Throughout the centuries, man has sought methods to preserve his food. This preservation aims to preserve their edibility and their gustatory and nutritional properties, it implies in particular to prevent the growth of microorganisms and to delay the reactions of deterioration of food. To the first and simple methods of conservation (drying), have succeeded the techniques of salting, conservation by sugar (jams) and fermentation (cheese, etc. . ) In the last century have appeared the conservation by heat and more recently by cold with the development of refrigeration facilities