was 100 percent scalded after 6 months' storage at 31° F. plus 6 days at 70°. 
Rome apples packed in sealed polyethylene-lined boxes immediately after harvest 
andl terran claymore Ss) se OMien or Onweeks alty Siun hadi S21) 52. 7. 77 .and 
95 percent scald respectively, after storage. 
(See also section on scald.) 
Effect of Firmness and Keeping Quality 
The modified atmospheres which develop within sealed polyethylene liners 
retard the rate of softening of apples in storage (8, 18, 28, 31, 37, 56, 64, 
78) and retard the rate of yellow color development (16, 28, Bik 52h 59, 64, 
76, 78). Gerhardt and Schomer (17) found that Golden Me Mteiods anol oat stored 6 
months at 32° F, in sealed polyethylene or Pliofilm liners were better in 
appearance, condition, and dessert quality than check fruit. Sealed polyeth- 
ylene liners delayed ripening of Golden Delicious, as apples in them had less 
yellow color after storage (28). Ryall and Uota (64) stored Yellow Newtown 
apples 6 months at 40° in sealed liners and found the fruit firmer, greener, 
and with less scald on removal, Okamoto, Horitsu, and Harata (56, 57) noted 
that Ralls apples after 6 months in sealed liners were firmer and more acid 
and superior in appearance to check fruit. Langerak (37) noted that Golden 
Delicious apples stored in polyethylene at low temperature were firmer and 
juicier, but flavor and aroma were often poor. Johansson (35) had good results 
with Cox's Orange and Ingrid Marie varieties in polyethylene. Several investi- 
gators (16, 17, 33, 34, 41, 61) have also found sealed polyethylene liners or 
bags beneficial in retarding ripening of pears. 
Some apple veriaties have not kept better and firmer in sealed box 
liners. Workman (78) stated that Delicious apples became mealy. However, 
Hardenburg (26) found that if a 1l-pound packet of hydrated lime was enclosed 
in sealed liners to absorb the carbon dioxide given off by Delicious apples, 
they stayed firmer than without the lime. 
Hardenburg and Siegelman (31) showed that the benefit of slower ripening 
usually was not obtained with nonsealed liners for Jonathan, Grimes, Arkansas, 
and Rome Beauty varieties, 
Both Gorini (19) and Okamoto, Haritsu, and Harata (57) have published 
very detailed studies of the keeping quality of apples in sealed polyethylene 
and included data on sugars, total acidity, moisture, firmness, and taste. Both 
studies included tests with two or more thicknesses of polyethylene. 
Respiration has been measured on apples taken from film-lined boxes (16, 
28, 56, 78). Gerhardt (16) showed that Golden Delicious apples previously held 
in various sealed films respired at a lower rate during cold storage than com- 
parable fruit without film proteetion. Hardenburg and Anderson (28) showed that 
the poststorage respiration rate of Golden Delicious from sealed polyethylene 
liners was less than that of fruit from perforated liners or from control boxes 
without film. Workman (78) reported that sealed liners reduced respiration of 
Rome Beauty apples, Okamoto, Horitsu, and Harata (56, 57) reported that the 
superior keeping quality of apples in sealed polyethylene was due to a retarded 
respiration rate in the modified atmosphere. 
Film Selection and Use 
Various cellophanes, Pliofilms, and polyethylenes have been evaluated 
for possible box liner application (16, 39, 49). Falch and Pernerstorfer (15) 
53 
