1 Introduction 1 Introduction 2 onions The nutritional content of 2 onion 2 3 The health onion 2 4 juice vegetable juice clarification method 3 1 Enzyme treatment 3 2 deal with ultrafiltration membrane 4 3 to clarify the 5-treated 5 to clarify the preservation methods of onion juice 5 1 Preservation potassium sorbate 5 1 Preservation of citric acid 5 6 Prospect of 6 2 Materials and Methods 6 1 Test materials， equipment and reagents 6 1 Test Materials 6 2 Test apparatus 6 3 Test Kit 7 2 Test Method 7 1 Preparation of onion juice 7 2 onion juice clarification 7 3 to clarify the clarification of onion juice preservation 7 3 Results and Analysis 7 1 onion juice pectinase treatment to determine the optimal dosage of 7 2 onion juice pectinase processing time to determine the optimum water bath 8 3 pectinase treatment of onion juice to determine the optimum water temperature of 9 4 Orthogonal analysis of onion juice pectinase to clarify the role of the optimal conditions for 10 5 to clarify the preservation of onion juice test 11 1 to clarify the degree of cold storage on the impact of 11 2 to clarify the degree of citric acid on the impact of 12 3 Potassium Sorbate onion juice during the period of preservation to clarify the impact of 14 degrees Potassium sorbate and citric acid 4 to clarify the impact of the degree of contrast 15 4 Conclusion 16 5 References 16 6 a vote of thanks 18
