17G Defects of Milk. 



results from its contamination with varieties of bacteria vegetating 

 on food substances, which enter into the milk directly from the 

 stable air or indirectly with the manure and litter. They then con- 

 vey to the milk this altered taste. Experiments to confirm these 

 views have been undertaken quite recently by Weigmann and 

 Wolf (Kiel). 



Defective flavors are frequently present in milk. 



Of 1,000 retentions made during 1909 in Munich, 90.50% were 

 on account of souring, 14.6% on account of soapy taste, 18.25% 

 rancid, 2.19% fecal contamination, 8.76% oily, 1.46% bitter, 

 2.92% granular, 2.19% sweet-coagulating, and 1.46% on account 

 of slimy conditions. 



Eepresentatives of the colon-aerogenes group may actually be 

 cultivated until they become aroma producers if they are allowed 

 to grow for instance upon media made from rape leaves. If an 

 adaptation of these and other bacteria to the ingesta within the 

 gastro-intestinal canal is admitted, then an acquisition of certain 

 other properties, depending on the consumed feed, is readily 

 conceivable. 



Weigmann and Ritland and Jensen demonstrated such "rape 

 bacteria" in milk having a rape-leaf taste; the milk at the same 

 time had a stale taste and an odor of dish-water. The author ob- 

 served a distinct phosphorus taste in cases in which the milk was 

 placed without being cooled into unclean or poorly cleaned covered 

 cans. 



Animal and fecal odors result when freshly drawn milk is 

 placed into covered cans without airing and cooling. In these 

 cases the vegetation of anaerobic and facultative anaerobic bacteria 

 may play a part, and the temperature may have an effect on the 

 bacterial elective conditions. The milk attains a taste like animal 

 viscera if it contains bacteria of the mycoid, megatherium or fluor- 

 escens group. 



Fishy taste of milk may result from pasturing cows on marshy 

 meadows which have been inundated. In these instances the pres- 

 ence of various other varieties of bacteria should be taken into 

 consideration. 



The multiplication of the Bacillus lactis saponacei (Weig- 

 mann) and the Bacillus sapolacticum (Eichholz), produces a soapy 

 condition of the milk. The milk attains a sharp, rancid, soap-like 

 taste, and when cold it reminds one of valerian ; in a warm state 

 it has a sharp, soapy odor. In shaking such milk a fine, vesicular, 

 persistent, tenacious foam results. The change appears in thor- 

 oughly cooled and excessively cooled milk, and in the cold season 

 of the year and in cold rainy summers the bacteria are psychro- 

 philic, originating from the feed and straw. 



The Bacillus lacticus saponacei grows well at room tempera- 

 ture, liquefies gelatin, and produces a slight yellowish shimmering 

 coloring matter; the growth is aerobic. The Bacterium sapolacti- 



