适度碾磨加工对黑米蒸煮及食味品质影响的研究

Effect of moderate milling processing on palability and cooking qualities of black rice

为改善黑米不易煮熟及煮熟后米饭口感较差、粗糙感明显的问题,文章以适度碾磨的方式对黑米进行适度加工,考察了碾磨度为2%、4%、6%、8%、10%等不同加工程度对黑米蒸煮特性及食味品质的影响。结果表明,轻碾黑米的浸泡吸水率大幅度增加,2%适度碾磨下浸泡20 min时其吸水率提高134%,但不同碾磨度之间差异较小;随着碾磨度的提高,适度碾磨黑米的蒸煮时间逐渐缩短,蒸煮吸水率、体积膨胀率和固形物损失率均呈现上升后平缓的变化趋势;适度碾磨黑米糊化特性的峰值糊化黏度(PV)、保持力(HS)、崩解值(BD)和最终糊化黏度(FV)值均与碾磨度呈正相关;适度碾磨黑米的熟米粒硬度在2%碾磨度时显著降低(P<0.05),继续增加碾磨度时无显著变化(P>0.05),弹性始终无明显变化,黏性则先显著上升后趋于稳定。结论:通过适度碾磨加工,能较好改善黑米蒸煮特性及食味特性,2%的适度碾磨即能显著提高黑米浸泡吸水率、缩短蒸煮时间,降低熟米硬度(P<0.05)。

In order to solve the difficulty to cook black rice,and the poor palability and roughness of rice after cooking,moderate milling method was used to process black rice.The effects of milling degree of 2%,4%,6%,8%,10%on palability of black rice were investigated.Results showed that soaking water absorption rate of lightly milled black rice ascended substantially,which increased by 134%when soaked for 20 minutes at 2%milling degree,while insignificant difference was observed from different milling degrees.With the increase of milling degrees,the cooking time of the objective samples was gradually shortened,the water absorption rate,volume expansibility and loss rate of solid content increased at the early stage and then came to a constant value.The peak viscosity(PV),holding strength(HS),breakdown(BD)and final viscosity(FV)were positively correlated with different milling degrees.The hardness of steamed grains decreased rapidly at 2%milling degree(P<0.05),and no obvious change was ever determined other than 2%milling degree(P>0.05).Steady springiness was observed,while the stickness increased sharply and then slowed down to a constant level.Conclusively,2%milling degree rised significantly the soaking water absorption rate,shortened the cooking time and reduced the hardness of steamed grains,thus moderate milling treatment can significantly improve the cooking properties and palability of black rice.