Abstract:To extend the storage period of lotus roots, changes in the appearance, texture, starch microstructure, and total phenol and phenolic acid contents of “Elian 5” lotus roots stored at -1 ℃ were compared with those stored at 4 ℃. The results demonstrated that storage at -1 ℃ could delay changes in the appearance of the lotus roots as well as the decreases in their L* value and total phenol content. The hardness and elasticity of the lotus roots stored at -1 ℃ were respectively 16.88% and 21.43% higher than those of roots stored at 4 ℃. However, the lotus roots stored at the two temperatures exhibited no significant differences in their chewiness (p>0.05). Moreover, storage at -1 ℃ alleviated breakage of the starch granules, thereby preserving their luster and cell wall arrangement. High-performance liquid chromatography analysis of the variations in phenolic acid contents revealed that storage at -1 ℃ could inhibit the increase in gallic acid and chlorogenic acid contents, thus suppressing the formation of browning substrates. Furthermore, the flavonoid content of the freezer-stored lotus roots decreased more slowly, while the content of non-flavonoids remained more or less unchanged. In summary, freezing storage can delay the quality deterioration of lotus roots and effectively maintain their phenolic acid content. These findings provide a theoretical reference for the prolonged storage of lotus roots.
