韧化处理对大米淀粉性质的影响

Effect of Annealing on Physicochemical Properties of Rice Starch

为韧化处理在大米淀粉改性中的应用提供理论依据,作者以余赤早籼米为原料,在不同温度(50~70℃)和水分质量分数(45%~65%)条件下对大米进行韧化处理,然后提取韧化处理后大米中的淀粉,以未经韧化处理提取的大米淀粉为对照,研究韧化处理对大米淀粉溶解度、膨润力、糊化特性、消化特性和冻融稳定性的影响。研究结果表明:与对照组相比,经韧化处理的大米淀粉溶解度和膨润力降低;峰值黏度、最终黏度、谷值黏度、回生值和衰减值均有所降低,糊化温度升高,不同韧化处理温度对衰减值的影响差异显著;淀粉中RDS(快消化淀粉)质量分数升高,RS(抗性淀粉)质量分数减少,SDS(慢消化淀粉)质量分数随着韧化处理条件的不同而不同,说明韧化处理提高了大米淀粉的消化性,也使大米淀粉冻融稳定性下降。

In order to provide a theoretical basis for the application of annealing treatment in the modification of rice starch,Yuchi early indica rice was used as a raw material and annealed at different temperature(50-70°C)and moisture content(45%〜65%).Then the starch in the annealed rice was extracted,and the unannealed rice starch was used as the control.The effects of annealing treatment on the solubility,swelling power,gelatinization,digestion and freeze-thaw stability of rice starch were studied.The results showed that compared with the control,the solubility and swelling power of annealed rice starch decreased.The peak viscosity,final viscosity,valley viscosity,retrogradation value and attenuation value decreased,while the gelatinization temperature increased.The effect of annealing temperature on attenuation value was significant.The content of RDS(fe.st digestible starch)in starch increased,the content ofRS(resistant starch)decreased,and the content of SDS(slowly digestible starch)varied with different annealing conditions,indicating that annealing treatment improved the digestibility of rice starch.However,the annealing treatment decreased the freeze-thaw stability of rice starch.