Changes in Quality Characteristics and Flavor Components of Quinoa Rice during Storage at Room Temperature

Quinoa is a specialty grain that meets humanity's basic nutritional needs. This article explored the quality changes of quinoa rice during storage at room temperature, which could promote the development of quinoa as a staple food. Quinoa rice was stored at 20 ℃ for various periods, including 0, 1, 5, 10, and 15 days. The texture characteristics, retrogradation, and dynamic change rules of flavor compounds of quinoa rice were determined by colorimeter, texture analyzer, X-ray diffractometer, differential scanning calorimetry and gas chromatography-mass spectrometry. The results showed that the ΔE^* of quinoa rice increased from 2.78 to 7.45, and the hardness increased from 0.61 N to 0.89 N after 15 days. The sensory evaluation score significantly decreased from 98.25 points to 65.40 points after 15 days (P<0.05). The ΔΗ significantly increased from 1.83 J/g to 15.51 J/g, and crystallinity increased dramatically from 4.82% to 10.71% (P<0.05) after 15 days. With the extension of storage time, the surface and cross-section of quinoa rice gradually changed rough, which was attributed to water evaporation and starch retrogradation. In terms of flavor substances, the relative contents of typical ones such as nonadecane and methyl palmitate in quinoa rice gradually decrease. Off-flavor compounds like benzaldehyde appeared after 10 days of storage, while phytone, 1-octen-3-ol, and methyl oleate emerged after 15 days of storage. The results of this experiment provide a theoretical foundation for developing quinoa rice products stored at room temperature.