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CN-117624743-B - Chitosan-coffee grounds nanoparticle compound and preparation and application thereof

CN117624743BCN 117624743 BCN117624743 BCN 117624743BCN-117624743-B

Abstract

The invention relates to a fruit juice flocculant, a chitosan-coffee grounds nanoparticle composite and preparation and application thereof, comprising the following steps of 1) obtaining coffee grounds, namely, drying the coffee grounds, sieving the coffee grounds to obtain the required coffee grounds, 2) dissolving the coffee grounds with water, heating, filtering, collecting filtrate, passing through a D101 macroporous resin column, eluting with water, dialyzing an eluent, drying to obtain coffee grounds nanoparticles, 3) mixing chitosan aqueous solution and the coffee grounds nanoparticles with the mass ratio (chitosan: water) of 1:100-400, adding the mixture into a reaction kettle, carrying out hydrothermal reaction, dialyzing and drying the reacted solution to obtain the chitosan-coffee grounds nanoparticle composite. The invention adopts the nano particles with the characteristics of good biocompatibility, small input amount, obvious flocculation effect, good oxidation resistance, visualization and the like to modify chitosan, synthesizes a novel flocculant and provides a novel thought for clarifying juice.

Inventors

  • WANG CAIQI
  • WANG XIBO
  • DENG YUANYUAN
  • LIU XIAOHAN

Assignees

  • 大连工业大学

Dates

Publication Date
20260505
Application Date
20231116

Claims (10)

  1. 1. The preparation method of the chitosan-coffee grounds nanoparticle compound is characterized by comprising the following steps: 1) The coffee grounds are dried, sieved by a sieve of 20-50 meshes, and the required coffee grounds are obtained after passing through the sieve; 2) Preparing nano particles which are derived from coffee grounds, namely dissolving 4-8 g of coffee grounds powder with water, heating 1-6 h, filtering, collecting filtrate, passing through a D101 macroporous resin column, eluting with water, collecting eluent with the volume of 2-6L, dialyzing to obtain trapped fluid, drying to obtain the coffee grounds nano particles, heating at 50-90 ℃ for 1-6 h, filtering with filter paper, quantifying the filter paper, phi=10-15 cm, and the aperture of 30-50 mu m, and dialyzing with a dialysis bag with the trapped molecular weight of 1000-3000 kDa; 3) The chitosan-coffee grounds nanoparticle composite is prepared by mixing chitosan and water in the mass ratio of 1:100-400, namely, 20-50 mL, with the coffee grounds nanoparticle prepared in the step 2), adding the mixture into a reaction kettle, carrying out hydrothermal reaction for 1-6 h, and dialyzing and drying the reacted solution to obtain the chitosan-coffee grounds nanoparticle composite, wherein the molecular weight cut-off of a dialysis bag used for dialysis is 1000-3000 kDa.
  2. 2. The method for preparing chitosan-coffee grounds nanoparticle composite according to claim 1, wherein in the step 2), water of10 to 50 times the mass of the coffee grounds is added to the coffee grounds in an amount of 4 to 8g times the mass of the coffee grounds for dissolution.
  3. 3. The method for preparing a chitosan-coffee grounds nanoparticle complex as claimed in claim 1, wherein in the step 2), the heating temperature is 80-90 ℃ for 1-3 hours.
  4. 4. The method for preparing the chitosan-coffee grounds nanoparticle composite according to claim 1 or 2, wherein in the step 2), the D101 macroporous resin column has a specification of 15-20 cm column length and 1.0-1.5 cm inner diameter, the impurities are removed by eluting with deionized water, the eluent is collected, the eluent is concentrated by rotary evaporation to obtain a coffee grounds nanoparticle solution, and the coffee grounds nanoparticle is obtained by dialysis and drying.
  5. 5. A method of preparing a chitosan-coffee grounds nanoparticle complex as claimed in claim 1, wherein in step 3), the hydrothermal reaction temperature is 160-200 ℃.
  6. 6. The method for preparing chitosan-coffee grounds nanoparticle complex as claimed in claim 1, wherein the dialysis bag used in the dialysis has a molecular weight cut-off of 1000-2500 kDa in the steps 2) and 3).
  7. 7. The method for preparing the chitosan-coffee grounds nanoparticle composite according to claim 1, The step 1) of obtaining the coffee grounds, namely grinding the coffee beans by a coffee machine, extracting by water or soaking the coffee beans in water, airing and drying the non-extracted part, and sieving the dried part by 20-50 meshes to obtain the coffee grounds.
  8. 8. A chitosan-coffee grounds nanoparticle complex prepared by the method of any one of claims 1 to 7.
  9. 9. Use of the chitosan-coffee grounds nanoparticle complex of claim 8 as a juice flocculant.
  10. 10. Use according to claim 9, characterized in that the chitosan-coffee grounds nanoparticle complex according to claim 8 is used as flocculant in apple juice flocculation; At 15-25 ℃, the chitosan-coffee grounds nanoparticle compound is added into apple juice with the concentration of 0.05-0.1 g/L; at the temperature of more than 25-40 ℃, the chitosan-coffee grounds nanoparticle composite is added into apple juice with the concentration of 0.05-0.3 g/L.

Description

Chitosan-coffee grounds nanoparticle compound and preparation and application thereof Technical Field The invention belongs to the technical field of natural products and nanoparticles, and particularly relates to a fruit juice flocculant, in particular to a chitosan-coffee grounds nanoparticle compound and a preparation method and application thereof. Background In recent years, with the improvement of living standard and the enhancement of health consciousness, the market demand of fruit juice is continuously increased, and sales are increased year by year. Proteins, pectin, polyphenols and the like in the juice cause turbidity of the juice, and influence the taste and color of the juice. This quality problem greatly limits the development of the juice industry, which is currently the main problem faced by the juice industry. The flocculant is used as a juice clarifying material with convenient use and remarkable effect, and can clarify the juice on the premise of ensuring the quality of the juice as much as possible, so that the method for clarifying the juice by adopting the flocculant is widely applied. Compared with flocculating agents such as bentonite and gelatin, chitosan is considered to be an ideal material for a fruit juice flocculating agent because of the characteristics of high cationic charge density, long polymer chains and safety and no toxicity. However, when chitosan is used as a juice flocculant, the problems of poor bridging effect, weak antioxidation capability and the like exist, and the application of chitosan in juice clarification is greatly limited. Nanoparticles are particles of the nanoscale, also known as ultrafine particles, having a particle size of between 1 and 100 nm. For nanoscale substances, due to their relatively high surface area, surface effects are common, and they have a number of special physical, chemical, biological and optical properties compared to conventional materials. Meanwhile, the nano particles have a space effect, and under the action of the quantum size effect, the photoelectric property, the thermal property, the mechanical property and the like of the nano particles can be changed, so that the nano particles are novel materials with excellent performance, multiple functions and wide application. The food-borne nano particles have obvious advantages, such as wide sources, low price, good biocompatibility and the like. Therefore, research on modification of chitosan by using food-borne nanoparticles has attracted great interest. Fresh coffee cherries are picked, roasted to beans (Illycaff re. Itally), ground (e.g., using a coffee machine) and brewed (or water extracted) to coffee or other products, and the waste (unextracted portion) from the overall process is referred to as coffee grounds. The invention adopts the nano particles with the characteristics of good biocompatibility, small input amount, obvious flocculation effect, good oxidation resistance, visualization and the like to modify chitosan, synthesizes a novel flocculant and provides a novel thought for clarifying juice. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a chitosan-coffee grounds nanoparticle compound which adopts water to extract nanoparticles in coffee grounds and forms water-soluble chitosan-coffee grounds nanoparticles with chitosan, and can be used for flocculating turbid substances in apple juice. The invention also provides the chitosan-coffee grounds nanoparticle compound prepared by the method and the application thereof. In order to achieve the above purpose, the invention adopts the following technical scheme: 1) The coffee grounds are obtained by grinding and extracting coffee beans (Illycaff DEG C, itally) by a coffee machine, airing the non-extracted part, and sieving (30 meshes) to obtain the coffee grounds powder. 2) Dissolving coffee grounds powder with deionized water, heating for 3-5h, filtering with filter paper, collecting filtrate, passing through D101 macroporous resin column, eluting with deionized water to remove impurities, collecting eluate, concentrating by rotary evaporation to obtain coffee grounds nanoparticle solution, dialyzing (retaining liquid), and lyophilizing to obtain nanoparticles; 3) The chitosan-coffee grounds nanoparticle compound is prepared by mixing chitosan solution with the mass ratio (chitosan: water) of 1:200-400 and the coffee grounds nanoparticle prepared in the step 1), adding the mixture into a reaction kettle, and carrying out hydrothermal reaction for 1-4h. And dialyzing (intercepting liquid) the reacted solution, and freeze-drying to obtain the chitosan-coffee grounds nanoparticle compound. Specifically, in the step 1), 4-8g of coffee grounds are added with 20-30 times of deionized water for dissolution. Specifically, in the step 1), the heating temperature is 50-90 ℃ and the heating time is 3-5h. Specifically, in the step 1), the eluent is eluted by deionized water, and t