Effect of convective drying on total anthocyanin content, antioxidant activity and cell morphometric parameters of strawberry parenchymal tissue (fragaria x ananassa Dutch)

The effect of convective drying of strawberries (Fragaria x ananassa Dutch) on the contents of anthocyanins (AcyTot) and antioxidant capacity (TEAC), as equivalents of Trolox, was evaluated as well as its relation to cell morphological changes in the mesocarp by means of determining the variations in Area (A), Perimeter (P), Feret Diameter (Fe) and Fractal Dimension of parenchymal tissue cells. A decrease in anthocyanin content caused by drying at 60, 70 80 and 90 ° C and 1 m/s airflow was observed. ACyTot and TEAC showed correlation (r = 0.784). The decrease in ACyTot and TEAC in samples dehydrated at 60 °C, was associated to the decrease in values of A, P, Fe and FD found in samples dried at this temperature whereas no changes in A, P and Fe were found in samples dried at 70-90 °C in relation to those observed at 60 °C. The cell contour resulted smoother after high-temperature drying, as indicated by the decrease in FD. The antioxidant activity related to changes in ACyTot and TEAC took place at progressively higher levels in samples that changed morphology in the same proportion among each other.