magistrsko delo
Mojca Bahor (Author), Blaž Cigić (Reviewer), Rajko Vidrih (Mentor)

Abstract

Namen magistrske naloge je bil ugotoviti, kako osvetljevanje s svetlobo svetlečih diod in/ali tretiranje ribeza z vročo vodo vpliva na kemijsko sestavo in CIE barvnih parametrov L*, a*, b* črnega ribeza. Črni ribez je bil tretiran z vročo vodo, s temperaturo 50 °C, 4 min in/ali izpostavljen UV-B svetlobi (310 nm) ter modri svetlobi (444 nm), 21 dni pri 0,5 °C. Netretirani vzorci so bili shranjeni 21 dni na 0,5 °C. Vzorcem črnega ribeza smo določali antioksidativni potencial (AOP) z metodo prostega radikala DPPH˙, vsebnost skupnih fenolnih spojin s Folin-Ciocalteu reagentom in skupnih flavonoidov z AlCl3. Barvo kožice plodov smo merili s kromametrom Minolta in s sistemom CIE L* a* b*. Rezultati analiz so pokazali trend naraščanja AOP, skupnih fenolov in skupnih flavonoidov. Največji vpliv na spremembo AOP, skupnih fenolov in flavonoidov v ribezu je imela modra svetloba. Prav tako je imela modra svetloba največji vpliv na spremembe barvnih parametrov L*, a*, b*, C* in h°. Vzorci, izpostavljeni UV-B svetlobi in hkrati tretirani z vročo vodo, so se statistično razlikovali od z vročo vodo netretiranih kontrolnih vzorcev in netretiranih vzorcev osvetljevanih z UV-B svetlobo. Tretiranje z vročo vodo je pokazalo trend zaviranja sinteze skupnih fenolov in flavonoidov.

Keywords

črni ribez;Ribes nigrum L.;svetloba;osvetljevanje;svetleče diode;LED;antioksidativni potencial;fenolne spojine;flavonoidi;kromameter;CIELAB sistem;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [M. Bahor]
UDC: 634.732:547.56:66.094.3.097.8:577.1
COBISS: 5117560 Link will open in a new window
Views: 734
Downloads: 223
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Other data

Secondary language: English
Secondary title: Influence of light emitting diodes of different wavelength on chemical composition of black currant (Ribes nigrum L.)
Secondary abstract: The purpose of the master’s thesis was to determine the effect of light-emitting diodes irradiation and/or hot water dipping (HWT) on the chemical composition and CIE colour L*, a*, b* parameters of black currant. Black currant was treated with hot water at 50 °C for 4 min and/or exposed to UV-B (310 nm) and blue LEDs (444 nm) for 21 days at 0,5 °C. Non-treated control was also stored at 0,5 °C for 21 days. The following analyses were carried out before and during treatments: antioxidant potential (AOP) was determined using DPPH˙ radical, content of phenolic compounds with Folin-Ciocalteu assay and total flavonoid content with AlCl3. The fruit colour was measured using Chroma Meter Minolta and the CIE L*, a*, b* system. The results showed a trend of an increase of the AOP, total phenolic and flavonoid content for all treatments during 21-day storage period. Blue light irradiation resulted in the highest increase of AOP, total phenolics and flavonoids as well as changes in colour parameters (L*, a*, b*, C* and h°). Only the samples treated with HWT and illuminated with UV-B differed significantly from non-treated control and non-treated UV-B. HWT showed trend to retard the synthesis of phenols and flavonoids.
Secondary keywords: black currant;Ribes nigrum L.;light;lighting;light-emitting diodes;LED;antioxidant potential;phenolic compounds;flavonoids;Chroma Meter;CIELAB system;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: IX, 50 f.
ID: 11270689