Study On The Effects Of Ozone And Negative Ions In The Fresh-keeping Of Hen Eggs

This paper reviewed the technological development of the egg storage, and summarized the research results in experiments on the application of ozone and negative ions to preservation of eggs. In the 4 weeks research, the effects of using ozone or negative ions for eggs storage in 30℃, RH 80% were compared. Firstly, study the changes in internal quality, physical-chemical properties and total bacteria of eggs during storage after dealt with ozone and negative ions. Secondly, test the efficacy of ozone and negative ions in disinfection of three kinds of bacteria (Escherichia coli, Staphylococcus aureus and Salmonella), which are playing an important role in the safety of eggs. Thirdly, study the effects of lysozyme after dealing with ozone and negative ions. Finally, study the changes in the nutrition of eggs during storage. The main results were as follows:1. Eggs dealt with ozone and negative ions have shown good effects in internal quality, physical-chemical properties (including weight losing, yolk index, Haugh unit and albumen pH value) and total bacteria of eggs during storage, however, the CK showed bad effects in those index. By considering the index of internal quality and physical-chemical properties, the negative ions groups were better than ozone groups, while the ozone groups had better effects in index of total bacteria than the negative ions groups.2. Ozone had significant impact in reduing bacteria including Escherichia coli, Staphylococcus aureus and Salmonella, bactericidal effect was rising along with time expanding. The antibacterial rate of Escherichia coli, Staphylococcus aureus and Salmonella after 4min was 54.17%,85.24%,89.16% respectively. The negative ions had the same trend like ozone, but underperformed than zone:the antibacterial rate of Escherichia coli, Staphylococcus aureus and Salmonella after 7min was 20.76%,25.24%,58.97% respectively.3. Both ozone and negative ions were capable to restrain the activity of egg white lysozyme. The activity of egg white lysozyme had decreased by 24.12%,38.39%,53.70% after dealt with ozone for 10min,20min,30min; the activity of egg white lysozyme had decreased by 38.39%,50.71%,62.65% after dealt with negative ions for 10min,20min, 30min. The contents of the secondary structures of egg white lysozyme had changed after in treated with ozone and negative ions. Theα-helix increased after dealt with ozone while thea-helix was decreased after dealt with negative ions. The space structure modified after denaturation. Although ozone and negative ions showed good effects in keeping eggs fresh, they were also a double-edged sword to restrain the activity of egg white lysozyme. Therefore, ozone and negative ions have no effects with the activity of egg white lysozyme, for ozone and negative ions have enough ability to disinfect than lysozyme.4. Eggs dealt with ozone and negative ions have shown good effects in nutrition including moisture, protein, fat and amino acid of eggs during storage. The contents of moisture, protein and fat of ozone groups were higher than CK by 0.49%,0.18%,0.10%. The contents of amino acid exceeded than CK except proline. However, the contents of moisture, protein and fat of negative ions were higher than CK by 0.48%,0.28%,0.20%. The content of amino acid exceeded than CK except histidine.5. Ozone and negative ions have shown good effects in keeping fresh of eggs at 30℃, RH 80%. Analysis by synthesis all the index, negative ions groups have good effects on egg fresh keeping. These results provide valuable reference for egg fresh-keeping in warm areas and seasons.