香蕉汁贮藏期间二次沉淀的研究

Research on Second Sedimentation during Banana Juice Storage

研究了香蕉汁贮藏期间发生二次沉淀的原因。成分分析发现，香蕉汁二次沉淀物中总糖含量占干基的80.25％，气相色谱分析发现，总糖中85.72％的单糖是葡萄糖。沉淀物与碘液反应呈淡紫红色，波长扫描最大光吸收值在480～520nm范围，表明二次沉淀物主要是由糊精组成。虽然沉淀物中含有少量蛋白质与酚类化合物，但糊精老化凝沉是香蕉汁发生二次沉淀的主要原因。

The causes of the second sedimentation during banana juice storage were discussed. Component analysis showed that 80.25 % of the second sediments was carbohydrates, among which contained 85.72% glucose by GC analysis. The mixture of sediment reacted with KI-I2 solution was red-lavender and its largest absorbance wavelength was in the range from 480 to 520 nm. The results showed that the sediments were mainly composed of dextrins. There were small amounts of haze-active phenols and protein in banana juice, however, dextrin retrogradation was the most important factor for the sedimentation of banana juice.