Enhanced yield of bioactivities from onion (Allium cepa L.) skin and their antioxidant and anti - [alpha] - amylase activities

Mariana Gois Ruivo da Silva (Author), Mihaela Skrt (Author), Draženka Komes (Author), Nataša Poklar Ulrih (Author), Lea Pogačnik (Author)

Abstract

There is increasing concern for reduction of the ecological impacts of industrial waste caused by fruits and vegetables. To reduce costs of onion waste disposal while obtaining value-added products, onion skin can be used to extract quercetin, a natural flavonoid with antioxidant, anti-inflammatory and anti-cancer effects. The aim was to optimize quercetin extraction from brown onion (Allium cepa L.) skin through investigation of the effects of different parameters on quercetin yield. Operational parameters for conventional maceration extraction and for ultrasound-assisted extraction were compared: solvent type, mass-to-liquid ratio, extraction time and temperature. Antioxidant capacity was determined using DPPH· radical scavenging assays and quercetin yield using HPLC/DAD. Anti-α-amylase activity of onion skin extracts was investigated using α-amylase inhibition assays. Optimal extraction conditions of quercetin from onion skin were obtained with maceration extraction, 50% ethanol, 1:100 mass-to-liquid ratio, 25 °C, for 15 min. Under these conditions, the antioxidant capacity (expressed as quercetin equivalents) was 18.7 mg/g and the mass fraction of quercetin was 7.96 mg/g. The onion skin extracts showed a dose-dependent relationship between dry extract concentration and α-amylase inhibition, which confirms that this onion skin extract can be considered as an anti-diabetes agent.

Keywords

čebula;Allium cepa L.;antioksidanti;antioksidativna učinkovitost;ekstrakcija;kvercetin;bioaktivne snovi;

Data

Language:	English
Year of publishing:	2020
Typology:	1.01 - Original Scientific Article
Organization:	UL BF - Biotechnical Faculty
UDC:	66.061:635.25:547.56
COBISS:	13140483
ISSN:	1422-0067
Views:	354
Downloads:	98
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	čebula;Allium cepa L.;antioksidanti;antioksidativna učinkovitost;ekstrakcija;kvercetin;bioaktivne snovi;
Type (COBISS):	Article
Pages:	str. 1-16
Volume:	ǂVol. ǂ21
Issue:	ǂno. ǂ8
Chronology:	2020
DOI:	10.3390/ijms21082909
ID:	13112525