CONTENTS 



SECTION IV 



BACTERIA IN TECHNICAL AGRICULTURE AND THE 

 INDUSTRIES 



CHAPTER PAGE 



XIV. RELATIONSHIPS OF MICROORGANISMS TO THE PRESERVA- 

 TION OF FOOD 173 



Agencies which bring about deterioration of foods 

 methods of preventing deterioration Sterilization by 

 heat Food preservation by pasteurization Preserva- 

 tion by low temperatures Preservation by chemicals 

 Preservation of foods by drying. 



XV. FERMENTATION OF CARBOHYDRATES ALCOHOLIC FER- 

 MENTATION IN FOODS COMMERCIAL PRODUCTION OF 



ETHYL ALCOHOL FUSEL OILS 183 



Agencies active in alcoholic fermentation Preliminary 

 preparation of carbohydrates for yeast fermentation 

 Alcoholic fermentation of sugar solutions Preparation 

 of distilled liquors Manufacture of commercial alcohol 

 Alcoholic fermentation in bread making Alcohol 

 production in other foods The commercial prepara- 

 tion of yeast Development of fusel oils in alcoholic 

 fermentation. 



XVI. LACTIC ACID FERMENTATION THE GENERA LACTOBA- 



CILLUS STREPTOCOCCUS AND BACTERIUM 192 



Organisms producing lactic acid The genus Streptococ- 

 cus The genus Lactobacillus The genus Bacterium 

 Technical utilization of lactic acid fermentation Asso- 

 ciative action Lactic acid bacteria in milk Soured 

 milk beverages Sour curd cheese The use of starter 

 Effects of pasteurization upon the souring of milk 

 Secondary changes in soured milk Lactic acid in cheese 

 manufacture Lactic acid in food preservation 

 Ensilage Sauerkraut Other fermented foods Lactic 

 acid in yeast manufacture Lactic acid in bread 

 making. 



XVII. ACETIC, BUTYRIC, OXALIC AND CITRIC FERMENTATION 

 THE GENERA ACETOBACTER, BACTERIUM, CLOSTRIDIUM, 



ASPERGILLUS AND ClTROMYCES 209 



Acetic fermentation Types of acetic acid fermentation 

 Groups of acetic bacteria The genus Acetobacter -- Vine- 

 gar manufacture Butyric fermentation Organisms 

 producing butyric fermentation Formation of other 

 volatile acids Oxalic fermentation Citric acid fer- 

 mentation. 



