Physiochemical Changes of European Pear cv. Conference and Asian Pear cv. Yali during Cold Storage

This study evaluated the physiochemical changes of one commercial European pear variety 'Conference' and one Asian pear variety 'Yali' during 60 days of storage at 1 degrees C. Content of organic acids, ethylene and formation of CO2 were determined using HPLC/UV-VIS and GC/FID and TCD detectors, respectively. This study presents an evaluation of the influence of the above-mentioned factors and long-term storage on quality parameters, including the antioxidant capacity of an important European and Asian pear cultivar. There was a significant effect of temperature on respiration rate in both varieties. Development of the respiration intensity had a similar course in European and Asian pears. The high values of CO2 production at the beginning of storage for the variety 'Conference' (14.08 mg center dot kg(-1)center dot h(-1)) and 'Yali' (23.37 mg center dot kg(-1)center dot h(-1)) were followed by a sharp decline of 80% and 83% at later stages of storage at 1 degrees C, respectively. Ethylene formation in fruit increased with storage time and was the highest after 60 days in cold storage, especially in 'Yali' (7.14 mu L center dot kg(-1)center dot h(-1)). The results show the relation between ethylene formation and ripening-related fruit parameters. The 'Yali' variety showed negligible changes in soluble solids content and flesh firmness during storage ranging from 0.35 to 0.60 MPa. The most represented sugar determined enzymatically was fructose and malic acid was the dominant organic acid in pear fruit. Antioxidant activity determined using the FRAP and DPPH methods did not change significantly during 60 days of storage.