UV-B Radiation as Abiotic Elicitor to Enhance Phytochemicals and Development of Red Cabbage Sprouts

Abstract

Background: The main objective of this study was to evaluate the effect of periodical UV-B illumination during red cabbage germination on morphological development and the phenolics and carotenoid accumulation. Methods: During a sprouting period of 10 days at 20 °C in darkness, seedlings received 5, 10, or 15 kJ m−2 UV-B (T5, T10, and T15) applied in four steps (25% on days 3, 5, 7, and 10). UV untreated sprouts were used as control (CTRL). After 10 days of germination, the sprouts were harvested and stored 10 days at 4 °C as a minimally processed product. Phenolic and carotenoid compounds were analysed 1 h after each UV-B application and on days 0, 4, 7, and 10 during cold storage. Results: The longest hypocotyl length was observed in T10-treated sprouts. The total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant capacity (TAC) increased during germination following a sigmoidal kinetic, especially in the UV-B-treated samples, which reported a dose-dependent behaviour. In this way, T10-treated sprouts increased the TPC by 40% after 10 days at 4 °C compared to CTRL, while TAC and TFC increased by 35 and 30%, respectively. Carotenoids were enhanced with higher UV-B doses (T15). Conclusions: We found that UV-B stimulated the biosynthesis of bioactive compounds, and a dose of 10 kJ m−2 UV-B, proportionally applied on days 3, 5, 7, and 10 days, is recommended.

Comprehensive Modulation of Secondary Metabolites in Terpenoid-Accumulating Mentha spicata L. via UV Radiation

“…Carotenoids are known to be strong antioxidants and are involved in plant photoprotection, playing a central role in the dissipation of excessive light energy [95]. Many studies have found a stimulatory effect of UV on carotenoids, suggesting a conserved response [6,26,44,45,96]. However, the results of this study showed that carotenogenesis was not affected immediately after the application of a low dose of UV.…”

Effect of Ultrasound-Assisted Extraction with Probe or Bath on Total Phenolics from Tomato and Lemon By-Products

“…The determination of TPC was carried out according to the method described by Singleton and Rossi [7] with some modifications by Martínez-Zamora et al [8]. The TPC was calculated using a gallic acid standard and expressed as g of gallic acid equivalent per kg of dried weight (g GAE/kg dw).…”

Effect of postharvest UV-B and UV-C radiation on the bioactive quality of broccoli and radish sprouts

“…Total antioxidant capacity was determined through the free radical scavenging capacity generated by DPPH• and ABTS+. In the DPPH assay [12] , 194 μL of DPPH• solution was added to 21 μL of sprout extract [13] in a 96-well plate. The mixture was incubated for 30 min at room temperature in the dark.…”

“…The ABTS assay was performed following the method described by Martínez-Zamora et al [14] . For this, 200 μL of activated ABTS + solution (32 µM) was added to 11 μL of sprout extract [13] in a 96-well plate, incubated for 20 min at room temperature in the dark, and changes in absorbance at 414 nm were measured. Each sample was analyzed in triplicate.…”