Comparison of chemical composition and antioxidant capacity of commercially available blueberry and blackberry wines in Illinois

Moderate wine consumption may reduce the incidence of certain age-related chronic diseases such as heart disease, hypertension, metabolic disease, and neurodegenerative disease. Blueberry and blackberry wines commercially available in Illinois were evaluated for chemical and quality components relevant to consumers in order to study their potential health benefits. Total polyphenolic content was measured by the Folin-Ciocalteu method, total anthocyanin content by the pH differential test, and in vitro antioxidant capacity (AC) by the oxygen radical absorbance capacity (ORAC) method. Color was measured using Hunter colorimetry and quality parameters including pH, °Brix, acid content, glucose-fructose, and percent alcohol were measured using Fourier transform infrared spectroscopy. Blackberry wines (n= 6) had an average total polyphenolic content of 2212.5 ± 1090.3 mg ellagic acid equivalents (EAE) per liter, total anthocyanin content of 75.56 ± 70.44 mg/L, and AC of 26.39 ± 17.95 mmol trolox equivalents (TEs) per liter. Blueberry wines (n= 4) had an average total polyphenolic content of 1623.3 ± 645.5 mg EAE per liter, total anthocyanin content of 20.82 ± 12.14 mg/L, and AC of 21.21 ± 7.71 mmol TE per liter. Strong positive correlations were found between °Brix and glucose-fructose concentration (r= 0.90), total acid and malic acid (r= 0.90), and between total polyphenols and AC (r= 0.88). The results suggest that fruit wines made from blueberries and blackberries may have potential health applications and therefore could contribute to the economy of the wine industry.