High-performance whey protein-potassium alginate composite edible film and preparation method thereof
A high-performance biodegradable composite edible preservation film was prepared by combining whey protein with potassium alginate and adjusting with glycerol. This method solved the problem of poor toughness of whey protein film, improved mechanical properties and preservation effect, and reduced the harm caused by the use of petrochemical plastics.
Patent Information
- Application Number
- CN202511100710.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-11-18
AI Technical Summary
Existing whey protein membranes are tough and easily broken, and there is a lack of effective improvement methods to enhance their mechanical and preservation properties. The environmental and health hazards of petrochemical plastic products are also becoming increasingly prominent, necessitating the development of safe, edible, and biodegradable alternatives.
A composite edible preservation film was prepared by solution casting using a combination of whey protein and potassium alginate. Glycerin was added as a plasticizer, and the pH of the film-forming solution was adjusted to improve the cross-linking of whey protein and potassium alginate, thereby enhancing the mechanical properties and water permeability of the film.
A high-performance, biodegradable whey protein-potassium alginate composite edible film was prepared, which improved the mechanical properties and water permeability of the film, effectively protecting food and reducing harm to the environment and health.
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Figure CN120966054A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of edible film materials, and particularly relates to a high-performance whey protein-potassium alginate composite edible film and a preparation method thereof. BACKGROUND
[0002] An edible film is a kind of film formed by using natural edible materials as raw materials, adding edible plasticizers, reducing agents and crosslinking agents, and covering the surface (or the inside) of food in the form of wrapping, coating, microcapsule and the like, so as to achieve the effect of blocking the penetration of water vapor, oxygen or various solutes. At present, edible film preservation is one of the research hotspots of food preservation technology. By uniformly covering the surface of food with an edible film, not only can the biochemical reaction between water molecules and oxygen in the air and food be reduced, but also the respiration and transpiration of food and the loss of nutrients can be reduced, thereby playing a role in preserving food. Compared with traditional plastic food packaging materials, edible film packaging materials have the advantages of wide source, easy processing, good physical and mechanical properties, biodegradability, safety and environmental protection and the like.
[0003] Whey protein is a kind of protein rich in amino acids and has high nutritional value, good film-forming property, certain mechanical property and good gas barrier property. However, single whey protein film has poor toughness and is easy to break, and there are still many deficiencies in practical application. In recent years, it has been found that a composite coating film composed of multiple components can not only retain the advantages of each component in the film-forming matrix, but also improve and enhance the deficiencies of single film-forming agent in mechanical property and preservation performance, so as to better meet the needs of packaging and preservation of different foods. Studies have shown that the addition of natural polysaccharide substances to protein film-forming agents can impart good transparency and gas barrier property to edible films, and effectively improve the mechanical strength of edible films, thereby optimizing and enhancing the overall performance of edible films. For example, it has been found that the addition of chitosan to whey protein can significantly improve the tensile strength of edible film and improve the performance of moisture barrier.
[0004] At present, due to the harm of petrochemical plastic products to the environment and human body, the "white pollution" has been widely concerned and has become the consensus of the society, and therefore it is inevitable to reduce and replace the use of petrochemical plastic products in food. In order to solve this problem, people have developed safe and edible and degradable new preservative films. In recent years, whey protein, as a kind of protein with nutritional value and film-forming property, can be compounded with various natural polysaccharides to build food preservative films, showing potential application value. However, there is no technical method for developing a whey protein film by compounding potassium alginate with whey protein to improve the whey protein film, and there is no report on the use of the same for improving the performance of the whey protein film. SUMMARY
[0005] The present application aims to provide an edible and degradable whey protein-potassium alginate protein polysaccharide composite food preservative film with good preservation capacity, and a preparation method of the preservative film, so as to realize the industrialization of the edible and degradable preservative film, and reduce the potential harm of traditional petrochemical plastic packaging film to the environment and the health of consumers.
[0006] To achieve the application target, the present application adopts the following technical solution steps:
[0007] Step S1, dissolve whey protein in deionized water, heat and stir to obtain a whey protein solution;
[0008] Step S2, add potassium alginate to the whey protein solution, heat and stir to obtain a whey protein-potassium alginate mixed solution;
[0009] Step S3, add glycerol to the mixed solution of step S2, continue to heat and stir to obtain a whey protein-potassium alginate-glycerol mixed solution;
[0010] Step S4, adjust the pH of the film-forming solution obtained in step S3, and then naturally cool to room temperature and stand to obtain a uniform film-forming solution;
[0011] Step S5, ultrasonic treatment is performed on the film-forming solution obtained in step S4 to eliminate air bubbles in the film-forming solution;
[0012] Step S6, pour the film-forming solution obtained in step S5 into a culture dish and place it in an oven for low-temperature baking, and then take it out and peel off after the film is completely dried.
[0013] In step S1, the dosage ratio of whey protein to deionized water is 2-10 g / 100 mL, and the heating temperature is 50-90 DEG C.
[0014] In step S2, the dosage ratio of potassium alginate to deionized water is 0.4-1.6 g / 100 mL, and the heating temperature is 50-90 DEG C.
[0015] In step S3, the dosage ratio of glycerol to deionized water is 2-10 g / 100 mL, and the heating temperature is 50-90 DEG C.
[0016] In step S4, the pH of the film-forming solution is adjusted, and the pH adjustment range is 6-10.
[0017] In step S5, the temperature of the oven is 40-80 DEG C.
[0018] A high-performance degradable whey protein-potassium alginate composite edible preservative film is prepared by the above preparation method.
[0019] Compared with the prior art, the technical solution of the present application has the following beneficial effects:
[0020] This invention combines whey protein and potassium alginate, two edible and biodegradable materials, and prepares a high-performance biodegradable composite edible preservation film via solution casting. By changing the blending ratio of whey protein and potassium alginate, the mechanical properties and water permeability of the film are improved, allowing it to maintain good performance under different humidity environments and effectively protect food.
[0021] This invention improves the mechanical and water permeability properties of the film by adding the plasticizer glycerin. Furthermore, by adjusting the pH of the film-forming solution, this invention regulates the microstructure of whey protein and improves the protein-polysaccharide cross-linking of whey protein and potassium alginate, thereby further improving the mechanical and water permeability of the film and enhancing its protective ability for food. Attached Figure Description
[0022] Figure 1 The effect of potassium alginate addition on water vapor permeability and tensile strength;
[0023] Figure 2 This is a diagram showing the apparent state of the composite film-forming solution;
[0024] Figure 3 This is a diagram showing the state of the composite edible plastic wrap during drying;
[0025] Figure 4 Infrared spectra of whey protein, potassium alginate, and the composite membrane. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below.
[0028] Example 1
[0029] Whey protein was added to deionized water to make the whey protein solution concentration 8% (w / v). The solution was heated and stirred until completely dissolved at 80°C. Potassium alginate was added to the whey protein solution to make the potassium alginate concentration 0.8% (w / v). The solution was heated and stirred until completely dissolved at 80°C. 4% (w / v) of glycerol was added to the whey protein-potassium alginate mixture to form a film, and the pH was adjusted to 7. The mixture was kept at a constant temperature of 80°C and stirred continuously until the film-forming solution was homogeneous. Heating and stirring were then stopped, and the film-forming solution was allowed to stand and cool to room temperature. The cooled film-forming solution was poured into petri dishes for casting and placed in a 60°C oven. After the film was completely dry, it was removed and peeled off to obtain the whey protein-potassium alginate composite film.
[0030] Example 2
[0031] Whey protein was added to deionized water to make the whey protein solution concentration 8% (w / v). The solution was heated and stirred until completely dissolved at 80°C. Potassium alginate was added to the whey protein solution to make the potassium alginate concentration 0.9% (w / v). The solution was heated and stirred until completely dissolved at 80°C. 4% (w / v) glycerol was added to the whey protein-potassium alginate mixture to form a film, and the pH was adjusted to 7. The mixture was kept at a constant temperature of 80°C and stirred continuously until the film-forming solution was homogeneous. Heating and stirring were then stopped, and the film-forming solution was allowed to stand and cool to room temperature. The cooled film-forming solution was poured into petri dishes for casting and placed in a 60°C oven. After the film was completely dry, it was removed and peeled off to obtain the whey protein-potassium alginate composite film.
[0032] Example 3
[0033] Whey protein was added to deionized water to make the whey protein solution concentration 8% (w / v). The solution was heated and stirred until completely dissolved at 80°C. Potassium alginate was added to the whey protein solution to make the potassium alginate concentration 1.0% (w / v). The solution was heated and stirred until completely dissolved at 80°C. 4% (w / v) of glycerol was added to the whey protein-potassium alginate mixture to form a film, and the pH was adjusted to 7. The mixture was kept at a constant temperature of 80°C and stirred continuously until the film-forming solution was homogeneous. Heating and stirring were then stopped, and the film-forming solution was allowed to stand and cool to room temperature. The cooled film-forming solution was poured into petri dishes for casting and placed in a 60°C oven. After the film was completely dry, it was removed and peeled off to obtain the whey protein-potassium alginate composite film.
[0034] Example 4
[0035] Whey protein was added to deionized water to make the whey protein solution concentration 8% (w / v). The solution was heated and stirred until completely dissolved at 80°C. Potassium alginate was added to the whey protein solution to make the potassium alginate concentration 1.1% (w / v). The solution was heated and stirred until completely dissolved at 80°C. 4% (w / v) of glycerol was added to the whey protein-potassium alginate mixture to form a film, and the pH was adjusted to 7. The mixture was kept at a constant temperature of 80°C and stirred continuously until the film-forming solution was homogeneous. Heating and stirring were then stopped, and the film-forming solution was allowed to stand and cool to room temperature. The cooled film-forming solution was poured into petri dishes for casting and placed in a 60°C oven. After the film was completely dry, it was removed and peeled off to obtain the whey protein-potassium alginate composite film.
[0036] Example 5
[0037] Whey protein was added to deionized water to make the whey protein solution concentration 8% (w / v). The solution was heated and stirred until completely dissolved at 80°C. Potassium alginate was added to the whey protein solution to make the potassium alginate concentration 1.2% (w / v). The solution was heated and stirred until completely dissolved at 80°C. 4% (w / v) of glycerol was added to the whey protein-potassium alginate mixture to form a film, and the pH was adjusted to 7. The mixture was kept at a constant temperature of 80°C and stirred continuously until the film-forming solution was homogeneous. Heating and stirring were then stopped, and the film-forming solution was allowed to stand and cool to room temperature. The cooled film-forming solution was poured into petri dishes for casting and placed in a 60°C oven. After the film was completely dry, it was removed and peeled off to obtain the whey protein-potassium alginate composite film.
[0038] Experimental Section
[0039] (a) Tensile strength
[0040] The composite film was cut into strips 150mm long and 10mm wide, and then subjected to a tensile test on a film stretching machine until it broke. The effective tensile length was set to 50mm, and the stretching speed was set to 5mm / min. Before the test, the film was equilibrated for 1 day at 23℃ and 40% relative humidity. The tensile strength was calculated using the following formula:
[0041] TS=F / (d·W) Equation 1
[0042] In the formula, TS represents tensile strength, F represents the maximum pressure at which the whey protein composite membrane breaks, d represents the thickness of the whey protein composite membrane, and W represents the width of the whey protein composite membrane.
[0043] (ii) Water vapor transmission rate
[0044] Using the pseudo-cup method, 3.0 g of anhydrous calcium chloride was added to a glass cup (mouth diameter 1.7 cm, depth 3.0 cm). The mouth of the cup was covered with a prepared coating film. The mass of the glass cup after sealing was weighed. The glass cup was then placed in a constant temperature and humidity chamber (25℃, RH 50%). The mass of the glass cup was weighed every 1 hour, and the data was recorded. The measurement was continued for 9 hours. The water vapor transfer rate was expressed as the slope of a plotted curve showing the change in the mass of water vapor passing through the membrane into the glass cup relative to time.
[0045] WVT = F / A (Equation 2)
[0046] In Equation 2, WVT is the water vapor transport rate; F is the slope of the linear graph; and A is the area exposed to vapor transport (m²). 2 .
[0047] WVP=WVT·e / S·(RH1-RH2)·1 Equation 3
[0048] In Equation 3, WVP is the water vapor transmission rate, g·mm / m2·h·KPa; S is the saturation pressure at 25℃, KPa; (RH1-RH2) is the humidity difference between the inside and outside of the cup; and e is the thickness of the membrane, mm.
[0049] (III) Light transmittance
[0050] Select a coating sample with uniform thickness and no damage, cut it into strips of 40mm × 10mm, attach them to the inside of a cuvette, use a dry and clean blank cuvette as a control, set the wavelength of the ultraviolet spectrophotometer to 600nm, and measure the transmittance of the coating sample, and take the average value.
[0051] Figure 1 The effect of potassium alginate addition on water vapor transmission rate and tensile strength was investigated. It was found that with increasing potassium alginate addition, the water vapor transmission rate of the edible film generally increased, reaching its lowest value at 0.9%. Tensile strength, however, showed a trend of first increasing and then decreasing, reaching its maximum value at 1.0%, slightly better than at 0.9%.
[0052] Table 1 shows the effect of potassium alginate addition on the film transmittance. It can be seen that with the increase of potassium alginate addition, the transmittance of the coating first increases and then decreases, reaching its maximum when the potassium alginate addition is 1.0%. The transmittance is second only to the 1.0% addition when the potassium alginate addition is 0.9%. Considering the antioxidant and preservative properties of the coating in practical applications, 0.9% potassium alginate, with its relatively good water vapor transmission rate, should be selected as the most suitable addition amount.
[0053]
[0054] Table 1
[0055] Figure 2 This is a diagram showing the apparent state of the composite film-forming solution. Figure 3 This is a diagram showing the state of the composite edible plastic wrap during drying. Figure 4 Infrared spectra of whey protein, potassium alginate, and the composite membrane.
[0056] The high-performance whey protein-potassium alginate composite edible film and its preparation method provided by this invention have the following advantages:
[0057] This invention combines whey protein and potassium alginate, two edible and biodegradable materials, and prepares a high-performance biodegradable composite edible preservation film via solution casting. By changing the blending ratio of whey protein and potassium alginate, the mechanical properties and water permeability of the film are improved, allowing it to maintain good performance under different humidity environments and effectively protect food.
[0058] This invention improves the mechanical and water permeability properties of the film by adding the plasticizer glycerin. Furthermore, by adjusting the pH of the film-forming solution, this invention regulates the microstructure of whey protein and improves the protein-polysaccharide cross-linking of whey protein and potassium alginate, thereby further improving the mechanical and water permeability of the film and enhancing its protective ability for food.
[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a high-performance biodegradable whey protein-potassium alginate composite edible preservation film, characterized in that, Includes the following steps: Step S1: Dissolve whey protein in deionized water, heat and stir to obtain whey protein solution; Step S2: Add potassium alginate to the whey protein solution, and continue heating and stirring to obtain a whey protein-potassium alginate mixed solution; Step S3: Add glycerol to the whey protein-potassium alginate mixed solution, and continue heating and stirring to obtain a whey protein-potassium alginate-glycerol mixed solution; Step S4: Adjust the pH of the whey protein-potassium alginate-glycerol mixed solution, then allow it to cool naturally to room temperature and stand to obtain a uniform film-forming solution. Step S5: The film-forming liquid is subjected to ultrasonic treatment to eliminate air bubbles in the film-forming liquid; Step S6: Pour the film-forming solution obtained in step S5 into a culture dish and place it in an oven for low-temperature baking. After the film is completely dry, remove it and peel it off.
2. The preparation method of a high-performance biodegradable whey protein-potassium alginate composite edible preservation film as described in claim 1, characterized in that: In step 1), the ratio of whey protein to deionized water is 2–10 g / 100 mL, and the heating temperature is 50–90 °C.
3. The preparation method of a high-performance biodegradable whey protein-potassium alginate composite edible preservation film as described in claim 1, characterized in that: In step S2, the ratio of potassium alginate to deionized water is 0.4–1.6 g / 100 mL, and the heating temperature is 50–90 °C.
4. The preparation method of a high-performance biodegradable whey protein-potassium alginate composite edible preservative film as described in claim 1, characterized in that: In step S3, the ratio of glycerol to deionized water is 2–10 g / 100 mL, and the heating temperature is 50–90 °C.
5. The preparation method of a high-performance biodegradable whey protein-potassium alginate composite edible preservation film as described in claim 1, characterized in that: In step S4, the pH of the film-forming solution is adjusted, with the pH adjustment range being 6-10.
6. The preparation method of a high-performance biodegradable whey protein-potassium alginate composite edible preservation film as described in claim 1, characterized in that: In step S6, the temperature of the oven is 40–80°C.
7. A high-performance biodegradable whey protein-potassium alginate composite edible preservation film, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 6.
8. The application of the high-performance biodegradable whey protein-potassium alginate composite edible preservation film according to claim 7, characterized in that: Used for food packaging films.