| Abstract | Cilj je bio ispitati kinetiku otpuštanja polifenolnih spojeva iz aronije tijekom probave u želudcu i tankom crijevu. Da bi se odredila količina polifenolnih spojeva prije probavnog procesa, provedena je kemijska ekstrakcija aronije i ekstrakcija pomognuta enzimima. In vitro probava aronije provena je simuliranjem probave u želudcu i tankom crijevu, u različitim vremenskim periodima (5, 10, 15, 20, 30, 60 i 120 min). Identifikacija i kvantifikacija polifenolnih spojeva provedena je RP-HPLC metodom (Reversed-Phase High-Performance Liquid Chromatography). U aroniji su prije i nakon probave u želudcu i tankom crijevu identificirane fenolne kiseline (neoklorogenska i klorogenska kiselina), antocijani (cijanidin-3-galaktozid, cijanidin-3-glukozid, cijanidin-3-arabinozid i cijanidin-3-ksilozid) i flavonoli (kvercetin-3-rutinozid, kvercetin-3-galaktozid i kvercetin-3- glukozid). Prije probave u najvećem postotku u aroniji su bili prisutni antocijanini (66 %), zatim fenolne kiseline (26 %) te flavonoli (8 %). Slična postotna raspodjela pronađena je nakon probave u želudcu (antocijanini 58 %, fenolne kiseline 36 %, flavonoli 6 %), dok se postotna raspodjela u tankom crijevu razlikovala (fenolne kiseline 56 %, antocijanini 27 %, flavonoli 17 %). Ove promjene moguće su zbog različite pH vrijednosti tijekom probave u želudcu i tankom crijevu. Dobiveni podatci (količina polifenolnih skupina otpuštena tijekom probave \((c_{t)})\) vs vrijeme (t)) analizirani su nelinearnom regresijom upotrebljavajući modificirane jednadžbe prvog i drugog reda. Predviđeno je brzo vrijeme otpuštanja polifenola (\(t_{1/2}\) prvi red: želudac 0,94 - 2,31 min, tanko crijevo 0,82 - 4,10 min; drugi red: želudac 0,63 do 1,02 min, tanko crijevo 0,77 do 2,50 min). Visoka korelacija između \((C_{00})\) predviđenih modelom i eksperimentalnim vrijednostima ukazuje na mogućnost upotrebe modela za analiziranje simulirane probave. |
| Abstract (english) | The aim was to study the kinetics of the release of polyphenolic compounds from chokeberry during digestion in the stomach and small intestine. In order to determine the amount of polyphenolic compounds before the digestion, chemical and enzyme-assisted extraction were performed. In vitro digestion of chokeberry was conducted by simulating digestion in the stomach and small intestine, in different time periods (5, 10, 15, 20, 30, 60 and 120 min). Identification and quantification of polyphenolic compounds was performed using the RP-HPLC method (Reversed-Phase High-Performance Liquid Chromatography). Phenolic acids (neochlorogenic and chlorogenic acid), anthocyanins (cyanidin-3-galactoside, cyanidin-3-glucoside, cyanidin-3-arabinoside and cyanidin-3-xyloside) and flavonols (quercetin-3-rutinoside, quercetin-3-galactoside and quercetin-3-glucoside) were identified in chokeberry before and after the digestion in the stomach and small intestine. Before digestion, anthocyanins (66 %) were present in the highest percentage in chokeberry, followed by phenolic acids (26%) and flavonols (8%). A similar percentage distribution was found after digestion in the stomach (anthocyanins 58%, phenolic acids 36%, flavonols 6%), while the total distribution in the small intestine differed (phenolic acids 56%, anthocyanins 27%, flavonols 17%). These changes are possible due to different pH values during digestion in the stomach and small intestine. The obtained data (the amount of polyphenolic groups released during digestion \((c_{t)})\) vs time (t) were analyzed by non-linear regression using modified equations of the first and second order. The rapid release time of polyphenols was predicted (\(t_{1/2}\) first order: stomach 0.94 - 2.31 min, small intestine 0.82 - 4.10 min; second order: stomach 0.63 to 1.02 min, small intestine 0.77 to 2.50 min).The high correlation between \((C_{00})\) predicted by the model and experimental values indicated the possibility of using equations to analyze simulated digestion. |
