EVALUATION OF VARIABLES AFFECTING THE EXTRACTION OF COMPOUNDS FROM ARUGULA MICROGREENS GROWN UNDER DIFFERENT LIGHT SPECTRA

Abstract

This study aimed to evaluate the influence of different light spectra on the morphological, growth, and physicochemical characteristics of arugula microgreens, as well as to identify the process variables of ultrasound-assisted extraction that affect total phenolic content. Seeds of Eruca sativa Mill were grown in trays under a control treatment (white light without spectral filtering), as well as under yellow, green, and purple filters. Harvesting was performed seven days after sowing. The evaluated parameters included hypocotyl length, cotyledon length, shoot height, yield, fresh mass, dry mass, moisture content, and ash content. The extraction procedure was conducted using a 2⁴⁻¹ fractional factorial design with three center points, considering time, ultrasound amplitude, temperature, and solvent volume. Microgreens grown under green and purple light showed the highest values for growth and yield, with emphasis on hypocotyl length under green light (4.40 cm) and yield under purple light (91.90 g/m²). The highest moisture content was observed under purple light (95.15%). In the factorial design, temperature was the only significant factor affecting phenolic extraction (p = 0.029), whereas amplitude showed a tendency to influence the process (p = 0.106), but was not significant at the 5% level. It was concluded that spectral modulation during cultivation altered agronomic performance and biomass composition, while temperature was the main operational factor for maximizing the extraction of phenolic compounds.