Research on Physicochemical Properties and Molecular Structure of Black Rice Flour Mixed with Different Starches

Abstract

In order to improve the gel properties of black rice, mung bean starch, potato starch and corn starch were mixed with black rice flour. The pasting properties and texture properties of compounded system, and the molecular structure characteristics of the complex system were tested, and further analyzed by low-field NMR analyzer, Fourier transform infrared spectroscopy and X-ray diffraction. The results showed that with the increase of starch concentration, the pasting viscosity of the starch-black rice flour complex system increased significantly, while the pasting time and temperature were reduced. Mung bean starch and potato starch significantly enhanced the water holding capacity and swelling capacity of the compound system, while potato starch and corn starch significantly reduced the solubility. All three starches promoted the formation of the gel network structure and improved the texture properties of the gel, including the hardness, elasticity, chewiness and resilience of the gel. In addition, the three starches enhanced the hydrogen bond interaction between the starch chains of the compound system, reduced the water holding capacity of the gel, and enhanced the molecular short-range structure order and relative crystallinity of the system. The above research showed that three kinds of starch improved the quality of black rice gel, and mung bean starch had the best improvement effect.

Keywords

• starch
• black rice flour
• pasting property
• texture
• molecular structure characteristic