Maceriranje lišća masline u repičinom ulju i učinak na hidrofilne fenole, klorofile te hidrolitičko i oksidacijsko kvarenje ulja
| Autor: | Benček, Mihaela |
|---|---|
| Přispěvatelé: | Majetić Germek, Valerija, Koprivnjak, Olivera |
| Jazyk: | chorvatština |
| Rok vydání: | 2018 |
| Předmět: |
Klorofili
Kvaliteta ulja Maceriranje Maslinovo lišće Polifenoli Rafinirano repičino ulje polifenoli kvaliteta ulja maceration chlorophylls [words] rafinirano repičino ulje olive leaves maslinovo lišće klorofili BIOTEHNIČKE ZNANOSTI. Prehrambena tehnologija refined rapeseed oil BIOTECHNICAL SCIENCES. Food Technology maceriranje oil quality polyphenols |
| Popis: | U radu je istražena učinkovitost prirodnog maceriranja svježeg i parom tretiranog suhog maslinovog lišća u rafiniranom repičinom ulju, te stupnja usitnjenosti lišća (cijelo, rezano, mljeveno lišće) i vremena maceriranja na prelazak bioaktivnih tvari (polifenola) i pigmenata (klorofila) u ulje. Istražen je i utjecaj ovih postupaka pripreme ulja na pokazatelje kvalitete ulja. U uljima dobivenim maceriranjem praćene su promjene masenih udjela ukupnih fenolnih tvari, ukupnih klorofila i specifičnih apsorbancija u UV području (K232 i K270 ), koji su određeni spektrofotometrijski. Udjel slobodnih masnih kiselina određen je titracijski. Kod lišća sorte Oblica određen je udjel vode, udjel suhe tvari, udjel ukupnih fenola te morfološke karakteristike lista. Udjel ukupnih fenola i klorofila statistički se značajno povećao u uljima maceriranim sa svježim i sa suhim parenim lišćem, a na njihov prijelaz u ulje u velikoj mjeri utječe stupanj usitnjenosti lišća. Najveći udjel ukupnih fenola postignut je u ulju s cijelim (220,4 mg/kg) a najmanji u ulju s mljevenim lišćem (87,6 mg/kg) nakon sedam dana maceriranja. U uljima s cijelim lišćem udjeli ukupnih klorofila bili su vrlo niski (≤ 0,5 mg/kg), dok su najveći udjeli ukupnih klorofila dobiveni u uljima s mljevenim parenim suhim lišćem nakon 28 dana maceriranja (79,70 mg/kg). Prirodno maceriranje maslinovog lišća narušilo je kvalitetu rafiniranog repičinog ulja, ali blago i u podjednakoj mjeri kod ulja sa svježim i sa parenim suhim lišćem. The study explored the efficiency of the natural maceration of fresh and steam blanched olive leaves in refined rapeseed oil, as well as effect of degree of fragmentation (whole, cut, milled leaves) and maceration time on transfer of bioactive compounds (polyphenols) and pigments (chlorophylls) in oil. Effect of these oil preparation procedures on oil quality indicators has also been investigated. In oils obtained by maceration, changes of mass fraction of total phenolic compounds, chlorophylls and specific UV absorbances (K232 and K270), were determined spectrophotometrically. The free fatty acid content was determined by titration. In the leaves of Oblica olive tree, the mass fraction of water, dry matter and total phenols as well as the morphological characteristics of the leaf, were determined. The mass fraction of total phenols and chlorophylls statistically significantly increased in oils obtained by maceration of fresh and steam blanched olive leaves, and was greatly influenced by fragmentation degree of the leaves. The highest mass fraction of total phenols was achieved in oil with whole leaves (220.4 mg/kg) and the lowest in oil with milled leaves (87.6 mg/kg), after seven days of maceration. The total chlorophylls in the oils with whole leaves was very low (≤ 0.5 mg/kg), while the highest mass fraction of total chlorophylls was obtained in the oils with milled steam blanched leaves after 28 days of maceration (79.70 mg/kg). The natural maceration of olive leaves deteriorated the quality of refined rapeseed oil, although slightly and in equal measure in oils with fresh and steam blanched olive leaves. |
| Databáze: | OpenAIRE |
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