Characterization of industrial broccoli discards (Brassica oleracea var. italica) for their glucosinolate, polyphenol and flavonoid contents using UPLC MS/MS and spectrophotometric methods

Abstract

The agrifood industry produces tons of waste and substandard products that are discarded at great expense. Valorization of industrial residues curbs issues related to food security and environmental problems. Broccoli (Brassica oleracea var. italica) is associated with varied beneficial health effects, but its production yields greater than 25% rejects. We aimed to characterize and quantify industrial broccoli by-products for their glucosinolate and polyphenol contents as a first step towards industrial bio-refining. Broccoli segments and rejected lots of 10 seed cultivars were analyzed using UPLC MS/MS. Variability in the contents of bioactive molecules was observed within and between the cultivars. Broccoli by-products were rich in glucosinolates (0.2-2% dry weight sample), predominantly glucoraphanin (32-64% of the total glucosinolates), whereas the polyphenolic content was less than 0.02% dry weight sample. Valorization of industrial residues facilitates the production of high value functional food ingredients along with socio-economic sustainability.

Keywords: Agrifood industry; Broccoli by-products; Food recovery; Functional food supplements; Glucosinolates; Polyphenols; Socio-economic sustainability; Valorization.