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dosporium butyri described by JENSEN, appeared to be of the 

 greatest significance in cases of rancidity. These moulds can 

 be easily found in rancid vegetable margarine by means of 

 the spots shown thereon. These spots are caused by colonies 

 of moulds which affect the fat locally. Usually they are easily 

 recognised under the microscope, especially when the fat contained 

 in the affected parts has been extracted with ether beforehand. 



In order to confirm the above facts, vegetable margarine (salted 

 and unsalted) prepared from sterilised constituents was inocu- 

 lated in glass dishes with the pure culture of the isolated microbes 

 and combinations of them. These experiments showed the rapidity 

 with which rancidity was brought about especially under the 

 simultaneous influences of Cladosporium butyri, Pénicillium 

 glaucum and Oidium lactis. After five days the samples were 

 undoubtedly rancid and after about seven weeks the percentage 

 of fatty acids of the oil in some cases was found to be about 

 10 7o (calculated to oleic acid). It was further proved that the 

 influence of these moulds on absolutely dry cocoa nut oil is of 

 no significance whatever, whereas only slight traces of water 

 are needed to cause rancidity. 



This settled without a doubt that the cause of rancidity of 

 vegetable margarine must be looked for in the presence and 

 the development of certain kinds of moulds. The preventative 

 means which may be applied are : 



1. avoidance of spores of moulds which infect vegetable 

 margarine during its manufacture, 



2. effectual suppression of the development of germs by 

 adding preservatives, as these germs in spite of the utmost 

 care and cleanliness may get into the margarine. 



Whilst the former must never be lost sight of, the latter 

 remains the only effective means. 



The action of a number of preservatives on the development 

 of the most frequent moulds (Pénicillium glaucum, Cladosporium 

 butyri, Oidium lactis) was examined. 



The following preservatives were used : common salt, sodium 

 formiate, kalium nitrate, sodium sulphate, sodium- and magnesium- 

 lactate, lactic acid, benzoic acid, benzoate of sodium, boric acid, 

 borax, o. toluylic acid and cinnamic acid. 



Common salt proved more preferable to other salts ; alkaline 



