摘要
以小麦淀粉为原料,采用微波湿热-循环冷冻的方法制备抗性淀粉。利用扫描电镜(SEM)、红外光谱仪(IR)、X-衍射仪、差式扫描量热仪(DSC)研究了抗性淀粉的颗粒形貌、结晶结构、热力学性质。试验结果表明:在淀粉乳质量分数25%,微波功率700 W,微波时间2 min,循环冻融6次(-18℃冷冻4 h,解冻1 h为1次冻融处理),抗性淀粉得率为15.85%。扫描电镜显示抗性淀粉由原来光滑球形变为表面粗糙的不规则片层结构;X-射线衍射图谱显示抗性淀粉的结晶结构由原淀粉的A型转变为更加稳定的B+V型;红外图谱表明(1 045/1 022)cm^(-1)峰强度比值增大,抗性淀粉颗粒内有序度增加;DSC图谱表明在115℃由于直链淀粉晶体熔融时吸热而造成1个较大的吸热峰,其热焓值为2 231 J/g,与原淀粉相比明显增大,表明抗性淀粉因直链淀粉重结晶形成,淀粉抗酶解作用增强。
Resistant starch was prepared under a combination of microwave and heat - moisture treatments and cycle freezing of wheat starch. Granule morphology, crystal structure, thermodynamic properties of resistant starch were studied by scanning electron microscopy （SEM）, infrared spectrometer （IR）, X -diffraction, differential scanning calorimetry （DSC）. The experimental results showed that the yield of resistant starch was 15.85% at the condition of the mass fraction of starch solution 25 % , the power of microwave 700 W, the time of microwave 2 min, the cycles of freezing and thawing 6 （ freezing 4 h at - 18 ~C, thawing 1 h . Scanning electron microscopy showed that the resistant starch increased from smooth spherical surface roughness becomes lamellar structure. X - ray diffraction pat- tern showed that the original crystalline structure of starch resistant starch type A converted to a more stable type B ＋ V. IR spectra showed that （1 045/1 022） cm-1 peak intensity ratio increased, the increase in resistant starch granule degree of order. DSC spectra showed that due amylose crystal melting endotherm caused when a large endothermic peak at 115 ℃, the enthalpy value of RS was 2 231 J/g and the value increased significantly as compared to native starch, indicated that the recrystallization increased of RS and enzymatic stability enhancement.
出处
《中国粮油学报》
EI
CAS
CSCD
北大核心
2017年第10期49-53,共5页
Journal of the Chinese Cereals and Oils Association
基金
国家重点研发计划课题(2016YFD0400203)
河南省科技攻关(162102210039)
关键词
抗性淀粉
微波
反复冻融
DSC
X-射线衍射结晶
resistant starch, microwave, freezing and thawing, differential scanning calorimetry, X -ray diffraction, crystallization
