FREEZING INJURY OF FRUITS AND VEGETABLES 19 



fruit, with or without drying of the pulp. Small pits or pitted 

 areas may also develop in the rind on any part of the fruit. In 

 fruit on the market, picked several days after it had been frozen on 

 the tree, the injury is manifest by woodiness of the pulp or by 

 open spaces between the segments due to the collapse and drying 

 out of some of the juice sacs. Cavities usually appear in the 

 orange pulp before open spaces develop between the segment walls. 

 Later, when considerable drying out of the pulp has occurred, 

 small open spaces between the segment walls may be found. Some- 

 times only one or two segments will show drying-out effects and 

 all or only a part of the segment may be affected. 



There are, of course, all degrees of dryness, from very slight to 

 total. In the practical handling of citrus fruit three degrees of 

 dryness are recognized: (1) Slightly open, when the cut surface 

 shows a slight open space between the segment walls and the juice 

 sacs but the surface of the pulp appears juicy. (2) Distinctly 

 open, when the cut surface shows large open spaces but the pulp 

 still appears juicy. (3) Dry, when the cut surface shows no large 

 open spaces but the fruit seems to have dried out evenly all through 

 and the color of the pulp shows it to be almost devoid of juice, or 

 when the fruit has dried out with some of the segments more or 

 less collapsed. 



Drying in oranges usually progresses from the stem end, 

 whereas in grapefruit it may proceed from either or both ends or 

 it may begin around the outside of the pulp. Drying is not found at 

 the center of the fruit except in extreme cases. If an orange that 

 has been frozen is examined a few days after it thaws, it will 

 usually show the hesperidin crystals already mentioned on the 

 membrane or rag that separates the segments of the pulp. On 

 the other hand, the crystals are sometimes visible when examina- 

 tion is made within a few hours after the freezing, whereas if it is 

 not made until several weeks afterward they may not be so numer- 

 ous or conspicuous, probably because the more severely frozen 

 fruit falls soon after the freeze. When examined on the market 

 tree-frozen fruit that has remained on the tree for several weeks 

 after freezing has a rind that is thicker than normal, especially 

 over the damaged part of the fruit. 



As differentiated from granulation, which sometimes occurs in 

 fruit on the tree, dryness from freezing results through the empty- 

 ing and subsequent collapse of juice sacs due to disappearance of 

 the juice. In granulation the juice sacs do not collapse but become 

 filled with gelatinous or solid matter. 



Parsnips 



Parsnips were kept in a %-bushel hamper in a 24° F. room for 

 28 hours. The hamper was papered over the sides and bottom. 

 On removal from the freezing room the roots around the sides and 

 on top were found to be frozen hard. Freezing was less severe at 

 the center. After 17 hours at 60° there was no sign of injury in 

 any of the roots in the hamper. After 10 days more at 60° the 

 roots were in good condition except for one small root affected 

 with rhizopus rot. 



