Method for degrading phytic acid in byproducts of agricultural products and food

Abstract

The invention discloses a method for degrading phytic acid in agricultural product byproducts. The method comprises the following steps: S1, crushing the agricultural product byproducts to 20-60 meshes; s2, crushing the agricultural product by-product obtained in the step S1 to 80-150 meshes; and S3, crushing the agricultural product by-product obtained in the step S2 to 280-320 meshes. The invention also provides a food prepared by the method for degrading phytic acid in byproducts of agricultural products. The method provided by the invention can greatly degrade phytic acid in agricultural product byproducts and improve the nutritional value of the agricultural product byproducts, so that the agricultural product byproducts are suitable for preparing food.

Description

Technical Field

[0001] The present invention relates to the technical field related to agricultural product processing, and more specifically, to a method for degrading phytic acid in agricultural product byproducts and food. Background Art

[0002] Phytic acid is widely found in agricultural by-products such as soybean meal (21.42 mg / g), grain bran (wheat bran contains about 25-58 mg / g, oat bran contains about 20 mg / g, and rice bran contains about 70.39 mg / g). As a proton donor, it produces hydrogen ions (H + ) and phytic acid anions, which are easily tightly combined with mineral (calcium, iron, magnesium, zinc, etc.) metal ions to form compounds, and are often cross-linked with proteins to form complex salts. Therefore, phytic acid is also regarded as an anti-nutritional factor, which seriously affects the solubility and functionality of micronutrients. Phytic acid makes the bioavailability of nutrients in agricultural and sideline products low, and people who mainly eat plant-based foods are prone to important nutrient deficiencies, which further causes public health problems such as osteoporosis, anemia, and malabsorption.

[0003] Therefore, reducing and removing the phytic acid content in agricultural and sideline products and improving the bioaccessibility of micronutrients are urgent problems to be solved. In the prior art, the commonly used means of eliminating phytic acid mainly include shelling, soaking, pulping, fermentation, heat treatment (such as microwave, infrared and extrusion treatment), ultrasound and high-pressure treatment, etc., and the means of degrading phytic acid for beans also include germination, cooking and other means. However, shelling has little effect on degrading phytic acid, and it is also easy to cause the loss of functional components such as cortical dietary fiber. Although the long-term soaking and pulping process can activate endogenous phytic acid enzymes to degrade phytic acid, it may cause the functional components in agricultural and sideline products to be lost as phytic acid is dissolved, and if the soaking is to achieve a higher phytic acid degradation rate, acid or alkali needs to be added to change the pH, and the resulting dephytic acid bran is not suitable for subsequent food processing applications. Wet removal of phytic acid will also lead to excessive wastewater, and environmental pressure is not conducive to its industrial processing. In addition, the heat-labile nature of phytic acid causes its content to drop significantly during heat treatment, but this also causes the loss of heat-sensitive phenolic acids and flavonoid functional substances, reducing the nutritional value of agricultural products. Ultrasonic and high-pressure treatments further remove phytic acid by desorbing the micronutrients bound to phytic acid and generating a large amount of negative pressure, causing cell deformation and damage, but it is obviously difficult to achieve large-scale industrial application.

[0004] Therefore, it is necessary to design a technical solution that can overcome the above-mentioned defects. Summary of the invention

[0005] An object of the present invention is to provide a method for degrading phytic acid in agricultural by-products and food, which can significantly degrade phytic acid in agricultural by-products, improve their nutritional value, and make them suitable for preparing food.

[0006] In order to achieve these purposes and other advantages of the present invention, according to one aspect of the present invention, the present invention provides a method for degrading phytic acid in agricultural product by-products, comprising: S1: crushing the agricultural product by-products to 20-60 mesh; S2: crushing the agricultural product by-products obtained by S1 to 80-150 mesh; S3: crushing the agricultural product by-products obtained by S2 to 280-320 mesh.

[0007] Furthermore, before S1, the agricultural product by-products are dried to a moisture content of no more than 10%.

[0008] Further, drying is performed at 45-60°C.

[0009] Furthermore, in S1, the agricultural by-products are crushed to 40 meshes, and in S3, the agricultural by-products obtained by the process in S2 are crushed to 300 meshes.

[0010] Furthermore, the agricultural product by-products include bran and soybean meal.

[0011] Furthermore, in S1, the oversize is repeatedly fed and processed until the undersize accounts for 90-95% of the total mass of the agricultural product by-products, and the undersize is taken for S2; in S3, the oversize is repeatedly fed and processed until the undersize accounts for 90-95% of the total mass, completing the degradation process.

[0012] According to another aspect of the present invention, a method for degrading phytic acid in agricultural product by-products is provided, comprising: S1: drying bran or soybean meal at 45-60°C to a moisture content of no more than 10%, crushing to 40 mesh, and repeatedly feeding the oversize material until the undersize material accounts for 90-95% of the total mass of the bran or soybean meal; S2: crushing the bran or soybean meal obtained by the S1 treatment to 80-150 mesh; S3: crushing the bran or soybean meal obtained by the S2 treatment to 300 mesh, and repeatedly feeding the oversize material until the undersize material accounts for 90-95% of the total mass.

[0013] According to another aspect of the present invention, there is also provided food, which is prepared by the method for degrading phytic acid in agricultural product by-products.

[0014] The present invention has at least the following beneficial effects: The invention firstly crushes the agricultural product by-products into 20-60 meshes, then into 80-150 meshes, and finally into 280-320 meshes, and greatly reduces the phytic acid content in the agricultural product by-products through graded crushing, thereby improving the nutritional value thereof. In addition, compared with the prior art, the invention causes less damage to the agricultural product by-products, does not require the addition of additional chemical reagents, and has less damage to trace nutrients, and is suitable for large-scale production and preparation of food.

[0015] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0016] The present invention is described in further detail below so that those skilled in the art can implement it according to the description.

[0017] It should be understood that the terms such as "having", "including" and "comprising" used in the embodiments of the present application do not exclude the existence or addition of one or more other elements or their combinations. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative position relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. When an element is referred to as "fixed on" or "set on" another element, it can be directly on the other element or there may be a centering element at the same time. When an element is referred to as "connecting" another element, it can be directly connected to another element or it can be indirectly connected to another element through a centering element. The description of "first", "second", etc. in the embodiments of the present application is only for descriptive purposes, and cannot be understood as indicating or implying its relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features.

[0018] It should be noted that the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0019] The embodiments of the present application provide a method for degrading phytic acid in agricultural product by-products, comprising: S1: Dry the bran or soybean meal at 45-60 ℃ to a moisture content of no more than 10%, crush to 40 mesh, and repeatedly feed the oversize material until the undersize material accounts for 90-95% of the total mass of the bran or soybean meal; In this step, the bran or soybean meal is preliminarily coarsely ground. For example, the dried bran or soybean meal is put into a multifunctional grinder for processing, and sieved to confirm that it reaches a 40-mesh particle size. The sieved material needs to be repeatedly fed and processed until the sieved material accounts for 90-95% of the total mass, and the sieved material is taken for standby use; S2: crushing the bran or soybean meal obtained by S1 into 80-150 mesh; In this step, the ultrafine grinding time is adjusted to perform secondary fine grinding. For example, the bran or soybean meal powder obtained in S2 is put into an ultrafine grinder for secondary grinding. The mechanical grinding time is changed according to the difference in the principle of the selected ultrafine grinder. Screening is performed to confirm that the particle size reaches 80-150 meshes, and the mixture is set aside. S3: crush the bran or soybean meal obtained in S2 to 300 mesh, and repeatedly feed the oversize material until the undersize material accounts for 90-95% of the total mass; In this step, the parameters of the superfine pulverizer are adjusted to perform superfine grinding. For example, the bran or soybean meal powder obtained in S2 is taken, and according to the difference in the principle of the selected superfine pulverizer, the equipment parameters of the superfine pulverizer are continuously adjusted to strengthen the grinding intensity of the by-product fine powder, and the sieve is screened to confirm that it reaches a particle size of 300 meshes. The sieved material needs to be repeatedly fed and processed until the sieved material accounts for 90-95% of the total mass, and the sieved material is taken for standby use; In this embodiment, bran or soybean meal is crushed to 40 mesh, 80-150 mesh and 300 mesh in sequence, and the grain size of soybean meal or bran is continuously reduced to gradually break up the dense tissue structure; as the crushing intensity increases, the by-product bran is processed to the cell level by ultrafine grinding, which destroys the integrity of the cell wall to further release the phytic acid concentrated in the aleurone cells, and significantly activates the activity of phytase, prompting it to degrade phytic acid, and hydrolyzes the phosphate residues of phytic acid, destroying its close combination with nutrients such as high-quality protein and minerals, thereby greatly improving the nutritional value.

[0020] Compared with shelling, soaking, pulping, fermentation, heat treatment, ultrasound and high-pressure treatment in the prior art, this embodiment causes less damage to agricultural product by-products, does not require the addition of additional chemical reagents, has less damage to trace nutrients, and is suitable for large-scale production and preparation of food.

[0021] The embodiments of the present application also provide food, which is prepared by the method of degrading phytic acid in agricultural product by-products. The obtained food has the advantages of the above method, high nutritional value, less damage to agricultural product by-products, no additional addition of chemical reagents, and less damage to trace nutrients.

[0022] The following is a description of specific embodiments.

[0023] Embodiment 1: Coarse grinding: Dry the agricultural by-products at 45°C to a moisture content of no more than 10%, crush them to 40 mesh, and repeatedly feed the oversize material until the undersize material accounts for 90% of the total mass of the agricultural by-products; fine grinding: crush the obtained agricultural by-products to 80-150 mesh; ultrafine grinding: crush the obtained agricultural by-products to 300 mesh, and repeatedly feed the oversize material until the undersize material accounts for 90% of the total mass.

[0024] Comparative Example 1: The agricultural product by-products were dried at 45°C until the moisture content was no higher than 10%, crushed with a multifunctional crusher for 1-2 minutes, and sieved to confirm that the particle size reached 40 meshes. The subsequent steps of Example 1 were not performed.

[0025] Comparative Example 2: The agricultural product by-products were dried at 45°C to a moisture content of no more than 10%, crushed to 40 mesh, and the oversize was repeatedly fed and processed until the undersize accounted for 90% of the total mass of the agricultural product by-products, and then crushed with an ultrafine grinder to make the final product reach a particle size of 80-150 mesh. The subsequent steps of Example 1 were not performed.

[0026] Comparative Example 3: The agricultural product by-products are dried at 45°C to a moisture content of no more than 10%. Without coarse grinding or fine grinding, they are directly crushed using an ultrafine pulverizer. The obtained agricultural product by-products are crushed to 300 mesh, and the oversize material is repeatedly fed and processed until the undersize material accounts for 90% of the total mass.

[0027] Comparative Example 4: The agricultural by-products were dried at 45 °C to a moisture content of no more than 10%, and then dry-heat treated (oven at 120 °C for 40 min).

[0028] Comparative Example 5: After sterilizing the sample treated in Comparative Example 1, the agricultural product by-product and double distilled water were placed in a conical flask according to a certain liquid-to-solid ratio, and then the activated Lactobacillus plantarum was added according to a certain inoculum amount. After uniform mixing, the mixture was fermented at a certain temperature for a certain time. After the fermentation, the mixture was placed in a forced air drying oven and dried at 40°C to obtain a solid-state fermentation product of Lactobacillus plantarum; wherein the inoculum amount of Lactobacillus plantarum was 15%, the liquid-to-solid ratio was 0.8, the fermentation time was 7d, and the fermentation temperature was 38°C.

[0029] Control group: No physical or chemical treatment is performed.

[0030] test: The bran and soybean meal were treated by using Example 1, Comparative Examples 1-5, and the control group, and the phytic acid content, mineral content, and phytase activity of the obtained products were detected. The results are shown in Table 1. The phytic acid detection method includes: Weigh 1 g of product sample, add 60 mL of 1.2% HCl•10% Na2SO4 solution, extract by ultrasonic for 30 min, centrifuge and take 2 mL of supernatant in a test tube, add 2 mL of 15% trichloroacetic acid (TCA), mix well and place in a 4 ℃ refrigerator for 1 h, centrifuge at 3000rpm for 20 min, take 1 mL of supernatant, dilute to 30 mL with distilled water, mix well, then take 3 mL of dilution and add 1 mL of 0.3% sulfosalicylic acid•0.03% FeC13•6H2O solution, mix well and place for 15 min, and measure the absorbance at 500 nm. Prepare a standard curve with phytic acid standard solution, and calculate the phytic acid content of the sample according to the standard curve.

[0031] Table 1 It can be seen from Table 1 that, compared with Comparative Examples 1-5 and the control group, the product obtained in Example 1 has significantly lower phytic acid content, higher mineral content and phytase activity, which proves that the method of Example 1 can significantly reduce the phytic acid content in agricultural product by-products and improve their nutritional value.

[0032] Comparison of Example 1 with Comparative Examples 1-5: Phytic acid content: Example 1 significantly reduced the phytic acid content (3.15% for bran and 4.35% for soybean meal) by crushing, which was more obvious than the control group and comparative examples 1 to 5. During the processing, Example 1 used graded crushing technology to better destroy the plant tissue structure, allowing the phytic acid to be released and degraded.

[0033] Mineral content: Example 1 can maintain a relatively high mineral content while reducing the phytic acid content. Compared with other groups, especially comparative examples 3 and 4 treated with heat and fermentation, the mineral content remains relatively stable. The mineral content of comparative example groups 1-4 is generally low, which may be related to the fact that the cell wall is not completely destroyed, and the minerals are tightly bound in the plant tissue, resulting in greater difficulty in release.

[0034] Phytase activity: The phytase activity of Example 1 was relatively high (3.08 U / g bran, 2.20 U / g soybean meal), which indicated that the enzyme activity was effectively activated and promoted the degradation of phytic acid during the crushing process. Compared with the control group (0.43 U / g bran, 0.51 U / g soybean meal) and comparative examples 1-5, the phytase activity of Example 1 was relatively ideal, proving that graded crushing can effectively release substrates and improve enzyme activity.

[0035] Analysis of Comparative Example 1: Crushed to 40 mesh: The phytic acid content of Comparative Example 1 (4.38% for bran and 5.73% for soybean meal) was significantly higher than that of Example 1. Since the crushed particles were coarse, the plant cell walls may not be fully destroyed, resulting in the incomplete release of phytic acid. In addition, the particle structure crushed to 40 mesh may limit the activity of phytase, making it impossible for the enzyme to fully act on phytic acid, so the enzyme activity was low (1.52 U / g for bran and 1.32 U / g for soybean meal).

[0036] Analysis of Comparative Example 2: Crushing to 80-150 mesh: Compared with Example 1, the particles crushed to 80-150 mesh (Comparative Example 2) may be due to the combination of coarse grinding and fine grinding, the degree of crushing is moderate, the cell wall is not fully destroyed, and the phytic acid is not fully released.

[0037] Analysis of Comparative Example 3: Direct ultrafine grinding: Comparative Example 3 adopts direct ultrafine grinding instead of coarse grinding and then fine grinding. The results show that although the phytic acid content (3.30% bran, 4.49% soybean meal) is close to that of Example 1, the mineral content and phytase activity are slightly lower (1.48% bran, 2.40% soybean meal), which may be related to the lack of coarse grinding stage. Although Comparative Example 3 is fully broken, the degree of starch damage is higher, causing the viscosity to rise rapidly. The increase in viscosity also makes it difficult for phytase to act, and the release of phytic acid is poor. Therefore, graded crushing helps to avoid excessive starch damage. In the coarse grinding stage, the cell wall will be partially destroyed and some starch molecules will be released, but the integrity of the overall starch granules will be retained. Although the viscosity will increase, due to the moderate fineness of the finely ground particles, the viscosity is usually not too high, so the contact and action of the enzyme are relatively small, and the enzymatic hydrolysis effect is better. However, direct ultrafine grinding usually causes more serious damage to the starch granules, and more starch is dissolved, resulting in a significant increase in viscosity. Excessive viscosity may affect the permeability of enzymes, thereby limiting the degradation of enzymes and even causing a decrease in the efficiency of interaction between substrates and enzymes. Therefore, it is necessary to fully crush and grade the crushing to avoid serious damage to starch granules during the crushing process, which will cause the viscosity to increase rapidly and affect the action of enzymes, and further affect the degradation of phytic acid.

[0038] Analysis of Comparative Examples 4 and 5: Heat treatment and fermentation: Although comparative examples 4 (heat treatment) and 5 (fermentation treatment) can also degrade phytic acid, the effect is quite different from that of Example 1, and heat treatment and fermentation treatment generally lead to the loss of other nutrients. In particular, heat treatment may lead to the loss of minerals, and the fermentation process may take a long time and require special equipment and conditions, so it is more complicated in industrial applications and is not suitable for large-scale promotion.

[0039] Summarize: The treatment effect of Example 1 is the best, which can effectively reduce the phytic acid content and increase the mineral content and phytase activity. Its step-by-step crushing treatment method is significantly better than other treatment methods, especially Comparative Examples 1-5, and is particularly suitable for large-scale industrial applications.

[0040] Although the ultrafine grinding of Comparative Example 3 can reduce phytic acid to a certain extent, its effect is slightly lower than that of Example 1, and its processing method may increase the viscosity of the product and affect the release of other nutrients.

[0041] Although the heat treatment and fermentation treatment of Comparative Examples 4 and 5 have certain effects in degrading phytic acid, they are often accompanied by the loss of other nutrients, and the operations are relatively complicated and are not suitable for industrial large-scale production.

[0042] In summary, the coarse grinding, fine grinding and ultrafine grinding of Example 1 have a certain synergistic effect, which gradually destroys the cell wall while ensuring that the viscosity of the product does not increase rapidly, thereby ensuring the full release of phytic acid and the full activation of phytase, effectively reducing the phytic acid content in agricultural product by-products, and improving their nutritional value. Moreover, it is easier to implement in large-scale industrial applications.

[0043] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A method for degrading phytic acid in agricultural product by-products, characterized in that: include: S1: crush agricultural by-products into 20-60 mesh; S2: crushing the agricultural product by-product obtained by the process in S1 into 80-150 meshes; S3: crushing the agricultural product by-product obtained by the treatment in S2 into 280-320 meshes.

2. The method for degrading phytic acid in agricultural product by-products according to claim 1, characterized in that: Before S1, the method further includes drying the agricultural product by-products to a moisture content of no more than 10%.

3. The method for degrading phytic acid in agricultural product by-products according to claim 2, characterized in that: Drying is carried out at 45-60°C.

4. The method for degrading phytic acid in agricultural product by-products according to claim 1, characterized in that: In S1, the agricultural by-products are crushed to 40 meshes, and in S3, the agricultural by-products obtained by S2 are crushed to 300 meshes.

5. The method for degrading phytic acid in agricultural product by-products according to claim 1, characterized in that: The agricultural product by-products include bran and soybean meal.

6. The method for degrading phytic acid in agricultural product by-products according to claim 1, characterized in that: In S1, the oversize is repeatedly fed and processed until the undersize accounts for 90-95% of the total mass of the agricultural product by-products, and the undersize is taken for S2; in S3, the oversize is repeatedly fed and processed until the undersize accounts for 90-95% of the total mass, completing the degradation process.

7. A method for degrading phytic acid in agricultural by-products, characterized in that: include: S1: Dry the bran or soybean meal at 45-60 ℃ to a moisture content of no more than 10%, crush to 40 mesh, and repeatedly feed the oversize material until the undersize material accounts for 90-95% of the total mass of the bran or soybean meal; S2: crushing the bran or soybean meal obtained by S1 into 80-150 mesh; S3: The bran or soybean meal obtained by the S2 treatment is crushed to 300 mesh, and the oversize is repeatedly fed and processed until the undersize accounts for 90-95% of the total mass.

8. Food, characterized in that The product is prepared by the method for degrading phytic acid in agricultural product by-products as described in any one of claims 1 to 7.

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