Proteins for foods, in addition to providing nutrition, should also possess specific functional properties that facilitate processing and serve as the basis of product performance. Functional properties of proteins for foods connote the physicochemical properties which govern the behavior of protein in foods. This general article collates the published information concerning the major functional properties of food proteins, e.g., solubility, binding properties, surfactant properties, viscogenic texturizing characteristics, etc. The effects of extraction and processing on functional properties and possible correlations between structure and function are discussed, in relation to practical performance in food systems. Modification of proteins to improve functional characteristics is briefly mentioned.

Functional properties of proteins in foods: A survey

Food uses of soybean oil protein are reviewed. Coverage includes soybean production, storage, and processing. Emphasis is on conversion of crude soybean oil into salad and cooking oils, shortening, margerine and lecithin products, the processing of defatted soybean flakes into flours and grits, protein concentrates and isolated proteins, and the various uses of the nutritional properties of the proteins are discussed.

Soybeans as a food source

This year the world population is expected to reach 4 billion and for the year 2000 the projected figure is 7 billion (1). Reduction of the death rates through effective public health measures without a concurrent reduction of birthrates is considered one of the prime causes of the rapid increase in population numbers (2, 3). Because birthrates and family planning are intimately interwoven with the social systems and cultures of individual nations, population control does not immediately follow a fall in the death rate. History suggests that population control occurs because of numerous factors, including social and economic change (3, 4). Obviously, the rapid growth of the human population is resulting in an increased demand for food (1, 5, 6). Experience has shown that augmenting food supplies is not as easy as controlling disease (1, 7). Assuming the figures that suggest an estimated half-billion people are at present protein-calorie malnourished (8, 9) are correct, then great concern is justified about our ability to provide adequate food for the increasing numbers of people that are projected for the future. An integral part of the population-food equation is the use of fossil energy. Energy is consumed in most food and fiber production, in public health activities, and in most endeavors to improve the quality of human life. As we prepare for the future with its rapidly growing world population, concern has been expressed about the limited energy and land resources that are available to increase food production, especially food protein production. In this article we analyze the energy and land demands for both animal and vegetable protein production in the United States, and then examine world food supply as it relates directly to world population density, dietary standards, and food production technology.

https://science.sciencemag.org/content/sci/190/4216/754.full.pdf

Energy and Land Constraints in Food Protein Production

The availability of soyabean meal for animal feed use in Asia and the Pacific is low. The potential usefulness of a wide variety of protein-rich plant materials which could replace soyabean meal in...

Feed resources for poultry production in Asia and the Pacific. II. Plant protein sources

Gossypol1 is a yellow coloring matter which occurs in various parts of the cotton plant. Longmore (1886) first isolated it as a crude pigment from cottonseed oil “foots,” a material which results from the refinement of crude cottonseed oil with sodium hydroxide and contains free fatty acids, phospholipids, gossypol, and other pigments. Marchlewski (1899) crystallized the acetic acid derivative of a compound from the same source, which he named “gossypol” to designate its origin, genus Gossypium (family Malvaceae), and its chemical nature as a phenol. Gossypol is found in the pigment “glands” (ovispherical bodies about 100 to 400 µm long) of the seed, leaf, stem, laproot bark, and roots of the cotton plant (Royce et al. 1941, Smith 1962). Studies of changes in the gossypol content of cottonseed during different stages of development of the bolls showed that the greatest increase in gossypol occurs between the time of maturity of the boll and the time it is about to open (Adams et al. 1960). Gossypol synthesis in all tissues of the cotton plant was induced in response to such irritants as pathogens, metabolic inhibitors, and cupric and mercuric ions (Bell 1967). Gossypol constitutes 20 to 40% of the weight of the pigment glands in cottonseed (Boatner 1948). Cottonseed usually contains 0.4 to 1.7% gossypol. The total world production of cottonseed is about 25 million tons/year (containing approximately 78,000 tons of gossypol) and about three to six million tons are produced in the United States (Decossas et al. 1968). An average ton of cottonseed gives about 335 pounds of oil and 945 pounds of meal (Altschul et al. 1958). If refined 60% protein cottonseed flour is prepared for human use, 300 to 400 pounds/ton is produced; the remainder can be used for animal feed. It is estimated that only onefourth of the cottonseed flour potentially available could satisfy the present worldwide shortage of protein (Gillham 1969).

Aaron M. Altschul

Papers

Processed Plant Protein Foodstuffs