Study On The Stability Of Blackcurrant Juice

Enzyratic techonology with best condition was primarily developed in the study withblacurrant fruit as matrial and stability of fruid juice was sysmetically discussed.The results showed that the best enzyratic condition of blacrrant juice was,enzyratictemperature 45℃,enzyratic time 4h,enzyratic content 0.4%.The concentrate clarifying syrup and turbidity syrup were extracted using the black currentfruits which grow in horticulture station of northeast agricultural university.In the experiment,theeffects of temperature,pH,appended matter ofdifferent concentration (Fe³⁺, Cu²⁺, Zn²⁺, Na⁺, Al³⁺,H₂O₂,glucose,sucrose,sodium benzoate)on the pigment stability and the changes of primarynutrition component(sugar, acid, Vc, color value)during in the storage were studied. Stability ofthe clarifying syrup was researched by different even press and stabilizer combination tests;criticalconcentration was gotten by the study on the relationship of turbidity after clarifying syrupproduction and the factors such as protein,Fe iron, starch, tannin etc.The results showed that the most absorbed wavelength of syrup diluent is 520nm;syruppigment can bear higher temperature and is affected greatly by pH4.2～8;Cu²⁺,Zn²⁺,Na⁺,Al³⁺,different concentration of glucose, sucrose has no obvious influence on syrup pigment butexcept Fe³⁺,and different concentration oxidant H₂O₂,antiseptic,sodium benzoate can destroy syruppigment seriously.Syrup was stored in room temperature and in refrigerator.To make sure the suit storecondition,contents about sugar, acid,Vc,color value of these two kinds storage fruits were measuredevery other 10 days;and the changes of main components were analyzed.The results showed thatthe Syrup in refrigerator is steadier than in room temperature.In the study, based on the contents of protein, Fe²⁺, starch, tannin acid and shelf-life simulationof concentrate clarifying syrup, getting rid of effect factors of turbid as well as single ingredient andorthogonal,test,the critical concentration was confirmed: protein 260mg·L^-1,Fe²⁺ 17.48mg·L^-1,tannin2.8mg·L^-1,acid 150mg·L^-1. Under the condition of even press, temperature and times, the best treating process was gottenby the orthogonal test.At the same time,in the study, the effect of different stabilizer and theircombination on stability of the clarifying syrup about colloid such as Xanthan,CMC,pectin wereinvolved,By measuring precipitation delamination degree,the optimum condition is gotten: underthe temperature 60℃,and 25MPa, 20MPa, homogenization separately;the content of stabilizer isXanthan 0.15%,CMC0.05%,pectin 0.05%.