改良纤维素膜在南香杂柑果汁超滤澄清中的应用

Clarification of Nankou juice by ultra-filtration using modified fibre membranes

选用南香杂柑(Citrus unshiu×Citrus clementina)为材料,采用Millipore BioProcess Division的Ultracel-PL系列改良纤维素膜对南香果汁进行超滤澄清试验。结果表明,Plctk-30ku膜的最佳操作条件为:操作压力为30Pa,温度为40℃,流速为0.10m·s-1;Plctk-30ku膜对总可溶性固形物、还原糖、总酸、维生素C等主要营养成分的保留率超过80%,D-柠檬烯的保留率为90.2%,而对果胶及类胡萝卜素的保留率在1%以下,主要营养成分及香气的保留率均比对照膜(Plcgc-10ku)要好。因此Plctk-30ku膜对南香果汁有较好的澄清效果,适合作为果汁浓缩的前处理。

The conditions of ultra-filtration using modified membrane, i.e. Plctk-30 ku for the clarification of Nankou hydrid orange juice were optimized by single factor test and orthogonal design. And then the main nutritional components and aromatic compounds of the juices before and after ultra-filtration using modified membranes of Plcgc-10 ku and Plctk-30 ku were analyzed. The results showed that the optimum conditions for Plctk-30 ku operation were： 30 Pa of pressure, 40℃ and 0.10 m· s^-1 of flow velocity. After ultra-filtration under this combination of parameters for Plctk-30 ku, the values of total soluble solids, total sugar and total acid and ascorbic acid in juices retained more than 80% of those before ultra-filtration while D-limonene, the particular aromatic compound in citrus fruit was hold at 90.2%. But the contents of pectin and carotenoids of juice decreased to the level less than 1%. The retained rate of low molecular nutritional compounds and volatiles for the Plctk-30 ku was higher than that of Plcgc-10 ku. These facts indicate that Plctk-30 ku should be suitable for the pretreatment of concentration of Nankou juice.