7th International Food Safety Congress-Abstract Book The influence of UV irradiation on physicochemical properties of ethanol Rosa canina L. extract http://creativecommons.org/licenses/by-nc-nd/4.0/legalcode application/pdf 12577 bytes Jovanović, Aleksandra A. Balanč, Bojana Živković, Jelena Šavikin, Katarina P. Čutović, Natalija Gnjatović, Marija Bugarski, Branko M. International Association for Food Protection 2022 eng https://phaidrabg.bg.ac.rs/o:29835 info:eu-repo/semantics/conferenceProceedings ABSTRACT Rosa canina hip is known for its preventive and curative activities against a wide range of renal, inflammatory, gout, and gastric diseases. However, the functionality, stability, and bioavailability of its active compounds, particularly polyphenols, within products mostly depend on several factors, among all, UV irradiation, which is widely used in food and pharmaceutical industries. In the present study, R. canina extract was prepared using percolation, 70% ethanol, and solidto-solvent ratio of 1:2 at 25°C. Physico-chemical properties of the extract before and after UV irradiation were determined via analyzing total polyphenol content (TPC, Folin-Ciocalteu assay), total flavonoid content (TFC, colorimetric assay), total protein content (Bradford assay), antioxidant potential (ABTS and DPPH assays), extraction yield, pH value, zeta potential, conductivity, density, surface tension, and viscosity. Zeta potential and conductivity were determined by photon correlation spectroscopy (PCS); each sample was measured three times at room temperature. Density and surface tension were measured using silicon crystal (as the immersion body) and Wilhelmy plate, respectively, in Force Tensiometer. Viscosity was determined using Rotavisc lo-vi device equipment with the chamber, adapter, and spindle. Each sample (6.7 mL) was examined three times at room temperature. The statistical analysis was performed by using the analysis of variance (one-way ANOVA) followed by Duncan's post hoc test within the statistical software, STATISTICA 7.0. The differences were considered statistically significant at p<0.05, n=3. TPC of non-treated extract was 9.64±0.98 mg gallic acid equivalent (GAE)/mL, whereas in UV irradiated extract TPC was 9.54±0.30 mg GAE/mL; no statistically significant difference in TPC between native and UV irradiated extracts. TFC of the non-treated extract was 1.65±0.18 mg catechin equivalent (CE)/mL, while in UV irradiated extract TFC was 1.75±0.13 mg CE/mL. Total protein content was 0.827±0.039 and 0.800±0.030 mg/mL for non-treated and UV irradiated extracts, respectively. ABTS radical scavenging potential was 0.676±0.023 and 0.538±0.012 mmol Trolox/mL for non-treated and UV irradiated extracts, respectively. In DPPH assay, IC50 was 10.74±0.48 and 17.78±1.03 µg/mL for non-treated and UV irradiated extracts, respectively. The extraction yield was 32.8±0.2 and 31.3±1.0%, and pH values amounted 4.33 and 4.49 for native and UV irradiated samples, respectively. Zeta potential was -0.587±0.020 and -0.052±0.001 mV, while conductivity was 0.046±0.002 and 0.650±0.012 mS/cm for nontreated and UV irradiated extracts, respectively. Density was 0.931±0.001 and 0.969±0.001 g/mL, the surface tension was 25.4±0.2 and 23.3±0.4 mN/m, and viscosity was 4.21±0.01 and 5.49±0.07 mPa/s for non-treated and UV irradiated extracts, respectively. UV irradiation did not influence total polyphenol, flavonoid, and protein content, but statistically significantly decreased the antioxidant potential of the extract. Additionally, UV irradiation caused the increase in conductivity, density, and viscosity of the extract, and the decrease in zeta potential, i.e. the stability of the system and surface tension. The presented study provides evidence of the influence of UV irradiation on physico-chemical properties of R. canina extract that can add value and improve the quality of the existing food, and functional food products.