Sodium alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fillets
By using the combination of oligosaccharide zinc complex and brown algae in the fish fillet packaging materials, the existing packaging materials are solved, and the effective antibacterial and extended shelf life of fish fillets is achieved.
Patent Information
- Application Number
- CN202510080736.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-04-25
AI Technical Summary
The existing fish fillet packaging materials are costly, limited resources and non-degradable, making it difficult to effectively inhibit aquatic product corruption, resulting in environmental pollution and food safety issues.
A brown algae membrane containing a chitosaccharide zinc complex was developed, and the chitosaccharide zinc complex was synthesized by alcohol precipitation and dialysis, and mixed with brown algae and glycerol to prepare a film with antibacterial and mechanical strength through casting, calcification and drying processes.
This membrane has excellent antibacterial activity for refrigeration and preservation of fish fillets, which can effectively extend the shelf life of fish fillets, and also has the advantages of rich resources, environmental protection, non-toxic, biodegradable and sustainable antibacterial.
Smart Images
Figure CN119875168A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of aquatic product preservation, and in particular relates to an alginate film containing a chitosan oligosaccharide zinc complex for refrigerating and preserving fish fillets. Background Art
[0002] Aquatic products are generally considered to be a healthy source of nutrition due to their high content of protein and polyunsaturated fatty acids and rich mineral elements. During the storage of aquatic products, spoilage bacteria can fully utilize nutrients such as glycogen and its decomposition products, protein and its amino acids, fat and its fatty acids, and decompose them into small molecules such as organic alcohols, aldehydes, and acids through extracellular proteases and lipolytic enzymes, which are the key factors causing the spoilage of aquatic products.
[0003] Antimicrobial materials can directly contact with the food surface or release antimicrobial substances to the food surface, causing the destruction of the cell wall and cell membrane structure of bacteria and other microorganisms, or chemically reacting with certain enzymes in the cells, causing small molecules such as adenosine triphosphate, nucleotides and amino acids to quickly flow out of the bacterial cells, thereby causing the bacterial cells to lyse and die. In addition, some antimicrobial active substances can inhibit cell respiration, interfere with cell metabolism, and cause bacterial inactivation.
[0004] The chemical structure of chitosan oligosaccharide (COS) contains a large number of active -NH2 and -OH, which makes it easier to graft active functional groups to form a variety of derivatives and synthesize new chitosan oligosaccharide derivatives with excellent antibacterial activity. Zhao Hui et al. used chitosan oligosaccharide as the skeleton, introduced glycidol and trimethylammonium chloride on the amino group to form chitosan oligosaccharide quaternary ammonium salt, and obtained amphiphilic chitosan oligosaccharide quaternary ammonium salt with both hydrophilic and hydrophobic groups by introducing alkyl hydrophobic side chain groups, and showed good antibacterial properties. The total colony count of E. coli treated with amphiphilic chitosan oligosaccharide quaternary ammonium salt reached a minimum of 1.95×105 CFU / mL, and the more hydrophobic functional groups grafted, the better the antibacterial effect. Yuan Xiaoxian et al. used chitosan oligosaccharide and 2,4-dichlorophenoxyacetic acid as raw materials to obtain the product chitosan oligosaccharide-O-2,4-dichlorophenoxyacetic acid. By inserting antibacterial carboxyl groups on the hydroxyl groups of chitosan oligosaccharide and retaining the amino groups with antibacterial activity in chitosan oligosaccharide, the antibacterial activity of chitosan oligosaccharide can be improved to the greatest extent. The study found that chitosan oligosaccharide-O-2,4-dichlorophenoxyacetic acid showed inhibitory effects on both E. coli and S. aureus. The antibacterial activity of chitosan oligosaccharide-O-2,4-dichlorophenoxyacetic acid on E. coli was 1.86~2.20 times that of COS, and the antibacterial activity of chitosan oligosaccharide on S. aureus was 1.38~1.58 times that of COS.
[0005] At present, the packaging materials for fish fillets are all made of polymer compounds, which are costly and have limited resources. At the same time, they are poorly degradable and cannot be naturally decomposed, which can easily cause serious environmental pollution. Therefore, the development of sustainable antibacterial materials that are rich in resources, environmentally friendly, non-toxic, and biodegradable has become a research hotspot. So far, there has been no report on alginate films containing chitosan oligosaccharide zinc complexes with good antibacterial effects that can be used for the refrigeration and preservation of fish fillets. Summary of the invention
[0006] The present invention aims to solve the above technical problems existing in the prior art and provides an alginate film containing a chitosan oligosaccharide zinc complex for refrigerating and preserving fish fillets.
[0007] The technical solution of the present invention is: an alginate film containing a chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets is prepared according to the following steps: Step 1. Mix chitosan oligosaccharide and zinc salt solution for reaction, and obtain chitosan oligosaccharide zinc complex by alcohol precipitation and dialysis; Step 2. uniformly mixing the alginate solution, the chitosan oligosaccharide zinc complex and glycerol to obtain a mixed solution; Step 3. Casting the mixed solution into a film-forming mold, adding CaCl2 solution for calcification after drying to obtain an alginate film blank; Step 4. After the alginate film blank is dried, an alginate film containing chitosan oligosaccharide zinc complex is obtained.
[0008] Preferably, in step 1, chitosan oligosaccharide and zinc salt solution are mixed for reaction by ultrasonically mixing chitosan oligosaccharide and zinc salt in a mass ratio of 1-3:1-3, and reacting for 1-5 hours at a temperature of 25-65° C. and a pH of 2-6.
[0009] Preferably, the mass concentration of the alginate solution in step 2 is 0.5-3%, the dosage ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 5-15 mg / mL, and the volume ratio of the glycerol to the alginate solution is 10-50%.
[0010] Preferably, the drying temperature of step 3 is 25-65° C., and the drying time is 1-5 h; the mass concentration of the CaCl 2 solution is 1-10%, and the calcification time is 1-5 min.
[0011] Preferably, the drying temperature in step 4 is 25-65° C., and the drying time is 1-3 h.
[0012] Preferably, the viscosity of the alginate is greater than 900 mPa•s; and the molecular weight of the chitosan oligosaccharide is 1 kDa-3 kDa.
[0013] The invention uses chitosan oligosaccharide as a raw material, adopts a low-temperature liquid phase synthesis method to synthesize a chitosan oligosaccharide-zinc complex, adjusts the antibacterial property of the complex by adjusting the zinc ion binding amount, then adds the chitosan oligosaccharide-zinc complex into an alginate solution, uses glycerol as a cross-linking agent, and obtains an alginate film after casting, calcification, and drying. The alginate film not only has excellent antibacterial activity against positive bacteria and negative bacteria of aquatic product corruption, but also has high mechanical strength, can be used as an outer packaging material for fish fillets for refrigeration and preservation of fish fillets, and has the advantages of abundant resources, environmental protection, non-toxicity, biodegradability, sustainable antibacterial, etc. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is the XRD diagram of the chitosan oligosaccharide zinc complex prepared in Examples 1 and 2 of the present invention.
[0015] Figure 2 It is the infrared spectrum of the chitosan oligosaccharide zinc complex prepared in Example 1 of the present invention.
[0016] Figure 3 The graph is a curve showing the change of TVBN value when the alginate film prepared in Examples 1 and 2 of the present invention is used for refrigerated preservation of fish fillets. DETAILED DESCRIPTION
[0017] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. Example 1
[0018] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonication at a mass ratio of 1:3, reacted at 25°C and pH=5 for 3 hours, and chitosan oligosaccharide zinc complex is obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 4 hours to obtain a mixed solution; the mass concentration of the alginate solution is 2%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 10 mg / mL, and the volume ratio of the glycerol to the alginate solution is 40%.
[0019] Step 3. Cast the mixed solution into a film-forming mold, dry at 40°C for 4 hours, and then add a 4% CaCl2 solution for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 30° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex. Example 2
[0020] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt were respectively mixed by ultrasonication at a mass ratio of 1:1, reacted at 30°C and pH = 4 for 3 hours, and chitosan oligosaccharide zinc complex was obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 5 hours to obtain a mixed solution; the mass concentration of the alginate solution is 2%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 15 mg / mL, and the volume ratio of the glycerol to the alginate solution is 30%; Step 3. Cast the mixed solution into a film-forming mold, dry at 40°C for 4 hours, and then add a 4% CaCl2 solution for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 30° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex. Example 3
[0021] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonication at a mass ratio of 3:1, reacted at 40°C and pH=3 for 5 hours, and chitosan oligosaccharide zinc complex is obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 5 hours to obtain a mixed solution; the mass concentration of the alginate solution is 2%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 10 mg / mL, and the volume ratio of the glycerol to the alginate solution is 40%; Step 3. Cast the mixed solution into a film-forming mold, dry at 40°C for 4 hours, and then add a 4% CaCl2 solution for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 30° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex. Example 4
[0022] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonication at a mass ratio of 1:2, reacted at 35°C and pH 6 for 1 hour, and chitosan oligosaccharide zinc complex is obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 5 hours to obtain a mixed solution; the mass concentration of the alginate solution is 1%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 5 mg / mL, and the volume ratio of the glycerol to the alginate solution is 20%; Step 3. Cast the mixed solution into a film-forming mold, dry at 40°C for 4 hours, and then add a CaCl2 solution with a mass concentration of 8% for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 40° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex. Example 5
[0023] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonication at a mass ratio of 1:2, reacted at a temperature of 30°C and a pH of 6 for 2 hours, and chitosan oligosaccharide zinc complex is obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 5 hours to obtain a mixed solution; the mass concentration of the alginate solution is 3%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 5 mg / mL, and the volume ratio of the glycerol to the alginate solution is 20%; Step 3. Cast the mixed solution into a film-forming mold, dry at 40°C for 4 hours, and then add a CaCl2 solution with a mass concentration of 8% for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 40° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex. Example 6
[0024] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonication at a mass ratio of 1:3, reacted at 25°C and pH=5 for 2 hours, and chitosan oligosaccharide zinc complex is obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 5 hours to obtain a mixed solution; the mass concentration of the alginate solution is 3%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 5 mg / mL, and the volume ratio of the glycerol to the alginate solution is 20%; Step 3. Cast the mixed solution into a film-forming mold, dry at 50°C for 5 hours, and then add a CaCl2 solution with a mass concentration of 8% for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 30° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex. Example 7
[0025] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonication at a mass ratio of 2:3, reacted at 25°C and pH=5 for 2h, and chitosan oligosaccharide zinc complex is obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 5 hours to obtain a mixed solution; the mass concentration of the alginate solution is 3%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 5 mg / mL, and the volume ratio of the glycerol to the alginate solution is 20%; Step 3. Cast the mixed solution into a film-forming mold, dry at 50°C for 5 hours, and then add a 3% CaCl2 solution for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 40° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex. Example 8
[0026] The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets of the present invention is prepared according to the following steps: Step 1. Chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonication at a mass ratio of 3:1, reacted at 40°C and pH=5 for 2h, and chitosan oligosaccharide zinc complex is obtained by alcohol precipitation and dialysis; Step 2. The alginate solution, the chitosan oligosaccharide zinc complex and glycerol are mixed and stirred for 5 hours to obtain a mixed solution; the mass concentration of the alginate solution is 3%, the amount ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 10 mg / mL, and the volume ratio of the glycerol to the alginate solution is 30%; Step 3. Cast the mixed solution into a film-forming mold, dry at 50°C for 5 hours, and then add a 3% CaCl2 solution for calcification for 3 minutes to obtain an alginate film blank; Step 4. Dry the alginate film blank at 40° C. for 1 hour to obtain an alginate film containing chitosan oligosaccharide zinc complex.
[0027] The XRD pattern of the chitosan oligosaccharide zinc complex prepared in Example 1-2 of the present invention is as follows Figure 1 As shown. Figure 1It can be seen that the two main diffraction peaks of chitosan oligosaccharide appear near 2θ=13° and 2θ=22.5°, which basically conform to the characteristic peaks of type I and type II crystal forms of chitosan oligosaccharide, but the diffraction intensity is not large, the crystallinity is not high, and the chitosan oligosaccharide is amorphous. The diffraction peaks of chitosan oligosaccharide zinc complex become narrower and sharper, mainly because the amino groups on the main chain of chitosan oligosaccharide react with zinc ions, resulting in a reduction in free amino groups. In addition to the characteristic absorption peaks of chitosan oligosaccharide, new absorption peaks with relatively high intensity appear at 2θ=8.4° and 33.5°, which may be the crystal absorption peaks of chitosan oligosaccharide complexes with zinc ions. Compared with the JCPDS16-0850 standard card, the diffraction peaks at 2θ=37.8° and 2θ=58.8° are basically consistent with it, indicating that there is still a small amount of zinc chloride remaining. The characteristic peaks of some chitosan oligosaccharides are weakened, mainly because after the chitosan oligosaccharide reacts with zinc ions, the original chain structure is depolymerized and the strong hydrogen bonds are reduced.
[0028] The infrared spectrum of the chitosan oligosaccharide zinc complex prepared in Example 1 of the present invention is as follows Figure 2 As shown. Figure 2 It can be seen that the infrared absorption spectra of chitosan oligosaccharide and chitosan oligosaccharide zinc complex are generally similar. This is because the chitosan oligosaccharide content in the chitosan oligosaccharide zinc complex accounts for a large part and dominates the structure of the complex. -1 It is the stretching vibration of the overlapping peaks of -NH2 and -OH of chitosan oligosaccharide. After coordination with zinc ions, the absorption peak red-shifts to 3390.75 cm -1 At the same time, the absorption peak becomes flat, indicating that -NH2 and -OH participate in the reaction; at 1630 cm-1 is the bending vibration absorption peak of -NH2, after chelating with zinc ions, its absorption peak shifts to a low frequency of 1592.25 cm -1 , indicating that Zn 2+ Forms N-Zn coordination bond with N atom; 1078.49 cm - 1 is the absorption peak of CO stretching vibration of hydroxyl group shifted to 1070 cm -1 ; Chitooligosaccharide is located at 1322 cm -1 The CN vibration stretching peak at 1320 cm -1 The above series of vibrations all undergo red shift. This is because after chitosan oligosaccharide coordinates with zinc ions, the O atom on the active group -OH and the N atom on NH2 transfer part of their electrons to the zinc ion, thereby reducing its electron cloud density and weakening the bond force constant, thereby causing the vibration peak to move to the low wave number band.
[0029] The alginate film prepared in the embodiment of the present invention is used for refrigeration and preservation of fish fillets. Specifically, the alginate film, PE film and SA film prepared in Examples 1 and 2 of the present invention are used as packaging materials for fish fillets, and stored at 4°C for 6 days. The TVBN value of the fish fillets is measured every day. The measurement method is based on GB 5009.228-2016 "National Food Safety Standard Determination of Volatile Basic Nitrogen in Food". The results are as follows Figure 3 As shown in the figure, the results show that as the storage time increases, the TVB-N content of each group of fish fillets shows an upward trend, which further proves that the volatile nitrogen-containing substances produced after the protein is decomposed by enzymes and microorganisms. Among them, the blank group increased most significantly, and the SA film group was close to the national standard limit of 30 mg / 100ml (29.71 mg / 100ml) on the 3rd day, which was close to the odor found in the sensory analysis, and there was a protein rancid smell. Compared with the sodium alginate and commercially available cling film groups, the composite film treatment group exceeded the national standard limit on the 6th day, which can extend the shelf life of refrigerated grass carp by about 2 to 3 days. It can be seen that the addition of the active substance chitosan oligosaccharide zinc complex can effectively reduce the amount of volatile basic nitrogen produced by grass carp during storage, thereby achieving the purpose of extending the shelf life.
Claims
1. An alginate film containing a chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets, characterized in that Prepared according to the following steps: Step 1. Mix chitosan oligosaccharide and zinc salt solution for reaction, and obtain chitosan oligosaccharide zinc complex by alcohol precipitation and dialysis; Step 2. uniformly mixing the alginate solution, the chitosan oligosaccharide zinc complex and glycerol to obtain a mixed solution; Step 3. Casting the mixed solution into a film-forming mold, adding CaCl2 solution for calcification after drying to obtain an alginate film blank; Step 4. After the alginate film blank is dried, an alginate film containing chitosan oligosaccharide zinc complex is obtained.
2. The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets according to claim 1, characterized in that In the step 1, chitosan oligosaccharide and zinc salt solution are mixed for reaction, and chitosan oligosaccharide and zinc salt are respectively mixed by ultrasonic according to a mass ratio of 1-3:1-3, and reacted for 1-5 hours at a temperature of 25-65° C. and a pH of 2-6.
3. The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets according to claim 2, characterized in that The mass concentration of the alginate solution in step 2 is 0.5-3%, the dosage ratio of the chitosan oligosaccharide zinc complex to the alginate solution is 5-15 mg / mL, and the volume ratio of the glycerol to the alginate solution is 10-50%.
4. The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets according to claim 3, characterized in that The drying temperature of step 3 is 25-65° C., and the drying time is 1-5 h; the mass concentration of the CaCl 2 solution is 1-10%, and the calcification time is 1-5 min.
5. The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets according to claim 4, characterized in that The drying temperature of step 4 is 25-65° C., and the drying time is 1-3 hours.
6. The alginate film containing chitosan oligosaccharide zinc complex for refrigeration and preservation of fish fillets according to claim 4, characterized in that The viscosity of the alginate is greater than 900 mPa•s; the molecular weight of the chitosan oligosaccharide is 1 kDa-3 kDa.