Chemical composition and antioxidant activity of fruits of three plum cultivars grafted on four rootstocks

Abstract

Chemical and antioxidant properties of fruits of three plum cultivars (‘Čacanska Rana’, ‘Čacanska Lepotica’ and ‘Čacanska Najbolja’) grafted on four rootstocks (Myrobalan, ‘Pixy’, ‘Fereley’ and ‘St. Julien A’) were studied in the region of Belgrade (Serbia). Chemical composition of plum fruits was found to be more cultivar- then rootstock-dependent. The average values for soluble solids, total sugars, inverted sugars, sucrose, and total acids content in cultivar/rootstocks combinations ranged from 11.7 to 14.2%, from 9.5 to 11.5%, from 6.6 to 7.6%, from 2.7 to 3.9%, and from 0.71 to1.11%, respectively. The contents of soluble solids and total sugars were the highest in fruits of ‘Čacanska Najbolja’, while the lowest contents were found in fruits of ‘Čacanska Rana’ cultivar. Total phenolic content (TPC) in the skin and flesh of plums was in the range from 4.44 to 15.93 mg GAE g-1, and from 0.38 to 0.86 mg GAE g-1 respectively. TPC in the skin was 6–20 times higher than in the flesh of the same cultivar/rootstock combinations. Differences in TPC among rootstocks were not statistically significant, but significant differences among cultivars were found. Radical scavenging activity (RSA) in the skin and flesh ranged from 39.08 to 78.49 μmol TE g-1, and from 10.40 to 16.97 μmol TE g-1 respectively. Significant differences in RSA were found among cultivars and cultivar/rootstock combinations, whereas differences between rootstocks were not significant. The highest RSA was found in fruits of ‘Čacanska Najbolja’ cultivar.