56 EXPERIMENT STATION BULLETIN 354 



quantities of any one variety ranging from one to 13 quarts per picking. 

 The berries at any one picking varied within the Hmits of ripeness found 

 in commercial grades. 



At the start of the experiment representative berries from a mixed 

 sample were used for moisture and ascorbic acid analyses. Due to the 

 sHght differences in maturity normally present, it was found that this type 

 of sampling did not produce desirable checks ; hence, a pint of whole berries 

 from the larger mixed sample was blended in a dry Waring blendor and 

 aliquots removed for the determinations. Considerable difficulty was en- 

 countered with the moisture determination. Drying in a 100° oven caused 

 visible charring of the samples, and in both the vacuum oven at 65° and the 

 convection oven running at 68-72°, the samples continued to lose weight 

 constantly, even after 70 or 80 hours drying time. After numerous trials, 

 the convection oven was finally operated at 68-72° and the drying time re- 

 duced to 20 hours. -The ascorbic acid content was determined by the Mor- 

 rell method, using a Klett-Summerson photoelectric colorimeter. 



In all varieties the June-picked berries contained more ascorbic acid 

 than those picked in July, some varieties containing considerably more of 

 the vitamin than others. Seasonal variation was found not to be a constant, 

 but to vary among varieties. 



All fresh berries held for periods of 12 and 24 hours at room or refrig- 

 eration temperatures lost varying amounts of ascorbic acid. These losses not 

 only varied considerably between varieties picked on the same day, but al- 

 so within the same variety during the growing season. The intra-varietal 

 variation was as great as 40 per cent (fresh weight basis) in some cases. 

 The apparent per cent loss from holding the fresh berries for 24 hours at 

 room temperatures was highest in Fairfax and Pathfinder, where it ap- 

 proximated 50 per cent (dry weight basis) ; the lowest was Catskill and 

 Howard 17 approximating 30 per cent; Narcissa and Dresden was about 

 40 per cent. 



In the studies with sliced berries held 24 hours under refrigeration 

 with and without sugar, both samples definitely lost ascorbic acid. Again 

 both inter- and intra-varietal dift'erences were noted, but the per cent 

 losses among varieties were not in the same order as the losses when whole 

 berries were held in a similar manner. The limited data tend to show, 

 however, that the sugared, sliced berries did not lose quite as much of the 

 vitamin as did the unsugared. 



When the fresh berries were quickly' frozen at a temperature approxi- 

 mately -10°F and held in cold storage at temperatures ranging from to 

 -f-10°F for periods of two, four, and six months all varieties showed pro- 

 gressive losses. Over a period of 6 months the data showed losses ranging 

 from 54 per cent for Catskill to 100 per cent for Narcissa, but the apparent 

 rate of loss in the two, four, or six-month periods was not consistent among 

 varieties. Varieties that started with a relativelv high 'vitamin content re- 

 tained at the end of the second month of storage as much of the vitamin 

 as other varieties had when fresh. 



In a comparison between samples frozen and samples held at room 

 temperature, the apparent percentage loss in four months of cold storage 

 was practically the same as the loss in holding fresh berries for 24 hours 

 at room temperature. 



