大米淀粉制备工艺对其糊化特性和粒度分布的影响

Impact of Isolation Process on Pasting Properties and Particle Size Distribution of Rice Starch

以籼米和粳米为原料,大米淀粉糊化特性和粒度分布作为评价手段,比较了碱法、中性蛋白酶法、碱性蛋白酶法(pH=8、pH=10)4种制备大米淀粉的工艺。结果表明,碱法制备的大米淀粉蛋白质残存率显著低于酶法,而3种酶法蛋白质去除率一致,但碱法部分破坏了淀粉颗粒的天然结构;经RVA糊化曲线分析,采用碱性蛋白酶法(反应条件pH=10)、中性蛋白酶法得到的籼米淀粉以及采用中性蛋白酶法得到的粳米淀粉能较好地保持天然淀粉的糊化特性;通过粒径分布检测,确定采用中性蛋白酶法处理粳米能制备得到粒径分布均匀的大米淀粉。综合各个评价指标,以粳米为原料,采用中性蛋白酶法可得到淀粉破坏小、粒径分布均匀、蛋白质残留率低的大米淀粉。

The pasting properties and particle size distribution of long-shapedrice and round shapedrice starches isolated from alkaline process,neutral protease process and alkali protease(pH= 8,pH=10) were compared.The results indicated that the protein residual rate of rice starch from alkaline isolation was lower than that from enzymatic isolation,but former damaged the starch granules partially.And the pasting curve of the long-shapedrice starch from neutral protease and alkali protease(pH =10) isolation was similar to that of native long-shapedrice flour,while the pasting curve of the round-shapedrice starch from neutral protease and alkali protease(pH =10) isolation was similar to that of native round-shapedrice flour.The neutral protease isolation also produced the smallest franule size of round-shapedrice starch.In conclusion,the quality of round-shapedrice starch isolated from neutral protease process was the greatest.