粳性糜子淀粉与小米淀粉理化性质的比较

Comparison of physicochemical properties of starches from japonica proso millet and millet

以7种粳糜为试验材料,小米为对照,采用碱提取法制备淀粉,研究粳糜与小米淀粉理化性质的差异.结果表明,粳糜淀粉颗粒与小米淀粉相似,大多呈棱角圆滑的多面体型,颗粒粒径为4.32-11.04μm,淀粉晶型为A型,结晶度为35.625%-40.050%,比小米淀粉(32.58%±0.96%)高;粳糜淀粉的平均冻融析水率(52.1%)与小米淀粉(53.5%±0.24%)相似,冻融稳定性差;粳糜淀粉的峰值黏度(均值0.953 Pa·s)小于小米淀粉(1.169 Pa·s),抗老化能力(0.595 Pa·s)高于小米淀粉(1.144 Pa·s),但糊化温度(78.296℃)比小米淀粉(76.20℃)高;粳糜淀粉凝胶的硬度(1018.1 g)和弹性(0.86 mm)大于小米淀粉凝胶,黏聚性(0.39)小于小米淀粉凝胶(0.43).

The starch was extracted from 7 kinds d japonica proso millet and millet by Alkali soaking method so as to compare their physicochemical properties. The results showed that, the shapes of japonica proso millet and millet starches were similar. The range of granule size was 4.32 -11.04 μm. The mierocrystalline structures of both japonica proso millet and millet starches were type A. The degree of crystallization of japonica proso millet starch was 35. 625% - 40. 050%, higher than millet starch （ 32.58%-0.96% ）. The syneresis rate of japonica proso millet （52.1%） and millet （53.5%-0.24% ） starches were similar, therefore, both japonica proso millet and millet starches had poor freeze-thaw stability. The peak viscocity of japonica proso millet （0.953 Pa·s） was lower than millet starch （1.169 Pa·s）, but the anti-aging ability （0.595 Pa·s） was higher. The pasting temperature （78.296 ℃ ） of japonica proso millet was higher than millet starch （76.20 ℃ ）. The hardness （1018.1 g） and springi- ness （0.86 mm） of japonica proso millet starch gel was higher than millet and the cohesiveness （0.39） was lower than millet starch gel （0.43）.