Bioaccessibility, permeability and antioxidative activity of olive pomace-based nutraceuticals

Tijekom proizvodnje maslinovog ulja iz ploda masline (Olea europaea L.) nastaju velike količine otpada u obliku otpadnih voda i komine (krutog ostatka). Njihov kemijski sastav karakterizira značajan udio fenolnih spojeva koje nalazimo i u maslinovom ulju. Osnovni cilj ovog istraživanja bio je funkcionalna karakterizacija ekstrakta komine masline (EKM) i to u kontekstu istraživanja biodostupnosti i intestinalne permeabilnosti karakterističnih aktivnih sastavnica EKM-a: hidroksitirosola (HTS), tirosola (TS) i oleuropeina (OLE) te istraživanje lokalnog antioksidacijskog učinka neprobavljive frakcije EKM-a na stanice crijevnog epitela. Zaključak ove studije je da je EKM bogat izvor biološki aktivnih i biodostupnih fenola HTS-a, TS-a i OLE-a, a njihov sadržaj i biodostupnost usporedivi su ili bolji u odnosu na maslinovo ulje. Također, zaključeno je da navedeni fenoli međusobno ne interferiraju na razini permeabilnosti što je važan preduvjet za daljnji razvoj kompleksnih nutraceutika iz komine masline. EKM ostvaruje značajne antioksidacijske učinke na stanice crijevnog epitela koji su posljedica direktnog antiradikalnog učinka, ali i učinaka na produkciju endogenih antioksidansa stanice. Matriks EKM-a, prisutnost i vrsta ciklodekstrina u formulaciji te prisutnost hrane u probavnom sustavu značajno utječu na sve promatrane parametre. Stoga rezultati studije ukazuju na važnost usmjerene, ali sveobuhvatne funkcionalne karakterizacije u procesu oblikovanja visoko vrijednih nutraceutika komine masline te naglašavaju mogućnosti uvođenja jednostavnih intervencija tijekom formulacije koje će rezultirati poboljšanom funkcionalnošću završnog proizvoda.During the production of olive oil from the olive fruit (Olea europaea L.) large amounts of waste is generated in the form of wastewater and pomace (solid residue). Their chemical composition is characterized by a significant proportion of phenolic compounds that are also found in olive oil. The main goal of this study was a functional characterization of olive pomace's extract (OPE), namely, the bioavailability and intestinal permeability study of characteristic active components of OPE: hydroxytyrosol (HTS), tyrosol (TS) and oleuropein (OLE) and local antioxidantive effect of indigestible OPE fraction on intestinal epithelial cells. The conclusion of this study is that OPE is a rich source of biologically active and bioavailable phenols HTS, TS and OLE, and their content and bioavailability are comparable or better comparing to olive oil. Also, it was concluded that these phenols do not interfere with each other at the level of permeability, which is an important prerequisite for the further development of complex nutraceuticals from olive pomace. OPE achieves significant antioxidative effects on intestinal epithelial cells as a result of direct antiradical effect, but also of the endogenous cells' antioxidants production. The OPE matrix, the presence and type of cyclodextrin in the formulation and the presence of food in the digestive system significantly affect all the observed parameters. Therefore, the results of the study indicate the importance of targeted but comprehensive functional characterization in the process of formulating high-value olive pomace nutraceuticals and emphasize the possibility of introducing simple interventions during formulation that will result in improved final product functionality