ANNUAL REPORT, 1931 211 



reach the size attained by the largest ones produced by some other varieties, 

 the average size of all the berries is probablj^ greater than that of any other 

 variety. 



4. Flavor of the berries. This is very good, though perhaps a bit too tart 

 to satisfy some. 



5. Keeping quality of the berries. The keeping and shipping qualities of 

 the fruit appear to be as good as those of the berries of any variety, except pos- 

 sibly Pioneer and Kubel. 



6. Picking quality. The berries pick easily and do not tear in picking. They 

 cling to the bushes well and maintain a satisfactory condition while doing so, 

 thus making frequent pickings unnecessary. 



7. Cost of pruning. This is decidedly less than it is with some of the more 

 important varieties under cultivation, especially Cabot and Pioneer. 



DEPARTMENT OF DAIRY INDUSTRY 

 J. H. Frandsen in Charge 



Factors Affecting the Aging Time of Ice Cream Mixes. (K. E. Wright). 

 One phase of the work — the adsorption of lecithin on the fat globule in ice cream — 

 has been completed during the year and is about ready for publication. The 

 following conclusions have been drawn: 



1. It has been definitely shown that lecithin aids emulsifi cation of an ice 

 cream mix when incorporated under favorable conditions. 



2. The high concentration of lecithin in buttermilk appears to be associated 

 with the low surface tension of the latter. Therefore, lecithin would tend to con- 

 centrate at the interface of a fat-serum dispersion to act as an emulsifying agent. 



3. Proof has been presented that lecithin functions better as an emulsifying 

 agent when it is allowed to be directly adsorbed to the fat surface. 



4. Cataphoretic measurements have failed to reflect any influence exerted 

 by varying amounts of lecithin and so tend to indicate a fat-lecithin-protein 

 system because protein influenced the behavior of the globules. 



5. The reason for the failure of past attempts to improve whipping property 

 of an ice cream mix has been attributed to a disturbance of the hydrophilic col- 

 loidal nature of lecithin. 



6. The aging of an ice cream mix has been considered to be a process of ad- 

 sorption of lecithin by the fat surface in which the amount of aging will tend to 

 be in inverse relation to the amount of hj'drophilic lecithin present. 



The Utilization of Frozen Fruits in Ice Cream and Ices. (M. J. Mack 

 in cooperation with the Department of Horticultural Manufactures). This 

 project, which has included four different fruit crops, is nearing completion. 



During the past year fruits, principally strawberries, have been frozen in 

 syrups varying from 30 to 60 per cent sucrose, 80 per cent invert syrup, and in 

 partial vacuum with either sugar or sugar syrups. These have been compared 

 with the standard pack containing 2 to 3 pounds of fruit to 1 of cane sugar. 

 These packs have been exaniined and then used in ice cream. 



Fruit packed in 40 per cent syrup has been found to be the equivalent of, if 

 not superior to, the standard sugar pack. Fruit frozen under partial vacuum 

 has the advantage of no discoloration at the surface. 



Fruit ice creams made from the above packs were found to be excellent. 

 The ice cream maker should feel free to buy frozen fruits packed in either sugar 



