the changes of antioxidant capacity and pot harvest quality of thompson navel and blood orange fruits during storage

abstract antioxidant capacity and quality of fruits usually changed during storage. in the current study, the changes of antioxidant capacity and postharvest quality of two blood (pigmented) orange cultivars (‘tarocco’ and ‘morro’) and ‘thompson navel’ orange, after 60 days storage at 7ºc and 90 rh% was investigated. during fruit storage weight loss, tss, ta, tss/ta, vitamin c, total phenol, anthocyanins and also juice antioxidant capacity by dpph scavenging activity test were determined. fruit weight loss in blood oranges was more than ‘thompson navel’ orange and increased gradually during cold storage. fruit tss declined in blood orange significantly but was constant in ‘thompson navel’ orange. in contrast, ta decreased the most in ‘thompson navel’ orange. vitamin c slightly increased during storage time but total phenolics increased only in ‘taracco’. the results showed that antioxidant capacity in oranges fruits decreased with storage time and ‘morro’ fruits with the anthocyanin synthesis and accumulation during postharvest time had shown the highest antioxidant capacity. finally, the results showed that quality of oranges decrease during long term storage except to blood orange that increase antocyanin and phenolic contents.