食品科学 ›› 2022, Vol. 43 ›› Issue (23): 89-96.doi: 10.7506/spkx1002-6630-20211104-056

• 食品工程 • 上一篇    下一篇

超声波处理对糯米全粉凝胶特性的影响及其机制

杨秋晔,刘亚伟,刘洁   

  1. (河南工业大学粮油食品学院,河南 郑州 450001)
  • 出版日期:2022-12-15 发布日期:2022-12-28

Effect and Possible Mechanism of Ultrasonic Treatment on the Gel Properties of Waxy Rice Flour

YANG Qiuye, LIU Yawei, LIU Jie   

  1. (College of Food Science and Engineering, Henan University of Technology, Zhengzhou 450001, China)
  • Online:2022-12-15 Published:2022-12-28

摘要: 为探究超声波处理对糯米全粉凝胶特性的影响及其作用机制,本实验以糯米全粉为原料,以反映凝胶黏弹性的损耗角正切值(tan δ)为优化指标,采用正交试验优化超声波处理糯米全粉的条件,得到最佳工艺参数为:超声波功率130 W、超声时间20 min、料液比1∶2,在此条件下糯米全粉凝胶的tan δ为0.82。通过扫描电子显微镜观察到原糯米全粉(waxy rice flour,WRF)中的淀粉颗粒团聚在一起,超声波处理糯米全粉(ultrasound treated waxy rice flour,UT-WRF)中的淀粉颗粒分散分布。UT-WRF凝胶的储能模量(G’)、损耗模量(G’’)、硬度、弹性均小于WRF凝胶,而峰值黏度和黏附性均大于WRF凝胶。淀粉作为糯米全粉的主要组分,质量分数达84.34%;分析从WRF和UT-WRF中提取的淀粉发现,两种淀粉的形态结构、糊化特性、冻融稳定性、流变学特性、质构特性均无明显变化。对比从UT-WRF与WRF中提取的蛋白质对比发现,UT-WRF中提取的蛋白质结构松散,孔洞密集,β-折叠与无规卷曲相对含量显著上升,二硫键含量以及热稳定性显著下降(P<0.05)。结论:超声波处理糯米全粉时,主要是通过改变其中第二大组分蛋白质基质的构象从而改变全粉的凝胶特性。

关键词: 糯米全粉;蛋白质;淀粉;超声波处理;凝胶特性

Abstract: This study was undertaken in order to explore the effect and possible mechanism of action of ultrasonic treatment on the gel properties of waxy rice flour. An orthogonal array design was applied to optimize the conditions of ultrasonic treatment based on loss tangent (tan δ) as a measure of gel viscoelasticity. The optimum process parameters were determined as follows: 130 W of ultrasonic power, 20 min of ultrasonic time, and 1:2 of solid-to-liquid ratio. The tan δ value of the rice flour gel treated under the optimized conditions was 0.82. The scanning electron micrographs showed that starch granules in waxy rice flour (WRF) were aggregated and became dispersed after ultrasound treatment. Moreover, the storage modulus (G’), loss modulus (G’’), hardness and springiness of WRF decreased, while the peak viscosity, and adhesiveness rose. The starch content of WRF was 84.34%. Ultrasound treatment had no significant effect on the granular morphology, gelatinization properties, freeze-thaw stability, rheological properties or texture properties of starch from WRF. The structure of proteins from ultrasound-treated WRF was looser with more holes in it, the relative contents of β-sheet and random coil significantly increased, and the disulfide content and the thermal stability significantly decreased as compared to proteins from WRF (P < 0.05). In conclusion, ultrasound treatment can change the gel properties of WRF by changing the conformation of proteins in it.

Key words: waxy rice flour; protein; starch; ultrasonic treatment; gel properties

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