| Abstract | Korištenjem postupka subkritične ekstrakcije provela se ekstrakcija bioaktivnih komponenti iz ljuske crvenog luka i taloga kave. Subkritična ekstrakcija bioaktivnih komponenti odvijala se sekvencijskim šaržnim postupkom gdje se prilikom ekstrakcije komponenti iz ljuske crvenoga luka koristio etanol u koncentracijama od 96 %, 75 % i 50 % te voda, a kod ekstrakcija iz taloga kave korišten je etanol u koncentracijama od 96 % i 50 % te voda. Prethodno subkritičnoj ekstrakciji uzorci ljuske crvenoga luka i taloga kave podvrgnuti su odmašćivanju na automatskom uređaju za ekstrakciju (SoxROC) upotrebom n-heksana kao otapala te je ekstrahirano 10, 58 ± 1, 63 g/100 g s.t. masti iz taloga kave i 1, 26 ± 0, 30 g/100 g s.t. masti iz ljuske crvenog luka. Iz taloga kave ukupno je ekstrahirano 5, 57 ± 0, 20 g/100 g polifenola, 4, 27 ± 0, 15 g/100 g flavonoida, 2, 88 ± 0, 14 g/100 g topivih proteina te 4, 54 ± 0, 24 g/100 g šećera. Iz ljuske crvenog luka ukupno je ekstrahirano 8, 40 ± 0, 38 g/100 g polifenola, 8, 16 ± 0, 47 g/100 g flavonoida, 3, 47 ± 0, 11 g/100 g topivih proteina te 4, 11 ± 0, 10 g/100 g šećera. HPLC-PDA metodom određeno je da su redom najzastupljeniji polifenoli u talogu kave kafein, klorogenska kiselina, kafeinska kiselina te ferulična kiselina, dok je najzastupljeniji flavonol ljuske crvenog luka kvercetin. |
| Abstract (english) | Using the subcritical extraction procedure, the extraction of bioactive components from brown onion skins and spent coffee grounds was carried out. The subcritical extraction of bioactive components from brown onion skins was carried out by a sequential batch process where ethanol was used in concentrations of 96%, 75% and 50% and water. Ethanol in concentrations of 96% and 50% and water was used for extractions from spent coffee grounds. Prior to subcritical extraction, samples of brown onion skins and spent coffee grounds were subjected to defatting on an automatic extraction device (SoxROC) using n-hexane as a solvent. 10.58 ± 1.63 g/100 g d.w. fats were extracted from coffee grounds and 1.26 ± 0.30 g/100 g d.w. fats from brown onion skins. A total of 5.57 ± 0.20 g/100 g of polyphenols, 4.27 ± 0.15 g/100 g of flavonoids, 2.88 ± 0.14 g/100 g of soluble proteins and 4.54 ± 0.24 g/100 g of sugars were extracted from spent coffee grounds. A total of 8.40 ± 0.38 g/100 g of polyphenols, 8.16 ± 0.47 g/100 g of flavonoids, 3.47 ± 0.11 g/100 g of soluble proteins and 4.11 ± 0.10 g/100 g sugars were extracted from brown onion skins. Using the HPLC-PDA method, it was determined that the most abundant polyphenols in spent coffee grounds are caffeine, chlorogenic acid, caffeic acid and ferulic acid, while the most abundant flavonol in brown onion skins is quercetin. |
