Prospecção Química e Biológica de Flores de Viola x wittrockiana

Abstract

Foods with functional potential have been expanding commercially due to increased consumer demand for food that has a nutritionally healthy appeal or features that help maintain health. The amor-perfeito (Viola x wittrockiana) is an edible flower, which has a wide variety of colors. The objective of this study was to evaluate the bioactive potential of Viola x wittrockiana flowers from different colors by determining the content of bioactive compounds, the profile of phenolic compounds and anthocyanins, and antioxidant and antibacterial activities, and also to evaluate the sugar present, proximal composition, fatty acid profile and preference for color. The plants of the species Viola x wittrockiana were cultivated, and the flowers were collected at flowering stage, lyophilized and stored in ultra freezer at - 80 ºC, until the analyzes were performed. The contents of 80.27 g of total carbohydrates, 10.14 g of crude protein, 1.67 g of fat and 7.92 g of ash per 100 g of dry sample were obtained. The total energy value was 376.67 Kcal per 100 g dry sample. Palmitic acid was the major fatty acid, followed by linoleic acid. Petals with "blue and white" and "ruby red" staining were preferred by judges of the sensory preference test. The "orange" flowers presented the highest levels of carotenoids, flavonoids and phenolic compounds, not statistically differing from flowers of "blue" color in relation to the content of phenolic compounds. The highest levels of ascorbic acid were observed in the flowers of "purple and white" and "violet and yellow" staining, and in the latter was also observed the highest content of tocopherols. The major sugar of amor-perfeito flowers was glucose. A greater number of anthocyanins were identified in the "red ruby stain" flowers. The major phenolic compound in all amor-perfeito colorations was the rutine. The inhibitory effect of the DPPH radical was around 90%, and the ABTS radical ranged from 41.77 to 55.17%. Extracts of the flowers were efficient against Escherichia coli when using the diffusion disc method. From the results, it can be concluded that the edible flowers of Viola x wittrockiana can enrich a menu through its functional potential, besides acting as an antimicrobial agent.