STUDY OF THE INTERFERENCE OF THE EXTRACTION TIME AND ETHANOL CONCENTRATION IN THE OBTAINING OF ANTOCYANINS FROM ISABEL GRAPE (Vitis labrusca)

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  • Presentation type: Pôster
  • Track: Process Engineering and Emerging Technologies (ET)
  • Keywords: Natural pigments; phenolic compounds; Antioxidant potential;
  • 1 Centro de Ciências Humanas, Sociais e Agrárias / Universidade Federal da Paraíba
  • 2 UFPB
  • 3 Universidade Federal da Paraíba
  • 4 Universidade Federal de Sergipe

STUDY OF THE INTERFERENCE OF THE EXTRACTION TIME AND ETHANOL CONCENTRATION IN THE OBTAINING OF ANTOCYANINS FROM ISABEL GRAPE (Vitis labrusca)

Camila Sampaio Mangolim

UTFPR

Abstract

Anthocyanins are pigments with shades ranging from red to blue, responsible for coloring various vegetables, such as red grapes. As they are soluble in water, they have a great potential to be applied as natural dyes in foods, also due to their antioxidant character. The most used methods to extract these components use methanol, which is toxic to humans, being necessary other methodologies that extract these compounds to be applied in food. Thus, this research aimed to evaluate the interference of two important parameters in the extraction of anthocyanins from Isabel grapes (Vitis labrusca): extraction time and ethanol concentration. The study was carried out from an experimental design of two factors at two levels each with three central points. The ethanol concentrations used were 30, 50 and 70%, and the extraction time was 30, 60 and 90 min. For extraction, the seedless grape was crushed using a 1:2 ratio of grape:ethanol solution (w:v) adjusted to pH 2. The extraction was carried out under stirring for 30-90min, and the extracts obtained were analyzed for color, titilable acidity, pH, anthocyanin content (by the differential pH method) and total phenolic compounds, using Folin-Ciocalteau reagent and gallic acid as standard . The extracts showed low pH values ranging from 2.23 to 2.62 and soluble solids ranging from 8.5 to 17.90 °Brix. For anthocyanins and phenolic compounds, the use of 50% ethanol for 60 min showed better performance in the extraction of these components, resulting in an average of 224 mg GAE/100 g of grapes and 65.14 mg anthocyanins/100g of grapes. There was a predominance of reddish color in the extracts, with a* varying between 1.07 and 4.79, and a dark hue, with L* values between 17 and 19.5. The extracts have great potential to be used as a natural coloring in foods.

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