Enhancing Growth and Antioxidant Functionality of Hydroponic Barley Sprouts Through Light Treatments in Smart Farm Systems

Smart farming has emerged as a pivotal alternative for ensuring stable crop production by precisely modulating environmental variables, such as light and temperature, independently of fluctuating climatic conditions. This study aimed to verify the feasibility of mass-producing high-functional barley sprouts by scaling up laboratory-optimized growth conditions to a large-scale, commercial-grade smart farm system. After a 9-day cultivation period, the harvested barley sprouts under mixed LED treatment (SB3) exhibited significantly (p < 0.05) enhanced growth compared with other groups. Both antioxidant activity and functional metabolite accumulation were markedly superior in LED treatments (SB2, SB3) relative to those under fluorescent lamps; notably, SB3 yielded the highest concentrations of policosanol (155.70 ± 3.60 mg/100 g) and saponarin (178.7 ± 7.49 mg/100 g). Multivariate statistical analyses, including principal component analysis (PCA) and variable importance in projection (VIP), identified light intensity and germination rate as the most critical determinants, showing strong positive correlations with both biomass and functional compound accumulation (r = 0.812–0.994 and r = 0.830–0.945, respectively). Field-scale validation confirmed that the application of bio-blocks (B.B.) improved germination rates by over 80% compared to the control, demonstrating that high light intensity effectively synergizes with growth and functional enhancement. In conclusion, this study underscores that lab-scale optimization can be successfully translated to industrial-scale smart farms. These findings provide a robust strategic foundation for the mass production of high-value functional ingredients and are expected to contribute considerably to the advancement of sustainable, controlled-environment agriculture.