frozen peaches contained added ascorbic acid, 

 the values were higher than those normally 

 found in fresh fruit. All fruits investigated 

 varied in ascorbic acid content of both solids and 

 liquids. For each type of fruit, a few samples 

 showed extreme variation. However, values for 

 most of the samples fell near the mean for the 

 group. This is demonstrated by the fact that a 

 large proportion of the samples (ranging from 63 

 of 64 samples for orange juice to 35 of 48 for 

 peaches and raspberries) had ascorbic acid values 

 at least 80 percent as high as the mean ascorbic 

 acid value for that particular fruit. 



The ratio of oxidized to reduced ascorbic acid 

 in sohds was highest in raspberries, 0.71; this 

 fruit was also most variable in oxidation ratios, 

 with a range of 0.22 to 8.75. In grapefruit, most 

 of the ascorbic acid was in the reduced form; the 

 oxidation ratio in solids was only 0.11. For the 

 other fruits, the ratios ranged from 0.51 in pine- 

 apple to 0.60 in strawberries. As was the case 

 with reduced ascorbic acid, a few extreme values 

 were responsible for much of the variation in 



individual values. A large proportion of the 

 samples (ranging from 41 of 48 samples for 

 raspberries to 35 of 48 for grapefruit and peaches) 

 had ascorbic acid oxidation values that exceeded 

 the mean value by no more than 20 percent. 

 Distribution of ascorbic acid oxidation ratios for 

 the fruits investigated are shown in figure 1 . 



Ratios of o.xidized to reduced ascorbic acid in 

 liquids were similar to those for solids. In the 

 liquids, ratios of oxidized to reduced ascorbic acid 

 were very low for grapefruit, 0.08, and orange 

 juice, 0.09. Highest values were obtained in 

 raspberries, 2.06, and strawberries, 1.15. Rasp- 

 berries had the widest range in oxidation ratios, 

 0.20 to 4.61, and the highest coefficient of variation, 

 74, for oxidation ratios. 



The low oxidation ratios found in both the solid 

 and liquid portions of grapefruit appear to denote 

 good ascorbic acid stability in this fruit rather 

 than superior storage conditions, since the results 

 of other quality evaluations for grapefruit are 

 similar to those obtained for the other fruits 

 investigated. The ascorbic acid oxidation ratio 



Table 16.— Frozen fruits: Ascorbic acid 



Fruit 



Grapefruit sections 



Orange juice concentrate. 



Peaches, sliced 



Pineapple chunks 



Raspberries, red 



Strawberries, sliced 



Grapefruit sections 



Orange juice concentrate 



Peaches, sliced 



Pineapple chunks 



Raspberries, red 



Strawberries, sliced 



Grapefruit sections 



Orange juice concentrate . 



Peaches, sliced 



Pineapple chunks 



Raspberries, red 



Strawberries, sliced 



Solids 



AsA ' 

 (mg./lOO g.) 



Mean 3 



39.3 



17.5 



7.3 



12.9 



36.0 



Range 



22. 5- 48. 7 



8. 9- 28. 2 



4. 2- 14. 



. 8- 23. 



11. 3- 50. 2 



C.V." 



14 



25 



27 

 38 

 19 



DH+DK2 



(mg./lOO g.) 



Mean' 



4.3 



9.3 



3.6 



5.9 



20. 3 



Range 



2. 2- 7. 2 



5. 0-13. 8 



. 5-16. 



3. 0-18. 



10. 5-32. 



C.V. 



34 



23 

 83 

 41 

 23 



DH+DK 



AsA 



Mean' 



0. 11 



58 

 51 

 71 

 60 



Range 



0. 04-0. 19 



. 18-1. 35 

 . 07-2. 00 



. 22-8. 75 

 . 29-1. 82 



Liquids 



60. 8 

 41. 

 64.5 

 8.2 

 7.3 

 32.7 



34. 3- 78. 



13 



5.2 



32. 7- 51. 



7 



3.5 



36. 9-102. 6 



15 



17.4 



4. 0- 14. 



23 



4.0 



0- 13.0 



29 



7.0 



13. 7- 55. 



20 



20. 7 



2. 0-11. 



0- 5.8 



8. 8-25. 5 



. 8-12. 



2. 0-27. 



10. 0-36. 



43 



0.08 



30 



.09 



16 



.28 



68 



. 51 



59 



1. 13 



28 



.69 



0. 04-0. 17 

 0- . 16 

 . 12- . 50 

 . 09-1. 70 

 . 20-4. 61 

 . 30-1. 43 



AsA in solids/AsA in liquids 



Mean ' 



0.66 



.27 



.90 



2. 06 



1. 12 



Range 



0. 43-1. 09 



. 14- . 53 

 . 62-1. 49 

 . 10-6. 76 

 . 30-1. 59 



C.V." 



20 



27 

 18 

 54 

 15 



C.V." 



37 



43 



82 



180 



43 



36 

 30 

 27 

 69 

 74 

 54 



' Reduced ascorbic acid. 



2 Dehydroascorbic acid plus diketogulonic acid. 



' Mean of 48 samples, except for orange juice concen- 

 trate which is a mean of 64 samples. 

 " Coefficient of variation. 



17 



