(1) Field of Invention
The present invention is concerned with the utilization of tubers of the camote or boniato and all other plants producing light-fleshed tubers in the family Convolvulaceae, with the purpose of producing various flours from the tubers, and other valuable edible products and industrial products.
(2) Description of The Background
To increase the number of food products and forms of food products is of the greatest importance to persons with food allergies, and will become of even greater importance as food allergies are diagnosed in increasing numbers of people. As the potential problems of food allergies are more recognized, increasing numbers of people are looking for non-wheat items to include in their diets, to increase variety and aid in the prevention of food allergies.
Food allergies and intolerances have been known to exist for hundreds of years. The symptoms vary with each individual, and can include congestion, asthma, diarrhea, headaches, dizziness, joint pains, hives, eczema and in the most severe cases can cause anaphylaxis and even death. In recent decades, along with most other diseases related to the immune or auto-immune system, the incidence of food allergies has increased. In addition the number of foods to which a given individual reacts, and the severity of the reactions seems to be increasing. Indications are that food allergies/intolerances will continue to become increasingly more common and severe.
The need for new food sources and alternatives parallels the increase in food allergies. As the number of foods an individual can eat begins to dwindle, it becomes increasingly more difficult to maintain a nutritious, well-balanced diet from the foods remaining, and the search for new foods intensifies. For many food allergy patients, the allergy problem steadily becomes more severe as the patient is unable to avoid becoming malnurished.
There is, then, a real need for alternatives to the food products that are the common and accepted staples in the American diet. These food products need to be from hypoallergenic foods so they have the best chance of being well tolerated by the greatest numbers of people. The hypoallergenic food products need to provide acceptable substitutes for the most hyperallergenic food products--wheat, corn, and other members of the grass family, legumes, milk and milk products, eggs, nuts, and yeast.
The alternative food products should be from less common or less well known foods. Such foods will have been eaten less often, if at all, and there will be a lower chance for a person to have developed allergies to the new foods. Products from such uncommon foods could probably be tolerated by most persons, and the risk of developing allergies to the foods would be low.
The alternative food products need to be developed from foods in separate food families. This is important because food allergy patients can easily develop allergies to foods that are closely related to the foods they ar already allergic to. New food products from as many new food families as possible (for example sweet potato products from the morning glory family), are much more needed than are food products from uncommon foods in a common food family (such as millet from the grass family). Alternative food products from food families not frequently included in peoples' diets will increase substantially the foods that people can eat in their rotation diets.
The alternative food products need to be highly concentrated foods. The above list of hyperallergenic foods includes mos of the concentrated carbohydrates in the normal American diet. When people have to exclude these foods from their diets, the plant sources they have left to eat are primarily green leafy vegetables, tubers, and fruits. These food sources are high in fiber, but are relatively low in carbohydrates. A person who must rely on potatoes or sweet potatoes as their main source of carbohydrates, must eat about 5 pounds each day. It is very hard for many adults to eat this much food, but it is even more difficult for allergic children who may have to eat almost as much.
The alternative food products need to be as close to the eliminated foods as possible, in form and texture. For example, breads, pastas, cereal, cookies are needed from hypoallergenic sources, and these need to be as similar in taste and texture to their hyperallergenic counterparts as possible. This will make it possible for person to enjoy foods they are used to, and will make them more likely to stay on their diets. Also people who are concerned that they may have food allergies are more likely to seek medical treatment if they know they will have pleasant alternatives in their diets.
Alternative food products are needed that consist of one primary ingredient, and this ingredient serves to replace wheat and other grains, milk, eggs, nuts, yeast, and sugar. The food allergies of individuals vary so greatly, that as the number of ingredients in a product increases, the number of individuals that can use the product decreases. Similarly, the products need to be free of additives, preservatives, and so forth, and should be completely free of pesticides and other chemicals.
Other characteristics that are important in new food products include convenience, portability, and variety. Many patients must change their diets at a time when they are very ill, and they simply do not have the strength to perform the food preparation needed when working with fresh fruits and vegetables.
Until now there has been no alternative food product which could meet all of the above criteria. Many food products have been developed, but essentially all contain either wheat, or other grains, soy or legumes, milk, eggs, nuts, yeast, or sugar, or they don't have the characteristics of the common food products. Many specialty flours such as amaranth, have been combined with wheat flour to make new products, and these are not useful to the food allergic patient. Until now, there has been no attempt to completely replace wheat products with a non-grain flour source that also does not contain other main ingredients such as eggs, milk, sugar, and yeast.
The properties of flour and starch from orange sweet potatoes are well known, and have been reported in the patent literature as early as the 1840's. Dried, ground sweet potatoes were patented for use as an ingredient in a coffee blend (U.S. Pat. No. 100,587 issued in 1870) because dried orange sweet potatoes look and taste like burned bricks. The caroteen pigment concentrates during drying and causes the disagreeable taste and color. The other patented uses of orange sweet potato flour are limited, including: rehydratable powders primarily for sweet potato pie or pumpkin pies; adding pureed, cooked sweet potato pulp to various doughs to produce doughnuts and pastas. This is probably due to the strong taste of orange sweet potato powder, the fact that when rehydrated, orange sweet potato flour loses cohesion, and will not keep a shape or hold trapped air.
There appear to be no clear references to white sweet potato varieties in the patent literature, although there are numerous mentions of processes for combining cooked or raw starches or flours from starchy tubers with various ingredients. Sweet potatoes (probably orange varieties) are frequently used as examples of `other tubers`.
Previous products of white sweet potato flour were made by a high speed impact method which produced a flour of wide particle-size distribution, with the fibrous portions of the tuber remaining in the larger particle sizes, and rendering the flour unsuitably heavy and gritty. When screened, the large particles were removed; this produced a lighter and less gritty flour, but one poorly suited for producing breads and other products where consistency and lightness are important. In addition it has been found that previous shreds had a high moisture content that made them susceptible to spoilage during dehydration and produced inferior products that spoiled easily.
It has now been found that a flour having reduced moisture content, improved fiber utilization, and more uniform particle size distribution can be prepared that will have improved storage capability and will provide products of palatable consistency.