Highland barley-oat alcohol soluble protein fiber membrane as well as preparation method and application thereof

Abstract

The invention provides a highland barley-oat alcohol soluble protein fiber membrane as well as a preparation method and application thereof, and belongs to the technical field of food packaging. The composition comprises the following raw materials: highland barley alcohol-soluble protein, oat alcohol-soluble protein, glycerol and a phospholipid compound. The ratio of the total mass of the highland barley gliadin and the oat gliadin to the mass of the glycerol and the phospholipid compound is (20-30): (1.5-3.5): (1-3); the mass ratio of the highland barley alcohol-soluble protein to the oat alcohol-soluble protein is (6-8): (2-4); the feed also comprises a raw material bacteriostatic agent. Compared with a highland barley-corn / sorghum / millet gliadin fiber membrane, the highland barley-oat gliadin fiber membrane has the advantages that the mechanical property, the water blocking property and the antibacterial property are obviously improved, and the edible nanofiber membrane with excellent mechanical property, water blocking property and antibacterial property is successfully prepared; and a new technical path is provided for green and sustainable development of the food packaging industry.

Description

Technical Field

[0001] This invention belongs to the field of food packaging technology, specifically relating to a barley-oat gliadin fiber membrane, its preparation method, and its uses. Background Technology

[0002] Packaging plays a crucial role in protecting food, extending its shelf life, and reducing food waste. Synthetic plastics are widely used in food packaging due to their high mechanical strength, high barrier properties, and low cost. However, their toxicity, non-degradability, and the cost of raw materials (petroleum) not only limit their application in food packaging but also cause serious environmental pollution. Therefore, developing environmentally friendly, safe, non-toxic, biodegradable, and high-performance alternative packaging materials has become an urgent need in the food packaging industry.

[0003] Edible packaging materials are typically made from natural biopolymers, such as polysaccharides (starch, cellulose, chitosan, etc.), proteins (soy protein, whey protein, gelatin, etc.), and lipids (beeswax, vegetable oil, fatty acids, etc.). They have good biocompatibility and biodegradability, are green and environmentally friendly, widely available, and low in cost. At the same time, by adding antioxidants, antibacterial agents, and other ingredients, packaging materials can be endowed with functions such as preservation and antibacterial properties, further enhancing the quality and added value of food.

[0004] Gliadin is a biodegradable, water-insoluble protein that can form ideal nanofiber membranes. Currently, both domestically and internationally, most nanofiber membranes are prepared by using zein as the main raw material and combining it with other gliadin or functional substances. However, the resulting nanofiber membranes suffer from drawbacks such as high brittleness, low mechanical strength, and poor water resistance and antibacterial properties. Therefore, developing an edible nanofiber membrane with excellent mechanical strength, water resistance, and antibacterial properties, as well as being easy to process, cost-effective, and safe, is of great significance for promoting the green transformation of the food packaging industry, ensuring food safety, and protecting the ecological environment. Summary of the Invention

[0005] The purpose of this invention is to provide a barley-oat gliadin fiber membrane, its preparation method, and its uses.

[0006] This invention provides a barley-oat prolysin fiber membrane, which comprises the following raw materials: barley prolysin, oat prolysin, glycerol, and phospholipid compounds; the total mass ratio of the barley prolysin and oat prolysin to the mass ratio of glycerol and phospholipid compounds is (20~30):(1.5~3.5):(1~3).

[0007] Furthermore, the total mass ratio of the barley prolysin and oat prolysin to the mass ratio of glycerol and phospholipids is 25:2.5:(1~3).

[0008] Furthermore, the characteristic is that the mass ratio of barley prolysin to oat prolysin is (6~8):(2~4).

[0009] Furthermore, the mass ratio of barley prolysin to oat prolysin is 6:4; the phospholipid compound is dehydrolecithin.

[0010] Further, the barley prolysin is prepared by the following method: dried barley lees are pulverized and sieved, the sieved sample is added to an organic solvent, stirred and heated, centrifuged, the supernatant is added to water to precipitate, the precipitate is collected by centrifugation and freeze-dried to obtain barley prolysin; the oat prolysin is prepared by the following method: oat rice is ground and sieved, then soaked in petroleum ether to defatted oat flour, the defatted oat flour is weighed and added to an organic solvent, stirred and centrifuged, the supernatant is added to water to precipitate, the precipitate is collected by centrifugation and freeze-dried to obtain oat prolysin.

[0011] Further, the organic solvent includes ethanol, isopropanol, or n-propanol; in the preparation of barley prolysin, the drying temperature of barley lees is 60-80℃, the sieve is 30-50 mesh, the ratio of the sieved sample to the organic solvent is 1:(8-12) g / ml, the heating temperature is 35-45℃, and the time is 100-150 minutes; in the preparation of oat prolysin, the sieve is 70-90 mesh, the petroleum ether soaking and defatting temperature is 4-25℃, the ratio of defatted oat flour to organic solvent is 1:(8-12) g / ml, the stirring temperature is 2-6℃, and the time is 2-4 hours.

[0012] Furthermore, it also includes raw material antibacterial agents.

[0013] Furthermore, the ratio of the mass of the antibacterial agent to the total mass of barley prolysin and oat prolysin is (20~30) : (0.1~1).

[0014] Furthermore, the ratio of the mass of the antibacterial agent to the total mass of barley prolysin and oat prolysin is 25:0.5; the antibacterial agent includes at least one of eugenol, eugenol, cinnamaldehyde, thymol, carvacrol, and citral.

[0015] The present invention also provides a method for preparing a barley-oat prolysin fiber membrane, which is prepared by adding barley prolysin and oat prolysin to an organic acid solution containing glycerol and phospholipids, or adding barley prolysin and oat prolysin to an organic acid solution containing glycerol, phospholipids, and an antibacterial agent, and then obtaining the barley-oat prolysin fiber membrane by electrospinning.

[0016] Furthermore, the organic acid solution includes at least one of ethanol, acetic acid, formic acid, and lactic acid.

[0017] This invention also provides the use of barley-oat gliadin fiber membranes in the food packaging field.

[0018] This invention involves blending barley prolysin and oat prolysin in a specific ratio, adding glycerol, phospholipids, and an antibacterial agent. The resulting barley-oat prolysin fiber membrane, formed through electrospinning, exhibits excellent mechanical, water-blocking, and antibacterial properties. Its tensile strength reaches 179.33–187.26 kPa, elongation at break reaches 19.25–25.81%, contact angle reaches 138.81–141.02°, and inhibition zone diameter reaches 17.53–19.12 mm. Compared to barley-corn prolysin fiber membranes, barley-millet prolysin fiber membranes, and barley-sorghum prolysin fiber membranes, it demonstrates significantly improved mechanical, water-blocking, and antibacterial properties. Furthermore, the phospholipids also significantly influence the mechanical, water-blocking, and antibacterial properties of the barley-oat prolysin fiber membrane. This invention successfully prepared an edible nanofiber membrane with excellent mechanical properties, water-blocking properties, and antibacterial properties. The preparation method is simple to operate, safe and environmentally friendly, and under mild conditions. It not only effectively improves the performance of nanofiber membranes, but also provides a new technical path for the green and sustainable development of the food packaging industry.

[0019] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions, or alterations can be made without departing from the basic technical concept of the present invention.

[0020] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Detailed Implementation

[0021] The raw materials and equipment used in this invention are all known products, obtained by purchasing commercially available products.

[0022] In this embodiment of the invention, β-cyclodextrin, hydrogenated lecithin, lecithin, glycerol, and eugenol were purchased from Aladdin Reagent Company; zein was purchased from Sigma Company.

[0023] In this embodiment of the invention, barley prolysin, oat prolysin, millet prolysin, and sorghum prolysin are prepared by the following methods: 1. Preparation of barley prolysin: Barley lees were dried to a fixed weight at 70°C in an electric drying oven (DHG-9070B, Jinan, China); the dried sample was pulverized and passed through a 40-mesh sieve; 100g of the sieved sample was added to 1000ml of 75% ethanol aqueous solution and stirred with a magnetic stirrer for 5min; then heated in a 40°C water bath (HH-S6, Jinan, China) for 120min, followed by centrifugation at 5000g for 15min, the supernatant was poured into a 20L stainless steel pot, 8L of water was added, barley prolysin was precipitated, and finally centrifuged at 5000g for 15min, the precipitate was collected and freeze-dried to a fixed weight to obtain barley prolysin.

[0024] 2. Preparation of oat gliadin: Oat rice was ground and passed through an 80-mesh sieve, and then defatted by soaking in petroleum ether at 10℃ to obtain defatted oat flour; 100g of defatted oat flour was weighed, 1000ml of 75% ethanol solution was added, and the mixture was magnetically stirred at 4℃ for 3h, then centrifuged at 10000r / min for 15min to separate the supernatant (gliadin solution) and precipitate. After adding 2000ml of deionized water, the supernatant was centrifuged at 5000g for 15min, the precipitate was collected and freeze-dried to a fixed weight to obtain oat gliadin.

[0025] 3. Preparation of millet prolysin: Millet was ground and passed through an 80-mesh sieve, and then defatted by soaking in petroleum ether at 10℃ to obtain defatted millet flour; 100g of defatted millet flour was weighed, 1000ml of 75% ethanol solution was added, and the mixture was magnetically stirred at 4℃ for 3h, then centrifuged at 10000r / min for 15min to separate the supernatant (prolysin solution) and precipitate. After adding 2000ml of deionized water, the supernatant was centrifuged at 5000g for 15min, the precipitate was collected and freeze-dried to a fixed weight to obtain millet prolysin.

[0026] 4. Preparation of sorghum prolysin: Sorghum seeds were ground and passed through an 80-mesh sieve, and then defatted by soaking in petroleum ether at 10℃ to obtain defatted sorghum powder; 100g of defatted sorghum powder was weighed, 1000ml of 75% ethanol solution was added, and the mixture was magnetically stirred at 4℃ for 3h, then centrifuged at 10000r / min for 15min to separate the supernatant (prolysin solution) and precipitate. The supernatant after adding 2000ml of deionized water was centrifuged at 5000g for 15min, the precipitate was collected and freeze-dried to a fixed weight to obtain sorghum prolysin.

[0027] Example 1: Preparation of barley-oat gliadin fiber membrane Barley prolysin and oat prolysin were added to acetic acid containing 2.5 wt% glycerol, 3 wt% dehydrolecithin, and 0.5 wt% eugenol at a mass ratio of 6:4, with a total protein mass concentration of 25%. The mixture was magnetically stirred at 25°C and 500 rpm for 30 min. Nanofibers were then prepared on an electrospinning machine (HZ-11) with a voltage of 17 kV and the distance from the needle tip to the current collector maintained at 13 cm. The electrospun membrane was then peeled off and set aside for later use, which is the barley-oat prolysin fiber membrane.

[0028] Example 2: Preparation of barley-oat gliadin fiber membrane Referring to Example 1, the only difference is that the mass ratio of barley prolysin to oat prolysin is 8:2.

[0029] Example 3: Preparation of barley-oat gliadin fiber membrane Referring to Example 1, the only difference is that the mass fraction of dehydrolecithin is 1 wt%.

[0030] Comparative Example 1: Preparation of Barley-Zephyll-Based Protein Fiber Membrane Referring to Example 1, the only difference is that oat gliadin is replaced with zein.

[0031] Comparative Example 2: Preparation of Barley-Oat Glycolyl Fiber Membrane Referring to Example 1, the only difference is that dehydrolecithin is replaced with lecithin.

[0032] Comparative Example 3: Preparation of Barley-Oat Glycolyl Fiber Membrane Refer to Example 1, except that dehydrolecithin is not added.

[0033] Comparative Example 4: Preparation of Barley-Oat Glycolyte Fiber Membrane Referring to Example 1, the only difference is that dehydrolecithin is replaced with β-cyclodextrin.

[0034] Comparative Example 5: Preparation of Barley-Millet Glycoprotein Fiber Membrane Referring to Example 1, the only difference is that oat gliadin is replaced with millet gliadin.

[0035] Comparative Example 6: Preparation of Barley-Sorghum Glycol Protein Fiber Membrane Referring to Example 1, the only difference is that oat gliadin is replaced with sorghum gliadin.

[0036] Comparative Example 7: Preparation of Barley Glycol Protein Fiber Membrane Refer to Example 1, except that oat gliadin is not added.

[0037] Comparative Example 8: Preparation of Oat Glycoprotein Fiber Membrane Refer to Example 1, except that barley prolysin is not added.

[0038] Experimental Example 1: Performance Testing of Glycol-Soluble Protein Fiber Membranes 1. Experimental Methods (1) Mechanical property test: The fiber membrane was cut into strips of 5mm×30mm and tensile test was performed using a yarn fiber tensile tester. The clamping length of the sample was 10mm and the tensile speed was 10mm / min.

[0039] (2) Wettability test: The static contact angle of the fiber membrane was measured using an OCA25 contact angle meter, and the surface hydrophobicity of the fiber web was characterized by the angle.

[0040] (3) Antibacterial performance test: Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus were selected as research subjects. The fiber membrane was made into a 5 mm diameter disc using a punch and sterilized under ultraviolet light for 30 min; 100 μL of bacterial suspension (1×106 CFU / mL) was evenly spread on the sterilized culture medium, and then the fiber membrane was attached to the surface of the culture medium and incubated in a constant temperature incubator at 37℃ for 24 h. The diameter of the inhibition zone was measured with vernier calipers.

[0041] 2. Experimental Results As shown in Table 1, the mechanical and antibacterial properties of the barley-oat prolysin fiber membranes prepared in Examples 1-3 were significantly higher than those of the fiber membranes prepared in Comparative Examples 1-8. Specifically, compared to the barley-corn prolysin fiber membrane of Comparative Example 1, the barley-oat prolysin fiber membranes prepared in Examples 1-3 exhibited significantly higher tensile strength (37.32%-39.98%), higher elongation at break (57.14%-68.04%), larger contact angle (22.3%-23.51%), and larger antibacterial zone diameter (50.03%-54.18%). Compared to the barley-sorghum prolysin fiber membrane of Comparative Example 6, their tensile strength was increased by 47.09%-49.33%, their elongation at break was increased by 60.21%-70.32%, and their contact angle increased by 8.57%. The diameter of the inhibition zone increased by 21.96% to 28.45%; the barley-oat prolysin fiber membrane showed significantly improved mechanical properties, water-blocking properties, and antibacterial properties compared to the barley-corn / sorghum prolysin fiber membrane; compared to the barley-millet prolysin fiber membrane of Comparative Example 5, its tensile strength increased by 42.38% to 44.81%, its elongation at break increased by 68.47% to 76.48%, and its inhibition zone diameter increased by 41.64% to 46.50%. The barley-oat prolysin fiber membrane showed significantly improved mechanical properties and antibacterial properties compared to the barley-millet prolysin fiber membrane. Meanwhile, the mechanical properties of the fiber membranes in Comparative Examples 1 and 5-6 were worse than those of the barley prolysin fiber membrane in Comparative Example 7, and the water-blocking performance of the barley-corn prolysin fiber membrane was also lower. This further indicates that the combination of corn, millet, and sorghum prolysins with barley prolysins in the method of this invention is actually detrimental to the performance of the fiber membrane. The experimental results show that only the combination of barley prolysins and oat prolysins can yield a fiber membrane with excellent mechanical properties, water-blocking properties, and antibacterial properties.

[0042] Compared with Comparative Examples 2-4, Examples 1-3 showed that in Comparative Example 2, replacing dehydrolecithin with lecithin significantly reduced the mechanical properties, water-blocking properties, and antibacterial properties of the barley-oat gliadin fiber membrane. In Comparative Example 3, without dehydrolecithin, the mechanical properties and water-blocking properties were further reduced compared to Comparative Example 2, and the antibacterial properties were also significantly reduced compared to Examples 1-3. In Comparative Example 4, replacing dehydrolecithin with β-cyclodextrin also significantly reduced the mechanical properties, water-blocking properties, and antibacterial properties. This indicates that dehydrolecithin has a significant impact on the mechanical properties, water-blocking properties, and antibacterial properties of the barley-oat gliadin fiber membrane.

[0043] Table 1 Performance test results of alcohol-soluble protein fiber membranes In summary, the barley-oat prolysin fiber membrane formed by electrospinning a mixture of barley prolysin and oat prolysin in a certain proportion with the addition of glycerol, hydrogenated lecithin, and eugenol exhibits excellent mechanical properties, water-blocking properties, and antibacterial properties. Compared with barley-corn prolysin fiber membranes, barley-millet prolysin fiber membranes, and barley-sorghum prolysin fiber membranes, it shows significantly improved mechanical properties, water-blocking properties, and antibacterial properties. Furthermore, dehydrolecithin also has a significant impact on the mechanical properties, water-blocking properties, and antibacterial properties of the barley-oat prolysin fiber membrane.

Claims

1. A highland barley-oat prolamin fiber film, characterized in that, It includes the following raw materials: barley prolysin, oat prolysin, glycerol, and phospholipids; the total mass ratio of the barley prolysin and oat prolysin to the mass ratio of glycerol and phospholipids is (20~30):(1.5~3.5):(1~3).

2. The highland barley-oat prolamin fiber film according to claim 1, characterized in that, The total mass ratio of barley prolysin and oat prolysin to the mass ratio of glycerol and phospholipids is 25:2.5:(1~3).

3. The highland barley-oat prolamin fiber film according to any one of claims 1-2, characterized in that, The mass ratio of barley prolysin to oat prolysin is (6~8):(2~4).

4. The highland barley-oat prolamin fiber film according to claim 3, characterized in that, The mass ratio of barley prolysin to oat prolysin is 6:4; the phospholipid compound is dehydrolecithin.

5. The highland barley-oat prolamin fiber film according to claim 3, characterized in that, The barley prolysin is prepared as follows: dried barley lees are pulverized and sieved. The sieved sample is added to an organic solvent, stirred and heated, centrifuged, and the supernatant is added to water to precipitate. The precipitate is collected by centrifugation and then freeze-dried to obtain barley prolysin. The oat prolysin is prepared as follows: oat rice is ground and sieved, then soaked in petroleum ether to defatted oat flour. The defatted oat flour is weighed and added to an organic solvent, stirred and centrifuged, and the supernatant is added to water to precipitate. The precipitate is collected by centrifugation and then freeze-dried to obtain oat prolysin.

6. The highland barley-oat prolamin fiber film according to claim 1, characterized in that, It also includes raw material antibacterial agents.

7. The highland barley-oat prolamin fiber film according to claim 6, characterized in that, The ratio of the mass of the antibacterial agent to the total mass of barley prolysin and oat prolysin is (20~30) : (0.1~1).

8. The highland barley-oat prolamin fiber film according to claim 7, characterized in that, The mass ratio of the antibacterial agent to the total mass of barley prolysin and oat prolysin is 25:0.5; the antibacterial agent includes at least one of eugenol, eugenol, cinnamaldehyde, thymol, carvacrol, and citral.

9. The method for preparing the barley-oat prolysin fiber membrane according to any one of claims 1 to 8, characterized in that, The barley-oat prolysin fiber membrane was prepared by adding barley prolysin and oat prolysin to an organic acid solution containing glycerol and phospholipids, or by adding barley prolysin and oat prolysin to an organic acid solution containing glycerol, phospholipids, and antibacterial agents, and then preparing the membrane by electrospinning.

10. The use of the barley-oat gliadin fiber film according to any one of claims 1 to 8 in the field of food packaging.

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