the preparation of raw materials had many points in common as far as their preparation is concerned and may, therefore, be considered together,in most cases fruits and vegetables will be contaminated to some extent with soil which, as previously stated,is a frequent carrier of spoilage organisms the first operation,therefor of these materials is usually the removal of any adhering soil.
in some cases,particularly with vegetables and some fruits a skin or outer covering must be removed before the food can be packed. this operation varies considerably in difficulty,the skin of tomatoes,for example,are easily removed by scalding and subsequent cooling,while potatoes require much more vigorous treatment.
the efficiency of this peeling operation is of considerable importance as pieces of skin not only spoil the appearance of the pack,but many also give rise to spoilage due to the fact that they may carry a considerable number of spoilage organisms. this is particularly true in the case of root vegetables and potatoes.