Paulauskiene A., Danilcenko H., Jariene E., Gajewski M., Seroczyńska A., Szymczak P., Korzeniewska A.

The aim of this work was to investigate electrochemical characteristics and antioxidant activity of pumpkin fruits and to determine the influence of these properties on pumpkin fruits quality. Pumpkins were grown at the experimental field of Lithuanian Agricultural University in Kaunas. Total 11 cultivars of Lithuanian and Polish origin were chosen for the experiment: ‘Stofuntovaja’, ‘Bambino’, ‘Kroška’, ‘Žemčiužina’, ‘Miranda’, ‘Golosemiannaja’, ‘Justynka’, ‘Ambar’, ‘Amazonka’, ‘Karowita’, ‘Otylia’. Chemical analysis and electrochemical characteristics of pumpkin were performed. Electrochemical parameters were measured in homogenized fresh fruit samples. P value (as combined parameter of pH, redox potential and electrochemical conductivity) was used for evaluation of pumpkins quality. The lowest P value and redox potential in the pumpkins fruit indicate the best quality of ‘Kroška’ and ‘Miranda’ cultivars. Pumpkins of this variety are the most suitable for being eaten raw. Fruits of other pumpkin varieties showed significant differentiation of biochemical and electrochemical characteristics. Carotenoids content varied from 0.90 to 11.25 mg×100 g-1. Antioxidant activity, expressed as percentage of DPPH inhibition, varied from 12% for ‘Žemčiužina’ to 89% for ‘Justynka’. Relationship between measured quality parameters of fruits was also determined. Strong correlation between total carotenoids content and antioxidative activity was found.

Key words: antioxidant activity, carotenoids, electrochemical properties, pumpkin, quality