多酚和蛋白质对苹果浓缩汁二次混浊的影响

Effects on Apple Juice Concentrate Re-haze with Polyphenols and Proteins

采用18000r/min冷冻(-4℃)离心20min的方法处理经二次混浊处理了3个批次的果汁,测定上清液的相应指标,与未处理的果汁做空白对比,由相应的成分的变化,确定混浊物的成分。结果表明:和二次混浊有关的多酚主要是原花青定的聚合体;表儿茶素、儿茶素小分子的酚类不直接参与二次混浊,却是形成二次混浊的前体物质;和二次混浊有关的蛋白质疏水性氨基酸含量高,其中脯氨酸含量大。

Three batches of apple juice concentrate were treated by the second haze, method and then centrifuged for 20 nan （-4 ℃, 18000 r/min） with the superior clear solution collected at last. Determined the solution indexes of polyphenol and protein and compared them with the juices without being treated. The re-haze compounds were ascertained through the change of the indexes. The results showed that： the main phenolic compounds in the re-haze substances are polymers of procyanidin.Catechin and epicatechin are the precursors of formation of haze. The amino acids of protein in haze juice are hydrophobic and the contents of proline are higher in haze juice than in normal juice.