藜麦淀粉和藜麦抗性淀粉的理化性质

Physicochemical Properties of Quinoa Starch and Quinoa Resistant Starch

该文以藜麦为原料,提取藜麦淀粉(quinoa starch,QS),通过糊化老化、磷酸化交联和淀粉-脂质复合物形成的方法分别制备三型、四型和五型藜麦抗性淀粉(quinoa resistant starch,QRS),对比分析4种淀粉的理化性质。结果表明:温度为55~85℃时,QS的持水性高于其他3种抗性淀粉,较高的持水性使其析水率降低,因此,QS的冻融稳定性最强。QS的糊化温度为62.32℃,淀粉糊为假塑性流体,呈现弱凝胶特性。QS的透明度和溶解度都低于QRS3,但与QRS4和QRS5没有显著性差异。3种抗性淀粉的膨胀度都低于QS,其中QRS3的膨胀度最低。QRS5的碘吸收曲线在相同波长下的吸光度最大,说明QRS5中直链淀粉含量最高。3种抗性淀粉的抗消化性都优于QS。综上所述,藜麦淀粉和3种藜麦抗性淀粉在理化性质上存在较大差异。

Quinoa starch(QS)was extracted from quinoa.The types 3,4,and 5 quinoa resistant starch samples(QRS)were prepared via pasting and retrogradation,phosphorylation crosslinking,and starch-lipid complex formation,respectively.The physicochemical properties of the four kinds of starch samples were compared.The results showed that the water-holding capacity of QS was higher than in the other three resistant starch samples within the temperature range of 55-85℃.Since the higher water holding capacity reduced the water segregation rate,QS displayed the strongest freezing-thawing stability.QS had the gelatinization temperature of 62.32℃,and the starch paste was a pseudoplastic fluid with weak gel characteristics.Although QS had lower transparency and solubility than QRS3,it displayed no differences in the two properties from QRS4 and QRS5.The swelling power of the three resistant starch samples was lower than that of QS,with QRS3 displaying the lowest value.The iodine absorption curve of QRS5 exhibited the largest absorbance value at the same wavelength,indicating that QRS5 had the highest amylose content.The three resistant starch samples were superior to QS in terms of anti-digestibility.In conclusion,the differences in the physicochemical properties were evident between QS and the three quinoa resistant starch samples.