Experimental And Theory Study On Fresh-keeping Packaging Of Lotus Roots Slices

In this thesis, experimental and theory research on fresh-keeping packaging of lotus roots slices based on ozone have been carried out, Its main research are as follows:First, the enzymatic browning mechanism of lotus roots-slices inhibited by ozone is analyzed.Second, the freshness evaluation criteria of lotus roots slices is established.Third, some comparative experiments on fresh-keeping packaging of lotus roots slices with different gas and different film and different ozone content were carried out in the different temperature. The results showed that:The high oxygen permeability coefficient of PE, HDPE film doesn't fit the lotus roots slices fresh, its surface color and flavor cannot be guaranteed, while low oxygen permeability coefficient of PA/PE film with ozone can perfectly maintain the normal white and flavor of lotus roots slices.The affect for fresh-keeping packaging of lotus roots slices by relative amount of ozone filling is obvious.If the PA / PE film is used as packaging material, with storage temperature of 5°C, it can restrain the breathing intensity and brown changing of lotus roots slices effectively. Their storage period can prolong to 20 days.Fourth, the breathing model of lotus roots slices fresh-keeping packaging based on ozone is established.Fifth, using the measured data of packaging components gas changes with time, the model parameters were identified by Genetic Algorithm (GA). According to the relationship between temperature and breathing rates for different storage temperatures, lotus roots slices respiratory rate are determined. Obvious linear relationship between R₃ and temperature is discovered by experiment in low temperature (0～10℃), In addition, the changes of gaseous concentration in package bag at different temperature were simulated. The results showed that the simulative value and the actual value can be good matched at 7.5℃.A new type of technology of fresh-keeping packaging for fruits and vegetables was proposed also a theoretical foundation for studying and application for fresh-keeping packaging based on ozone was laid in this study.