ANNUAL REPORT, 1944-45 31 



Group Effective Moderately Ineffective Total 



Effective 



Germicides and fungicides 6 2 2 10 



Wetting agents 3 6 9 



Surface active agents 3 2 5 



Dispersing agents 4 4 



Emulsifying agents 4 4 



Detergents 1 1 2 



Contact insecticides 1 1 



Insecticidal spreading agent 1 1 



Unknowns 3 3 6 



15 7 20 42 



Of the effective and moderately effective materials, 3 are substituted phenols, 

 7 are quaternary ammonium compounds, 3 are phosphonium compounds, 8 are 

 alkyl aryl sulfonates, and 1 is an alphatic sulfonate. 



All of the effective sterilizing materials were non-corrosive to 18-8 stainless 

 steel, but three were objectionably Corrosive to monel metal. 



The results to date indicate that, of the 42 materials investigated, three have 

 possibilities of being equal to or better than chlorine for sterilizing dairy equip- 

 ment, and some may have a place in conjunction with cleansing agents. 



Improving the Flavor and Keeping Properties of Milk and Some of Its Products. 



(W. S. Mueller.) The only sure means of preventing the oxidation of fat in dairy 

 products is to remove practically all of the oxygen from the container in which 

 the product is packed and to replace it with an inert gas. Because of the diffi- 

 culties involved, manufacturing procedures would be simplified if the same results 

 could be obtained by the use of an antioxidant. During the past year the value 

 of cacao shell and cocoa powder as antioxidants has been studied. 



Sixteen different extracts of cacao shell and cocoa powder were prepared and 

 tested, together with a number of other materials. Two accelerated tests, known 

 as the Swift Fat Stability Test and the Incubation Test, were used, and the 

 materials are listed in decreasing order of effectiveness in butter oil: Caffeic 

 acid, gallic acid, nordihydroguaiaretic acid (N.D.G.A.), propyl gallate, tannic 

 acid, tocopherol, palmetal-1-ascorbic acid, tetrachloropara-benzoquinone, and 

 Viobin. The best antioxidant obtained from cacao products falls near the middle 

 of this group. While the cacao antioxidant was not so effective as some of the 

 other materials studied, it did have some advantages. For instance, it did not 

 impart a foreign flavor to the butter oil, while caffeic acid, gallic acid, N.D.G.A., 

 propyl gallate, tannic acid, and tocopherol, in equal amounts, gave an objection- 

 able flavor; also, it was most effective in the presence of copper, which is signi- 

 ficant because some dairy products contain 4 or more p.p.m. of copper when 

 packed for storage. 



The antioxidants were used only in accelerated tests, and final conclusions 

 cannot be drawn until long keeping tests have been made on dried ice cream mix, 

 dried milk, butter, and butter-type spreads. 



Study of Packaged Ice Cream. (J. H. Frandsen.) Results of scorings this year 

 indicate that bulk ice cream is more palatable than packaged ice cream as gen- 

 erally found on the market. The results are only preliminary, and further studies 

 will be made in an effort to develop a packaged product that will be as palatable 

 as bulk ice cream. When this is accomplished, it will probably result in a very 

 much larger precentage of ice cream being sold in packaged form. 



Packaged ice cream can be handled with less shrinkage and less labor than 

 bulk ice cream. Machine-packaged ice cream can be kept at a lower tempera- 

 ture than bulk ice cream, and therefore keeps in better condition after it is sold 

 to the consumer. 



