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CN-122011843-A - Tryptophan/taurine composite material for improving oxidation resistance, preparation method and application

CN122011843ACN 122011843 ACN122011843 ACN 122011843ACN-122011843-A

Abstract

The invention belongs to the technical field of new materials, and discloses a tryptophan/taurine composite material for improving oxidation resistance, a preparation method and application thereof, wherein the composite material comprises, by weight, 28-32 parts of chitosan, 0.048-0.055 part of tryptophan, 0.028-0.035 part of taurine and 0.72-0.78 part of montmorillonite. According to the invention, tryptophan and taurine are loaded in the chitosan-based composite membrane, so that the oxidation resistance of the membrane is remarkably improved. The ABTS free radical clearance of the composite membrane is improved to 73.86 percent. The improvement of the performance obviously enhances the capability of the film for removing active oxygen generated by fruits and vegetables during storage, effectively delays the oxidation process and improves the fresh-keeping effect of the fruits. The film material can keep the freshness of fruits in a high oxidation environment, and is particularly suitable for fruits and vegetables which need high-efficiency antioxidation protection.

Inventors

  • LI LI
  • Miao Yile

Assignees

  • 浙江大学

Dates

Publication Date
20260512
Application Date
20260108

Claims (8)

  1. 1. A tryptophan/taurine composite material for improving oxidation resistance is characterized by comprising the following components in parts by weight: 28-32 parts of chitosan, 0.048-0.055 part of tryptophan, 0.028-0.035 part of taurine and 0.72-0.78 part of montmorillonite.
  2. 2. The tryptophan/taurine composite material according to claim 1, wherein the composite material comprises the following components in parts by weight: 30 parts of chitosan, 0.051 part of tryptophan, 0.0313 parts of taurine and 0.75 parts of montmorillonite.
  3. 3. The method for preparing tryptophan/taurine composite material according to claim 1 or 2, comprising the following steps: (1) Weighing chitosan to be dissolved in acetic acid solution with the mass concentration of 1%, stirring by using a magnetic stirrer, and stirring at the rotating speed of 600rpm until the chitosan is completely dissolved, so as to obtain uniform chitosan solution; (2) Mixing the chitosan solution prepared in the step (1) with tryptophan and taurine and montmorillonite thoroughly, stirring at 600rpm until the tryptophan, taurine and montmorillonite are completely dissolved, adding glycerol with a final mass concentration of 0.5% (w/v) as a plasticizer and tween 80 with a final mass concentration of 0.1% (w/v) as a surfactant, stirring at 600rpm for 1h, and regulating the pH to 4.5 with acetic acid. And carrying out ultrasonic treatment on the solution for 1 hour, removing bubbles, ensuring that the solution is uniform and bubble-free, and obtaining the tryptophan/taurine composite material.
  4. 4. The method according to claim 3, wherein the ratio g/mL of the 1% acetic acid solution to the chitosan in the step (1) is 30:2000.
  5. 5. The method according to claim 3 or 4, wherein the ratio of tryptophan to taurine to montmorillonite in ml/g of the chitosan solution prepared in the step (1) in the step (2) is 500:0.051:0.0313:0.75.
  6. 6. Use of a tryptophan/taurine composite material according to claim 1 or 2 for maintaining freshness of fruits in a highly oxidizing environment.
  7. 7. Use of the tryptophan/taurine composite material according to claim 1 or 2 for storage and transportation of fruits and vegetables.
  8. 8. Use of the tryptophan/taurine composite material according to claim 1 or 2 for reducing moisture loss of fruits and vegetables.

Description

Tryptophan/taurine composite material for improving oxidation resistance, preparation method and application Technical Field The invention belongs to the technical field of new materials, and particularly relates to a tryptophan/taurine composite material capable of improving oxidation resistance, a preparation method and application thereof. Background At present, the following technical problems exist in the prior art: Problem 1 pure chitosan film has limited antioxidant capacity, chitosan only depends on limited hydroxyl and amino groups to play an antioxidant role, and the number of the groups is relatively small, so that a large amount of active oxygen generated during fruit storage is difficult to cope with. From the molecular structure level, the hydroxyl and amino groups in the chitosan molecules have certain hydrogen supply capability and can react with free radicals, but the chitosan molecules have low reactivity due to limited quantity and can only capture a small amount of free radicals through weak hydrogen bonding. In addition, the free radical clearance of a single chitosan film is generally low, and the DPPH free radical clearance is generally lower than 15%, so that the chitosan molecule has limited capability of inhibiting oxidation during fruit storage, and the simple chitosan film is difficult to delay browning and oxidative deterioration after fruit picking, and is difficult to maintain the flavor and quality of the fruits. Problem 2-more voids exist in the molecular structure of the pure chitosan film, which constitute channels for permeation of water molecules, so that the water vapor transmission rate of the pure chitosan film is usually more than 0.4 g.m -2·h-1·Pa-1·mm-1·10-3. In addition, the microstructure uniformity of the chitosan film is poor, and in the film forming process, the chitosan film is influenced by various factors, such as solvent volatilization rate, temperature fluctuation and the like, so that local permeation channels are easy to form. From a microscopic perspective, the chitosan molecules have irregular aggregates when arranged, and the gaps among the molecules around the aggregates are large, so that the aggregates become rapid channels for moisture migration. When the fruits are in a storage environment, the high water vapor transmittance can cause the accelerated water loss of the fruits, shrink the fruit peel, harden the texture and seriously affect the appearance and the taste of the fruits. Meanwhile, in a high humidity environment, rapid migration of moisture may provide suitable conditions for microorganism growth, and may cause mass propagation of microorganisms to cause fruit rot. The preparation and modification of chitosan-based films at present mostly adopts organic acids such as acetic acid as solvent to dissolve chitosan, and the mechanical and barrier properties are enhanced by glutaraldehyde or heavy metal nano particles (such as nano silver) as crosslinking agents and functional additives. However, glutaraldehyde has a certain cytotoxicity, and heavy metal nanoparticles may migrate from the film matrix into food, so that it may be harmful to human health, pollute the environment, and difficult to meet the development requirements of food contact materials and green packages. Therefore, the development of non-toxic, environmentally friendly alternative strategies has become an important direction in chitosan-based thin film research. By searching, the following patent publications related to the present patent application are found: Patent 1 of the comparison document discloses a food-source fruit and vegetable preservative, a preparation method and a use method (CN 120167500A) of the food-source fruit and vegetable preservative. According to the technical scheme, the anti-oxidation characteristic and the antibacterial efficiency of the preservative are synchronously improved through the synergistic effect of the composite components in the preservative. The antibacterial efficiency is verified by equivalent data of the antibacterial rate (91.3%) of escherichia coli, however, the declared antioxidant property of the preservative is mainly based on theoretical explanation and the appearance observation of fruits and vegetables after storage, and the quantitative determination of key antioxidant indexes such as DPPH and ABTS free radical clearance is lacking. Therefore, the prior experimental evidence of the patent is not enough to fully prove that the fruit has clear and quantifiable protective effect on inhibiting oxidative browning of the fruit after picking. This limitation makes it difficult to provide convincing technical support in meeting the post-harvest preservation requirements of readily oxidizable agricultural products. Reference 2 "a method for producing a polyvinyl alcohol hydrogel having high strength and self-lubricating (CN 112625269B)", discloses a high-strength PVA hydrogel formed by repeated freeze thawing of PVA, hydroxyprop