Casca de gogoia (Tacinga inamoena):fonte de corantes naturais

Abstract

It originates from the Caatinga biome, the gogoia (Tacinga inamoena) is a cactus recognized as a potential source of bioactive compounds, presenting natural pigments in the bark of its fruits, in the final stage of maturation. In this context, the present study had the objective of extracting pigments from the peel of the gogoia fruits using green solvents and producing natural powder dye using the cashew gum as a coadjuvant drying agent for application in food systems. Initially the physical measurements of the fruits in natura were investigated and, later, the peel was removed for colorimetric evaluation using the parameters provided by the CIELab system. The bark was subjected to the lyophilization process, contributing to the conservation and concentration of the components demonstrated through physico-chemical analysis. The physico-chemical analyzes: moisture, water activity, pH, total titratable acidity and total soluble solids, as well as the content of pigments, betalain and carotenoids, were carried out in the in natura and lyophilized bark. Extracts were prepared using a raw material: solvent ratio of 1:10 (m / v), varying the concentration of ethanol and pH of the solution constant at 6.6. The extracts were quantified with respect to the betalain and carotenoid content by UV-vis spectrophotometric method and selected the one with the highest pigment content. Analyzes of antioxidant activity by free radical DPPH • (EC50), quantification and identification of the phenolic profile were performed. The selected extract was concentrated in a rotary evaporator, added to cashew gum and subjected to the lyophilization process. The powdered dye from the obtained gogoia bark was evaluated for staining through the CIELab system and physico-chemically characterized. The powder dye was applied to traditional Greek yoghurt in different concentrations for comparison of the tintorial potential in relation to commercial samples of this product. The fruits showed different physical characteristics, such as shape, weight, diameter and number of seeds per fruit. The analyzes showed that the gogoia bark is a source of natural pigments, such as betalains and carotenoids, with the betalains group predominating, mainly with a higher content of betaxanthine. The in natura peel had a moisture content higher than 80%, acid pH (4.72) and low total titratable acidity, when compared to the lyophilized peel, an increase in total soluble solids and acidity was observed, and the pH remained acidic (4). , 42). Regarding color, significant values were observed in the colorimetric coordinate b *, which shows the yellow coloration (+ b *) observed in the samples after the drying process. The selected extract, extracted with 70% ethanol from the lyophilized gogo bark, after its concentration was able to react with 50% of the radical present in the DPPH • solution, indicating to have antioxidant activity (150.99 μg / mL) while the content of total phenolics was 154.07 g Gallic acid / 100 g dry extract of gogoia bark. The profile of phenolic compounds identified 14 compounds, being 8 phenolic acids and 6 flavonoids, whose highlight was 2,5-dihydroxybenzoic acid and rutin, as favonoid. Cashew gum used as a carrier to the gypsum bark pigment allowed to obtain a natural dye in powder form with colorimetric aspects of a bright yellow powder. An easy solubilization of the powdered dye from the gogoia bark was observed when it was added to the Greek type yogurt, showing promising results as a possible substitute for the artificial dye used in commercial yoghurt flavored passion fruit.