52 MASS. EXPERIMENT STATION BULLETIN 347 



proper proportions and methods of handling have been determined and it was 

 found that, although in most instances the combinations were successful, the use 

 of fresh, canned, or frozen strawberries and peaches produced a mild flavor unless 

 reinforced with fruit extract. The chocolate combination was the poorest accord- 

 ing to the consumers' comments. Butter pecan proved to be the most popular. 

 Storage of these types of spreads is limited to two weeks at 45°-50° F. The con- 

 sistency and body of these spreads were good in all cases where drained fruits 

 were used. 



Further experiments with new and desirable flavors will be undertaken, and the 

 addition of dried aromatic plants to milk to be made into cheese offers many 

 possibilities. 



A Study of the Effect of Organic and Inorganic Iodine on Some of the Milk 

 and Digestive Enzymes. (J. H. Frandsen, W. S. Mueller, and Myer Glickstein.) 

 A previous study on the effect of inorganic iodine on the enzymes revealed the 

 fact that enzymatic activity was inhibited in most cases if sufficient iodine was 

 added to the substrate. In the present study, similar experiments are now being 

 conducted in an endeavor to note the effects of organic iodine on the enzymes 

 as well. 



Results up to date show that in concentrations as high as 100 p. p.m. of both 

 types of iodine, the activities of different enzymes are affected differently. 



When the substrate is not preserved with toluene, organic iodine stimulates 

 catalase activity more than does inorganic iodine. Both kinds of iodine, however, 

 showed a fairly marked increase in the production of oxygen by catalase over 

 the control series containing no added iodine. In those samples preserved with 

 toluene, there is no difference between the inorganic and organic iodine. 



In the case of peroxidase, the control and the inorganic iodine series showed 

 little appreciable differences in their purpurogallin numbers. The organic iodine 

 group, however, showed an increase in peroxidase activity by over five times that 

 of the other two groups. 



Over a period of 16 da^s' incubation there was an increase of .159 percent 

 acidity, in reference to lipolytic activity, for the control group, as compared to 

 .0855 percent and .1000 percent for the inorganic and organic iodine groups 

 respectively. 



The results also showed a rather marked stimulation of rennin activity by 

 organic iodine when compared with the group containing no iodine. Inorganic 

 iodine is not quite so effective in stimulating this enzyme as is organic iodine. 



In reference to steapsin or pancreatic lipase, the control and organic iodine 

 groups are practically similar in their effects. In the case of inorganic iodine, 

 there was a marked inhibitory effect on this enzyme. 



Work is now in progress with the proteolytic enzymes such as pepsin, trypsin, 

 and protease. No results can as yet be given on these enzymes. 



DEPARTMENT OF ECONOMICS 

 Alexander E. Cance in Charge 



Recent Changes in Consumer Demand for Milk and Some Factors Affecting it. 



(David Rozman.) In connection with this project, field work was carried on in 

 Northampton, Holyoke and Pittsfield. In each of these cities information was 

 obtained from individual families representing a cross section of the population, 

 on the consumption of fluid milk at the time of the investigation as well as the 



