Partial characterization of a new kind of Chilean Murtilla-like berries

Abstract

The aimof this research was to characterize a newkind of ChileanMurtilla-like berries (Myrteolanummularia (Poiret) Berg. Myrtaceae, called by locals as Daudapo) vs.well known Murtilla, blueberries, raspberries and black chokeberries. Polyphenols, flavonoids, flavanols and tannins and the level of antioxidant activity by ABTS, FRAP and CUPRAC radical scavenging assays ofmethanol extract of studied berry sampleswere determined andcompared. It was found that the contents of the polyphenol compounds and the level of antioxidant activity in extracts of berries differ significantly (Pb0.05). The significantly highest contents of polyphenol compounds were inmethanol extract of non-ripe Murtilla (121.31±5.9 mg GAE/g for polyphenols; 14.43±0.7, 31.79±1.5, and 9.93±0.3 mg CE/g for flavonoids, tannins and flavanols, respectively). Also the antioxidant activity according to ABTS, FRAP and CUPRAC was significantly highest in methanol extract for non-ripe Murtilla (878.18±41.2, 486.92±23.3 and 1012.42± 43.2 μMTE/g, respectively). The amount of polyphenol compounds and their antioxidant activities ofMurtilla berries are significantly higher than in other studied berries and are comparable with blueberries and raspberries, however, these indices in theMurtilla-like non-ripe berries were the following: 31.55±1.4 mg GAE/g for polyphenols; 5.22± 0.3, 12.16±0.6 and 2.24±0.1mg CE/g for flavonoids, tannins and flavanols; ABTS, FRAP and CUPRAC: 244.22± 12.1, 81.32±3.9 and 203.83±9.3 μM TE/g, respectively. The correlation between the polyphenol compounds and the antioxidant activities were relatively high. DPPH kinetic measurements were used to compare, distinguish and discriminate the antiradical activity among berry methanolic extracts by multivariate analysis. 3-D fluorescencewas used as an additional tool for the characterization of the polyphenol extracts during various stages of ripening and different berries cultivars. The interaction betweenmethanol polyphenol extracts ofMurtilla-like and bovine serum albumin (BSA) showed that the new kind of berries has a strong ability, as other studied berries, to quench the intrinsic fluorescence of BSA by forming complexes. In conclusion, for the first time these berries were analyzed and compared with widely consumed cultivars, using their polyphenols' composition, antioxidant activities and fluorescence properties. The ability ofMurtilla-like berries to quench the intrinsic fluorescence of BSA and relatively high content of polyphenol compounds can be used as a new source of antioxidants. © 2011 Elsevier Ltd. All rights reserved.