ANNUAL REPORT, 1930 287 



269 Packaged Ice Cream. K. E. Wright. 12 pp. December, 1930. 



The public has been slow to accept factory-packaged ice cream on account of its 

 lighter weight and poorer texture. 



The problem of weight can be most logically solved by drawing the mix at an over- 

 run of about 50 per cent, although the light weight can be partially compensated by 

 increasing the percentage of butterfat or by reducing the price to a weight basis or 

 by a combination of these. Because of the low overrun required in packaged goods, 

 it was found necessary to retard the overrun of easily whipped mixes in order to 

 enable the drawing of the mix at the proper consistency. The substitution of butter 

 for a part of the cream was found to be the most effective practical means of ef- 

 fecting a low constant overrun. 



The texture of the ice cream as influenced by freezing was largely determined by 

 the temperature of the semi-frozen product at the beginning of the hardening pi-o- 

 cess. The rate of freezing in the ordinary freezer and in the hardening room was 

 found to be a minor factor in influencing the texture in comparison to the initial 

 hardening temperature. The size of the crystals determining the texture seems to 

 be influenced by a specific range of temperature depending on the mix rather than 

 by a progressive lowering of the drawing temperature of the mix. The results 

 showed that the texture improvement due to gelatin and aging was caused by aging 

 the gelatin, and that the effect on texture was more noticeable when a warm initial 

 aging temperature was employed. 



Control Bulletins 



53 Tenth Annual Report on Eradication of Pullorum Disease in Massachu- 

 setts, 1929-1930. H. Van Roekel, K. L. Bullis and G. L. Dunlap. 23 pp. 

 May, 1930. 



54 Inspection of Commercial Fertilizers. H. D. Haskins. 64 pp. December 

 1930. 



55 Inspection of Commercial Feedstuffs. Philip H. Smith. 44 pp. December, 

 1930. 



56 Seed Insjiection. F. A. McLaughlin. 42 pp. December, 1930. 



57 Inspection of Agricultural Lime Products. H. D. Haskins and H. R. 

 DeRose. 6 pp. December, 1930. 



Meteorological Reports 



493-504, inclusive. Monthly reports giving daily weather records, together with 

 monthly and annual summaries. 



Reports of Investigation in Journals 



(Numbered Contributions^) 



101 Mineral Supplements for Dairy Cows. J. B. Lindsey and J. G. Archibald. 

 Jour. Dairy Sci. 13:102-116. March, 1930. 



102 Nitrogen Fixation in Field Soil under Different Conditions of Cropping 

 and Soil Treatment. Leon A. Bradley and James E. Fuller. Soil Sci. 

 30:49-57. July, 1930. 



104 The Effect of Initial Cooling Temperature on Gelatin in the Aging of 

 the Ice Cream Mix. K. E. Wright. Jour. Dairy Sci. 13:406-415. Septem- 

 ber, 1930. 



1 Nos. 103 and 108 were cancelled. Nos. 109 and 110 have not yet been printed. 



