20.500.12556/RUL-128259 Enhanced yield of bioactivities from onion (Allium cepa L.) skin and their antioxidant and anti-α-amylase activities 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. Allium cepa L. anti-α-amylase activity antioxidant capacity extraction optimization quercetin čebula Allium cepa L. antioksidanti antioksidativna učinkovitost ekstrakcija kvercetin bioaktivne snovi true false true Angleški jezik Slovenski jezik Članek v reviji 2021-07-07 14:46:40 2021-07-07 14:46:41 2022-09-07 04:14:02 0000-00-00 00:00:00 2020 0 0 15 str. iss. 8, art. 2909 Vol. 21 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 66.061:635.25:547.56 1422-0067 10.3390/ijms21082909 13140483 RAZ_Gois_Ruivo_da_Silva_Mariana_2020.pdf RAZ_Gois_Ruivo_da_Silva_Mariana_2020.pdf 1 FEDCA8977A6E2B63860F1727F0C6276B 1c0601436313877885726793edc98796a1844e005a3c487c48900824abfae9d3 988b7717-df21-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144940 https://www.mdpi.com/1422-0067/21/8/2909 1 3eea8515-df21-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144939 Biotehniška fakulteta 0 0 0