Study on Influencing Factors and Controlling Methods of the Insoluble Substance Which Formed at High Temperature in Onion Juice Concentrate

Abstract:

Onion juice concentrate generates insoluble substance after diluted by high temperature tap water. This study is to explore the formation of the insoluble substance and establish reasonable control method. The content of metal ions of iron，zinc，calcium and potassium in the onion juice concentrate which generates insoluble substance after diluted by high temperature tap water is significantly higher than the normal onion juice concentrate. The total phenolics，protein，flavones and reducing sugar contents of the abnormal onion juice concentrate are higher than the normal one. Normal onion juice concentrate which added calcium，zinc，iron and magnesium ions generate insoluble substance after diluted by high temperature tap water. A certain amount of citric acid，sodium citrate，ethylenediamine tetraacetic acid disodium and sodium hexametaphosphate were added to the abnormal onion juice concentrate and were diluted by high temperature tap water respectively. The results showed that the two treatment groups added ethylenediamine tetraacetic acid disodium and sodium hexametaphosphate didn't generate the insoluble substance. The optimum adding amount，respectively is 0.1 g/kg，3.0 g/kg diluent.