16 



MASS. 1-:XPERIMENT S'l'ATlON BULLliTIN 296 



in the diet, replacing; an equal weight of stairh. Accurate records were kept of 

 the weight of the aiiinials aud of the food consumed. The data are presented in 

 Table 8. 



Table 8. — Vit.\min G (B2) in t'R.\N berries 



These data indicate that craidierries contain very lit lie, if any, vitamin G. Dried 

 cranberry equivalent to 20 grams of fresh cranberry daily caused no significant 

 increase in weight over the controls. Here again some destruction of the vitamin 

 may have occurred during the drying process, but considering the large amount 

 fed, there can be no more than a slight trace present in fresh cranberries. 



Vitamin D 



The method of testing for vitamin D was that developed by Steenbock and Black 

 (39). Young rats were weaned when they weighed between 45 and 50 grams at 

 about 24 days of age. They were placed on the Steenbock No. 2965 ration con- 

 sisting of yellow corn 76, wheat gluten 20, calcium carbonate 3, and sodium chlor- 

 ide 1 part. The animals developed rickets in from 28 to 40 days. At this time 

 dried cranberry was added at the rate of 15 and 25 per cent of the diet. This was 

 fed to the animals for a ten-day period, at the end of which X-ray photographs were 

 taken, then the animals chloroformed and line tests carried out. Negative con- 

 trols were carried to indicate that spontaneous healing had not occurred, and posi- 

 tive controls which received cod-liver oil, in order to allow comparisons. 



Animals on both amounts of cranberry showed no improvement over the nega- 

 tive controls. Hence, it was concluded that cranberries contain no significant 

 amounts of vitamin D. 



SUMMARY 



The American cultivated cranberry, V. niacrocarpon, is a very good source of 

 vitamin C, the minimum daily protective amount for guinea pigs being 3.5 to 4.5 

 grams. Varietal differences were slight. 



There was a gradual loss of vitamin C in cold storage. However, the loss was 

 only slight during the active marketing season. After four to six months the loss 

 was approximately 20 per cent, and after seven to ten months 60 to 70 per cent. 

 Good keeping quality seemed to be associated with good vitamin C retention. 



Inasmuch as vitamin C in cranberries, apples, and possibly other fruits decreases 

 during storage of the fruit, this point must be considered in making vitamin C 

 assays. 



Freezing did not injure the antiscorbutic properties of whole, sliced, crushed, or 

 sweetened cranberries. Temperature of freezing and temperature and length of 

 storage had little effect. There was some evidence, however, that thawing and 

 subsequent freezing lowered the vitamin C content. 



