Effects Of Different Processes On Blueberry And The Quality Of Its Jam Products

Blueberry has great value in nutrition and health,highly processed goods of blueberry are not much at present.This paper studies the effect of different softening ways and crushing time on the typical components of blueberry;effect of different recipes and time of concentration on quality of high and low sucrose blueberry jam;high and low sucrose blueberry jam processing technology was optimized using two ways of ordinary pressure and vacuum concentration;effect of different recipes on quality and structure of high and low sucrose blueberry jam;effect of different methods and time of sterilization on quality of high and low sucrose blueberry jam;and studies the rheology of high sucrose blueberry jam.Effect of different processes on quality of blueberry,the conclusion was:the content of Vc and anthocyanins in blueberries increased at first and then decreased with softening time increasing.Effect of different processes on quality of high and low sucrose blueberry jam,the conclusions were:the best way of softening was softening by steam and softening time was 90s,the best crushing time was 90s.The best time of ordinary pressure concentration of high sucrose blueberry jam was 25min and temperature was 120?.The best condition of vacuum concentration of high sucrose blueberry jam were:vacuum degree was 0.1 MPa,temperature was 55?,time was 30min.The best time of ordinary pressure concentration of low sucrose blueberry jam was 30min and temperature was 120?.The best condition of vacuum concentration of low sucrose blueberry jam were:vacuum degree was 0.1 MPa,temperature was 55?,time was 35min.Study of high and low sucrose blueberry using single factor and orthogonal experiment,the conclusions were:the optimum technological condition of high sucrose blueberry jam for the amount of adding sugar was 50%,citric acid was 0.6%,pectin was 0.3%,the way of concentration was vacuum concentration.The optimum technological condition of low sucrose blueberry jam for the amount of adding sugar was 25%,citric acid was 0.3%,pectin was 0.6%,the way of concentration was vacuum concentration.Effect of different methods and time of sterilization on quality of high and low sucrose blueberry jam,the conclusion was:the best method of sterilization was boiling water and the time of sterilization was 15min.Rheology of high sucrose blueberry jam was studied:jam showed non-newtonian pseudoplastic fluid,Shear stress increased and viscosity decreased gradually With the increase of shear rate.Under the condition of the same shear rate,the shear stress and apparent viscosity decreased gradually with the increase of temperature.and there was a yield stress,the structure was destroyed When the shear stress reaches a certain value.