Utjecaj ultrazvučne ekstrakcije na kemijski sastav lista masline (Olea europea L.)

master's thesis

• Title (english): The impact of ultrasound-assisted extraction on the chemical composition of olive leaf (Olea europea L.)
• Author: Dolores Šaško
• Mentor: Maja Dent (mentor)
• Committee member: Tomislav Bosiljkov (predsjednik povjerenstva)
• Committee member: Tonči Rezić (član povjerenstva)
• Committee member: Maja Repajić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Analytical Chemistry); Zagreb
• Defense date and country: 2023-12-22, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Listovi masline predstavljaju agroindustrijski otpad, a time i ekološki izazov. Kao rješenje se nameću načela održivosti i analiza kemijskog sastava s ciljem stvaranja inovativnih proizvoda. Cilj ovog rada bio je provesti ekstrakciju potpomognutu ultrazvukom (UAE) primjenom različitih otapala (voda, 30 i 50 %-tni etanol) i vremena (5 - 40 minuta), a za usporedbu i klasičnu ekstrakciju refluksiranjem (KE). Udjeli vlage, pepela, masti i celuloze određeni su gravimetrijskim metodama, a udjeli ukupnih šećera, fenola i antioksidacijska aktivnost Uv/Vis spektrofotometrijom. Maksimalne rezultate pokazali su ekstrakti dobiveni primjenom KE kroz 40 minuta, no zbog skraćivanja vremena ekstrakcije UAE ima prednost. Maksimalni ekstrakcijski kapacitet UAE izolacije ukupnih šećera (17,64 %) postignut je primjenom 50 %-tnog etanola kroz 5 minuta, a ukupnih fenola (1602,51 mg/100 g) primjenom vode kroz 30 minuta, čime je ujedno ostvarena i maksimalna antioksidacijska aktivnost (429,01 mg AAE/100 g). Između udjela fenola i antioksidacijske aktivnosti u ekstraktima 30 %-tnog etanola i vode utvrđena je korelacija.

Abstract (english)

Olive leaves represent agro-industrial waste, posing an ecological challenge. As a solution, the principles of sustainability and the analysis of the chemical composition are imposed with the aim of creating innovative products.The aim of this study was to perform ultrasound-assisted extraction (UAE) using different solvents (water, 30 % and 50 % ethanol) and durations (5 - 40 minutes), with classical heat-reflux extraction (CE) for comparison. Moisture, ash, fat, and cellulose contents were determined using gravimetric methods, while total sugars, phenols and antioxidant activity were assessed via UV/Vis spectrophotometry. Extracts obtained with CE over 40 minutes showed maximum results, but due to time efficiency, UAE has an advantage. UAE achieved the maximum extraction capacity for total sugars (17.64 %) using a 50 % ethanol for 5 minutes and for total phenols (1602.51 mg/100 g) with water for 30 minutes, simultaneously achieving maximum antioxidant activity (429.01 mg AAE/100 g). A correlation was identified between phenol content and antioxidant activity in 30 % ethanol and water extracts.

• Keywords: list masline; ultrazvučna ekstrakcija; šećeri; fenoli; antioksidacijska aktivnost
• Keywords (english): olive leaf; ultrasonic-assisted extraction; sugars; phenols; antioxidant activity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:267575
• Study programme: Title: Food Safety Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane (magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2024-06-18 08:29:21