Valentina Usenik1, Franci Stampar, Damijana Kastelec. 1. University of Ljubljana, Biotechnical Faculty, Agronomy Department, Chair for Fruit Growing, Viticulture and Vegetable Growing, Ljubljana, Slovenia. valentina.usenik@bf.uni-lj.si
Abstract
BACKGROUND: Plums are a rich source of nutritive and bioactive compounds. The objective was to evaluate the impact of fruit tissue (flesh and peel), ripening stage and cultivar on the composition of phytochemicals in plums (Prunus domestica L.) and to analyse the relation between total antioxidant activity (TAA) and the measured variables. RESULTS: The content of total sugars and total organic acids was higher in flesh but total phenolic content (TPC) and TAA was statistically higher in plum peel. The composition of sugars depended on fruit tissue, ripening stage and the cultivar. Ripening and fruit tissue affected the composition and concentrations of organic acids. TPC of 'Haganta' peel increased during ripening but there was no significant time trend for 'Jojo' peel and flesh of both cultivars. The composition of phenolics in peel depended on the cultivar, but in flesh on the cultivar and ripening. Ripening resulted in increased total anthocyanins and TAA in peel. TAA(peel) was positively correlated with TPC(peel) , total anthocyanins(peel), cyanidin 3-glucoside(peel) and peonidin 3-rutinoside(peel) in the cultivar 'Haganta'. CONCLUSION: The composition of phytochemicals in P. domestica fruit depends on fruit tissue, ripening stage and the cultivar. Peel contributes to the TAA on average 20 times more than flesh.
BACKGROUND:Plums are a rich source of nutritive and bioactive compounds. The objective was to evaluate the impact of fruit tissue (flesh and peel), ripening stage and cultivar on the composition of phytochemicals in plums (Prunus domestica L.) and to analyse the relation between total antioxidant activity (TAA) and the measured variables. RESULTS: The content of total sugars and total organic acids was higher in flesh but total phenolic content (TPC) and TAA was statistically higher in plum peel. The composition of sugars depended on fruit tissue, ripening stage and the cultivar. Ripening and fruit tissue affected the composition and concentrations of organic acids. TPC of 'Haganta' peel increased during ripening but there was no significant time trend for 'Jojo' peel and flesh of both cultivars. The composition of phenolics in peel depended on the cultivar, but in flesh on the cultivar and ripening. Ripening resulted in increased total anthocyanins and TAA in peel. TAA(peel) was positively correlated with TPC(peel) , total anthocyanins(peel), cyanidin 3-glucoside(peel) and peonidin 3-rutinoside(peel) in the cultivar 'Haganta'. CONCLUSION: The composition of phytochemicals in P. domestica fruit depends on fruit tissue, ripening stage and the cultivar. Peel contributes to the TAA on average 20 times more than flesh.