Changes in bioactive compounds, antioxidant ve antimicrobial activities of wild strawberry (Fragaria vesca) during different heating temperatures

In this study, effect of heat treatment on bioactive compounds (total anthocyanins ve total phenolics) ve visual colour of wild strawberry pulp was studied. Antimicrobial ve antioxidant activities were also evaluated over the temperature range 60?90°C during 80 minutes total monomeric anthocyanins ve total phenolics degraded with increasing heating temperature ve time. First-order reaction models were determined for the degradation of monomeric anthocyanins ve total phenolics. The activation energies for the degradation of anthocyanins ve total phenolics were found as 21.3 kj mol-1 ve 19.0 kj mol-1, respectively. The change in visual colour of wild strawberry pulp was also determined using CIE L* a* b* colour parameters. The loss of colour parameters also followed first-order raection kinetics. Activation energy for colour loss was found in the range of 11.9-40.5 kj mol-1. Antioxidant activities of heat treated wild strawberry pulp were determined as 22.7-25.6 µmol TE g-1 at the beginning of heating in the temperature range 60-90°C. These values were found as 24.0-28.1 µmol TE g-1 after 80 minutes heating at the applied temperatures. Results relieved that methanolic extracts of wild strawberry pulp posses antibacterial activity against Staphylococcus aureus ve Micrococcus luteus. However, no antimicrobial activity was found against Escherichia coli ve Salmonella enteriditis.Key words: Total monomeric anthocyanins, total phenolics, common strawberry, antioxidant activity, antimicrobial activity, colour