Study On Concentrated Blueberry Juice Processing Technology Its Workshop Design

Blueberries are now one of the highest nutritional value of fruits,known as the "21st century functional health berry",called the king of fruits.But blueberries are seasonal fruits and fresh blueberries are not easy for storage.Processing it into concentrated blueberry juice can not only improve the storage stability of blueberries,but also make it convenient for transportation,save costs for packaging and transportation,and resolve origin raw fruits and vegetables.Using bluecrop blueberries as raw material,the study shows the production of concentrated blueberry juice,rheological properties,browning during the key process stages and the designation of juice production workshop.Contrast steam blanching and microwave technologies to protect color of blueberry,and determine the optimal blanching parameters by PPO activity and blueberry color.Optimal conditions for blanching:100? steam blanching 120s;microwave 200 W,60s.After enzymatic treatment,Using the juice yield and clarity for as marker,and using response surface method based on the single factor,the study shows the best enzymatic hydrolysis conditions:enzyme ratio(Pectinase:cellulase)5:1,the amount of enzyme 0.53%,time 90min,emperature 40 C.Through the analysis of the quality of concentrated blueberry juice,the concentrated temperature is 70 C.Using GC-MS to analysis aroma composition in blueberry juice and concentrate blueberry juice,showed that compared with blueberry juice,alcohol in juice concentrate substances decreased obviously.Esters and ketones increased slightly N-aldehydes,vinyl material increased significantly,and heterocyclic substances vary significantly.Through the study of the rheological properties of the blueberry juice,65°Brix concentrated blueberry juice is shear thinning fluid.Mathematical model of the combined effects of temperature and concentration on the viscosity is:?=8.8217e((0.0084x2-0.3961x+19.197)/RT)+0.0176x.Through analysis the material which can easily causing browning in blueberry juice concentrate processing,found that the main change of the color during blanching stage is caused by stripping of anthocyanins and total phenolics substances;the main reason of non-enzymatic browning in enzymatic process is oxidation of ascorbic acid and phenol;in concentration and sterilization process,the Maillard reaction and the oxidation of phenols has made outstanding contributions to the browning.The workshop design of annual production of 4000t concentrated blueberry juice was designed.The material balance,water,electricity,vapor calculation and equipment selection have been carried on,and also including the drawing of process flow diagram and workshop floor plan by using Auto CAD.