Produtividade e atividade antioxidante do broto de feijão mungo-verde (Vigna radiata L.) em função de elicitores

Abstract

The present work is aimed at giving subsidies for professionals to produce food with aggregate or functional qualities, providing healthier options for consumers. The goal was to verify the effects of the exogenous application of salicylic acid (SA), ascorbic acid (AA) and tocopherol for the production of biomass and the contents of antioxidant phenolic compounds in mung bean sprouts (Vigna radiata L.). The experiment was conducted at the UNOESTE seed laboratory, in an experimental design that was entirely randomized, repeated four times, and analyzed through ANOVA and the Tukey test (p<0,05) for the comparison of means. The seeds were divided into 4 sub-samples composed of 50 seeds for each treatment. 12mL of distilled water was added, and the seeds were germinated under a constant temperature of 25 oC. 24 hours later, seedlings with uneven development (sprouting either too early or too late) were replaced with others in order to ensure a homogeneous set for each repetition. There were 4 trials with AS, in concentrations of zero; 115,1; 230,2 and 575,5 mg L-1 (one application of 12 mL of the solution; two applications of 12 mL; two applications of 6 mL and one application of 6 mL). Three trials were conducted with the AA, in concentrations of zero; 0,147; 1,468 and 14,68 g L-1 (one application of 12 mL of the solution; two applications of 12 mL; two applications of 6 mL). Three trials were conducted with the TOC, in concentrations of zero; 25; 50 and 100 mg L-1 (one application of 12 mL of the solution; two applications of 12 mL; three applications of 12 mL). The standard seedlings that were obtained five days after sowing were measured for the length of both the aerial part and the root and, after being segmented, were taken to a greenhouse set at 60 oC for 48 hours in order to obtain their dried masses. The same procedure was repeated in order to obtain dried ethanol extracts that were used to determine both their total fenol contents (TFC) and the antioxidant activity through the method of free radical DPPH. The hypocotyls were frozen (at -80 oC) in order to determine both their content of total soluble proteins and the activity of the superoxide dismutase (SOD) enzyme. The exogenous application of SA in a dosage of 230 mg L-1 did not exhibit negative effects on the growth parameters and increased both the content of total phenolic compounds and the antioxidant activity of the sprouts. It was concluded that, with respect to the AA, the lowest concentration (0,147 g L-1 in two applications of 6 mL of the solution) provided the best results for both sprout growth and the antioxidant power of the extracts. With respect to tocopherol, there was no statistical difference for different concentrations and number of applications made with respect to growth; however, the concentration of 25 mg L-1 increased the total phenol content of the extracts that were obtained, while the extract that was obtained with a concentration of 100 mg L-1 has shown a larger capacity of inhibiting the free radical DPPH with three applications of 12 mL of the solution. All the products that were used worked as stimulants of the antioxidant functions of the sprouts and, when in higher concentrations, they have reduced the biometric parameters, such that they were considered to be more adequate when in lower concentrations.