Multifunctional in vitro antioxidant evaluation of strawberry (Fragaria virginiana Dutch.)

Berries have shown the highest potential antioxidant activity among fruits using a unique antioxidant method. The antioxidant activity of aqueous-organic extracts of strawberry (Fragaria virginiana Dutch., var. camarosa) were determined using three methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) radical scavenging, antioxidant ferric-reducing power (FRAP), and inhibition of Cu(II)-catalysed in vitro human low-density lipoprotein (LDL) oxidation. A serving (100 g) of strawberry had a DPPH center dot activity equivalent to that of 183 mg vitamin C and to that of 483 mg vitamin E. In addition, strawberry extracts showed high efficiency in the FRAP assay and in the in vitro inhibition of LDL oxidation. Regression linear analysis between radical scavenging activity (EC50 parameter) and total phenol content from strawberry extracts gave a statistically significant correlation (r = 0.984, P < 0.05). In conclusion, strawberry showed significant antioxidant capacity in both aqueous and lipophilic models.