为研究微波对马铃薯淀粉单、双螺旋结构和消化性的影响及消化性与单、双螺旋 结构之间的关系，分别以 2． 06W/g 和 6． 63W/g 的微波功率处理马铃薯淀粉，通过差示扫 描量热仪、X 射线衍射、¹³C CP/MAS NMＲ 以及体外消化性测定等方法对微波处理前后淀 粉的单、双螺旋结构和消化性进行比较分析． 发现: 随着微波功率的增加，淀粉的单、双螺 旋含量降低，无定形含量增加，糊化热焓和相对结晶度降低; 低功率( 2． 06W/g) 微波对消 化性影响较小，而高功率( 6． 63 W/g) 微波显著降低了马铃薯淀粉的抗性淀粉含量，相应 地提高了慢消化淀粉 SDS 和快消化淀粉 ＲDS 的含量; 微波会破坏淀粉内部单、双螺旋结 构，使其含量降低，且随着功率的增加，破坏程度增大; 淀粉内单、双螺旋含量的降低引起 消化性的改变，低功率微波使其降低较少，因而对消化性影响较小，而高功率微波使其显 著降低，因而显著改变了淀粉的消化性．

Potato starch was microwave-treated respectively with the power of 2. 06 and 6. 63W/g,and the single and double-helical structures of native and microwave-treated starches and their digestibility were analyzed by means of DSC,XRD,¹³C CP/MAS NMR and in vitro digestion，so as to reveal the effects of the microwave treat- ment on the single and double-helical structures and digestibility of the potato starch as well as the relationship be- tween the single and double-helical structures and the digestibility.The results show that (1) as the microwave power increases,the contents of the single helix，the double helices,the gelatinization enthalpy and the relative crystallinity decrease,while the amorphous components increase; (2) the low-power (2. 06W/g) microwave has a small effect on the digestibility,while the high-power (6. 63W/g) microwave significantly decreases the content of the resistant starch and correspondingly increases the contents of the slowly-digestible starch and the rapidly-di- gestible starch; (3) the microwave treatment destroys the internal single and double-helical structures of the starch and thus decreases their contents，and the extent of the destruction gradually increases with the increase of the mi- crowave power; and (4) the reduction in the contents of the single and double-helical components causes the starch digestibility to change.In addition,the low-power microwave rarely decreases the contents of the single and double-helical components and thus hardly influences the starch digestibility,while the high-power microwave sig- nificantly decreases the contents of the single and double-helical components and thus results in a drastic change in the starch digestibility.