食品科学 ›› 2020, Vol. 41 ›› Issue (11): 22-27.doi: 10.7506/spkx1002-6630-20190611-118

• 基础研究 • 上一篇    下一篇

黄变对大米流变特性以及内部结构的影响

肖悦,刘敏,刘金光,孙辉,张志平,周中凯   

  1. (1.天津科技大学食品工程与生物技术学院,天津 300457;2.国家粮食和物资储备局科学研究院,北京 100037;3.广东环境保护工程职业学院食品工程系,广东 佛山 528216)
  • 出版日期:2020-06-15 发布日期:2020-06-22
  • 基金资助:
    “十三五”国家重点研发计划重点专项(2016YFD0400104-4)

Effect of Postharvest Yellowing on Rheological Properties and Internal Structure of Rice

XIAO Yue, LIU Min, LIU Jinguang, SUN Hui, ZHANG Zhiping, ZHOU Zhongkai   

  1. (1. College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; 2. Academy of National Food and Strategic Reserves Administration, Beijing 100037, China; 3. Department of Food Engineering, Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China)
  • Online:2020-06-15 Published:2020-06-22

摘要: 本实验通过测定黄变前后大米的流变性能以及热特性、黏度和结构,研究黄变前后大米内部结构的差异性。结果表明,黄变米的总色差降低,直链淀粉质量分数升高,支链淀粉质量分数、蛋白质量分数以及脂肪质量分数降低,糊化温度升高,黏度及崩解值降低,流变学特性分析结果表明黄变后大米的储能模量和损耗模量相应降低,颗粒分子间缔合、排列紧密,流动性和耐剪切性增强,触变环面积减小,表现出明显的非牛顿流体特征。大米的傅里叶变换红外光谱无明显差异,但黄变米在1 047 cm-1及1 022 cm-1处峰强度比值增加,说明黄变会使大米内部短程有序结构含量增加。通过研究黄变前后大米内部结构的差异性,有助于建立黄变预警机制以及黄变米的工业应用。

关键词: 大米, 黄变, 流变特性, 分子结构, 淀粉

Abstract: In the present study, postharvest yellowing rice (PHY) and normal rice flours were evaluated by measuring their rheological, thermal, viscosity and structure properties and the differences in their internal structure were investigated. The results showed that a decrease in total color difference, increase in the content of amylopectin, decrease in the contents of amylopectin, protein and lipid, elevation in gelatinization temperature, and reduction in viscosity and breakdown value were found in PHY as compared to normal rice flour. The rheological properties indicated that the storage modulus and loss modulus of PHY decreased relative to the control, and the molecules were closely arranged, along with enhanced fluidity and shear resistance, and reduced thixotropic loop area, suggesting that PHY had distinct non-Newtonian fluid characteristics. There was no significant difference between the infrared spectra of PHY and normal rice except that the peak intensity of PHY at 1 047 and 1 022 cm-1 was increased when compared with normal rice, which indicated that postharvest yellowing will increase the short-range ordered structure of rice. Exploring the differences in internal structure and rheological properties between PHY and normal rice will be helpful to establish a rice yellowing early warning system and extend the application of postharvest yellowing rice.

Key words: rice, postharvest yellowing, rheological properties, molecular structure, starch

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