diplomsko delo
Katarina Geč (Author), Petra Terpinc (Reviewer), Lea Pogačnik (Mentor)

Abstract

Jagode aronije so znane po visoki vsebnosti fenolnih spojin, še posebej procianidinov, antocianinov in flavonolov. V okviru diplomskega dela smo v sadežih aronije in njenih izdelkih določali vsebnost skupnih fenolnih spojin (SFS) in antioksidativno učinkovitost (AOU). Med seboj smo primerjavi sokove aronije (znamke Mediterra, Eden, Volovec in stisnjen sok zamrznjenih sadežev), posušene jagode aronije (znamke Mediterra in Volovec) in prah aronije (znamke Mediterra in liofiliziran prah pripravljen v laboratoriju). Iz posušenih izdelkov aronije smo pripravili vodni ekstrakt z 2 % ocetno kislino in etanolni ekstrakt. SFS smo določali spektrofotometrično z uporabo Folin-Ciocalteujeve metode. Najvišje vrednosti SFS smo določili v liofiliziranem prahu in sicer 242 µmol/g ekvivalenta klorogenske kisline. Med posušenimi jagodami in sokovi aronije nismo določili večjih razlik v vsebnosti SFS. AOU smo določali z metodo lovljenja DPPH• radikala in rezultate podali kot ekvivalent troloksa. Z najvišjo AOU se je izkazal liofiliziran prah aronije. V vodnem ekstraktu smo določili 157 µmol/g, v etanolnem ekstraktu pa 197 µmol/g AOU. Med sokovi smo najvišjo vrednost SFS, ki je znašala 34 mM, in najvišjo vrednost AOU, ki je znašala 44 mM, določili v soku Eden. S pripravo prahu aronije v laboratoriju smo ugotovili, da liofilizacija omogoča dobro ohranjanje bioaktivnih komponent sušenih izdelkih aronije.

Keywords

Aronia melanocarpa;sok aronije;posušene jagode aronije;prah aronije;antioksidanti;skupne fenolne spojine;antioksidativna učinkovitost;analizne metode;Folin-Ciocalteu;DPPH;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [K. Geč]
UDC: 634.74:641.1:66.094.3.097.8
COBISS: 4935544 Link will open in a new window
Views: 1365
Downloads: 406
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Other data

Secondary language: English
Secondary title: Determination of antioxidants in aronia (Aronia melanocarpa) and its products
Secondary abstract: Aronia berries are famous for their high content of phenol compounds, particularly procyanidins, anthocyanins and flavonoids. The aim of this graduation thesis was to determine total phenolic content (TPC) and antioxidant activity (AA). In the study we compared aronia juices (trademarks Mediterra, Eden, Volovec and juice which was squeezed in the laboratory), dried aronia berries (trademarks Mediterra and Volovec) and aronia powder (trademark Mediterra and laboratory-prepared lyophilised powder). From dried aronia products we prepared water extract with 2 % acetic acid and ethanol extract. Using the Folin-Ciocalteu method, TPC was determined spectrophotometrically. The highest TPC was found in lyophilised powder, where chlorogenic acid equivalent was 241,8 µmol/g. We found no major differences in TPC content between dried berries and aronia juices. AA was determined with DPPH• radical scavenging method and the results were expressed as trolox equivalents. The highest AA was found in lyophilised aronia powder. The water extract contained 157 µmol/g, whereas the ethanol extract contained 197 µmol/g of AA. Between juices, the highest TPC content, 34 mM, and the highest AA content, 44 mM, was determined in Eden juice. The laboratory preparation of aronia powder showed that lyophilisation is good for preservation of bioactive components of dried aronia products.
Secondary keywords: Aronia melanocarpa;aronia juice;dry aronia berrys;aronia powder;total phenolic compounds;antioxidants;antioxidant activity;analytical methods;Folin-Ciocalteu;DPPH;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VIII, 23 f., [3] f. pril.
ID: 10955099