Plant Foods for Human Nutrition

, Volume 66, Issue 1, pp 48–57

Characterization of Industrial Onion Wastes (Allium cepa L.): Dietary Fibre and Bioactive Compounds

  • Vanesa Benítez
  • Esperanza Mollá
  • María A. Martín-Cabrejas
  • Yolanda Aguilera
  • Francisco J. López-Andréu
  • Katherine Cools
  • Leon A. Terry
  • Rosa M. Esteban
ORIGINAL PAPER

DOI: 10.1007/s11130-011-0212-x

Cite this article as:
Benítez, V., Mollá, E., Martín-Cabrejas, M.A. et al. Plant Foods Hum Nutr (2011) 66: 48. doi:10.1007/s11130-011-0212-x

Abstract

The food industry produces a large amount of onion wastes, making it necessary to search for possible ways for their utilization. One way could be to use these onion wastes as a natural source of high-value functional ingredients, since onion are rich in several groups of compounds, which have perceived benefits to human health. The objective of this work is to gain knowledge of any differences between the different onion wastes obtained from industry and non-commercial bulbs to use them as food ingredients rich in specific compounds. The results showed that brown skin and top–bottom could be potentially used as functional ingredient rich in dietary fibre, mainly in insoluble fraction, and in total phenolics and flavonoids, with high antioxidant activity. Moreover, brown skin showed a high concentration of quercetin aglycone and calcium, and top–bottom showed high concentration of minerals. Outer scales could be used as source of flavonols, with good antioxidant activity and content of dietary fibre. However, inner scales could be an interesting source of fructans and alk(en)yl cystein sulphoxides. In addition, discarded onions (cvs Recas and Figueres) could be used as a good source of dietary fibre, and cv Recas also as a source of phenolics compounds.

Keywords

Alk(en)yl cystein sulphoxides Antioxidant activity Dietary fibre Flavonols Fructans Onion wastes 

Abbreviations

ACSOs

alk(en)yl cystein sulphoxides

DF

Dietary fibre

DM

Dry matter

DP

Degree of polymerization

FOS

Fructooligosaccharides

FRAP

Ferric reducing ability assay

GAE

Galic acid equivalents

ICP-MS

Inductively coupled plasma mass spectrometry

IDF

Insoluble dietary fibre

MCSO

(+)-S-methyl-L-cysteine sulphoxide

NSC

non-structural carbohydrates

PCSO

(+)-S-propyl-L-cysteine sulphoxide

PECSO

trans-(+)-S-1-propenyl-L-cysteine sulphoxide

QE

Quercetin equivalents

SDF

Soluble dietary fibre

TDF

Total dietary fibre

TFA

Trifluoroacetic acid

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Vanesa Benítez
    • 1
  • Esperanza Mollá
    • 1
  • María A. Martín-Cabrejas
    • 1
  • Yolanda Aguilera
    • 1
  • Francisco J. López-Andréu
    • 1
  • Katherine Cools
    • 2
  • Leon A. Terry
    • 2
  • Rosa M. Esteban
    • 1
  1. 1.Departamento de Química Agrícola, Facultad de Ciencias/Instituto de Ciencias de la Alimentación (CIAL)Campus de la Universidad Autónoma de MadridMadridSpain
  2. 2.Plant Science LaboratoryCranfield UniversityBedfordshireUK