MOLD SPOILAGE IN FOOD PRODUCTS 251 



corn meal preparatory to alcoholic fermentation. It also produces a 

 little alcohol itself. R. Oryzae is a similar mold obtained from Java- 

 nese raji, a ferment used in the preparation of the alcoholic beverage 

 arrak from rice. R. Tritici is^obtained from a preparation grown on 

 wheat meal. 



The use of Neurospora sitophila in Java to produce a fermented 

 food product has been described. Ground peanuts are inoculated 

 with spores of this mold and pressed into cakes, which on incubation 

 develop the bright orange color of the fungus. A number of proteo- 

 lytic, saccharolytic, and lipolytic enzymes have been studied in N. 

 sitophila and probably many of these take part in the ripening of 

 the product. 



MOLD SPOILAGE IN FOOD PRODUCTS 



The ability of molds to grow (though slowly) at relatively low 

 temperatures, and their ability to multiply in media of high osmotic 

 pressure or high acidity, fit them for growth in a number of food 

 products which have been treated in various ways to prevent bac- 

 terial decomposition. Thus we find them as important causes of 

 spoilage in preserved fruits and jellies, pickles, butter and cheese, 

 salted, dried, and smoked meats, and stored fruits and vegetables. 

 Storage for a sufficient length of time in a sufficiently humid atmos- 

 phere is the condition w^hich may lead to mold development. 



The absence of air and the temperatures of processing are sufficient 

 to eliminate molds as an important problem in commercially canned 

 foods. However, the imperfect sealing of mason jars used in home 

 canning frequently allows mold development on home-packed fruits, 

 jellies, and vegetables. Species of Aspergillus and Penicillium are 

 most frequently found. Of commercial products packed in sealed 

 containers, tomato catsup seems to be most commonly contaminated 

 with molds. This is apparently due to the use of overripe tomatoes 

 which have not been properly processed. Methods of enumerating 

 mold mycelia and spores, as well as yeasts and bacteria, in catsup 

 have been described by Howard. ^^ Molds may also develop in cans 

 of sweetened and condensed milk, forming small masses known as 

 buttons. According to Rogers, Dahlberg, and Evans ^* this condi- 

 tion is due mainly to Aspergillus repens, though other molds may 

 also be responsible. They grow until the residuum of air in the 

 product has been used up, and may be prevented by low storage 

 temperatures or by sealing the cans under vacuum. 



