The paper describes the use of photochemiluminescence assay (PCL) and DPPH method for the measurement of lipid-soluble antioxidants capacity (ACL) of six commercially available cold-pressed, non-refined flaxseed, walnut, rapeseed, pumpkin seed, evening primrose and black cumin oils. The coldpressed plant oils are rich in various valuable bioactive compounds, e.g., tocopherols, tocotrienols, carotenoids, sterols, phospholipids and may reveal the antioxidant properties. The photochemiluminescence analysis (PCL) and free radical scavenging activity toward DPPH . were fully applicable for the evaluation of the antioxidant capacity of lipophilic fraction of samples and the outcomes correlated (r ¼ 0.91). The highest ACL exhibited black cumin oil in case of both methods.Practical applications: Photochemiluminescence analysis and radical scavenging activity toward DPPH . were fully applicable for the evaluation of the antioxidant capacity of lipophilic fraction of oil samples. However, providing a simple and reliable analytical method to detect the antioxidant capacities at very low concentrations of antioxidants in the sample is of major interest. Photochemiluminescence analysis shows many advantages over the other methodologies as it is fully automatic, sensitive, quick and does not require any time-consuming or complicated sample preparation steps that is needed in case of, e.g., DPPH method.

This paper presents a study on the antiradical properties of red fruits commonly consumed in Europe, i.e. strawberry (Fragaria ananasa), raspberry (Rubus ideaus), blackberry (Rubus fruticosus), cranberry (Vaccinium macrocarpon) and pomegranate (Punica granatum) extracts by various in vitro tests as well as the determination of qualitative and quantitative features of their phenolic compounds. Our results indicated richness of red fruits in phenolic compounds and variability of their chemical mixtures dominated generally by anthocyanins, ellagic acid and their derivatives. The selected fruit extracts exhibited notable antiradical activity by DPPH, ABTS, ORAC and PCL assays with significant correlation to phenolic content and remarkable influence of the chemical composition. This investigation indicated that the red fruits examined constitute prosperous natural sources of antiradical substances of high value which would benefit the product quality and consumers' health.