Experimental Study On High Pressure And Low Temperature Preservation Of Animal And Plant Tissue

Compared with atmospheric freezing/thawing and liquid nitrogen freezing, the high pressure and low temperature technology has received wide attention for less freezing/thawing time, and fine ice crystals with uniform size distribution. In this paper, high pressure freezing and high pressure thawing on chicken heart and soybean is carried out, and comparison study with the traditional way is also conducted. The main research work and results are as follows:(1) In chicken heart treatment of different freezing processes, the High Pressure Freezing process has shorten the treatment time, and form finer ice crystals with uniform size distribution in the samples which lead to less damage of the chicken heart texture.(2) The different effects of different processes on chicken heart are investigated through the analysis of the thawing time, the drip loss and texture. Treated by the combination of PSF and PAT, the time of freezing and thawing process is greatly shortened, texture and micro-structure of heart are well maintained, and the drop loss decreases. The quality parameters measured by texture analyzer are more close to the fresh heart.(3) The studies on soybean by different freezing process are conducted with the germination rate and the growth characteristic of soybean as investigation subjects. Treated by the high pressure and low temperature process, the germination rate, growth condition and Malnutrition compositions of soybean are improved, while the results of the liquid nitrogen freezing process are adverse.(4) The pressure and temperature in the high pressure and low temperature process on the soybean are optimized by response surface method to get the best germination rate. The predicted sprout values are 89.47% and 95.95% with mung bean and soybean, respectively, which is in good accordance with those of experimental results (mung bean sprouts of 89%, soybean sprouts of 95.9%). It is shown that the model can get good prediction of the germination rate of soybean at different pressure and temperature conditions.