Dissertation > Excellent graduate degree dissertation topics show

Modification for PVA-Based Composite Packaging Material with Nano-SiO2 and Its Influence on Fresh Preservation Effect of Salted Duck Eggs

Author: LeiYanXiong
Tutor: ZhangJianHao
School: Nanjing Agricultural College
Course: Of Food Science
Keywords: Poly vinyl alcohol (PVA) Nano-SiO2 Response surface methodology (RSM) Salted duck eggs Performance characteristics of formed film Fresh preservation effect
CLC: TS253.46
Type: Master's thesis
Year: 2011
Downloads: 29
Quote: 0
Read: Download Dissertation

Abstract


Salted duck egg is a kind of famous Chinese traditional egg product, which is loved by masses of consumers in our country, and at present the production and consumption amount is very large. But now the cooked salted duck eggs are commonly packaged using vacuum package, of which the cost is higher than coating package and could cause "white" pollution. In addition, the mechanization degree of traditional process is so low. The coating fresh-keeping package of salted duck eggs could consume lower package material, and easily realized mechanization and automation. Therefore, researching and exploring biodegradable coating material for salted duck egg packaging are of great significance, which could realize modern automated production of traditional salted duck egg, and be characterized by high efficiency saving energy and green environmental protection.Because of polyvinyl alcohol (PVA) is biodegradable and of good safety, so it shows wide application prospect in food packaging area recently. However, its strong hydrophilicity makes a high water permeability of formed film, which greatly impacts its application in food preservation packaging. Nano-SiO2, as a kind of modified material, can compound with many macromolecule polymer resins, thus enhancing the performance characteristics of the polymer film and the preservation effect for foods. In this paper, nano-SiO2 was used to modify PVA-based composite coating packaging material. The properties of formed film and the preservation effect of packaging were determined and analyzed. Based on the previous studies, the preservation effect of coating-packaging salted duck egg, with nano-SiO2composite coating material, for long-term storage was further investigated. The detailed contents are as follows:1.Study on modification for PVA-based composite coating material with nano-SiO2 The PVA-based composite coating material was modified with Nano-SiO2, and its preparation method was optimized by response surface methodology (RSM). The mathematical model was builed by using the water vapor transmission rate of formed film as response and nano- SiO2, steric acid and glutaraldehyde as influencing factors. The main and interactive effects of all three factors on the water vapor transmission rate of formed film were analysed. Furthermore, the microstructure and internal morphology of the formed film of polyvinyl alcohol-based nanocomposite coating material was scaned by infrared spectroscopy (FT-IR) and electron microscopy (SEM), respectively. The FT-IR and SEM results showed that there was an hybridization reaction occurred between nano-SiO2 and PVA by forming Si-O-C bond; nano-SiO2 was well dispersed in the composite coating material, which could effectively enhance the water vapor barrier performance of the PVA-based composite coating materia. Response surface experiment results indicated that the water vapor transmission rate of formed film of optimal group decreased by 31.43% (P<0.05) compared with that of the control group. There were significant interactions among nano-SiO2, stearic acid and glutaraldehyde on the water vapor transmission rate of formed film. The addition of nano-SiO2 could increase the added level of stearic acid and glutaraldehyde in the composite coating material, and thereby decreased the water vapor transmission rate of nanocomposite film. The water vapor transmission rate of composite film decreased and water vapor barrier performance increased with the content increase in nano-SiO2 within a certain range in 100 mL 5% (W/VH2O) of the PVA solution.2. Study on the packaging properties of formed film of PVA-based nanocomposite coating materialThe package efficiency properties of the formed film of PVA-based nanocomposite coating material was investigated by measuring the water vapor transmission rate, water absorption rate, light transmission rate, gas permeability property, and antibacterial property of the film and by comparing with PVA film and common PVA-based composite film (no nano-SiO2). The results showed that the water vapor and gas permeability of nano-SiO2 composite film reduced, water resistance and the light transmission rate were elevated compared with those of single PVA film and nonmodified PVA-based composite film. Whereas, the permeability such as water vapor transmission rate (18.78g·m-2·d-1), water vapor absorption rate (1.40%), O2 penetration rate (0.055g·m-2·d-1) and CO2 penetration rate (0.174g·m-2·d-1) decreased significantly by 8.61 g·m-2·d-1,1.07 times, 17.91% and 18.31%, respectively, compared with those of ordinary PVA-based composite films. In addition, at 600nm wavelength, light transmission rate (23.9%) increased by about 1.34 times, and adding appropriate amount of nano-SiO2 could also strengthen the antibacterial activity of the nano-SiO2 modified composite film.3. Study on the storage preservation effect of salted duck eggs by packaging of PVA-based nanocomposites coating materialThe salted duck eggs coated by ordinary PVA-based composite coating material were used as control experiment, and the salted duck eggs coated by nano-SiO2 modified PVA-based composite coating material were used as experimental treatment group. All the salted duck eggs of the two groups were stored at normal temperature for 6 months, and at the end of the storage, the physical and chemical as well as microbiological and sensory indices of the eggs of each group were measured and compared between two different treatment. The results showed that, after 6 months storage, the average water loss rate (6.53%) of the salted duck eggs coated with PVA-based nanocomposites coating material decreased by 14.53% compared with the control group (7.64%). Moreover, the aerobic plate count (362 CFU·g-1) and total volatile basic nitrogen content (7.97 mg/100g) also decreased significantly (p<0.05). This result indicated that coating the salted duck eggs with PVA-based nano-SiO2 composite coating material could effectively prevent the water loss in salted duck eggs, inhibit microbial growth and reproduction, and reduce the production of total volatile basic nitrogen, which well protected the color and flavor of salted duck eggs for 6 months storage.

Related Dissertations

  1. Studies on Extraction, Isolation, Purification and Antioxidation Activity of Flavonoids from the Fruits of Avicennia Marina,S793.9
  2. Research on Preparation of Nano-SiO2 and Its Modification of Polyethylene Terephthalate(pet),TB383.1
  3. Polyamidoamine dendrimer modified inorganic nano-materials and properties,TB383.1
  4. Research on the Foaming Process and Properties of Polypropylene with Supercritical CO2,TQ328.06
  5. Studies on the Extraction Technology and Finger Print of Isoflavones in Belamcanda Chinenis (L.)DC,TQ461
  6. Experimental Researches on Improvement of High Liquid Limit Clay in Nanchang by Nano-SiO2 and Lime,TU442
  7. SBR modified asphalt emulsion and its nano- SiO_2 composite modified asphalt emulsion research,U414
  8. The Preparation, Structure and Properties of EVOH/nano-SiO2 Packaging Composites with High-barriers,TB484
  9. Preparation and Characterization of PDCPD/Nano-SiO2 Composite,TB332
  10. The Study on Process of Preparing Quartz Ceramics by Nano-SiO2,TQ174.75
  11. Experiment Study on Heat Transfer Performance for Adsorbent of Composite Nano-SiO2,TB383.1
  12. Synthesis and Application of Vinyl Chloride-isobutyl Vinyl Ether Copolymer Modified with Nano-SiO2 by Suspension Polymerization in Aqueous Medium,TB383.1
  13. Preparation and Characterization of Vinylidene Chloride Copolymer/Inorganic Nanoparticle Composites and Porous Carbons,TQ424.1
  14. Preparation and Property of Epoxy/SiO2 Dental Composite Resin Materials,TQ323.5
  15. Study on Ep Resin Modified Nano-Silica and Mechanical Properties of Composites,TB332
  16. Preparation and Properties of Polyimide Films with Low Dielectric Permittivity,TB383.2
  17. Nano Si_O2 modified epoxy adhesive and bonding process and mechanism of SiC ceramics,TQ174.6
  18. Desalination of Salted Duck Egg White by Ultrafiltration and Research the Functional Characteristics of Desalted Duck Egg White,TS253.46
  19. Study of Anti-Corrosion Performance of Nano-SiO2 Modified Epoxy Coatings,TB383.1
  20. Preparation of Nano-slurry and Its Application in Water-based Anti-corrosion Coatings,TB383.1

CLC: > Industrial Technology > General industrial technology > Industrial common technology and equipment > Packaging Engineering > Packaging materials
© 2012 www.DissertationTopic.Net  Mobile