434 CHAPTER XXI 



The Deterioration of Raw Sugar. — Raw sugar when kept under certain 

 conditions loses in polarization. This process, which annually causes the 

 loss of large sums of money, is known as " deterioration." Possibly the 

 earliest reference to this matter is due to Ligon,^ (1673), who writes : — 

 " Sugar should be kept drie in good casks, that no wet or moist aire enter." 

 It is now definitely established that the deterioration of sugar in storage 

 is due to the action of micro-organisms combined with conditions suitable 

 for their growth. The first observation connecting cause and effect is due 

 to van Dijk and van Beek,^ who in 1829 published the results of an investi- 

 gation on the cause of the blackening of loaf sugar in an Amsterdam refinery. 

 They determined the cause as due to the presence of a mould Conferva 

 mucoroides, and the source of infection as the troughs in which the implements 

 were washed. Later, Payen^ examined a similar phenomenon in a Paris 

 refinery, identifying as the cause moulds described as Glyciphila erythrospora 

 and G. elceospora. 



As regards the deterioration of raw sugar in bulk, Dubrunfaut^ in 1869 

 identified micro-organisms as the cause, ascribing the damage to the lactic 

 ferment. He was followed by Gayon^ in 1880, who observed yeasts, torulae 

 and moulds in deteriorating West Indian sugars, and who also isolated 

 therefrom an invertase. 



In the cane sugar industry proper, the first observation is that of Maxwell,^ 

 who in 1896 in Louisiana ascribed the damage to the lactic and butyric 

 acid ferments. 



Shorey'^ in 1898 in Hawaii found evidence that the damage was due to a 

 species of Penicillium, and attributed the infection to the air drawn through 

 the sugar in the centrifugals. 



Kammerling^ in 1899 in Java, in a study of the flora of Javan sugars, 

 found Penicillium, Aspergillus, Sterigmatocystis, Citromyces and also Monilia 

 and Torulce. He believed that the bags were the source of infection, that 

 the hyphomycetae or moulds caused the initial damage, torulse and monilia 

 becoming active only after the sugars had absorbed water. 



Greig-Smith and Steele^ in 1903 in Australia found one dominant organism 

 in sugars of cosmopolitan origin, and to this they gave the name Bacillus 

 levaniformans. 



Lewton-Brain and Deerr^*' in 1907 in Hawaii isolated from Hawaiian 

 sugars five species of bacteria, all of which were capable of causing deteriora- 

 tion in sugars under favourable conditions. 



Owen^^ in 1911 in Louisiana isolated from sugars a number of bacteria 

 which he identified as belonging to the Mesentericus group. In particular, 

 he found B. mesentericus, B. mesentericus ruber and B. vulgatus. 



Browne,^^ in examining Cuban sugars in New York in 1918, found that 

 the commonest micro-organisms present were a torula, two species of monilia 

 and a bacterium. Penicillium and Oidium were also present. Owen,^^ 

 in later work, found, as well as bacteria, yeasts and moulds, the identified 

 forms being all Aspergillus, one of which was superficiall}^ similar to Peni- 

 cillium glaucum. 



In the beet sugar industry, similar observations have been made, mainly 

 by Lexa^* and by Schone,^^ who have found the same classes of organisms 

 as those mentioned above. 



The foregoing observations of different investigators are not contra- 

 dictory amongst each other ; the absence of torulae from one set of 

 deteriorating sugars where bacteria were present does not imply that torulae 



