Sugars and organic acids contents of European (Pyrus communis L.) and Asian (Pyrus serotina Rehd.) pear cultivars

The content of sugars (glucose, fructose, sucrose, sorbitol) and organic acids (citric, malic, fumaric. tartaric) was analysed with HPLC (High Performance Liquid Chromatography) in pear fruits of 18 European (Pyrus communis L.) and 4 Asian (Pyrus serotina Rehd.) cultivars. The cultivars differed in the content of different sugars and organic acids. Fructose varied in the European pear cultivars from 23.7 g kg(-1) in cv. 'Conference' to 66.1 g kg(-1) in cv. 'Clapp Favorite' and in the Asian cultivars from 27.9 g kg(-1) in cv. 'Shinseiki' to 45.7 g kg(-1) in cv. 'Koshui'. Sorbitol varied in the European pear cultivars from 12.5 g kg(-1) in cv. 'Conference' to 24.9 g kg(-1) in cv. 'Beurre Bosc' and in the Asian cultivars from 5.0 g kg(-1) in cv 'Shinseiki' to 19.0 g kg(-1) in cv. 'Kumoi'. The Asian pear cultivars contained more total sugars than the European ones. The early cultivars of pears contained more than 1.0 g kg(-1) of citric acid and the late ones less than 1.0 g kg(-1) The cvs. 'Williams Bon Chretien', 'Early Morettini', 'Princess Mariane', 'Koshui' and 'Hoshui' contained more citric than malic acid. In the cvs. 'Concorde', 'Conference' and 'Beurre Alexandre Lucas' no citric acid was traced. The content of tartaric acid was traced only in cv. 'Hardy'.