Phenolic compounds, antioxidant activity and Cu, Zn, Cd and Pb content in wild and cultivated cranberries and blueberries

Abstract

The aim of this study was to determine the content of Cu, Zn, Cd and Pb and the total polyphenol (TP) content as well as the total antioxidant capacity (TAC) in wild cranberries and blueberries collected from different localities of the Slovakia and to compare them with properties of six cranberry and six highbush blueberry cultivars obtained from the research centre. Compared with cultivated cranberries (Cu, Zn, Cd and Pb content: 0.642, 1.496, 0.015 and 0.050 mg/kg FM) in wild fruits, higher Cu (by 37%) and lower Zn, Cd and Pb (by 8%, 7% and 44% respectively) were determined using atomic absorption spectrometry method. In wild blueberries, higher Cu, Zn and Pb (by 16%, 209% and 80% respectively) and similar Cd contents were determined compared with cultivated fruits (Cu, Zn, Cd and Pb content: 0.483, 0.541, 0.003 and 0.055 mg/kg FM). The TP contents estimated by spectrophotometry using Folin-Ciocalteau reagent were in intervals 1405-3161 (cranberries) and 1300-3077 (blueberries) expressed as mg GAE/kg FM. While the average TP content determined in wild cranberries was by 31% lower than that in cultivated cranberries, in wild blueberries it was by 97% higher compared with highbush blueberry cultivars. The values of TAC determined by spectrophotometry method using 2,2-diphenyl-1-picrylhydrazyl were in range 20.67-22.22 (cranberries) and 14.03-24.79 (blueberries) expressed as mmol TE/kg FM. In wild cranberries and blueberries, the lower average TAC values compared with cultivated berries were determined (by 1% and 28%, respectively).

Phytochemical Properties and Antioxidant Activities of Extracts from Wild Blueberries and Lingonberries

“…The water extracts of berries are important from the household brewing and consumption [ 20 – 22 ]. For incorporation into a functional beverage, aqueous alcohol have been used with the aim to maximizing the active ingredients [ 23 – 25 ]. As previously observed [ 26 , 27 ], an increase in the extraction temperature can promote higher phenolics solubility from plant materials, but also heat treatment may be responsible for their partial destruction.…”

“…Significantly lower results (0.36–0.41 mg GAE/g) for various lingonberry extracts (methanol, ethanol, acetone, ethyl acetate and their mixture with water) were reported for fruits harvested from southern Labrador area in Canada [ 31 ]. The average total polyphenol content determined in wild blueberries collected from different localities in Slovakia was 2.86 mg GAE/g and it was 97% higher compared to highbush cultivars (1.45 mg GAE/g) [ 23 ]. The variation between the results presented in this paper and the previously published data can be explained by the influence of cultivar, ripening stage, weather and soil conditions as well as various applied extraction methods.…”

Mineral Composition of Wild and Cultivated Blueberries

“…Hence, none of these berries would represent a risk to human health from this point of view. Vollmannova et al [ 11 ] found higher Cu, Zn, and Pb and similar Cd contents in wild blueberries collected in Slovakia in comparison with highbush blueberry cultivar; however, the soil content where the fruits were grown was not examined.…”

“…The content of anthocyanins and other phenolic compounds in different species of blueberry (wild and cultivated) are quite often determined and compared [ 6 – 10 ]. Concentration of essential elements, which are also the important components of blueberry fruits, was rarely reported [ 11 , 12 ]. Trace elements play an important role in the functioning of the human body.…”

Bioactivities and Health Benefits of Wild Fruits

“…However, in another study, the antioxidant capacities of fruits of wild and cultivated cranberries were similar, without a statistically significant difference ( p < 0.05) [ 70 ]. Furthermore, wild cranberries exhibited a lower average antioxidant capacity than cultivated berries [ 71 ]. Similarly, hydroalcoholic extracts of wild murtilla ( Ugni molinae ) fruit showed weaker DPPH· and ABTS· scavenging capacity than cultivated ones [ 72 ].…”