comparisons of color-difference meter readings can 

 be made between only those fruits for which the 

 same color standard was used (grapefruit and 

 pineapple; raspberries and strawberries). 



Of the fruits investigated, grapefruit appeared 

 to vary least in color. This is indicated by the 

 comparatively low ranges in color-difference 

 meter readings and panel color scores and by the 

 high panel score, 4.8. Color-difference meter L 

 and aL values for pineapple were similar to those 

 for grapefruit, but somewhat more variable. 

 The 6l values for pineapple were higher than the 

 corresponding value for grapefruit, indicating a 

 more yellow color. Panel color scores for both 

 pineapple, 4.4, and orange juice, 4.6, indicated 

 generally good color for these fruits. 



Color-difference meter readings for frozen 

 peaches covered a wide range. The presence of 

 brown spots on some of the samples investigated 

 was responsible for much of this variation. This 

 is reflected particularly by the wide range in color- 

 difference meter L values, 33.1 to 51.7. 



The red fruits, raspberries and strawberries, 

 showed the greatest variation in color. These 

 fruits ranged in color from the characteristic 

 bright red of the fresh berry to extremely dark 

 red. This is shown by the wide ranges in color- 

 difference meter L and a^ values and in panel 

 color scores. Panel color scores were lowest for 

 strawberries, 3.7, and raspberries, 3.8. A sum- 

 mary of sample distribution according to panel 

 color scores is shown in figm"e 5. 



Texture. — Texture of the frozen fruits was 

 evaluated by panel texture scores and, except for 

 orange juice, by shear-force readings. Results are 

 shown in table 20. Distribution of panel texture 

 scores for the fruits investigated is shown in 

 figure 6. 



Grapefruit, with a range in panel scores of 4.6 

 to 6.0 and a mean value of 5.1, was of consistently 

 good texture. Somewhat greater ranges in texture 

 scores were obtained for peaches and pineapple. 

 Mean texture scores for these fruits, however, 

 were near optimmn. 



Raspberries, with a range in panel scores of 2.8 

 to 4.8 and a mean value of 4.0, were considered to 

 be slightly softer than optimum in texture. The 

 texture of frozen strawberries was generally too 

 soft, ranging from 1.6 to 4.8 with a mean of 2.8. 

 Soft texture is often characteristic of frozen straw- 

 berries and does not necessarily indicate storage at 

 temperatiires above 0° F. 



Orange juice was rated for consistency rather 

 than firmness of texture. Therefore, the panel 

 scores cannot be compared directly with those for 

 the other fruits. 



Shear values, except for peaches, generally 

 agreed with panel texture scores. Shear values 

 for peaches were lower than would be expected on 

 the basis of the panel texture scores. 



Flavor. — A summary of sample distribution in 

 accordance with panel flavor scores is shown in 

 figure 7. Means, ranges, and coefficients of varia- 

 tions are given in table 20. Panel flavor scores, 

 except for strawberries, ranged from 3.8 for peaches 

 and grapefruit to 4.2 for orange juice. Straw- 

 berries had the widest sample-to-sample range, 1 .4 

 to 5.0, and the lowest panel score, 3.4. 



Clovd. — McCoUoch and Rice {15) evaluated the 

 quality of orange juice concentrate by determin- 

 ing cloud on reconstituted samples immediately 

 (thawing index) and after storage at 40° F. for 

 24 hours (sensitivity index). They reported a 

 decrease in the ratio of sensitivity index to thawing 

 index in samples that had been subjected to storage 

 at temperatures above 0° F. The values ob- 

 tained for the samples investigated here are given 

 in table 21. They are similar to those reported 

 by McColloch and Rice for samples stabilized 

 against cloud loss by heat treatment, and they 

 indicate generally good storage conditions for the 

 orange juice concentrate investigated. 



Table 21. — Frozen orange juice concen- 

 trate: Cloud values oj samples from selected 

 retail markets during four seasons 





Cloud 



Fruit and season 



Til 



SI 2 



SI 

 TI 



Orange juice concentrate (recon- 

 stituted) : 

 Spring _ 



0D» 

 0.50 



.58 

 .56 

 .55 



0.47 

 .57 

 .52 

 .56 



0.94 



Summer - _ _ - 



.98 



Fall 



.93 



Winter 



1. 03 







1 Thawing index. 



2 Sensitivity index. 



' Values are expressed as optical density. 



24 



