低聚果糖对大米淀粉回生特性的影响

Effects of Fructose-Oligosaccharides on Retrogradation Characteristics of Rice Starch

为明确低聚果糖对大米淀粉回生特性的影响,以广泛报道的抗回生添加剂β-环糊精为对照,研究低聚果糖处理对大米淀粉的回生值、析水率、硬度、直链淀粉浸出量和动态流变学的影响,并利用傅里叶变换红外光谱、低场核磁共振、扫描电镜、X射线衍射和激光共聚焦扫描显微镜对大米淀粉的回生特性进行分析。结果表明,与空白对照组(大米淀粉)相比,低聚果糖处理后能显著降低大米淀粉糊化后的峰值黏度、终值黏度和回生值。此外,在短期冷藏后低聚果糖处理组大米淀粉的析水率、硬度和渗漏直链淀粉含量分别显著降低了21.82%、16.26%和17.25%,有利于提高大米淀粉的保水性和稳定性。同时,低聚果糖处理组的储能模量、水流动性、相对结晶度降低和红外1 047 cm^(-1)/1 022 cm;比率降低,网络结构更加紧密,表现出较好的抗回生性。因此,低聚果糖在延缓以大米淀粉类产品的回生方面具有较大潜力。

To identify the effects of fructo-oligosaccharides on retrogradation characteristics of rice starch,we determined the setback viscosity,syneresis rate,firmness,amylose leaching,and dynamic rheology of rice starch paste blended with fructo-oligosaccharides in contrast to the widely reported anti-retrogradation additiveβ-cyclodextrin.The retrogradation characteristics of rice starch were analyzed by Fourier transform infrared (FTIR) spectroscopy,low field nuclear magnetic resonance (LF-NMR),scanning electron microscopy (SEM),X-ray diffraction (XRD) spectroscopy,and confocal laser scanning microscopy (CLSM).The results showed that fructo-oligosaccharide treatment significantly decreased the peak viscosity,final viscosity and setback value of gelatinized rice starch paste.In addition,after short-time refrigeration,fructo-oligosaccharide-treated rice starch exhibited lower syneresis rate (21.82%),hardness (16.26%) and amylose leaching (17.25%),indicating that fructo-oligosaccharides could improve the water retention and stability of rice starch.Also,fructose-oligosaccharides decreased the storage modulus,water mobility,relative crystallinity,and ratio between transmittance at wavenumbers of 1 047 and 1 022 cm^(-1) of rice starch paste,and made the network structure become more compact,showing better anti-retrogradation efficiency.Therefore,fructo-oligosaccharides have excellent potential in delaying the retrogradation of rice starch-based foods.