results in less staling. Electron beam-irradiated bread exhibits lower staling than unirradiated bread (0 kGy) at all storage days, demonstrating that electron beam irradiation effectively delays bread staling.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for delaying the aging of starchy foods, characterized in that: Here are the steps: Step 1: The starchy food is packaged in a polyethylene bag and then irradiated with an electron beam. The electron beam irradiation power is 150 kW and the irradiation dose is 3 to 12 kGy. Step 2: Storing the irradiated starchy food to obtain the anti-aging starchy food at a storage temperature of 4° C. for 1 to 12 days; Wherein, the starchy food is steamed bun, bread or starch gel.

2. The method for delaying the aging of starchy foods according to claim 1, wherein: When the starchy food is starch gel, the preparation method of the starch gel is as follows: starch and distilled water are mixed to form starch milk, which is heated in a boiling water bath while stirring; then the transparent starch slurry is poured into a mold, and naturally cooled to obtain the starch gel, wherein the ratio of starch to distilled water is 1:10~15 w / v.

3. The method for delaying the aging of starchy foods according to claim 2, wherein: The starch is at least one of corn starch, wheat starch, sweet potato starch, potato starch and mung bean starch.

4. The method for delaying the aging of starchy foods according to claim 2, wherein: The heating time in a boiling water bath is 20 to 30 minutes, and the cooling time is 1 to 3 hours.

5. The method for delaying the aging of starchy foods according to claim 1, wherein: The accelerator used for the electron beam irradiation treatment in step 1 is an electron linear accelerator with an energy of 10.0 MeV.

6. The method for delaying the aging of starchy foods according to claim 1, wherein: The specification of the polyethylene bag in step 1 is 240 mm×340 mm.

7. The method for delaying the aging of starchy foods according to claim 1, wherein: In the step 2, when the starchy food is starch gel, the starchy food is wrapped with plastic wrap during storage, and the plastic wrap is replaced every day to remove the emitted moisture; when the starchy food is steamed buns or bread, it is sealed and stored.

8. The method for delaying the aging of starchy foods according to claim 1, characterized in that: The irradiation dose in step 1 is 4-8 kGy.

9. An anti-aging starchy food prepared by the method according to any one of claims 1 to 8.

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