Metabolic and physiological responses of adzuki bean sprouts to led light qualities: yield-quality trade-offs and targeted spectral optimization

This study elucidated the regulatory effects of LED light qualities on functional components and amino acids in two adzuki bean sprout cultivars, focusing on food chemistry-based quality control. Darkness and red light promoted hypocotyl elongation and edible yield, while blue light significantly enhanced the accumulation of vitamin E (58-fold higher than D), vitamin C, soluble protein, and flavonoids, as well as DPPH free radical scavenging capacity. Light quality treatment (especially blue light) significantly increased the content of total free amino acids and 17 amino acids (including essential amino acids and sulfur-containing amino acids) compared to the darkness, Moreover, there were differences in amino acid metabolism among different genotypes. Red light benefits industrial yield, while blue light improves nutritional and functional quality, which may be associated with the regulation of nitrogen assimilation and secondary metabolism. These findings provide a LED light-quality-based technical strategy for precision production of high-functional-value adzuki bean sprouts.