Study On Compound Of Egg Preservative Coating And Effect Of Fresh-Keeping

In this study, the coating around the egg preservation is a key point, looking for a safe, efficient, low-cost preservative coating is crucial important. Focusing on screening antibacterial substances in egg preservative coating and preparing of egg preservative coating. This paper is divided into four parts:first antibacterial substances in egg preservative were screened; second the egg preservative coating was prepared; third the effects of preservative coating on egg preservation were compared; fourth the internal quality changes of eggs during storage were studied.The major results are as follows:1. Selected plant essential oils as an egg preservative in bacteriostatic coating material. Egg spoilage is mainly caused by microorganisms in fresh egg coating agent, so select a good antibacterial effect of antibacterial agent is the key. This experiment takes the Colibacillus, the Salmonella to be test strains, using the filter paper and the double dilution methods for the determination of the six kinds of essential oils. Six kind(kinds) of plant volatile oils to the Colibacillus and salmonella determination results are:Oil of cinnamon> ilex oil> perilla leaf oil> tea tree oil> eucalyptus oil> forsythia oil. cinnamon oil, ilex oil and perilla leaf oil have been selected from six kinds of essential oils. The compound bacteriostat’s formula is:cinnamon oil is 0.60mg/mL, ilex oil is 0.40mg/mL, perilla leaf oil is 0.30mg/mL, the compound bacteriostatic agent of the antibacterial spectrum is wider than a single antibacterial spectrum.2. According to the HLB value theory, preparation out three kinds of film emulsion preservative. The formula is:pullulan (4.00g), compound bacteriostat (0.13g), corn oil (10.00g), emulsifier (3.50g), add water to 100.00g; xanthan gum (0.20g), compound bacteriostat (0.13g), corn oil (10.00g), emulsifier (3.50g), add water to 100.OOg; sodium alginate (1.00g), compound bacteriostat (0.13g), corn oil (10.00g), emulsifier (3.50g), add water to 100.OOg. we have preparation out three kinds of oil-soluble preservative coating by adding essential oils and anti-oxidants in vegetable oil.The formula is:compound bacteriostat(0.13g), VE(0.03%), ciric acid (0.10‰), soybean oil(solvent); compound bacteriostat(0.13g), VE(0.03%), ciric acid (0.15‰), corn oil(solvent); compound bacteriostat(0.13g), VE(0.03%), ciric acid (0.15‰), sunflower seed oil(solvent). Preservation of these two types of coating have a safe, low cost, good performance characteristics of spray, and spray drying the surface of the egg is colorless and transparent, easily accepted by consumers.3. By studying the eggs in the experiments carried out under high temperature at 37℃, the results showed that:oil preservative coating> emulsion preservative coating > mineral oil> uncoated. Two kinds of film preservatives:Emulsifying and oil-soluble coating were selected. The formula of emulsion preservative coating is:xanthan gum (0.20g), compound bacteriostat (0.13g), corn oil (10.00g); The formula of oil preservative coating is:compound bacteriostat(0.13g),VE(0.03%), ciric acid (0.15‰), corn oil (solvent).Then preservation of eggs coating experiments were carried out at room temperature. Results show that the emulsifying film preservative can be stored for 100 days at room temperature, oil-soluble coating preservative can stored for 130 days at room temperature, while treatment by the mineral oil coating of eggs merely stored for 70 days at room temperature.4. In the storage period of eggs, the variations of internal quality were studied.The physical and chemical properties, the main functional properties and microbiological aspects of eggs, with the extension of storage time, the various indicators of eggs have undergone corresponding changes. With the extension of storage time, egg’s quality have been changed:the moisture content of egg white decreased. The moisture content of yolk increased; the viscosity and surface tention of egg white decreased; the TVBN value and free fatty acid content of egg increased; the foaming capacity of egg white and the emulsifying capacity of yolk decreased; colony amount increased.