Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/4/2013
Publication Date: 8/2/2013
Citation: Mattheis, J.P., Felicetti, D., Rudell Jr, D.R. 2013. Pithy brown core in ‘d’Anjou’ pear (Pyrus communis L.) fruit developing during controlled atmosphere storage at pO2 determined by monitoring chlorophyll fluorescense. Postharvest Biology and Technology. 259-264. Interpretive Summary: ‘d’Anjou’ pear fruit can develop a brown peel discoloration during cold storage. This disorder is named superficial scald and when present renders the fruit unmarketable. Cold storage in very low oxygen concentrations, called controlled atmosphere storage, can prevent superficial scald development, however, the low oxygen environment can induce other disorders. A technique whereby peel chemistry is non-invasively measured by monitoring fruit chlorophyll fluorescence was evaluated as a means to assess fruit response to low oxygen storage environments. No changes in peel chemistry were detected using this technique, however, internal browning developed in fruit stored in the lowest oxygen concentration during storage. The results indicate assessment of pear fruit peel chemistry by monitoring chlorophyll fluorescence does not provide a means to predict development of fruit internal browning.
Technical Abstract: Physiological responses and fruit quality of ‘d’Anjou’ pear fruit from five orchard lots were evaluated after cold storage in air or controlled atmospheres (CA) with the oxygen (O2) concentration based on assessment of fruit chlorophyll fluorescence (CF) or standard conditions (1.5 kPa O2). The pCO2 for all CA fruit was 0.5 kPa. Softening, acid loss, and peel degreening of all lots were delayed at one or more evaluation dates (2, 4, 6, 8 months) by previous storage at the CF pO2 compared with fruit stored in 1.5 kPa O2 or in air. Superficial scald developed on fruit previously stored in air but not on fruit stored in CA. Pithy brown core developed on fruit from all lots stored at the CF pO2 and on fruit stored at 1.5 kPa in 3 of the 5 lots. Pithy brown core incidence decreased with advanced harvest maturity. Post-storage ethylene and CO2 production were in most instances lowest for fruit stored at the CF pO2. A significant relationship between fruit ethanol content and pithy brown core incidence was observed. Results indicate low pO2 storage based on CF monitoring slows fruit ripening relative to fruit stored at 1.5 kPa O2, prevents scald development compared with fruit stored in air, however, development of pithy brown core in fruit stored at the CF pO2 was not accompanied by a change in CF.