超声波辅助酶处理对糙米理化特性的影响

The Influence of Ultrasound - Assisted Enzymatic Treatment on Physicochemical Properties of Brown Rice

利用超声波辅助酶对糙米的纤维素皮层进行了适当的处理,研究了酶处理后处理液中总糖的变化、糙米粉的黏度特性、糙米的吸水率以及糙米的蒸煮特性。随着处理时间的延长,纤维素酶、果胶酶、纤维素酶和果胶酶的复合酶3种酶液在超声波辅助下分解纤维素皮层得到的总糖量都不断增加,2.5 h时总糖含量分别为61.41、77.58、95.31 mg,是无超声波辅助下的1.16倍、1.06倍、1.47倍,表明低频率超声波对3种酶分解纤维素皮层均具有一定的促进作用,其中复合酶效果最好;酶处理后,糙米粉的峰值黏度、谷值黏度和最终黏度均升高,并且酶对纤维素皮层的分解一定程度上提高了糙米的吸水率和平衡后的含水率。糙米蒸煮后的硬度、黏着性、咀嚼性和回复性与分解得到的总糖量存在着显著的负相关性(P<0.05),相关系数分别为-0.828、-0.837、-0.853、-0.827。由此可见,用超声波辅助酶处理糙米,可以提高酶反应效率,缩短处理时间,从而更大程度地改善糙米的理化特性以及食用品质。

A novel ultrasound -assisted enzymatic technology was developed to approximately process cellulose cortex of brown rice. The total sugar content change, the viscosity properties of brown rice flour, the water absorption and cooking properties of brown rice after enzyme treatment were tested. With the increasing time for cellulase, pecti- nase and their complex to hydrolyze cellulose cortex of brown rice under ultrasound, the total sugar content was contin- uously increasing,and after 2.5 h of treatment,it reached 61.41 mg,77.58 mg and 95.31 mg respectively,which was 1.16,1.06 and 1.47 times higher than that in the enzyme treatment without ultrasound assistance, respectively. It was demonstrated that the low -frequency ultrasound have certain stimulative effect for the three enzymes on hydrolyzing cellulose cortex of brown rice, especially for the complex enzyme. The peak viscosity, trough viscosity and final viscosi- ty were all increased, and with the decomposition of cellulose cortex of brown rice, the water absorption capability of treated brown rice was enhanced, as well as the moisture content after being balanced. The hardness, adhesiveness, chewiness and resilience of cooked brown rice have a significantly negative correlation （P 〈 0.05 ） with the total sugar content hydrolyzed and the correlation coefficients were - 0. 828, - 0. 837, - 0. 853, - 0. 827, respectively. In a word, ultrasound assisted enzymatic treatment can be used to improve the efficiency of the enzyme reaction, reduce the processing time and enhance the physicochemieal properties and cooking quality of brown rice to a greater extent.