Ultrazvučno potpomognuta ekstrakcija bioaktivnih spojeva koprive

master's thesis

• Title (english): Ultrasonically assisted extraction of biactive compounds from stinging nettle
• Author: Anamaria Rašić
• Mentor: Jana Šic Žlabur (mentor)
• Committee member: Jana Šic Žlabur (predsjednik povjerenstva)
• Committee member: Sandra Voća (član povjerenstva)
• Committee member: Sanja Radman (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Sustainable Technologies and Renewable Energy Sources); Zagreb
• Defense date and country: 2021-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Kopriva (Urtica dioica L.) je višegodišnja vrsta koja pripada porodici koprivnjača (Urticaceae). Stoljećima se koristi kao funkcionalna namirnica te također pronalazi svoju primjenu u medicini, farmaciji, kozmetici te tekstilnoj industriji. Kopriva je biljna vrsta bogatog i složenog kemijskog sastava zbog čega je još uvijek predmet raznih istraživanja. Cilj ovog rada bio je utvrditi sadržaj bioaktivnih spojeva te odrediti nutritivni potencijal alkoholnih ekstrakata suhog lista koprive s obzirom na metodu i duljinu trajanja ultrazvučno potpomognute ekstrakcije. Alkoholni ekstrakti pripremljeni su iz praha suhog lista koprive (2 g) uz 50%-tni etilni alkohol (150 mL) kao otapalo. Pripremljene otopine tretirane su ultrazvukom visokog intenziteta prilikom čega je variran tip uređaja (sonda i kupelj) te vrijeme tretmana (5, 10, 15 i 30 min). Istraživanjem su određeni sljedeći fizikalno-kemijski parametri otopina: gustoća, električna provodljivost, sadržaj ukupnih kiselina, pH vrijednost te boja; dok je od specijaliziranih metabolita određen sadržaj: vitamina C, ukupnih fenola (flavonoida i neflavonoida), ukupnih klorofila, ukupnih karotenoida te antioksidacijski kapacitet. Najviše vrijednosti vitamina C, fenola, neflavonoida, ukupnih klorofila i karotenoida te antioksidacijskog kapaciteta zabilježene su u uzorku tretiranom ultrazvučnom sondom u vremenskom razdoblju od 15 minuta. Iz prethodno navedenog, može se zaključiti kako je tretman ultrazvučnom sondom iznimno učinkovit u izolaciji bioaktivnih spojeva u vrlo kratkom vremenu. Također, analizom alkoholnih ekstrakata koprive može se utvrditi kako se radi o nutritivno vrijednom proizvodu s brojnim potencijalnim funkcionalnim svojstvima.

Abstract (english)

Stinging nettle (Urtica dioica L.) is a perennial species of the nettle family (Urticaceae). It has been used for centuries as a functional food and is also used in medicine, pharmacy, cosmetics, and the textile industry. Stinging nettle is a plant species with a rich and complex chemical composition, which is why it is still the subject of various research. The aim of this study was to determine the content of bioactive compounds and to determine the nutritional potential of alcoholic extracts from dried nettle leaves with respect to the method and duration of ultrasound-assisted extraction. Alcoholic extracts were prepared from dried nettle leaf powder (2 g) using 50% ethyl alcohol (150 mL) as solvent. The prepared solutions were treated with high intensity ultrasound, varying the type of device (probe and bath) and the duration of treatment (5, 10, 15 and 30 min). The following physico-chemical parameters of the solutions were determined by the study: density, electrical conductivity, total acids content, pH and color; while the content of specialized metabolites is determined by: vitamin C, total phenols (flavonoids and non-flavonoids), total chlorophylls, total carotenoids and antioxidant capacity. The highest values of vitamin C, phenolics, non-flavonoids, total chlorophylls and carotenoids, and antioxidant capacity were determined in the sample treated with ultrasonic probe for a period of 15 minutes. It can be concluded that ultrasonic probe treatment is extremely effective in isolating bioactive compounds in a very short time. Moreover, the analysis of the alcoholic extracts of nettle can show that it is a nutritionally valuable product with many potential functional properties.

• Keywords: kopriva; ultrazvučno potpomognuta ekstrakcija; ultrazvučna sonda; ultrazvučna kupelj
• Keywords (english): nettle; ultrasonically assisted extraction; ultrasound probe; ultrasound bath
• Language: croatian
• URN:NBN: urn:nbn:hr:204:985690
• Study programme: Title: Horticulture; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka hortikulture (magistar/ magistra inženjer/inženjerka hortikulture)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-11-24 10:42:34