results do not diflfer greatly from those obtained 

 for ascorbic acid ratios. Raspberries, which 

 were highest in ascorbic acid ratios, 2.06, were 

 also highest in titratable acidity ratios, 2.55. 

 Acid ratios appear to be characteristically higher 

 for raspberries than for other fruits investigated. 

 A summar3^ of sample distribution in accordance 

 with this quaUty evaluation factor is given in 

 figure 3. Titratable acidity ratios for straw- 

 berries and pineapple were similar to ascorbic 

 acid ratios for these fruits. The titratable 

 acidity ratio for grapefruit, however, was con- 

 siderably higher than the ascorbic acid ratio 

 for this fruit. In peaches, the added ascorbic 

 acid would probably be a factor in the ascorbic 

 acid ratio, and similarity of this ratio to the 

 titratable acidity ratio would not be expected. 

 Guadagni and others {9), in work on frozen 

 raspberries of known history, have reported titrat- 

 able acidity ratios ranging from 1.05 to 1.27 for 

 samples subjected to storage at 20° F. for 5 days. 

 Since most of the samples of raspberries had 



NUMBER 

 i OF SAMPLES 



; 20 - 



titratable acidity ratios of 1.25 or less, it would 

 seem that they had been stored under conditions 

 more favorable than 5 days at 20° F. 



Effects of time and temperature on solids-to- 

 liquids ratios of titratable acidity have been 

 reported for raspberries only. The data in 

 figure 3 would indicate that the rate of migration 

 of acid from solids to liquids is a characteristic 

 of the individual fruit. Results for fruits other 

 than raspberries can therefore be evaluated best 

 when related to those of other quality evaluation 

 tests. In grapefruit, pineapple, and strawberries, 

 the ratios were generally low. In peaches, the 

 wide range in values would seem to denote 

 considerable variation in storage history. 



Soluble solids. — In the freshly frozen fruit, 

 most of the soluble solids would be in the hquid 

 portion of the fruit. Consequently the solids-to- 

 liquids ratio of soluble solids would be quite low. 

 If the fruit is exposed to temperatures above 

 0° F., some of the soluble solids will migrate 

 from the liquid to the solid portion of the fruit 



Grapefruit 10 



Peaches 



Pineapple 



Raspberries 



10- 



0-] 1 1 

 30- 



20- 



10- 



10- 



40- 



30- 



Strawberries 20 — 



10- 







FiGUBE 3. — Frozen fruits: Solids-to-liquids ratios of titratable acids. 



20 



