配合物沉淀法分离大米中直链淀粉的工艺参数优化及产物特性分析

Optimization of technique parameters of rice amylose separation by complex precipitation method and analysis of product characteristics

为了提高陈米的经济价值,通过分离陈米中的直链淀粉使其性质基本接近或优于糯米粉,为陈米的再利用提供新思路。以东北陈粳米为原料,利用配合物沉淀法分离大米淀粉中的直链淀粉,以产物米粉的直链淀粉含量为指标进行工艺优化,并将在最佳工艺条件下制备的米粉与原始米粉、商业糯米粉的特性进行比较。在单因素试验的基础上进行响应面试验,得出最优分离条件:正丁醇与异戊醇体积比2.5∶1、溶液pH 6.58、搅拌时间10 min、分散温度96.6℃,此时产物米粉中直链淀粉含量为3.23%,比原始米粉的直链淀粉含量降低了80.50%,与糯米粉的直链淀粉含量接近。产物米粉的灰分含量增加到3.15%,而蛋白质、脂质含量分别减少到2.93%和0.19%。与原始米粉相比,产物米粉的凝沉体积减小到1.26 mL,比糯米粉的凝沉体积2.10 mL还小;产物米粉的溶解度增大至0.85%,比糯米粉的溶解度0.71%略大;产物米粉的膨润力增大至13.33%,与糯米粉的膨润力13.63%接近;产物米粉的胶稠度增加至135.00 mm,比糯米粉的胶稠度116.00 mm更大;产物米粉的保水力上升至10.72%,比糯米粉的保水力8.62%更高。在产物米粉的糊化特性中,糊化温度和峰值时间相比于原始米粉显著降低,而与糯米粉接近。可见,产物米粉性质接近甚至优于糯米粉。

To improve the economic value and provide new instructions for the reuse of aged rice,the properties of aged rice were made close to or better than glutinous rice flour by separating amylose. The Northeast aged japonica rice was used as the raw material,and the amylose was separated by the complex precipitation method. The process was optimized with the amylose content of the product rice flour as an indicator,and the characteristics of the rice flour produced under the optimal conditions were compared with those of the original rice flour and commercial glutinous rice flour. On the basis of single factor experiments,the optimal separation conditions were obtained using the Box-Behnken center combination test and response surface analysis method. The optimal separation conditions were: the ratio of n-butanol to isoamyl was 2. 5,solution pH value was 6. 58,stirring time was 10 min,and dispersion temperature was 96. 6 ℃. Under this condition,the amylose content of the product rice flour was 3. 23%,which was 80. 50% lower than that of the original rice flour and close to the amylose content of the glutinous rice flour. The ash content of the product rice flour increased to 3. 15%,while the protein and lipid content decreased to 2. 93% and 0. 19%,respectively. Compared with the original rice flour,the sedimentation volume of the product rice flour was reduced to 1. 26 mL,which was smaller than that of the glutinous rice flour( 2. 10 mL),and the solubility increased to 0. 85%,which was slightly larger than the solubility of the glutinous rice flour( 0. 71%). The swelling power of the product rice flour increased to 13. 33%,which was close to glutinous rice flour( 13. 63%). The gel consistency of the product rice flour increased to 135. 00 mm,which was greater than that of glutinous rice flour( 116. 00 mm),and the water retention capacity increased to 10. 72%,which was higher than that of glutinous rice flour( 8. 62%). For the gelatinization characteristics of the product rice flour,the gelatinization temperature and peak time were significantly lower than those of the original rice flour,but close to those of the glutinous rice flour. Therefore,the properties of the product rice flour were close to or better than those of glutinous rice flour.