1116 EXPERIMENT STATION RECORD. 



Experiments on the regulation of the water content of export butter, 



E. Wai.leiv (Xonl. Mrjcri Tidn., 1!){]'J04), Xo. .',, pp. .j.)'-//.')). — Cliuriiinj>; experiments 

 were made under the auspices of Sixlerniaidand County Creamery Association, with 

 a view to studying the factors influencing the water content of Swedisli export })ut- 

 ter. Complete data for the churnings made during the months of Marcli, April, and 

 October, 1903, with the percentages of water contained in the different lots of butter, 

 are given in the paper. 



The Avater content ranged from 11.80 to 16..33 per cent, one of the churnings con- 

 taining over 14.50 per cent of water, and two less than 12 per cent. The deductions 

 drawn by the author from the results obtained are as follows: A high water content 

 is ol)tained by continuing the churning as far as can be done without danger of over- 

 churning, so that large butter granules are formed, but not lumps. The butter is 

 furthermore not worked at too low a temperature and not cooled too long or too 

 low between salting and working; if possil)le, it is cooled at 8 to 9° C, and it is also 

 preferably worked at this temperature, at which there is no special danger of over- 

 working.— f. M'. AVOLL. 



Studies upon the keeping quality of butter. I. — Canned butter, L. A. Rog- 

 ers {U. S. Dept. Agr., Bureau of Anhnal Industrij Bid. 57, pp. '24)- — This bulletin 

 deals with the changes oceuring in canned butter, the intention being to submit a 

 second paper treating of packed butter. The decomposition of sugar, casein, alliu- 

 min, and fat is discussed briefly, reference being made to the literature of thesubject. 



An examination was made of a number of samples of canned butter collected in 

 China, the Philippine Islands, Cuba, and Porto Rico and kept in Washington for 

 about one year. All of the samples showed more or less decomposition. Bacterio- 

 logical examinations gave negative results in most instances. The few micro-organ- 

 isms found belonged to the resistant spore-forming group. The increase in the amount 

 of free acid liberated by the breaking up of glycerids was comparatively small. 

 Sterile butter sealed in small tubes and kept at 23° C. for 100 days showed no increase 

 in acidity, indicating that the decomposition of butter under anjerobic conditions is 

 not due to physical agents such as heat and moisture. 



Two lots of freshly canned butter were kept at room temperatures and examined 

 at frequent intervals as regards condition, acid num]:)er, and bacterial content. In 

 from 250 to 300 days the samples showed a disagreeable fishy flavor and a strong, 

 penetrating odor. An increase in the acid number accompanied the progressive 

 change in flavor. The bacteria found were mostly of the lactic-acid type, although 

 small numbers of yeasts and a few liquefying bacteria were present. The lactic-acid 

 bacteria, constituting in some cases over 99 per cent of the total number, and the 

 yeasts decreased rapidly, being practically absent at the end of 100 days. The changes 

 in acidity and flavor progressed steadily after the disappearance of the micro-organ- 

 isms, showing that the changes were not due to the direct action of the living cells. 



Butter treated with th3'mol to prevent bacterial growth showed a progressive 

 increase in acidity, while butter from the same lot subjected to heat and also treated 

 with thymol remained practically unchanged as regards acid content; from which 

 the conclusion is drawn that the decomposition is due to an enzym unaffected by the 

 antiseptic but destroyed by the heat. The sources of this enzym, namely, secretion 

 with the milk in the udder and production in the milk or butter by micro-organisms, 

 are discussed. Experiments showed that a species of Torula isolated from butter 

 possessed distinct lipolytic action. The presence of a fat-splitting enzym inherent 

 in milk was shown in an experiment in which butter made from fresh nnheated 

 cream and treated with formaldehyde to prevent the growth of micro-organisms 

 showed an increase in acid content, while a control sample made under the same 

 conditions but subjected to heat to prevent the action of enzyms showed no change 

 in the acid content. 



