The increasing public concern over processed foods has encouraged the use of the words "natural" and "nutritional" to describe desirably foods. Although these two words have different meanings, their similarity in sound and frequent use together have made most consumers regard them synonymously.

Ironically, this situation has aroused the interest of the marketing people in the food processing industry - the same industry that first caused the concern with their highly processed "unnatural foods."

Recognizing the sales value contemporary expressions, the marketing people are in the process of stressing the word "natural" in the same way as such familiar food catchwords as "hearty," "instant" and "home-style."

It's a very convenient way out of the problem of describing the nutritional value of foods. In order to label a food nutritious, it would be necessary to subject the product in question to close scientific scrutiny - an exercise that more often than not indicates the shortcomings of processed foods.

The use of the terms "natural" or "natural-style" doesn't pose such problems. These words are not clearly defined and consequently don't limit the food manufacturer in any way. One national dairy producer advertises a "natural" ice-cream, indicating that all ingredients are derived from nature - a description equally fitting crude oil.

Unfortunately, most consumers do not look beyond the "natural" slogan.In the mind of most consumers, if it says "natural," it should be nutritious.

Numerous examples exist of commercially processed products that bear the "natural" label. Most of these products do not pose an obvious health problem. Unfortunately a glaring exception are the so-called junk foods. Although junk foods are not clearly defined, they most often refer to foods high in empty calories. All junk foods are highly processed and would be unlikely candidates for a "natural" calssifations, or so it would seem.

Enter the "natural-type" potato chips, recently introduced in the United States. The package indicates that htese chips are made from unpeeled potatoes, sea salt and safflower oil, and are devoid of preservatives. Natural junk foods - a Madison Avenue dream!

if the tendecy to classify "natural-type" chips as a nutritious food occurs, perhaps a more detailed examination of their composition might be worth while.

An average potato chip contains approximately 50 per cent fat. The remaining 10 per cent is made up of salt, protein, water, and other minor constinuents. Compared to natural cooked potatoes, chips contain about eight times the number of calories. What is more revealing, however, is a comparison of the components that make up these calories.

In cooked potatoes, 99 per cent of the calories come from the carbohydrate and protein components. The remaining 1 per cent of the calories comes from the fat. In chips, the carbohydrate and protein components amount to 38 per cent of the total calories. The fat increases from 1 per cent to 62 per cent of the calories!

Saturated fats have been implicated in a number of diseases. It is presumably for this reason that "natural-type" chips are made with safflower oil, which has long been known as a source of polyunsaturated fats.

Safflower oil is made by pressing the oil out of safflower seeds, after pressing, is extracted with solvent chemical hexane. The combined pressed and hexane-extracted oils are then refined undesirably materials such as free fatty acids. Following repeated alkali washing and rising the product is steam distilled to produce the clear, bland oil. All very natural.

Safflower oil, despite its refining, has some important nutritional characteristics. It is very high in linoleic acid - a nutritionally essential fatty acid. In addition, its ratio of polyunsaturated to saturated fatty acids is probably greater than any other commercially available oil.

Unfortunately, safflower oil tends to go rancid a little more quickly than most other commercially available oils.

However, modern plant genetics have solved that problem. Newly developed varieties of safflower yield an oil that doesn't go rancid nearly so quickly, and can therefore be used without preservatives. But the cost of this genetic "improvement" has been an 80 per cent content. It is obviously not the same safflower oil traditionally used for its nutritive value.

Since the "natural-type" potato chips are made without preservatives, it would be interesting to find out which type of safflower oil was used to produce this product. A safflower is a safflower is a safflower . . . or is it?

Potato chips are considered to be junk foods. Calling them "natural-type" attempt at token nutrition to raise chips into the realm of legitimate foods. Nevertheless, the advertising and marketing people of the food industry will not be denied. Except more of the same in the future.

Who could have known that Darwin's basic concept for his theory of evolution would be utilized by food marketers. We are truly in the age of "natural selection."