离子交换和吸附相结合抑制浓缩酥梨汁褐变的研究

Prevention and control of browning in Dangshan pear juice concentrate by ion exchange and absorption technologies

该文研究离子交换和吸附相结合技术在降低、控制浓缩砀山酥梨汁褐变中的应用。将20°Brix砀山酥梨汁依次经FPC-21阳离子交换树脂和XAD-16大孔吸附树脂处理后,减压浓缩至70°Brix,贮存,检测褐变指数等指标的变化。结果显示,阳离子树脂处理可降低酥梨汁的pH值、氨基态氮和褐变指数;降低pH值可提高吸附树脂对酥梨汁的脱色能力;降低pH值、氨基态氮可控制70°Brix浓缩酥梨汁贮存中褐变速度。采用阳离子树脂处理将酥梨汁的pH值降低为4.05,再经吸附树脂将色值提高为85%,浓缩至70°Brix的酥梨汁在37℃下贮存35 d后,色值仍大于45%,符合出口要求。

Reduction and control of browning in Dangshan pear juice concentrate （PJC） by ion exchange and absorption technologies were studied. 20 ^＊Brix Dangshan pear juice was treated with FPC-21 cation exchange resin and XAD-16 adsorption resin sequentially, and then concentrated to 70 °Brix, browning index （A440） and other characteristics were measured during storage. Results show that treating the pear juice with FPC-21 resin can reduced pH value, formol index and browning index. Reduction of pH value enhence the decolor ability of XAD-16 resin on pear juice. Reduction of pH value and formol index can control the browning rate of PJC during storage. 20 °Brix pear juice was treated with FPC-21 resin to reduce the pH value to 4.05, then treated with XAD-16 resin to rise color value （T440） up to 85%, and concentrated to 70 °Brix. The color value of PJC is over 45% after storing at 37℃ for 35 d, which can meet the export regulation.