Enhancing glucosinolate profiles in broccoli (Brassica oleracea) sprouts via electron beam irradiation: A functional food approach.

Developing non-thermal technologies to enhance health-promoting compounds is important for producing high-value functional foods. This study compared the effects of electron beam irradiation (EBI) applied to dry broccoli seeds before germination (FZZZ) with those of direct irradiation of sprouts (FZYM) on glucosinolate (GSL) enhancement. Low-dose FZZZ (2 kGy) increased total GSL content to 6556.85 μg/g, compared with 3174.58 μg/g in the control, whereas low-dose FZYM decreased total GSL content. Sprouts grown from irradiated seeds also showed increased vitamin C, soluble sugars, total free amino acids, and volatile sulfur-containing compounds. Metabolomic and amino acid analyses indicated that FZZZ increased the availability of sulfur amino acid precursors and remodeled methionine- and phenylpropanoid-related metabolism, whereas FZYM mainly induced stress-associated changes in lipid and nucleotide metabolism. qRT-PCR revealed selective regulation of genes involved in downstream GSL modification and hydrolysis rather than a coordinated activation of the entire GSL biosynthetic pathway. Overall, seed-stage EBI at 2 kGy is a promising strategy for enhancing GSL content in broccoli sprouts while maintaining growth and nutritional quality.