Study On Preparation Of The Functional Ozone Ice And Its Application

Ozone has attracted much attention in the field of food processing because of its high efficiency sterilization and no residue,but ozone's instability makes it difficult to preserve.Ozone ice is formed by freezing ozone water at low temperature,which not only retains the original performance and function of ozone,but also provides cold source for food preservation,and solves the problem of short half-life of ozone.However,in the process of preparing ozone ice,there are some disadvantages,such as low concentration of ozone water and low retention rate of ozone in ice,which are not conducive to the popularization and application of ozone ice.In this paper,the study,which based on studying the influence of the solubility and stability of ozone,is on systematically researching the preparation process of ozone ice and its influencing factors,the characteristics of ozone preservation and release of ozone ice,and explored the preservation effect of ozone ice through experiments.The main research contents were as follows:(1)High concentration ozone water was prepared by aeration method and the effects of different technological parameters on the concentration of ozone water were studied.Combined with the theory of gas-liquid mass transfer,the curve of ozone water concentration change with time was obtained through theoretical and experimental model derivation,and it was verified that the curve fitted well with the experimental results,realizing the control of ozone water concentration in the aeration process.On this basis,the stability of ozone water was studied.The results showed that both water temperature and pH could significantly affect the half-life of ozone water.The lower the water temperature was,the longer the half-life of ozone water would be.the appropriate adjustment of pH can promote the extension of the half-life of ozone water at the same time When the water temperature is 5?and the pH is 3,the half-life of ozone water is 780.1 min.This part of the work laid the theoretical and experimental foundations for the preparation of high-concentration ozone ice.(2)In view of the problem of low ozone retention rate in the process of preparing ozone ice,the effects of water temperature,pH,freezing temperature and ice making mold on the ozone retention rate in the ice were investigated.The results showed that the lower the water temperature and freezing temperature,the higher the ozone retention rate in ice.It was found that the stability of ozone ice increased with the decrease of storage temperature.The ozone ice stored under different conditions showed great attenuation in the first two days,and the attenuation rate was in the range of 30%?40%.Then the ozone concentration decreased slowly,and the decrease process showed a linear relationship between the concentration and time.In addition,the release of ozone ice with different concentrations and pH was studied.The results showed that the higher the concentration was,the more ozone was released by the ozone ice in unit time.but the pH had no effect on the process of ozone ice release.(3)The fresh-keeping experiment of Bream was carried out under the condition of 1±0.5?with different concentrations of ozone ice.The results showed that the ozone ice with the concentration of 4.62 mg·L^-1 had better preservation effect than the control group in color,smell and elasticity.The increase of pH and TVB-N was delayed.The total number of samplecolonies decreased by 1.77 lg CFU/g.The self-life of bream was extended by 4?5 days.Ozone ice with a concentration of 0.94 mg·L^-1 had no obvious effect on the preservation of bream.In this paper,a method to prepare high concentration ozone ice at conventional freezing temperature is developed.The preparation process of ozone water and ozone ice was optimized through experiments.It can reduce the loss of ozone and the manufacturing cost,and provided a reference for the industrial application of ozone water and ozone ice.