Analytical and Bioanalytical Chemistry

, Volume 403, Issue 4, pp 1019–1029

A novel application of microwave-assisted extraction of polyphenols from brewer’s spent grain with HPLC-DAD-MS analysis

  • Manuela M. Moreira
  • Simone Morais
  • Aquiles A. Barros
  • Cristina Delerue-Matos
  • Luís F. Guido
Original Paper

DOI: 10.1007/s00216-011-5703-y

Cite this article as:
Moreira, M.M., Morais, S., Barros, A.A. et al. Anal Bioanal Chem (2012) 403: 1019. doi:10.1007/s00216-011-5703-y

Abstract

This paper reports a novel application of microwave-assisted extraction (MAE) of polyphenols from brewer’s spent grains (BSG). A 24 orthogonal composite design was used to obtain the optimal conditions of MAE. The influence of the MAE operational parameters (extraction time, temperature, solvent volume and stirring speed) on the extraction yield of ferulic acid was investigated through response surface methodology. The results showed that the optimal conditions were 15 min extraction time, 100 °C extraction temperature, 20 mL of solvent, and maximum stirring speed. Under these conditions, the yield of ferulic acid was 1.31 ± 0.04% (w/w), which was fivefold higher than that obtained with conventional solid–liquid extraction techniques. The developed new extraction method considerably reduces extraction time, energy and solvent consumption, while generating fewer wastes. HPLC-DAD-MS analysis indicated that other hydroxycinnamic acids and several ferulic acid dehydrodimers, as well as one dehydrotrimer were also present, confirming that BSG is a valuable source of antioxidant compounds.

https://static-content.springer.com/image/art%3A10.1007%2Fs00216-011-5703-y/MediaObjects/216_2011_5703_Figa_HTML.gif
Figure

Response surface of FA yield (Y, %, w/w) as a function of extraction time (X1) and the other variables studied: a solvent volume (X3); b temperature (X2)

Keywords

Brewer’s spent grainPolyphenolsFerulic acidMicrowave-assisted extractionHPLC-DAD-MS analysis

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Manuela M. Moreira
    • 1
  • Simone Morais
    • 2
  • Aquiles A. Barros
    • 1
  • Cristina Delerue-Matos
    • 2
  • Luís F. Guido
    • 1
  1. 1.REQUIMTE—Departamento de Química e Bioquímica, Faculdade de CiênciasUniversidade do PortoPortoPortugal
  2. 2.REQUIMTE—Instituto Superior de Engenharia do PortoPortoPortugal