| Přispěvatelé: |
Ozimec, Siniša, Bogut, Irella, Bogdanović, Tomislav, Jurčević Agić, Ivančica, Rožac, Vlatko, Stević, Filip, Popović, Željko, Vereš, Marija |
| Popis: |
Cilj ovih preliminarnih analiza bio je procijeniti učinak visoke temperature (VT) na bioraspoloživost fenolnih spojeva i antioksidacijski potencijal klica brokule (Brassica oleracea L. convar. botrytis) tijekom in vitro simulirane probave čovjeka. Udio ukupnih flavonola bio je značajno viši u VT-klica nego u klica uzgojenih pri sobnoj temperaturi (ST). Ukupni fenoli, flavonoidi, antocijani, fenolne i hidroksicimetne kiseline nisu se razlikovali između VT-i ST-klica. VT nije značajno utjecala na koncentraciju vitamina C, kao ni na koncentraciju galne, benzojeve, kavene, p- kumarinske i sinapinske kiseline, tilirozida, kvercetina i kempferola. Jedini spoj na koji je VT utjecala bila je ferulična kiselina, snizila joj se koncentracija. Antioksidacijski potencijal izmjeren metodom ABTS bio je niži kod VT-klica, međutim mjereno metodama DPPH i FRAP nije se razlikovao između VT- i ST-klica. Tijekom probave, VT-klice imale su viši udio ukupnih fenolnih spojeva, međutim niži ukupnih antocijana u želučanoj fazi, u ostalim fazama nije bilo razlike između dvije skupine klica. Iako se ukupni flavonoidi nisu razlikovali između dvije skupine klica, ukupni flavonoli bili su povećani kod VT- klica u svakoj od faza probave. Ukupne fenolne kiseline nisu se razlikovale među klicama na početku probave, međutim u crijevnoj fazi VT-klice imale su značajno više ukupnih fenolnih kiselina. Ukupne hidroksicimetne kiseline bile su značajno veće u VT-klica nakon svake faze probave. Na koncentraciju vitamina C, tilirozida i kempferola VT nije značajno utjecala ni u jednoj od faza probave. U svakoj od faza VT-klice imale su povećanu koncentraciju benzojeve, a smanjenu kavene kiseline. Koncentracija galne kiseline u VT-klica bila je viša u želučanoj i crijevnoj fazi, ferulične je smanjena u svakoj od faza, osim u crijevnoj. Sinapinska kiselina u VT-klica je povišena u crijevnoj fazi, dok p-kumarinska uopće nije detektirana tijekom probave. Kvercetin je povišen u fazi usta i želučanoj, no nije zabilježen u crijevnoj. Prema metodama ABTS i DPPH, antioksidacijski potencijal bio je veći kod VT-klica nakon faze usta, međutim metodom FRAP zabilježen je niži potencijal. Metodom ABTS nisu primijećene razlike u antioksidacijskom potencijalu između VT- i ST-klica nakon želučane i crijevne faze, dok je metodama DPPH i FRAP zabilježen niži potencijal VT-klica nakon probave u crijevima. Metodom DPPH zabilježen je niži potencijal i nakon faze želuca. Rezultati ovih analiza pokazuju termoosjetljive i termostabilne fenolne spojeve u klicama brokule, njihovu bioraspoloživost tijekom simulirane probave i otkrivaju relevantnost VT za antioksidacijski potencijal klica prije i tijekom probave. / The aim of this preliminary study was to assess the effect of high temperature (HT) on the bioaccessibility of phenolic compounds and antioxidant potential of broccoli (Brassica oleracea L. convar. botrytis) seedlings during in vitro simulated human gastrointestinal digestion. Total flavonols were significantly higher in HT- seedlings than in seedlings grown under the room temperature (RT). Total phenolics, flavonoids, anthocyanins, phenolic and hydroxycinnamic acids did not differ between HT- and RT-seedlings. Neither the concentration of vitamin C, nor that of gallic, benzoic, caffeic, p-coumaric and sinapic acid, tiliroside, quercetin and kaempferol was significantly affected by HT. The only compound that was affected was ferulic acid, it was decreased. Antioxidant potential measured by ABTS method was lower in HT-seedlings, however measured by DPPH and FRAP methods it did not differ between HT- and RT-seedlings. During gastrointestinal digestion, HT-seedlings had increased total phenolics, however decreased total anthocyanins in gastric phase, in other phases there was no difference between the two groups of seedlings. While total flavonoids did not differ between the two groups of seedlings, total flavonols were increased by HT in each of digestion phases. Total phenolic acids did not differ between the seedlings at the beginning of digestion, however upon intestinal phase HT- seedlings had significantly more total phenolic acids. Total hydroxycinnamic acids were significantly higher ih HT seedlings after each of digestion phases. Vitamin C, tiliroside and kaempferol concentration was not significantly affected by HT in either of digestion phases. In each of the phases benzoic acid was increased, while caffeic was decreased. Gallic acid was higher in gastric and intestinal phase, ferulic was decreased in each of the phases, except intestinal. Sinapic acid was increased in intestinal phase, while p-coumaric was not detected during digestion at all. Quercetin was increased in salivary and gastric phase, however not detected in intestinal. According to ABTS and DPPH method, antioxidant potential was higher in HT-seedlings after salivary phase of digestion, however FRAP method revealed a lower potential. No changes in antioxidant potency were detected after gastric and intestinal phase with ABTS method, while DPPH and FRAP method showed a lower potency of HT-seedlings after intestinal digestion. With DPPH method a lower potency was detected after gastric phase as well. These results offer differentiation between thermosensitive and thermostable bioactive compounds in broccoli seedlings, their bioaccessibility during simulated digestion, and reveal relevance of HT for seedlings` antioxidant potential before and during digestion. |
