258 E. B. FRED AND W. H. PETERSON 



In recent years, some of the canning companies have found it 

 difficult always to secure a sauerkraut of good flavor, texture, 

 and color. One of the difficulties encoimtered, has been the 

 occurrence of a sauerkraut with a well defined pink or salmon- 

 pink color. Although not unfit for food, this pink colored sauer- 

 kraut is an undesirable product as it must be sold at a price lower 

 than that obtained for white kraut. 



From a review of the literature, it seems probable that micro- 

 organisms are involved in the formation of the pigment. In 

 1904 Butjagin, and a year later, Wehmer called attention to the 

 occurrence of pink producing organisms in sauerkraut. Henne- 

 berg in 1916 reported that the addition of 1.2 per cent of lactic 

 acid to cabbage resulted in the production of a reddish colored 

 kraut. The presence of large numbers of yeasts in sauerkraut, 

 and in a few cases of pink yeasts, has been reported by various 

 investigators. The distribution of these pink yeasts in nature 

 and the factors that influence pigment formation have been the 

 source of much study. Grosbusch (1915) isolated from apples 

 a colorless torula which under certain conditions formed a deep 

 red pigment. Some of the conditions which he found favorable 

 for pigment production, were low sugar content, certain kinds of 

 sugars, and a slightly acid reaction. Beijerinck (1919) decribed 

 a yeast producing a colorless substance which became a deep 

 red pigment in the presence of oxygen and iron salts. A complete 

 discussion of the literature of the pink yeasts vail be found 

 in the papers of Will (1907; 1912), Pringsheim and Bilewsky 

 (1911). In view of the occurrence in practise of the colored 

 sauerkraut it becomes a matter of some importance to discover 

 the cause, and if possible, the remedy for this undesirable t}T)e of 

 fermentation. 



EXPERIMENTAL 



Large samples of normal sauerkraut and pink sauerkraut were 

 secured from one of the canning companies and analyzed. This 

 kraut was six weeks old and judged proper for canning. The 

 comparative chemical and bacteriological analyses are given 

 below: 



