Organic acids, sugars, phenolic compounds and antioxidant activity of malus floribunda coccinella fruit, peel and flesh

Malus floribunda coccinella is a landscape tree that is generally planted for its pinky flowers and small reddish fruits. The red-fleshed fruits, called crab apples, are rich in anthocyanins and are assumed as an environmental pollution material during the fruit bearing season. The aims of this research were to determine the organic acids, sugars, sugar:acid ratio, color, phenolic compounds and antioxidant activity of the fruit and also to identify the phenolic compounds, monomeric anthocyanins content and antioxidant activities in the peel, flesh and whole fruit. Malic acid (25.394 g kg–1 FW) was the main organic acid of the fruit. In fruits, amounts of sucrose, glucose and fructose were found to be 0.497, 0.504 and 4.334 g 100 g–1 FW, respectively. Highest total phenolic concentration and antioxidant activity values were observed in the peel among the fractions, while protocatechuic and cinnamic acids, rutin, isorhamnetin-3-glucoside, quercetin, procyanidin B1, (+)-catechin and cyanidin-3-galactoside were predominant phenolics of the peel. Highest amounts of chlorogenic acid and (-)-epicatechin were determined in the flesh. Cyanidin-3-galactoside concentration in the flesh was approximately half the amount of that in the peel.