Effect of High Pressure CO2 on the Quality of Raspberry Juice
|Course||Agricultural Products Processing and Storage|
|Keywords||High pressure carbon dioxide Raspberries Quality PME|
High pressure carbon dioxide (High Pressure Carbon Dioxide, HPCD) technology as an important non-thermal processing techniques , one caused by an increasing number of consumers and Investigator interest . This paper studies the the HPCD technology raspberry juice processing and the quality and PME activity during storage . The main results and conclusions are as follows main results and conclusions are as follows : ( 1 ) OF HPCD processing make raspberry juice turbidity has changed dramatically, and has increased over time , the pressure increases ; viscosity decreases with increasing temperature and time ; browning index 10MPa and 20MPa , with the treatment temperature increases , but with the treatment time increased to 30 MPa, and 55 ° C under the conditions of processing , increased significantly with the treatment time browning index ; suspension stability with the processing time and an increase in temperature increases. Total phenolic and total anthocyanin content with the deal with the increase in temperature decreases ; no significant changes in the pH value, soluble solids content , color , particle size distribution . (2) by HPCD treatment group, the thermal control group and blank control group, and a viscosity at 4 ° C and stored at 5 weeks , with the increased processing time decreased; turbidity of each group has significantly increased ; processed sample after the suspension stability significantly higher than the heat-treated and untreated samples , are on the rise with the storage time , the suspension stability , the storage period between 28-35 days significantly increases ; particle size distribution of the heat-treated group and the control group starting at 21 days move toward large particle oF HPCD treatment group did not change significantly ; total anthocyanins and total phenols have declined during storage ; soluble solids content have significantly decreased heat treatment group decreased up oF HPCD treatment group decreased at least, the second untreated group ; raspberry juice of pH values ??and color during storage , no significant changes in the resistance . ( 3 ) by HPCD processed raspberry juice so that the PME activity decreased with increasing temperature, pressure and processing time , PME activity are decreased, and the temperature on the raspberry juice PME activity greatest impact . The processing conditions of 55 ° C , 30MPa, 60min case PME remnants of close to 5.7% . During storage , the activity was also reduced to varying degrees , OF HPCD group dropped most significantly in the first 14 days the enzyme is completely inactivated .