高温α-淀粉酶-挤压膨化耦合处理对全谷物糙米粉品质的影响

Effect of Thermostable α-Amylase Assisted Extrusion Treatment on Quality Properties of Whole Brown Rice Flour

以普通糙米、红米和黑米为原料,分析了高温α-淀粉酶-挤压膨化耦合处理对全谷物糙米粉径向膨化率、水溶性指数、吸水性指数、分散时间、结块率、黏度、糊化度以及还原糖、总蛋白质含量和可溶性蛋白质含量的影响。结果表明:3种全谷物糙米经过高温α-淀粉酶-挤压膨化耦合处理后其径向膨化率和糊化度均显著降低(P<0.05);水溶性指数显著升高(P<0.05)了2.51倍、1.89倍和2.73倍,吸水性指数显著降低(P<0.05)了77.29%、33.41%和67.44%;分散时间和结块率均显著降低(P<0.05),分散时间分别减少了64.60%、60.66%和65.40%,结块率分别降低了75.57%、84.64%和75.24%;冲调黏度均显著下降(P<0.05),加酶处理的糙米粉在低剪切速率下具有较低黏度,其黏度曲线趋于平直;还原糖和可溶性蛋白质含量显著提高(P<0.05),总蛋白质含量提高不显著(P>0.05)。

Using regular brown rice, red rice and black rice as raw material, the radial expansion rate, water soluble index, water absorption index, dispersion time, agglomerate rate,paste viscosity, gelatinization degree, reducing sugar and protein contents of brown rice flour produced by thermostable α-amylase assisted extrusion treatment was measured. The results showed that after thermostable α-amylase assisted extrusion treatment, the radial expansion rate and gelatinization degree in three types of whole brown rice were reduced significantly(P<0.05). The water soluble index was increased(P<0.05) by 2.51 times, 1.89 times and 2.73 times, respectively. And the water absorbent index was decreased significantly(P<0.05) by 77.29%, 33.41% and 67.44%.The dispersion time and agglomeration rate were also reduced significantly(P<0.05). The dispersion time was reduced by 64.60%, 60.66% and 65.40%, respectively. The agglomeration rate was reduced by 75.57%, 84.64% and 75.24%. The dissoving viscosity decreased significantly(P<0.05). The whole brown rice flour treated with enzyme had lower viscosity at low shear rate, and its viscosity curve tended to be straight. The content of reducing sugar and soluble protein was increased significantly(P<0.05), while the content of total protein had on obvious change(P>0.05).