METABOLIC PRODUCTS 



269 



A dramatic demonstration of the value of yeast as a source of vitamins 

 is reported by Bray (1928), onetime medical officer, Nauru, Central 

 Pacific. The mandating government prohibited the brewing of toddy 

 (palm wine) and allowed the sale of refined sugar. The results of these 

 dietary changes were appalling. Soon, 40 per cent of the infants born 

 in 1 year perished of infantile beriberi (thiamine deficiency) before reach- 

 ing the age of 6 months. The restoration of toddy and enforced con- 

 sumption of the dregs, i.e., the yeast, reduced the incidence of beriberi 

 to one death in 16 months. Truly, Bray was right in calling toddy the 

 elixir of life of the Nauruans. Piatt and Webb (1945) have noted that a 

 simple maize diet which was inadequate with respect to riboflavin and 

 nicotinic acid was made adequate in these respects by converting a por- 

 tion of the dietary maize into maize beer. 



The vitamin content of yeasts depends upon the species or strain and 

 the conditions of cultivation. Some representative data are presented 

 in Table 47. 



Table 47. Vitamin Content of Seven Food Yeasts 

 Results in milligrams per 100 g. of dry yeast. (Von Loesecke, Jour. Am. Dietet. 

 Assoc. 22, 1946. Published by permission of the American Dietetic Association.) 



Species 



Torula utilis 



Saccharomyces cerevisiae* 



S. cerevisiae 



S. cerevisiae f 



S. cerevisiae^ 



S. cerevisiae f 



S. cerevisiaeX 



Thiamine 



1.7 

 17.0 

 20.5 

 17.5 

 17.5 

 16.0 



3.0 



Riboflavin 



4.7 

 8.0 

 7.6 

 4.2 

 4.5 

 3.6 

 7.5 



Nicotinic 

 acid 



19.0 

 25.0 

 29.0 

 48.0 

 37,0 

 32.0 

 38.0 



Pantothenic 

 acid 



86.0 



112.0 

 122.0 

 86.0 

 72.0 

 74.0 

 13.5 



* Six per cent salt added. 

 t Debittered brewer's yeast. 

 t Primary yeast. 



The production of fats by fungi is discussed elsewhere in this chapter. 

 The usual fatty acids, including palmitic and oleic acids, are found in fat 

 synthesized by fungi. Apparently few studies have been made on the 

 value of fungi as sources of fat and essential minerals in human nutrition. 



CULTIVATION OF FUNGI FOR FOOD 



The ants were perhaps the first to cultivate fungi as a source of food 

 (see Leaoii, 1940, for discussion and references). Fungi have been used 

 for centuries in the Orient as food for man. The Chinese grow Hirneola 

 polytricha and the Japanese grow Armillaria shii-take on oak saplings. 

 The mushroom cultivated almost exclusively in the Occident is Agaricus 



