Comparative Polyphenolic Content and Antioxidant Activities of Some Wild and Cultivated Blueberries from Romania

Andrea Bunea,Olivia Dumitrita Rugina,Carmen Socaciu,Zoriţa Sconţa,Adela M Pintea,Claudiu I Bunea

doi:10.15835/nbha3926265

Abstract

Two wild and three cultivated blueberry varieties (‘Elliot’, ‘Bluecrop’ and ‘Duke’) from Romania were analyzed comparatively in order to determine the total polyphenols, total anthocyanins, total flavonoids content and measuring the antioxidant activity using three different single electron transfer-based assays, Trolox equivalent antioxidant capacity (ABTS), ferric reducing ability (FRAP), 2,2-diphenylpicrylhydrazil radical scavenging capacity (DPPH) and one hydrogen atom transfer-assay, oxygen radical absorbance capacity (ORAC). Total polyphenols content ranged from 424.84 - 819.12 mg GAE/100 g FW, total flavonoids ranged from 84.33-112.5 mg QE /100 g FW and total anthocyanins ranged from 100.58-300.02 C3GE/100g FW. The anthocyanins were separated and quantified using RP-HPLC-DAD. In Vaccinium myrtillus, petunidin-3-glucoside and delphinidin-3-glucoside have the highest contribution to the anthocyanin content while in Vaccinium corymbosum, peonidin-3-galactoside represent the major anthocyanin. Except for ORAC assay (r=0.765), all antioxidant activity values obtained were highly correlated with total polyphenol content (0.923≤ r ≤0.986). Wild blueberries had higher total polyphenols content and also antioxidant activity compared with cultivated ones.

Highlights

The interest for natural antioxidants, especially from fruits and vegetables, has increased in recent years
The objectives of this study were (1) to investigate total polyphenols, total flavonoids, total anthocyanins content of blueberry extracts, (2) to separate and characterize the anthocyanin content using RP-HPLC-diode-array SPDM20 A UV-VIS detector (DAD), (3) to measure the antioxidant activity using three different single electron transfer (SET)-based assays (ABTS, ferric reducing antioxidant power (FRAP), DPPH) and one HATbased method (ORAC), (4) to correlate the antioxidant methods applied with total polyphenol, total flavonoid and total anthocyanin content
Total polyphenols content The comparative data about total polyphenols, flavonoids and anthocyanins content in wild and cultivated blueberries are presented in Tab. 1

Summary

Introduction

The interest for natural antioxidants, especially from fruits and vegetables, has increased in recent years. Epidemiological studies indicated that a higher level of natural antioxidants (ascorbic acids, vitamin E, carotenoids and phenolics) in human everyday diet can protect against cardiovascular diseases, cataract, cancer and aging-related disorders (Steffen et al, 2003). Berries contain high concentration in bioactive compounds such as polyphenols, including anthocyanins, phenolic acids, tannins, carotenoids, vitamin A, C, E, folic acid and minerals such as calcium, selenium and zinc (Kresty et al, 2001; Pineli et al, 2011). Blueberries contain high level of anthocyanin and phenolic compounds with high in vitro antioxidant capacities compared with other fruits (Wang and Jiao, 2000). The total amount and the proportion between different classes of phenolic compounds in berries cultivar may vary (Beekwilder et al, 2005)

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