酶处理对橙汁混浊稳定性及微观结构的影响研究(英文)

橙汁因其均匀稳定混浊态的丧失而失去诱人外观。本文以橙汁为原料,采用果胶酶及蛋白酶处理,比较其混浊态稳定性及微观结构的变化。结果表明:果胶酶可加速橙汁的澄清,蛋白酶处理可减缓橙汁混浊态的丧失。经过酶处理后橙汁溷浊的微观结构发生了变化,用蛋白酶处理后的橙汁混浊体积较小,分布较均匀,呈筛状的网状结构;而用果胶酶处理后的橙汁形成了体积稍大的无定形物质且混浊成分之间有游离脂肪滴。脯氨酸是橙汁中含量最高的氨基酸,其可能与橙汁混浊中蛋白质的不溶有关。

Effects of Pectinase and Protease on Cloud Stability and Microstructure Study of Pasteurized Orange Juice

Pasteurized orange juice (POJ) loses its attraction during storage due to flocculation. This experiment examined thechanges in the turbidity and microstructure of POJ treated by pectinase and proteases. Obvious improvement in the cloudstability was found after adding pepsin and papain, while accelerative flocculation was noticed after pectinase treatment. Thiscould be well explained by the Scanning Electron Microscopy (SEM) observation. It revealed that the particles in papain-treatedPOJ cloud were well distributed and formed in sieve-like structure, whereas, those after pectinase treatment become bigger andamorphous with some free spherical-oil droplets noticed. Proline was the most abundant amino acid, which might contribute tothe inherent insolubility of orange juice cloud protein. It was suggested that the interaction of protein and pectin and the inherentinsolubility of protein were probably the most important factors in cloud loss of POJ during storage.