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Eruca sativa is a leafy vegetable widely consumed fresh in salads and recognized for the presence of bioactive compounds, such as glucosinolates (GLS) and flavonols. This plant is traditionally cultivated in soils but adapts well to soilless cultures, such as hydroponics and aquaponics. However, despite the good results in the literature on E. sativa cultivation in soilless systems, the influence of the culture systems and harvest time on the specialized metabolite-based chemical composition of E. sativa leaves is not entirely understood. Based on the above, this study aimed to evaluate the specialized metabolite composition of three different cultivation types, i.e., using soil (SCS), nutrient film technique (NFT)-based hydroponic (HCS), and aquaponic (ACS) culture systems, along three growing cycles, and collected at two commercial harvest times, i.e., 21 days after transplanting (DAT) to get early plant material, namely “baby leaf”, and 42 DAT as the traditional harvest time. The chemical composition was obtained by liquid chromatography coupled with mass spectrometry (LC-MS), and multivariate statistics supported the analysis of the whole dataset. The SCS was characterized to promote an important accumulation of two antioxidant flavonols, i.e., (kaempferol and isorhamnetin diglucopyranosides) in young leaves (21 DAT). The hydroponically-grown plants exhibited a smaller number of various compounds. The ACS-cultivated leaves accumulated indole-containing glucosinolates and a marker associated with harvest time, spirobrassinin, a cruciferous oxindoline phytoalexin. These findings constitute the first report of those compounds relevantly accumulated by the effect of soilless cultures and a starting point for further studies related to the metabolite regulation of E. sativa under hydroponics and aquaponics.

Integrated surveys of metabolic profiles and antioxidant capacity from Chenopodium quinoa have been limited and have particularly focused on an examination of seeds and leaves. According to this, the main aim of the present study was to address an evaluation of the antioxidant activity of crude ethanolic extracts from different plant parts (leaves, stems, roots, flowers, and seeds) harvested at different times during growth and processed by two distinct drying methods: Air-drying and freeze-drying. In order to characterize the resulting extracts, the total content of phenolics (TPC) and flavonoids (TFC) was then measured through the Folin−Ciocalteu method, while antioxidant capacity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH•) free radical scavenging and ferric-reducing antioxidant power (FRAP) methods. Parallel to this evaluation, extracts were profiled by LC-DAD-ESI-MS. Data analysis was supported by statistics. Most of the extracts obtained from freeze-dried samples showed higher TPC values ranging from 6.02 to 43.47 milligram of gallic acid equivalents per gram of plant material and a TFC between 1.30 and 12.26 milligram of quercetin equivalents per gram of plant material. After statistical analysis, a low correlation between TPC and TFC values was observed regarding antioxidant capacity from DPPH and FRAP measurements of both drying methods. A multivariate analysis showed that antioxidant components and antioxidant capacity in C. quinoa changed during growth and between plant parts and drying methods. These changes need to be taken into consideration when comparing the production/accumulation of beneficial bioactive compounds in this pseudocereal.