Utjecaj visoke temperature na biodostupnost polifenolnih spojeva i antioksidacijski potencijal klica brokule (Brassica oleracea L. convar. botrytis (L.) Alef)

master's thesis

• Title (english): Influence of high temperature on bioavailability of polyphenolic compounds and antioxidant potential of broccoli seedlings (Brassica oleracea L. convar. botrytis (L.) Alef)
• Author: Mihael Kolomaz
• Mentor: Ivana Šola (mentor)
• Committee member: Ivana Šola (predsjednik povjerenstva)
• Committee member: Sofia Ana Blažević (član povjerenstva)
• Committee member: Marin Ježić (član povjerenstva)
• Committee member: Duje Lisičić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2021-11-11, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Biljke se toplinskom stresu prilagođavaju promjenama u vlastitom kemijskom sastavu. Kupusnjače su zastupljene u prehrani ljudi i životinja, stoga je važno kako će visoka temperatura (VT) utjecati na njihovu nutritivnu vrijednost. Cilj ovoga rada bio je istražiti utjecaj VT (38°C) na biodostupnost različitih skupina i pojedinačnih polifenolnih spojeva u klicama brokule (Brassica oleracea L. convar. botrytis (L.) Alef.) prije i tijekom simulirane ljudske probave in vitro, kao i na njihov antioksidacijski potencijal, kako bi se utvrdio stupanj stabilnosti/podložnosti navedenih parametara prema VT. Spektrofotometrijski je određen udio različitih skupina spojeva, a metodom HPLC razdvojeni su, identificirani i kvantificirani metaboliti: L-askorbinska, galna, benzojeva, kavena, p-kumarinska, ferulična i sinapinska kiselina te tilirozid, kempferol i kvercetin. Antioksidacijski potencijal određen je metodama ABTS, DPPH i FRAP. VT značajno je povećala biodostupnost ukupnih flavonola i hidroksicimetnih kiselina klica brokule. Jedini spoj čija se koncentracija razlikovala u izvornom ekstraktu između pokusnih skupina je ferulična kiselina, kojoj se koncentracija pri VT snizila, pa bi je se moglo razmotriti kao biomarker VT okoliša. Što se tiče probave, biodostupnost benzojeve kiseline je veća, a kavene manja iz klica uzgojenih pri VT tijekom svih faza probave. Biodostupnost kvercetina u fazama usta i želuca bila je viša kod klica uzgajanih pri VT. VT je smanjila ili nije utjecala na antioksidacijski potencijal klica brokule u izvornom ekstraktu i nakon probave in vitro.

Abstract (english)

Plants adapt to heat stress by changing their own chemical composition. Brassicaceae are present in the diet of humans and animals, so it is important to know how high temperature (HT) will affect their nutritional value. The aim of this study was to investigate the influence of HT (38°C) on the bioavailability of different groups and individual polyphenolic compounds in broccoli sprouts (Brassica oleracea L. convar. botrytis (L.) Alef.) before and after in vitro simulated human digestion, as well as on their antioxidant potential, in order to determine the degree of stability/susceptibility of these parameters to HT. The proportion of different groups of compounds was determined spectrophotometrically, and individual metabolites were separated, identified and quantified by HPLC: L-ascorbic, gallic, benzoic, caffeic, p-coumaric, ferulic and synapic acid, and tyroside, kaempferol and quercetin. Antioxidant potential was determined by ABTS, DPPH and FRAP methods. HT significantly increased the bioavailability of total flavonols and hydroxycinnamic acids of broccoli sprouts. The only compound which concentration differed in the original extract between the experimental groups was ferulic acid; at HT its concentration decreased, so it could be assessed as a potential enviromental HT biomarker.. In terms of digestion, the bioavailability of benzoic acid was higher and caffeine lower from sprouts grown at HT during each phase of digestion. The bioavailability of quercetin in the salivary and gastric phase was higher in sprouts grown at HT. HT reduced or did not affect the antioxidant potential of broccoli sprouts in the original extract and after in vitro digestion.

• Keywords: klimatske promjene; kupusnjače; HPLC; flavonoidi; fenolne kiseline; probava in vitro; vitamin C
• Keywords (english): climate change; Brassicaceae; plant metabolites; HPLC; flavonoids; phenolic acids; vitamin C
• Language: croatian
• URN:NBN: urn:nbn:hr:217:189399
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2023-11-11
• Created on: 2021-11-12 13:29:38