STORAGE AND RIPENING OF PEARS 



William J. Bramlage 

 Department of Plant and Soil Sciences 



A high-quality pear is truly a delicacy, but it's a delicacy much 

 too seldom offered to the public. Storage or ripening at an improper 

 temperature very often results in the failure of pears to develop their 

 full potential quality. Recent work by Dr. S. W. Porritt of Summerland, 

 B. C, Research Station of the Canada Department of Agriculture has 

 clearly illustrated the sensitivity of pears to temperature conditions. 



Unlike apples, most pear varieties do not ripen normally in cold 

 storage. Porritt found that Bartlett pears ripened normally at 60° and 

 70° F, but not at lower temperatures. At 50 , they developed a dry tex- 

 ture and poor quality. At 30 , the fruit failed to soften, and further- 

 more, after extended storage time they even lost their capacity to ripen 

 when brought to 60-70°; this loss of ripening capacity was preceded by a 

 yellowing of the fruits at 30°, although they did not soften. 



Anjou pears differ from most other varieties. For one thing, they 

 will ripen normally at low temperatures. In Porritt's study, Anjous 

 ripened normally at temperature of 32° to 50°, though of course, the 

 lower the temperature, the more slowly they ripened. Anjous were also 

 different in that when held at 50° or higher, they failed to ripen prop- 

 erly unless they were first stored at 30-40°. Thus, they required a 

 period of cold storage prior to ripening. This requirement seems to be 

 intensified if the fruits are picked prematurely. 



Not unlike apples , storage temperature has a marked effect on the 

 storage life of pears. Porritt's results showed that for Bartletts, 

 storage life at 30° was extended 1+0% and 70% over that at 32° and 34°, 

 respectively; for Anjous, storage life at 30° was extended 3 5% and 125% 

 over that at 32 and 3M-°, respectively. A long storage life demands 

 good temperature control in the storage. 



Another factor that sharply influenced quality of pears was the 

 speed with which the fruits were brought to 30° after harvest. Porritt 

 held Bartlett pears at 65° for 1, 2, 3, or M- days before cooling them 

 to 30°, and also used periods of 4-, 6, 8, 10, or 14 days to cool the 

 pears from 65° to 30°. In every case , the longer the delay in cooling 

 to 30° , the more rapidly the pears deteriorated . The delay in cooling 

 had an especially striking effect on the occurrence of core breakdown; 

 for example, pears held at 65° for 0, 1, 2, or 4 days before storage at 

 30° developed 0, 26, 52, and 71% core breakdown, respectively, after 12 

 weeks in storage plus 10 days at 70 . 



From these results, which agree closely with results from other 

 studies, several guidelines can be laid down for handling of pears: 



1. After harvesting, cool the fruits as rapidly as possible; 



2. Store the pears at 30 ; 



