Varietal differences in nutritional profiles and functionality of radish sprouts: Food application potential

Radish sprouts, are among the most popular cruciferous vegetables on the market, are widely cultivated worldwide. This study investigated the changes in nutrients, bioactive compounds, antioxidant properties, and the functional characteristics of eight radish sprout varieties (red, green, and purple radishes) throughout germination. After 216 h of germination, all radish varieties exhibited significant increases in vitamin C, anthocyanins, total phenolics, and total flavonoids compared to ungerminated seeds. Among the varieties, the purple radish R8 exhibited the highest levels of bioactive compounds, with anthocyanin (879.09 ± 14.90 mg/100 g DW) and glucosinolate (211.43 ± 4.50 μmol/g DW) reaching their peak concentrations. Concurrently, R8 also had the strongest antioxidant capacity, despite having a lower crude protein content (28.30 ± 0.62 % DW) than that of the red radish varieties R1 (33.08 ± 0.62 % DW) and R2 (32.65 ± 1.54 % DW). Furthermore, germination improved processing characteristics such as solubility and digestibility by modifying protein structural properties. The R8 variety exhibited the highest water solubility and digestibility, enhancing product functionality. GC-MS analysis identified 78 volatile compounds, and the unique colors and volatile flavor profiles of different varieties contribute to their distinct sensory properties. In summary, our findings confirm that germination can enhance the nutritional value and antioxidant capacity of radish sprouts, and the metabolic differences between genotypes lead to varied accumulation of bioactive compounds. Moreover, the improved water-holding capacity and emulsifying properties of the freeze-dried radish sprout powder exhibited that radish sprouts can not only be consumed as fresh vegetables with high nutritional value, their freeze-dried powder also has broad potential applications in the food industry.