Evaluation of effects of in vitro human digestion simulation on phenolic profile and antioxidant potential of adoxaceae fruits growing in Turkey

Although there is a wide array of antioxidant activity studies on plants and contribution of their phenolic contents in the determined activity, bioavailability phenomenon of the active ingredients is often neglected. Design of this study based on evaluation of difference in antioxidant potentials and phenolic profiles of Adoxaceae fruits growing in Turkey, before and after in vitro gastrointestinal human digestion simulation. For this purpose, two different solvent extracts, methanol and water, were prepared from the fruits of Sambucus nigra L., Sambucus ebulus L. and Viburnum opulus L. and their activity profiles were comparatively investigated. After the digestion simulation procedure, total phenolic, phenolic acid, flavonoid and total proanthocyanidin contents were determined for all phases of digestion. High performance thin layer chromatography (HPTLC) was used for the measurement of selected phenolic molecules. Bioavailability index was calculated for all phenolic content assays and for the selected bioactive compounds for accurate determination of alterations in phenolic profile via in vitro human digestion. For revelation of the precise antioxidant potential of fruit extracts, a couple of free radical scavenging (DPPH and DMPD) and metal reducing potential (CUPRAC and FRAP) assays and in addition a total antioxidant capacity assay were conducted on all phases. The results showed that human digestion might have significant effect on phenolic profile and antioxidant properties of herbal extracts. Key words: Sambucus nigra L., Sambucus ebulus L., Viburnum opulus L., Antioxidant activity, Human digestion simulation, Chlorogenic acid