Application of Analytical Methods for the Determination of Bioactive Compounds in Some Berries

Fluorometry, ESI-MS, FTIR, and radical scavenging assays were used for characterization of bioactive compounds and the levels of their antioxidant activities. Polyphenols, flavonoids, anthocyanins, and ascorbic acid and the level of antioxidant activity of water extracts of "Murtilla-like" [Myrteola nummularia (Poiret) Berg.], and other widely consumed berries were determined and compared. The contents of bioactive compounds and the levels of antioxidant activities in water extracts differed significantly in the investigated samples (P < 0.05). "Murtilla-like" extracts contained polyphenols (mg GAE/g)-19.13 ± 0.9, flavonoids, (mg CE/g)-3.12 ± 0.1, anthocyanins (mg CGE/g)-120.23 ± 5. 4, and ascorbic acid (mg/g)-2.20 ± 0.1; and antioxidant activities (μmolTE/g) by ABTS and CUPRAC assays were 200.55 ± 8.7 and CUPRAC 116.76 ± 5.7, respectively. Chemometrical processing was done on the basis of kinetic data of two variables (concentration and reaction time) by DPPH scavenging reaction. Polyphenol content highly correlated with antioxidant capacity (R² from 0.96 to 0.83). The quenching properties of berries were studied by the interaction of water polyphenol extracts with a small protein such as BSA by 3-D fluorescence and FTIR spectroscopy. These methods were used as additional tools for the characterization of polyphenols. Wild-grown non-investigated berries were compared with widely consumed ones, using their bioactive composition, antioxidant activities, and antiproliferative and fluorescence properties. In conclusion, the antioxidant properties of "Murtilla-like" can be used as a new source for consumption. The bioactivity of "Murtilla-like" is comparable with blueberries and raspberries. 3-D fluorescence and FTIR spectroscopy can be applied as additional analytical tools for rapid estimation of the quality of food products.