Corn enzymolysis protein with high protein content and high micromolecule active substances and preparation method of corn enzymolysis protein

Abstract

The invention belongs to the technical field of corn protein processing, and particularly relates to corn enzymolysis protein with high protein content and high micromolecule active substances and a preparation method. The method comprises the following steps: S1, weighing corn protein powder, adding water into the corn protein powder, stirring, adding alkali to adjust the pH value, and then adding medium-temperature amylase for enzymolysis; s2, separating the materials to obtain filter residues; s3, adding water into the materials, stirring, and adding acidic cellulase for enzymolysis; and S4, raising the temperature of the material, adjusting the pH value with alkali, and adding alkaline protease for enzymolysis. The corn enzymolysis protein prepared by the method can be used as a high-quality functional protein to be applied to aquatic feed, so that the intestinal and liver health of aquatic animals is remarkably improved, the total dosage of protein raw materials in the aquatic feed is reduced, and the dosage of imported protein resources (such as fish meal) is reduced; pigmentation can be promoted, and the commodity performance of aquatic animals can be improved; therefore, the economic benefits of aquatic feed enterprises and farmers are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of corn protein processing, and particularly relates to a corn protein hydrolysate with high protein and high small molecular active substances and a preparation method thereof. Background Art

[0002] Currently, aquaculture accounts for about 60% of the supply of aquatic products. Therefore, the output of aquaculture will also increase from more than 49 million tons in 2020 to more than 60 million tons in 2030, which means that the demand for aquatic feed will continue to increase by about 20%. In the past two years, due to the high and frequent fluctuations in the price of protein raw materials, aquatic feed companies and farmers have been under tremendous pressure and burden. Therefore, developing a high-quality functional protein that can improve the utilization efficiency of the entire feed protein by aquatic animals, reduce the total amount of protein raw materials in aquatic feed, and reduce dependence on imported protein resources (such as fish meal) is an effective measure to support the sustainable development of the aquaculture industry.

[0003] Zein, a byproduct of my country's corn starch industry, has been widely used in feed, particularly poultry and aquatic feed. Due to its low protein digestibility, low xanthocyanin content, and high toxin content, zein has long been used as a common protein source primarily in aquatic feeds requiring coloring, failing to fully realize its value in aquatic feeds. While direct enzymatic hydrolysis of zein improves protein digestibility and xanthocyanin content, the introduction of additives during the enzymatic hydrolysis process reduces its protein content, making it an ineffective substitute for fish meal. Therefore, developing a method for increasing the protein content of zein while simultaneously boosting the content of small molecule active substances within the zein is crucial.

[0004] Defects of the technical solutions in the disclosed invention patents:

[0005] Patent CN101096696A discloses an industrial production method for enzymatically producing zein peptides from zein. This method primarily uses zein powder as raw material, and produces a white powdered zein peptide through enzymatic hydrolysis, separation, ultrafiltration, concentration, and spray drying. This method involves solid-liquid separation after protein hydrolysis, leaving only soluble small peptides. This not only reduces yield and increases production costs, but also results in waste of usable materials (such as insoluble protein), making it unsuitable for production as a feed ingredient.

[0006] Patent CN102505034A discloses a method for preparing active peptides from corn gluten meal. This method uses corn gluten meal as the raw material, first defatting it, then extracting alcohol-soluble proteins. The alcohol-soluble proteins are then hydrolyzed using a proteolytic method under optimized conditions. The hydrolyzate undergoes a series of separation and purification procedures to obtain a class of corn-derived active peptides. However, this method also suffers from low yields and high production costs, making it unsuitable for use as a feed ingredient. Summary of the Invention

[0007] The purpose of the present invention is to address the problems existing in the current background technology and provide a corn enzymatic protein with high protein and high small molecular active substances and a preparation method, which can significantly improve the intestinal and liver health of aquatic animals, reduce the total amount of protein raw materials in aquatic feed, and reduce the amount of imported protein resources (such as fish meal); it can also promote pigment deposition and improve the commercial performance of aquatic animals.

[0008] In order to achieve the above object of the invention, the technical solution of the present invention is as follows:

[0009] The invention discloses a corn enzymatic hydrolysate protein with high protein and high small molecular active substances. The crude protein, acid-soluble protein, 25%, 2-6 peptide (HPLC method) and 15% lutein content are greater than or equal to 650 mg / kg.

[0010] A method for preparing corn enzymatic protein with high protein and high small molecular active substances comprises the following specific steps:

[0011] S1: Weigh corn gluten powder and add 6-10 times water, stir, add alkali to adjust the pH to 5-6, then add medium-temperature amylase, the weight ratio of medium-temperature amylase to corn gluten powder is 0.1-0.5:100, maintain the temperature at 50-60°C, and continue enzymolysis for 2-4 hours;

[0012] S2: Separate the material processed in step S1 to obtain filter residue.

[0013] S3: Add 2-3 times the amount of water to the material treated in step S2, stir, maintain the temperature at 45-55°C, add acid cellulase, maintain the temperature at 45-55°C, and continue enzymolysis for 4-6 hours;

[0014] S4: raising the temperature of the material treated in step S3 to 55-65° C., adjusting the pH value to 9.0-9.5 with alkali, adding alkaline protease, maintaining the temperature at 55-65° C., and continuously performing enzymolysis for 6-10 hours.

[0015] In some embodiments of the present invention, the step S4 further includes: spray drying the enzymatic hydrolyzed solution obtained in step S4 to obtain powdered corn enzymatic protein.

[0016] In some embodiments of the present invention, the spray drying conditions are: material temperature 50-65°C, air inlet temperature 180-220°C, and exhaust temperature 80-90°C.

[0017] In some embodiments of the present invention, the base includes but is not limited to sodium hydroxide, sodium carbonate or calcium hydroxide.

[0018] In some embodiments of the present invention, the weight ratio of alkali to corn gluten meal in step S1 is 0.05-0.2:100, preferably 0.1:100.

[0019] In some embodiments of the present invention, the weight ratio of alkali to corn gluten meal in step S4 is 1.5-3.0:100, preferably 2.0-2.5:100.

[0020] In some embodiments of the present invention, the enzyme activity of the mesophilic amylase is 50,000-100,000 U / g, preferably 50,000 U / g.

[0021] In some embodiments of the present invention, the enzyme activity of the acid cellulase is 10,000-50,000 U / g, preferably 20,000-30,000 U / g.

[0022] In some embodiments of the present invention, the enzyme activity of the alkaline protease is 100,000-200,000 U / g, preferably 150,000-200,000 U / g.

[0023] In some embodiments of the present invention, the weight ratio of the mesophilic amylase to corn gluten meal is 0.1-0.5:100, preferably 0.2-0.4:100, and more preferably 0.3-0.4:100.

[0024] In some embodiments of the present invention, the weight ratio of the acid cellulase to corn gluten meal is 0.1-0.5:100, preferably 0.2-0.4:100, and more preferably 0.3-0.4:100.

[0025] In some embodiments of the present invention, the weight ratio of the alkaline protease to corn gluten meal is 0.1-0.5:100, preferably 0.2-0.5:100, and more preferably 0.4-0.5:100.

[0026] We applied the corn protein hydrolysate with the above characteristics to aquatic feed (taking Pelteobagrus fulvidraco feed as a reference). By examining its effects on the production performance and stress resistance of Pelteobagrus fulvidraco, we achieved the goal of improving the digestion, absorption, conversion and deposition efficiency of the entire feed protein in aquatic animals, reducing the total amount of protein raw materials in aquatic feed, and at the same time reducing the amount of imported protein resources (such as fish meal). It is a high-quality functional protein that can support the sustainable development of my country's aquaculture industry.

[0027] Compared with the existing technology, the beneficial effects of the present invention are:

[0028] (1) The present invention provides a corn enzymatic protein with high protein and high small molecular active substances, wherein the corn enzymatic protein has a crude protein content of ≥65%, a 2-6 peptide (HPLC method) of ≥15%, and a lutein content of ≥650 mg / kg.

[0029] (2) In the preparation method of the present invention, enzymatic hydrolysis and separation can further increase the protein content and protein digestibility, and produce abundant small molecule active substances such as small molecule peptides and luteins to improve the liver and intestinal health and commercial performance of aquatic animals, thereby increasing the utilization value of corn protein.

[0030] (3) The corn protein hydrolysate prepared by the present invention can be used as a high-quality functional protein in aquatic feed, significantly improving the intestinal and liver health of aquatic animals, reducing the total amount of protein raw materials used in aquatic feed, and reducing the amount of imported protein resources (such as fish meal); it can also promote pigment deposition and improve the commercial performance of aquatic animals; thereby improving the economic benefits of aquatic feed companies and farmers. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the appearance of the intestine of the control group yellow catfish;

[0032] Figure 2 This is the appearance of the intestine of the negative control group Pelteobagrus fulvidraco;

[0033] Figure 3 This is the appearance of the intestine of the experimental group yellow catfish. DETAILED DESCRIPTION

[0034] It should be noted that all features disclosed in this specification, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any manner.

[0035] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0036] Example 1:

[0037] This embodiment provides a method for preparing high-protein and high-small-molecule active substance corn protein suitable for aquatic animals, comprising the following specific steps:

[0038] S1: Raise the temperature of the water storage tank to 65°C, and weigh 3200kg of water into the enzymolysis tank. Weigh 400kg of corn gluten meal and put it into the enzymolysis tank. Weigh 0.4kg of sodium hydroxide, dissolve it in 0.4kg of water, and add it to the enzymolysis tank. Start stirring and set the material temperature to 55±1°C. After the temperature stabilizes, weigh 1.2kg of medium-temperature amylase and add it to the enzymolysis tank. Maintain the temperature at 55±1°C and continue enzymolysis for 3 hours.

[0039] S2: Separating the material processed in step S1 to obtain a filter residue;

[0040] S3: Place the material treated in step S2 into an enzymolysis tank, add 800 kg of water, start stirring, maintain the temperature at 50±1°C, add 1.2 kg of acid cellulase, and continue enzymolysis for 4 hours;

[0041] S4: Raise the temperature of the material treated in step S3 to 60±1°C, weigh 8.5 kg of sodium hydroxide, dissolve it in 8.5 kg of water, and add it to the enzymolysis tank. Start stirring, then weigh 1.6 kg of alkaline protease and add it to the enzymolysis tank. Maintain the temperature at 60±1°C and continue enzymolysis for 8 hours.

[0042] S5: spray-drying the enzymatic hydrolyzate obtained in step S4 to obtain powdered corn enzymatic protein A.

[0043] Example 2:

[0044] This embodiment provides a method for preparing high-protein and high-small-molecule active substance corn protein suitable for aquatic animals, comprising the following specific steps:

[0045] S1: Raise the temperature of the water storage tank to 65°C, and weigh 3200kg of water into the enzymolysis tank. Weigh 400kg of corn gluten meal and put it into the enzymolysis tank. Weigh 0.4kg of sodium hydroxide, dissolve it in 0.4kg of water, and add it to the enzymolysis tank. Start stirring and set the material temperature to 55±1°C. After the temperature stabilizes, weigh 1.6kg of medium-temperature amylase and add it to the enzymolysis tank. Maintain the temperature at 55±1°C and continue enzymolysis for 4 hours.

[0046] S2: Separating the material processed in step S1 to obtain a filter residue;

[0047] S3: Place the material treated in step S2 into an enzymolysis tank, add 800 kg of water, start stirring, maintain the temperature at 50±1°C, add 1.6 kg of acid cellulase, and continue enzymolysis for 6 hours;

[0048] S4: Raise the temperature of the material treated in step S3 to 60±1°C, weigh 8.5 kg of sodium hydroxide, dissolve it in 8.5 kg of water, and add it to the enzymolysis tank. Start stirring, then weigh 2.0 kg of alkaline protease and add it to the enzymolysis tank. Maintain the temperature at 60±1°C and continue enzymolysis for 10 hours.

[0049] S5: spray-drying the enzymatic hydrolyzate obtained in step S4 to obtain powdered corn enzymatic protein B.

[0050] Experimental Example 1:

[0051] In this experimental example, various indicators of corn gluten powder raw material, corn enzymatic protein A prepared in Example 1, and corn enzymatic protein B prepared in Example 2 were tested according to the GB / T method. The results are shown in Table 1.

[0052] Table 1 Indexes of corn gluten meal, corn enzymatic protein A, and corn enzymatic protein B

[0053]

[0054] As shown in Table 1, the corn protein hydrolysate prepared by the preparation method of the present invention has significantly higher crude protein, protein digestibility, small molecule peptides, antioxidant capacity and lutein content than corn protein powder.

[0055] Experimental Example 2:

[0056] Experimental Example 2: A commercial diet of yellow catfish was used as the control group (crude protein: 42%). On the basis of the control group, the animal and plant protein raw materials providing protein were reduced in equal proportion, and the protein content was reduced by 3 percentage points as a negative control group (crude protein: 39%); on the basis of the negative control group, 3% corn enzymatic protein A was added as the experimental group to examine the effects of each diet on the growth performance, liver and intestine health, and stress resistance of yellow catfish.

[0057] Experimental Example 2: 540 healthy juvenile Pelteobagrus fulvidraco, initially weighing approximately 6 g, were randomly divided into three treatment groups, each with three replicates and 60 fish per replicate. No significant differences in initial body weight were observed between the groups (P > 0.05). The experimental period was 70 days, and the experimental design is shown in Table 2.

[0058] Table 2 Experimental design

[0059]

[0060]

[0061] The diet of Experimental Example 2 was mainly composed of fish meal, chicken meal, corn gluten meal, flour, soybean oil, and lecithin oil, and vitamin and mineral element premixes were added. The composition of the experimental diet is shown in Table 3. The raw materials were pulverized through a 60-mesh sieve, thoroughly mixed, and granulated.

[0062] Table 3 Diet formula

[0063] raw material(%) control group Negative control group Experimental group fishmeal 25.00 23.10 20.08 Chicken powder 15.00 13.80 13.80 soybean meal 16.68 15.10 15.10 corn gluten meal 8.50 7.67 7.67 flour 15.00 15.00 15.00 soybean oil 4.03 4.35 4.52 Soybean lecithin oil 2.00 2.00 2.00 microcrystalline cellulose 0.20 4.91 4.47 Carboxymethyl cellulose 7.00 7.00 7.00 Calcium dihydrogen phosphate 1.22 1.43 1.52 Mineral element premix 2.00 2.00 2.00 Vitamin premix 1.00 1.00 1.00 Choline chloride premix 1.00 1.00 1.00 BHA 0.015 0.015 0.015 L-Lysine hydrochloride (78.8%) 1.35 1.59 1.76 L-Met (99%) 0.00 0.04 0.06 Corn Protein A 0.00 0.00 3.00 total 100.00 100.00 100.00

[0064] Animal experiments were conducted at the Dayi Aquatic Animal Nutrition Research Base. Fish were reared in outdoor cages and fed to a full stomach daily at 6:00, 12:00, and 18:00. The amount of food fed was determined based on feeding activity, ensuring that a small amount of feed remained in each tank within each treatment after one hour of feeding. Residual feed was collected one hour after feeding, dried, weighed, and recorded. Weather, water temperature, pH, feeding rate, residual feed amount, and feed intake were recorded daily.

[0065] Determination of growth performance indicators:

[0066] Weight gain rate (g / tail) = (final weight (g / tail) - initial weight (g / tail)) / initial weight × 100%

[0067] Specific growth rate = [ln final weight (g) - ln initial weight (g)] × 100 / number of test days

[0068] The results showed (see Table 4) A 3-point reduction in crude protein from a 42% crude protein diet significantly reduced the growth rate of yellow catfish by 11.7%. This suggests that supplementing corn protein hydrolysate A with a 39% crude protein diet would be valuable to investigate whether it improves protein deposition efficiency and growth in yellow catfish. The group supplemented with 3% corn protein hydrolysate A at a 39% crude protein diet showed a 21% increase in weight gain and a 10% increase in specific growth rate compared to the negative control group. Compared to the 42% protein group, the group showed a 7.7% increase in weight gain and a 4% increase in specific growth rate, exceeding the effect of the high-protein diet. This suggests that corn protein hydrolysate A significantly enhances the conversion and deposition efficiency of dietary protein in yellow catfish, promoting growth and saving the total amount of protein raw materials used in aquaculture feeds.

[0069] Table 4 Effects of corn protein A on growth performance of yellow catfish

[0070] Grouping control group Negative control group Experimental group Initial body weight (g) 5.9 5.9 5.9 Final body weight (g) 28.81±1.48 26.14±0.63 30.54±1.07 Weight gain rate (%) 388.32±25.09 342.99±10.58 417.71±18.10 Specific growth rate (% / d) 2.26±0.07 2.13±0.03 2.35±0.05

[0071] Experimental Example 3:

[0072] At the end of Experimental Example 2, 30 fish of matched size were selected and injected with 6% DSS to induce enteritis according to the 24h median lethal concentration of DSS for yellow catfish (two control groups were set up, injected with saline and DSS respectively), and the deaths were recorded within 24h and the mortality rate was calculated; samples were collected at 24h to observe the apparent status of intestinal inflammation and the integrity of tissue structure; and the fish were dissected after the poisoning to observe the intestinal enteritis 24h after the acute poisoning.

[0073] The results showed that (see Figure 1 ) Compared with the 42% crude protein group, the intestines of the 39% crude protein group were significantly redder, indicating more severe enteritis. This suggests that lowering protein levels can reduce the yellow catfish's ability to resist inflammation. Adding 3% corn protein hydrolysate to the 39% crude protein formula significantly alleviated intestinal inflammation, surpassing the 42% crude protein group. This suggests that corn protein hydrolysate can enhance the anti-inflammatory capacity of the intestines of aquatic animals and improve intestinal health.

[0074] The above-described embodiments merely represent specific implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection of the present application. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the technical concept of the present application, and all such variations and improvements fall within the scope of protection of the present application.

[0075] This background section is provided to generally present the context of the invention, and the work of the presently named inventors, the work to the extent described in this background section, and aspects of the description in this section that did not constitute prior art at the time of filing are neither explicitly nor implicitly admitted to be prior art to the present invention.

Claims

1. A method for preparing corn enzymatic protein with high protein and high small molecular active substances, characterized in that The following steps are involved: S1: Weigh corn gluten meal, add 6-10 times its mass of water to it, stir, add alkali to adjust the pH to 5-6, then add medium-temperature amylase, and continue enzymatic hydrolysis at 50-60°C for 2-4 hours; S2: Separate the material processed in step S1 to obtain a filter residue; S3: Add 2-3 times the amount of water to the material treated in step S2, stir, maintain the temperature at 45-55°C, add acid cellulase, maintain the temperature at 45-55°C, and continue enzymolysis for 4-6 hours; S4: raising the temperature of the material treated in step S3 to 55-65° C., adjusting the pH value to 9.0-9.5 with alkali, adding alkaline protease, maintaining the temperature at 55-65° C., and continuously performing enzymolysis for 6-10 hours.

2. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 1, characterized in that: After step S4, the method further includes: spray-drying the enzymatic hydrolyzed liquid obtained in step S4 to obtain powdered corn enzymatic protein.

3. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 1 or 2, characterized in that The alkali in step S1 includes but is not limited to sodium hydroxide, sodium carbonate or calcium hydroxide.

4. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 1 or 2, characterized in that: In step S1, the weight ratio of alkali to corn gluten meal is 0.05-0.2:

100.

5. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 1 or 2, characterized in that: The enzyme activity of the medium-temperature amylase is 50,000-100,000 U / g; the enzyme activity of the acid cellulase is 10,000-50,000 U / g; and the enzyme activity of the alkaline protease is 100,000-200,000 U / g.

6. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 1, characterized in that: In step S1, the weight ratio of the mesoamylase to the corn gluten meal is 0.1-0.5:

100.

7. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 1 or 2, characterized in that: In step S3, the weight ratio of acid cellulase to corn gluten meal is 0.1-0.5:

100.

8. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 1 or 2, characterized in that: In step S4, the weight ratio of alkaline protease to corn gluten powder is 0.1-0.5:100; the weight ratio of alkali to corn gluten powder is 1.5-3.0:

100.

9. The method for preparing a high-protein and high-small-molecule active substance corn enzymatic protein according to claim 2, characterized in that: The spray drying conditions are: material temperature 50-65°C, air inlet temperature 180-220°C, and exhaust temperature 80-90°C.

10. A corn enzymatic protein with high protein and high small molecule active substances prepared by the method of claim 1, characterized in that: The corn enzymatic protein has a crude protein content of ≥65%, an acid-soluble protein content of ≥25%, a 2-6 peptide content of ≥15%, and a lutein content of ≥650 mg / kg.

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