影响洋葱浓缩汁高温凝聚物形成因素及其控制

摘要

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.%洋葱浓缩汁(70°Brix)采用高温自来水稀释后会产生凝聚物,本研究对凝聚物形成的主要因素进行探究并建立合理的控制方法.对正常洋葱浓缩汁和稀释后产生凝聚物的非正常浓缩汁金属离子质量分数比较,产生凝聚物的浓缩汁铁、锌、钙、钾离子质量分数明显高于正常浓缩汁;此外,其总酚、蛋白质、黄酮、还原糖质量分数均高于正常浓缩汁;正常洋葱浓缩汁中加入钙、锌、铁、镁离子,高温自来水稀释后均产生凝聚物;向非正常浓缩汁中加入一定量的柠檬酸、柠檬酸钠、乙二胺四乙酸二钠、六偏磷酸钠,高温自来水稀释后,添加乙二胺四乙酸二钠、六偏磷酸钠的处理组无凝聚物形成,以稀释后溶液总质量计,最佳添加量分别是0.1、3g/kg.