Affiliations: [a]
Universidad Católica de Oriente, Facultad de Ciencias de la Salud, Rionegro, Colombia
| [b]
Universidad Nacional de Colombia Sede Medellín, Facultad de Ciencias, Medellín, Colombia
| [c] Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, Colombia
Correspondence:
[*]
Corresponding author: Benjamín Rojano; Universidad Nacional de Colombia Sede Medellín, Facultad de Ciencias. Medellín, Colombia. Tel.: +57 4 430 9381; E-mail: [email protected].
Abstract: BACKGROUND:Vaccinium meridionale is a fruit rich in polyphenols, with coloring and antioxidant properties. OBJECTIVE:Decoctions of the fruit were prepared and the effect of temperature, time and pH on oxidative stability and color parameters were evaluated. METHODS:To evaluate the oxidative stability the ORAC, FRAP, and DPPH methodologies and the quantification of phenols and anthocyanins by spectrophotometric tests were developed, while colors parameters were determined using a colorimeter and UV- VIS spectrums. RESULTS:Rising the temperature from 60 to 100°C increased phenol content, FRAP and ORAC values up to 724.24 mg gallic acid/L, 978.51 mg ascorbic acid/L and 14172μmol Trolox/L, respectively; anthocyanin content decreased above to 80°C. At pH of 3.60 to 7.40 the antioxidant and color properties were not altered, at pH 10 there was a reduction of the antioxidant activity of 48.9%, and loss of the red tones of the decoctions. CONCLUSION:The content of phenols increased with temperature, increasing the antioxidant capacity, however the anthocyanins were degraded above 80°C and 20 minutes of processing.
