Differences in Biochemical Composition between ‘Beurre d’Anjou’ and ‘Bose’ Pears during Fruit Development and Storage1

Abstract

Abstract A comparative study in 1979 and 1980 between ‘Anjou’, a long-keeping winter pear and ‘Bose’, a shorter keeping winter pear (both Pyrus communis L.) revealed that ethanol-insoluble matter, titratable acids, soluble solids, proteins, and free amino acids in fruit of both cultivars during fruit development, maturation, and storage period fluctuated from season to season and were not associated with their difference in postharvest life. Malic acid was the major fraction of organic acids in both cultivars, and it declined at a faster rate in ‘Bosc’ than in ‘Anjou’ during storage at −1.1°C. The amounts of citric, oxaloacetic, and fumaric acids were higher in ‘Bosc’ than in ‘Anjou’ and were maintained at constant levels throughout the storage period. Internal ethylene in both cultivars early in fruit development was about 0.3 ppm and decreased rapidly to below 0.07 ppm during late fruit development and harvest period. For 2 seasons, ‘Bosc’ was capable of ripening after less than 20 days of chilling at −1.1°C when its internal ethylene increased to 0.2 ppm, while ‘Anjou’ required at least 50 days of chilling to develop the ripening capacity coincident with an internal ethylene above 2.0 ppm. Internal ethylene accumulated in ‘Bosc’ about 8 times faster than in ‘Anjou’ during the first 60 days of storage at −1.1° and reached an equilibrium at 40 ppm for ‘Bosc’ and only 5 ppm for ‘Anjou’ during the remaining storage period. After any corresponding period of cold storage, both ethylene and CO2 productions of ‘Bosc’ at ripening temperature of 20° were higher than those of ‘Anjou’, and ‘Bosc’ also required fewer days to reach the climacteric peaks than did ‘Anjou’.