Laser-driven sustainable modulation of growth, metabolomics, bioactive compounds, and physical attributes in broccoli, radish, and kale sprouts

Abstract

Sprouts are valued for their bioactive compounds, yet conventional methods limit their biochemical potential. This study introduces a laser treatment (450 nm, 85 mW) to enhance the biochemical and physicochemical quality of broccoli, radish, and kale sprouts. Laser-treated seeds were germinated at 25 °C for 120 h and assessed for germination rate and biochemical properties, including total phenolics (TPC), flavonoids (TFC), antioxidant activity (DPPH), γ-aminobutyric acid (GABA), and phenylalanine ammonia-lyase (PAL) activity. UHPLC-HRMS-based metabolomics revealed enhanced glucosinolate and flavonoid pathways. Optimal exposure (180 s) significantly increased TPC (broccoli: 22.6, radish: 25.2, kale: 27.8 mg GAE/g), TFC (broccoli: 42.7, radish: 53.4, kale: 54.4 mg QE/g), and antioxidant activity (broccoli: 10.95, radish: 20.68, kale: 25.09 μmol TE/g). Laser treatment also elevated GABA (broccoli: 4.5, radish: 4.2, kale: 4.8 mg/100 g) and PAL levels (broccoli and kale: 17, radish: 15 mg/h/100 g). SEM, DSC, and texture analyses indicated greater surface roughness, improved thermal stability (ΔTd = +6–8 °C), and reduced compressibility (16–20 %) , reflecting beneficial physicochemical modifications.