食品科学 ›› 2019, Vol. 40 ›› Issue (17): 85-95.doi: 10.7506/spkx1002-6630-20190115-157

• 基础研究 • 上一篇    下一篇

不同糯米/粳米共混体系凝胶化行为及年糕品质

胡文轩,陈洁,许飞,陈玲   

  1. (1.河南工业大学粮油食品学院,河南?郑州 450001;2.华南理工大学食品科学与工程学院,广东?广州 510640)
  • 出版日期:2019-09-15 发布日期:2019-09-23
  • 基金资助:
    “十三五”国家重点研发计划重点专项(2016YFD04012021)

Effects of Different Glutinous and Japonica Rice Blends on Gelation Behavior and Quality of Rice Cake

HU Wenxuan, CHEN Jie, XU Fei, CHEN Ling   

  1. (1. College of Food Science and Technology, Henan University of Technology, Zhengzhou 450001, China; 2. College of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China)
  • Online:2019-09-15 Published:2019-09-23

摘要: 以糯米/粳米共混体系为对象,研究不同糯米、粳米质量比(糯粳比)对共混体系的糊化特性、流变学特性、傅里叶变换红外光谱及微观结构的影响,并对共混体系凝胶的动态流变学性质(储能模量(G’)、凝胶化速度(?g)与加速度(αg))加以分析,探究其凝胶化反应动力学行为,通过共混体系的特性分析年糕品质变化的原因。结果表明:糯米/粳米共混体系为弱凝胶体系,随糯米组分比例的增加,体系热糊的稳定性及冷糊的成胶性显著改变,黏度、衰减值及回生值显著减小(P<0.05),且非等温及恒温动态流变学特性中G’与?g降低,相位角正切(tan?δ)、活化能(Ea)及αg升高,频率扫描中糯粳比1∶2.5~1∶2.0共混体系的tan?δ曲线在低频区逐渐平滑;而低糯米组分共混体系(糯粳比1∶3.0~1∶5.0)在1∶3.0处的凝胶特性变化达到临界值,可形成较好的网格结构,且体系的吸水率较高,凝胶的稳定性较好。随糯米组分比例的增加,Power-Law拟合模型中的稠度系数及触变环面积减小,流动特性指数增大,即剪切稳定性、触变性更好,致使年糕的糊化度不断减小,在糯粳比1∶3.0时达到临界值90.48%;傅里叶变换红外光谱中997?cm-1/1?155?cm-1、1?020?cm-1/1?155?cm-1、1?654?cm-1/1?155?cm-1峰面积比的变化证明糯米组分比例的增加可增强共混体系键合水分子的能力,其键合的水分子通过与直链淀粉单螺旋结构之间的作用和扩大无定形区来改变凝胶化行为;糯粳比1∶3.0的共混体系无针状部分的形成,网格结构致密,且孔径大小及分布均匀,同时年糕的吸水率与弹性达到最大。

关键词: 糯米/粳米共混体系, 流变学特性, 凝胶化行为, 动力学, 傅里叶变换红外光谱, 年糕

Abstract: The gelatinization properties, rheological properties, Fourier transform infrared spectroscopy (FTIR) spectra and microstructure of glutinous (G) and japonica (J) rice blends at different ratios were studied. The gelation behavior was explored by analyzing storage modulus (G’), gelation velocity (?g) and gelation acceleration (αg) of the blend gels. The relationship of rice cake quality changes with the characteristics of the blend system was analyzed. The results indicated that the blend system was a weak gel system. The stability of hot paste and the gelling ability of cold paste considerably changed with the increase of glutinous rice, and the viscosity, breakdown and setback value decreased significantly (P < 0.05); the dynamic rheological properties G’ and ?g declined under both non-isothermal and isothermal conditions, whilst the opposite was true for the phase tangent (tan δ), activation energy (Ea) and αg. Meanwhile, in the frequency sweep, the tan δ curves of the blend systems with G/J ratio of 1:2.5–1:2.0 gradually became smooth in the low frequency range, while for the low-glutinous rice systems (G/J ratio = 1:3.0–1:5.0), the changes in gel properties reached a critical value at G/J ratio of 1:3.0, leading to the formation of a better network structure with higher water absorption rate and better gel stability. With increased proportion of glutinous rice, the consistency coefficient (K) from the Power-Law model and the thixotropic loop area decreased, and the flow characteristic index (n) increased, indicating good shear stability and thixotropy. As a result, in the gelatinization degree of rice cake decreased continuously, reaching a critical value of 90.48% at G/J ratio of 1:3.0. As indicated by the changes in peak area ratio at 997 cm-1/1 155 cm-1, 1 020 cm-1/1 155 cm-1, and 1 654 cm-1/1 155 cm-1 in the FTIR spectra, increased proportion of glutinous rice could enhance the water-binding capacity of the blend system, and the bound water molecules led to changes in the gelation behavior by interacting with the single helix structure of amylose and expanding the amorphous region. Therefore, the G/J ratio of 1:3.0 blend system formed a dense gel network structure without needle-like morphology and with uniform pore size distribution, and the resulting rice cake had the highest water absorption rate and elasticity.

Key words: glutinous/japonica rice blends, rheological property, gelation behavior, kinetics, Fourier transform infrared spectroscopy, rice cake

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