葡萄籽蛋白脱色试验研究

Study on Decolorization of Grape-seed Crude Protein

以宁夏葡萄籽为原料,采用碱溶酸沉淀法提取的葡萄籽粗蛋白呈紫褐色,对其脱色方法进行研究。通过比较活性炭及双氧水的脱色效果,确定了以双氧水为脱色剂的试验方法。结果表明,脱色时白度和产率的控制条件相互制约,需综合考虑实际需求选择脱色条件。经过正交试验优化并综合考虑白度和产率两项指标,当固液比为1∶25(g/m L)时,确定p H8.0、双氧水用量15 m L、脱色温度55℃、脱色时间40 min为最适脱色条件,该条件下脱色蛋白产率为78.21%,白度为14.71。

Grape-seed crude protein which was purple brown in color was extracted from the Ningxia local grape seed used as raw material, by an alkali-solution and acid-isolation method. Herein, the decolorization of crude protein was studied. A bleaching method with H2O2 as a kind of decolorant was finally selected through comparing the bleaching effects with active carbon and H2O2 The results showed that in bleaching, the conditions for whiteness and yield were restricting each other. Therefore, the bleaching conditions must be selected by comprehensively considering the actual demands. The optimum bleaching conditions were found by the singlefactor and orthogonal experiments and with the two aspects of whiteness and yield in consideration. The optimum conditions were that the solid-liquid ratio was 1 ： 25 （g/mL）, pH was 8.0, the quantity of H2O2 was 15 mL, the bleaching time was 40 min, and the bleaching temperature was 55 ℃ The decolorized grape seed protein with a whiteness of 14.71 was produced under the optimum conditions, and the yield of the decolorized grape seed protein was 78.21%.