ANNUAL REPORT, 1938 77 



Fresh cranberries contained about one international unit per gram of vitamin 

 A, no vitamin Bj, and approximately 0.15 Bourquin-Sherman units per gram 

 of vitamin B., (G). 



Currant Juice and Jelly. (Julius Novick and C. R. Fellers.) Currant juice 

 has a pH of 3.45 and contains approximately 2.04 percent citric acid, .46 percent 

 pectin, and 7.5 percent soluble solids. The fresh currants and juice, which are 

 high in vitamin C (180 international units per ounce), also contain considerable 

 carotene. Two short extractions in boiling water produced the most satisfactory 

 juice for jelly making. The optimum acid concentration in currant water extract 

 was from .3 to .5 percent. Excess acidity resulted in decreased viscosity and 

 jelly yields. Diastatic enzymes did not aid in clarifying the juice. The concen- 

 tration of juice prior to the addition of sugar definitely decomposed the pectin, 

 while sugar added at the start had no detrimental effect. 



Suitability of Dextrose as a Food Ingredient. (C. R. Fellers and A. S. Levine.) 

 Laboratory work has been extended to include canned fruits and vegetables, 

 jams, preserves, jellies, marmalades, fruit butters, soda fountain crushed fruits 

 and syrups, sweet pickles, and apple sauce. In general, from 20 to 33 percent of 

 the total added sugar may be in the form of dextrose. Because of crystallization, 

 the concentration of dextrose in fruit products must be under about 40 percent. 

 Improvement in qualit\' resulted in some products containing dextrose in place 

 of a part of the sucrose. A material saving in cost can be effected by using dex- 

 trose in place of sucrose in foods. A paper appeared in the Am. Jour. Public 

 Health for February, 1939, on the use of dextrose in the food industries and the 

 public health aspects involved. 



The Potato as an Anti-scorbutic. (Mary E. Lyons and C. R. Fellers.) Because 

 of its extensive use, the potato is of exceptional nutritional interest. Samples 

 were obtained from 10 potato-growing regions of the United States and compared 

 as to their content of vitamin C. No significant geographic variations in vitamin 

 C content were found. The average value of 87 international units per ounce 

 for the raw potato is just about equal to that of canned tomato juice. In eight 

 varieties the average loss in vitamin C during baking was 49 percent and in boil- 

 ing whole in the skin 37 percent. There was no correlation between size or mat- 

 urity of tuber and vitamin C content. By far the greatest concentration of 

 vitamin C in the baked potato is in the central core area. 



DEPARTMENT OF HORTICULTURE 

 R. A. Van Meter in Charge 



Horticultural Value and Culture of Perennial Asters. (Ray M. Koon, Waltham.) 

 Four hundred and twelve species and varieties of Asters have been observed and 

 evaluated as excellent, good, fair, or "of no horticultural value." Of these, 92 

 rate as excellent and 74 as good; the others hav'e little merit e.xcept for naturaliz- 

 ing or hybridizing. Many collected from other states and from abroad fail even 

 to equal their relatives growing wild in our fields and along our highways. 



Of those ranking as excellent, the following are recommended for the May-to- 

 October garden in Massachusetts: 



