Utjecaj pulsirajućeg električnog polja (PEF) i hladnog prešanja na iskorištenje i kemijski sastav ulja sjemenki grožđa

master's thesis

• Title (english): The effect of pulsed electric fields (PEF) and cold pressing on extraction yield and chemical composition of grape seed oil
• Author: Lucija Sobotinčić
• Mentor: Natka Ćurko (mentor)
• Mentor: Marina Tomašević (pomoć pri izradi, neposredni voditelj)
• Committee member: Karin Kovačević-Ganić (predsjednik povjerenstva)
• Committee member: Tomislava Vukušić Pavičić (član povjerenstva)
• Committee member: Sandra Balbino (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology and Analysis of Wine); Zagreb
• Defense date and country: 2023-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada bio je ispitati utjecaj tretiranja sjemenki komine grožđa pulsirajućim električnim poljem (PEF) prije hladnog prešanja na iskorištenje, kemijski sastav te antioksidacijski kapacitet ulja sjemenki grožđa sorte Graševina. Primijenjeni su različiti parametri PEF predtretmana jakosti električnog polja 12,5 i 15,6 kV/cm, tijekom 15 i 30 min (uz duljinu trajanja pulsa od 1 µs i frekvenciju od 100 Hz). Provedeno je spektrofotometrijsko određivanje ukupnih polifenolnih spojeva. Sastav pojedinačnih polifenolnih spojeva određen je primjenom tekućinske kromatografije visoke djelotvornosti (HPLC-DAD/MS). Sastav masnih kiselina određen je primjenom plinske kromatografije (GC-FID). Antioksidacijski kapacitet ulja određen je u hidrofilnoj i lipofilnoj frakciji ulja ORAC metodom (H-ORAC i L-ORAC). Primjena PEF predtretmana utjecala je na povećanje iskorištenja ekstrakcije, povećanje koncentracije ukupnih i pojedinačnih polifenola, kao i povećanje H-ORAC i L ORAC vrijednosti, posebice kod primjene električnog polja više jakosti te pri duljem vremenu tretiranja. Suprotno, navedeni PEF predtretmani nisu pokazali značajniji utjecaj na sastav masnih kiselina.

Abstract (english)

The aim of this study was to examine the effect of pulsed electric field (PEF) treatments prior to cold pressing on extraction yield, chemical composition and antioxidant capacity of Graševina grape seed oil. Different PEF pretreatments were applied: electric fields strength of 12.5 and 15.6 kV/cm, during 15 and 30 min (with pulse duration of 1 µs and pulse frequency of 100 Hz). Concentrations of total and individual polyphenols were determined by spectrophotometry and high performance liquid chromatography (HPLC-DAD/MS), respectively. Fatty acid composition was determined by gas chromatography (GC-FID). Antioxidant capacity was determined in hydrophilic and lipophilic fraction of oil by ORAC method (H-ORAC and L-ORAC). PEF pretreatments increased extraction yield, concentrations of total and individual phenolic compounds, as well as H-ORAC and L-ORAC values; particularly when higher electric fields strength and longer pretreatment time were applied. Contrary, composition of fatty acids was not affected by these pretreatments.

• Keywords: Graševina; sjemenke komine grožđa; ulje sjemenki grožđa; hladno prešanje; pulsirajuće električno polje (PEF)
• Keywords (english): Graševina; grape seed pomace; grape seed oil; cold pressing; pulsed electric fields (PEF)
• Language: croatian
• URN:NBN: urn:nbn:hr:159:613467
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-06-07 09:03:09