ANNUAL REPORT, 1937 51 



4. Pumping cream from pasteurizer to cooler by proper size centrifugal 

 pumps had no effect on the fat emulsion, while the use of oversize pumps de- 

 stablized the fat to some extent. Steam piston pumps do not affect the fat emul- 

 sion adversely; in fact, with cream which oiled off badly, the piston pumps par- 

 tially re-emulsified the fat which had separated. 



5. Cooling cream in the pasteurizing vat was found to be very undesirable 

 regardless of the type of agitation employed. The final temperature to which 

 cream is cooled over a surface cooler does not affect the fat emulsion so long as 

 freezing to the cooler does not occur. Freezing of cream to the cooler was found 

 to be one of the most serious causes of oiling off of cream in cofTee. 



6. Aging cream (without agitation) at low temperature caused no change in 

 the stability of the fat emulsion. Shipment at low temperature also had no effect 

 unless the cans were only partially filled, thus allowing for agitation, which proved 

 harmful. 



7. Reducing the fat content of pasteurized cream by the addition of milk or 

 skim milk had no effect on the tendency of the cream to oil off. 



8. Cream which had been improperly handled, so that droplets of oil would 

 separate from it if used in coffee, was made entirely stable by homogenization 

 at the pasteurization temperature. A pressure of 500 pounds was used. Attempts 

 to re-emulsify the fat by the use of a colloid mill and manually operated emulsor 

 were partially successful. 



9. Storage of cream for three days in a household refrigerator did not increase 

 the tendency to oil ofT when the cream was used in cofTee. 



A Study of the Changes that Occur in the Storage of Frozen Sweet Cream. 



(H. G. Lindquist.) The effect of adding sodium alginate (cocoloid) in amounts 

 of .05, .1, and .15 percent to 32 percent cream was studied. Sodium alginate in- 

 creased the viscosity of the cream before freezing. There was a slight increase 

 in pH, and the frozen cream containing sodium alginate showed less tendency 

 to oil off when thawed than did the frozen pure cream. When thawed, the frozen 

 cream containing sodium alginate whipped up into a firmer whipped cream with 

 less drainage than did the frozen pure cream. 



A Study of the Efficiency of Water Heaters, Electric Sterilizers, and Electrically 

 Operated Cooling Tanks. (J. H. Frandsen, H. G. Lindquist, and Myer Glick- 

 stein.) Electric water heaters were studied to determine whether they could be 

 used effectively as sterilizers when used to generate steam. In general, they were 

 found satisfactory if utensils were e.xposed to the steam for four to eight minutes 

 after they had been thoroughly washed. As a rule, the electric sterilizers and 

 steam generators are of simple construction and easy to operate. 



The effect of increasing the wattage in the heating element by 500 units does 

 not produce any decided or comparable difference in the destruction of bacteria. 

 Perhaps this is due to the great variation with which the bacteria are rinsed from 

 the cans. However, it took less time to generate steam with the larger heating 

 element. 



A Study of the Possibilities of Milk, Cream, and Plastic Cream in the Develop- 

 ment of New Products such as Combinations with Honey, Fruits, Cheese, and 

 other Flavors of Various Kinds. (J. H. Frandsen and Myer Glickstein.) A study 

 of the use of plastic cream and cheese in combination with certain fruits and nuts 

 has been made and the work is being continued. 



The successful incorporation of sweet fruits, sub-acid fruits, candies, nuts, 

 and certain aromatic ripened cheeses to bases such as plastic cream and cream 

 cheese proved to be popular and lent a variety of appeal to the palate. The 



