Analysis of commercial grape raisins: phenolic content, antioxidant capacity and radical scavenger activity

Seven different commercial grape raisins from the Spanish market were evaluated for total phenolic composition, antioxidant potential and scavenger activity. Commercial red raisins (from the Cardinal grape variety) generally had the significantly highest content of total phenolic compounds (406.9 mg/100 g raisin) and antioxidant capacity (27.88 mM Fe(II) and 10.73 mM trolox, respectively by applying FRAP and ABTS methods) while commercial white raisins had the lowest content for the parameters analyzed, especially for commercial Moscatel of Alexandria and Sultana raisins (ranging from 110.8 to 284.4 mg/100 g raisin for total phenolic compounds and ranging from 6.0 to 17.04 mM Fe(II) and from 2.43 to 8.94 mM trolox, respectively for antioxidant capacity by applying FRAP and ABTS methods). Finally, the Pearson test shows a very high correlation (0.95 and 0.97, α