蕨根淀粉颗粒形貌与糊化黏度特性

以马铃薯淀粉和红薯淀粉为对照,研究了蕨根淀粉的颗粒形貌及糊化黏度特性。蕨根淀粉颗粒多为圆形或椭圆形,少数呈棒状,颗粒表面光滑。颗粒大小差异较大,粒径为5~31μm。蕨根淀粉颗粒具有可见偏光十字,偏光十字位于颗粒一端,呈"Ⅹ"。蕨根淀粉的起糊温度明显低于红薯淀粉,与马铃薯淀粉相当。蕨根淀粉糊具有较好的热稳定性,较高的回生值,适宜加工粉丝类产品。蔗糖、NaCl、碱面和明矾的添加及pH值对蕨根淀粉糊化特性有影响。蔗糖使蕨根淀粉糊黏度增大;NaCl可提高蕨根淀粉糊的热稳定性,延缓体系老化;碱面、明矾的添加使蕨根淀粉糊的热稳定性下降;蕨根淀粉糊耐酸性差,在酸性条件下,蕨根淀粉发生明显水解作用,体系黏度降低。

Granule Characteristics and Pasting Properties of Fern-root Starch

In order to exploit its utilization,granule morphology and pasting properties of fern-root starch were studied,and compared with potato and sweet potato starch.Fern-root starch granules are roundness,elliptical oval or rod-shaped,having different size which varies from 5 to 31μm.The surface is smooth.It had a polarizing cross,which showed a "Ⅹ" shape.The pasting temperature of fern-root starch was similar to potato starch,lower than sweet potato starch.Fern root starch paste with good thermal stability and high setback is suitable for noodle.Gelatinization properties of fern-root starch were affected by the change of pH and the addition of sucrose,salt,dietary alkali and alum.Sucrose increased the viscosity of the starch.Salt increased thermal stability and descended aging level.Alkali and alum decreased starch thermal stability.The fern-root starch had poor acid resistance,which hydrolyzed apparently under acidic condition,and its viscosity was reduced.