Pleasing appearance in food needs to be effected through care of the product and not by artificially concealing its defects or by rendering the food itself defective. Manufactured foods are open to both dangers. Graham flour, in retaining bran, needs more special care to be clean than other flours that are essentially free from all scourings.

Rice when polished loses salts without which the body may develop nervous disorder of a serious nature (beriberi). Where rice is a chief article of diet, polishing it may become a menace; it is always a danger. Rice is, however, not to be avoided, but to be secured unpolished and uncoated. It is its quality, not appearance, that affects human health. Corn meal, a common, nutritious, cheap food, may cause devitalizing disease (through malnutrition) when it is produced or ground under unsanitary conditions or kept under such.

Ignorance or neglect may make foods unwholesome. Craft in commerce may, too. Whatever the cause of unfit food be it non-food preservatives, unsafe dyes, crude by-products, artificial additions for appearance or as concealed substitutions in food, or chemically constructed foods instead of nature-grown - in so far as it is unfit it cannot nourish. Such food is more than valueless; it is a dangerous food-burden.

Bacteria in food cause general deterioration and often specific disease. Meat and milk change so easily that only the greatest care keeps them safe foods. Water is open to so many sources of contamination that to insure its purity requires great care. Fats are less readily affected by bacteria, so do not deteriorate as easily. Green vegetables are more apt to carry bacteria of the soil and dust than themselves to deteriorate through the presence of these. Starchy vegetables uncooked do not readily support bacterial life, so do not deteriorate promptly.