Food Microbiology

Food may be contaminated from outside sources on the way from the field to the processing plant, or during transport, storage and distribution. There are thousands of different types of micro-organisms everywhere in air, water,soil and foods, and in the digestive tract of animals and human. Fortunately, the majority of microbes usefully functions in the environment and in some branches of of food industry, such as production of wine, beer, dairy products , bakery products, etc. On the other hand unwanted food spoilage is generally caused by microbes and contamination of food with pathogens causes food safety problems.The micro-organisms occurring on and in foods are divided into three groups: bacteria, yeast and molds. Molds are generally concerned in the food spoilage; their use in the food industry is limited.Yeasts are the most widely used microbes in the food industry due to their ability to ferment sugars to ethanol and carbon-dioxide. Some types of yeast, like baker’s yeasts are grown industrially, and some may be used as protein sources, mainly in animal feed. Bacteria are important in food microbiology may be divided into groups according to the fermentation product, e.g. lactic acid bacteria, propionic acid bacteria, acetic acid bacteria. Bearing in mind the food constituent attacked, prolytic, saccharolytic and lipolytic bacteria may be distinguished.