Análise fitoquímica experimental em microverdes de coentro produzidas em luz branca e proporções de luz vermelha e azul

Abstract

Microgreens are plants with cotyledons present and up to one pair of developed leaves. They are considered superfoods and harvested before their physiological maturity point, in addition to having a higher concentration of metabolites, vitamins and minerals, making them ideal for human consumption. In this context, coriander (Coriandrum sativum) stands out as a viable species for cultivation in this production style due to its compact size, short harvest period and health benefits. Therefore, the objective of this study was to conduct an experimental phytochemical analysis of coriander microgreens under different light ratios to identify the presence or absence of major bioactive metabolite groups. The study was conducted at the Northeast Olericulture Study Center (NEON), where polypropylene trays were filled with washed coconut coir and vermiculite in a 5:1 ratio. Sowing was done using the SSS system (substrate - seed - substrate), with 17g of coriander seeds from the Verdão cultivar distributed per tray. These trays were irrigated with distilled water to field capacity, a condition maintained until the 4o DAS. The trays were placed on metal shelves, where three LED strips were installed for plant lighting and the treatments consisted of different light qualities for coriander microgreen cultivation, with white light as control and three red (R) to blue (B) light ratios, described as 3R:1B, 4R:1B and 5R:1B. The experimental design was randomized blocks, with each shelf representing a block with 4 replicates, and each block containing 3 trays. Factors such as photoperiod and temperature were controlled, and from the 4o DAS onward, the trays were irrigated with Hoagland and Arnon (1950) solution at ¼ strength. Harvesting was performed on the 15o DAS and three trays from each treatment were randomly selected for fresh weight determination, phytochemical and physicochemical analyses. Tests were performed to detect the presence of the following metabolites: steroids and triterpenes, anthraquinones, saponins, tannins, reducing sugars, flavonoids, anthocyanins, cardiac glycosides, coumarins, alkaloids and amides. In the physicochemical analyses, titratable acidity was determined. Quantitative variables such as fresh weight and titratable acidity were subjected to ANOVA and compared by Tukey's test at 5% significance. The results showed that the light spectrum influences biomass gain, with the best results achieved by the 4R:1B and 5R:1B treatments. The qualitative analysis demonstrated the presence of bioactive compounds, but a homogeneous profile among treatments, indicating little or no influence on the detected metabolites, suggesting a genetic factor in the composition of these compounds in plants during their juvenile stage.