Utjecaj poplave i suše na fitokemijski sastav i antioksidacijski kapacitet pekinškog kupusa (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt)

master's thesis

• Title (english): Impact of flood and druoght on phytochemical composition and antioxidant capacity of Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt)
• Author: Petra Stić
• Mentor: Ivana Šola (mentor)
• Committee member: Ivana Šola (predsjednik povjerenstva)
• Committee member: Jasna Lajtner (član povjerenstva)
• Committee member: Sofia Ana Blažević (član povjerenstva)
• Committee member: Sven Jelaska (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2020-05-29, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Pojava ekstremnih uvjeta okoliša, kao što su poplave i suše, sve je češća. Biljke se okolišu prilagođavaju promjenama kemijskog sastava. Varijacije kemijskog sastava mogle bi imati značajan utjecaj na nutritivnu vrijednost biljaka, što je posebno važno kod prehrambenih vrsta, uključujući kupusnjače. S obzirom da je pekinški kupus sve zastupljeniji u prehrani, a podataka o njegovom metaboličkom odgovoru na sušu i poplavu nema, cilj ovog diplomskog rada bio je istražiti utjecaj simuliranih uvjeta suše i poplave na sadržaj fenolnih spojeva, šećera i fotosintetskih pigmenata, te antioksidacijski kapacitet ove vrste. Spektrofotometrijski je određen udio ukupnih fenola, flavonoida, hidroksicimetnih kiselina, flavonola, tanina, proantocijanidina, antocijana, topivih šećera te fotosintetskih pigmenata (klorofila a i b, karotenoida). Metodom tekućinske kromatografije visoke moći razlučivanja razdvojeni su, identificirani i kvantificirani kempferol, kvercetin, ferulična, sinapinska i L-askorbinska kiselina. Antioksidacijski kapacitet određen je metodama ABTS, DPPH, FRAP i metodom moći reduciranja. Poplava je uzrokovala povećanje koncentracije ferulične i sinapinske kiseline, kvercetina i kempferola, kao i antioksidacijskog kapaciteta određenog metodom ABTS, međutim smanjenje udjela fotosintetskih pigmenata u kineskom kupusu. Suša je uzrokovala povećanje koncentracije L-askorbinske kiseline. I suša i poplava povećale su udio šećera, a smanjile udio ukupnih tanina u pekinškom kupusu. Ostale mjerene parametre suša i poplava nisu značajno promijenile.

Abstract (english)

Extreme environmental conditions such as flooding and drought are becoming more common. Plants adapt to environment by changing phytochemical composition. Chemical composition variations could have a significant impact on plant nutritional value, which is especially important in plants intensely represented in diet, like most Brassicaceae species. Since Chinese cabbage is increasingly prevalent in diet and there is no information on its metabolic response to water stress, the aim of this work was to investigate the impact of simulated flooding and drought conditions on phenolic compounds content, sugars and photosynthetic pigments, and antioxidant capacity of this species. The content of total phenols, flavonoids, hydroxycinnamic acids, flavonols, tannins, proanthocyanidins, anthocyanins, soluble sugars and photosynthetic pigments (chlorophyll a and b, carotenoids) was determined spectrophotometrically. Using a high-performance-liquid-chromatography method, kaempferol and quercetin, ferulic, sinapic and L-ascorbic acid were separated, identified and quantified. The antioxidant capacity was determined by methods ABTS, DPPH, FRAP and reducing power. Flooding increased ferulic and sinapic acid, quercetin and kaempferol concentration, and antioxidant capacity determined by the ABTS method, however, decreased photosynthetic pigments in Chinese cabbage. Drought increased L-ascorbic acid concentration. Both flooding and drought increased concentration of soluble sugars, and reduced total tannins in Chinese cabbage.

• Keywords: klimatske promjene; kupusnjače; biljni metaboliti; flavonoidi; fenolne kiseline; vitamin C; tanini; šećeri; HPLC; spektrofotometrija
• Keywords (english): climate change; Brassicaceae; plant metabolites; flavonoids; phenolic acids; vitamin C; tannins; sugars; HPLC; spectrophotometry
• Language: croatian
• URN:NBN: urn:nbn:hr:217:116180
• Study programme: Title: Experimental Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra eksperimentalne biologije (magistar/magistra eksperimentalne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2022-05-29
• Created on: 2020-06-03 07:24:35