John P. Cherry

Electrophoretic characterization of six selected enzymes of peanut cultivars

Abstract The isozyme patterns (both anodic and cathodic) of esterase, catalase, leucine aminopeptidase, acid phosphatase, alcohol dehydrogenase and INT oxidase in individual seeds from several peanut cultivars ( Arachis hypogaea ) were characterized by polyacrylamide and starch gel electrophoresis in relation to the stages of seed development, maturity, and germination, geographic areas where grown and phylogenetic relationship. Of the six enzymes examined, only esterase contained cathodic isozymes, of which the patterns served to distinguish between the Spanish and the Virginia-type peanuts. Anodic esterase and acid phosphatase zymograms of early developing and germinating peanuts could be distinguished from those of predormant and mature seeds and the latter showed much intravarietal variation which was consistent among cultivars and the geographic areas where grown. Anodic isozymes of catalase, leucine aminopeptidase, alcohol dehydrogenase and INT oxidase were synthesized very early in peanut development and remained constant through maturity and to at least 24 hr germination; they were consistent within and between peanut cultivars and they were not influenced by the environmental conditions of the areas where the peanuts were grown. The consistency of the isozyme patterns within and between cultivars supports the suggestion that plant breeding programs used to develop superior cultivars have produced genetic uniformity in peanuts.

A Review of Lecithin Chemistry and Glandless Cottonseed as a Potential Commercial Source

Industrial lecithin can be fractionated as phospholipids and glycolipids after neutral lipids and protein-containing contaminants are removed. The polar lipids are very reactive and are difficult to extract and purify from oilseeds. Their purity and special properties can be improved by a number of methods including solvent fractionation, hydrogenation, sulfonation, and ethoxylation. Studies are determining the role of the polar lipids of lecithin in (a) the synthesis of triglycerides in maturing seeds, (b) the structure of biological membranes, and (c) the molecular basis of the functionality of food ingredients. Lecithin, having both polar and nonpolar groups, has high surface activity and is reactive with both oil and protein, making it an excellent emulsifying agent in food systems; lecithin also slows autoxidation and enzyme hydrolysis of fats. Cottonseed lecithin is low in linolenic acid, prevents flavor deterioration of soybean oil and can be used to stabilize sunflower oil against color change during high temperature use. Gossypol binds to lecithin in oil from glanded cottonseed economically negating it as a commercial source of this product. New cultivars producing glandless, or gossypol-free cottonseed, may have potential as commercial sources of edible lecithin.

Peanut protein and product functionality

Interest in the potential of peanut seed as a source of edible vegetable protein products has been stimulated by an increase in our understanding of protein physicochemical properties, improved protein extraction, fractionation and characterization techniques, advanced technologies to produce high quality and diverse protein ingredients and understanding the interrelationship between physicochemical, functional and nutritional characteristics of protein products. Further expansion in the processing and utilization of peanut products may be constrained by economic conditions rather than by limitations in functionality, nutritional quality, or consumer acceptability. Should changes occur to improve the competitive position of peanuts, the potential contributions of their protein products may be more fully realized.

Potential for Improving Cottonseed Quality by Genetic and Agronomic Practices

Potential utilization of cottonseeds as edible food sources accentuated the need for research on their composition. Studies included evaluation of cottonseed composition; e.g., seed grade, protein, amino acids free fatty acids, oil, fatty acids, cyclopropenoid fatty acids, total gossypol, differential settling as an indicator of potential performance of cottonseed in the liquid cyclone process, and extractability of nonstorage and storage proteins and their gel electrophoretic properties. These extended studies were used to develop a data base on composition of various cottonseed cultivars grown in different locations of Texas that resemble environmentally most of the regions of the United States cotton belt. Tests showed that most constituents of cottonseed vary; statistically significant variables include cultivar, location, and their interaction term, cultivar x location. These data suggest that breeding and agronomic practices could be used to alter cottonseed composition. Although protein quantity of cottonseed from various cultivars differ and can be influenced by agronomic practices, this variability is not reflected in quality of cottonseed protein as detected by gel electrophoretic techniques. Analyses showed that both genetic and agronomic factors influenced formation of edible flour with high protein and low free gossypol content.

Proteins and enzymes from seeds of Arachis hypogaea L. IX. Electrophoretically detected changes in 15 peanut cultivars grown in different areas after inoculation with Aspergillus parasiticus

Abstract Dehulled and testa-free peanuts from 15 cultivars of Arachis hypogaea L. (representing most of the commercial acreage in the United States) were all susceptible to invasion by Aspergillus parasiticus when kept in moist chambers at 30°C. Gel electrophoretic patterns of proteins and seven enzymes (esterase, peroxidase, catalase, leucine aminopeptidase, acid phosphatase, alcohol dehydrogenase and an achromatically detected oxidase) of contaminated seeds, cotyledons and axial tissues from these cultivars showed the same sequence of changes from 0 to 5 days after contamination, distinguishable from a “standard” profile of uninoculated peanuts. During the 5 days, the following transitions occurred: (a) decomposition of high molecular weight globulins (conarachin, arachin) to smaller components; (b) quantitative depletion of these proteins; (c) changes in the composition of enzymes, such as the depletion of alcohol dehydrogenase and acid phosphatase, intensification of esterase and peroxidase, and production of new isozymes of esterase, peroxidase, leucine aminopeptidase, catalase and oxidase; and (d) synthesis of aflatoxins. Manu of the new isozymes in contaminated peanuts were also observed in zymograms from extracts of fungal tissue only, collected from the exterior surface of seeds. Transformations such as the rapid catabolism of peanut proteins coincide with the changes in isozyme patterns during the invasion of Arachis hypogaea seeds by Aspergillus parasiticus.

Characterization of isoperoxidase activity in Arachis hypogaea cultivars

Abstract Isoperoxidases (both anodic and cathodic) from individual seeds of several peanut cultivars ( Arachis hypogaea ), after ammonium sulfate precipitation of the major storage protein, arachin, from the extracts were characterized by polyacrylamide gel electrophoresis with respect to seed development, maturity and germination and the geographic areas where grown. All cultivars had a major cathodic isozyme near the origin of the gels. Much anodic intra- and inter-varietal isozyme polymorphism was observed in mature seeds collected from different geographic areas. These polymorphic isozymes were consistently present during the earlier stages of seed development (the activities decreased quantitatively and became variable during the later stages of maturation), and most were observed in each peanut upon germination, the latter showing quantitative increases in activity.

Cottonseed Protein Derivatives as Nutritional and Functional Supplements in Food Formulations

Cottonseeds contain protein with desirable food functional and nutritional properties. Storage globulins make up most of the protein stored in cottonseed and can be separated into five fractions by gel filtration chromatography. Each fraction is distinguishable from the other by its amino acid and polyacrylamide gel electrophoretic properties. Proteins of cottonseed contribute greatly to the functional properties of emulsions, co-isolates, and texturized derivatives. For example, increasing the amount of high protein cottonseed flour in wheat suspensions from 2% to 10% improved the capacity (54-97 ml of oil) and viscosity (5,000-100,000+ cps) of emulsions. The 10% suspension formed emulsions with increasing oil capacity (84-100 ml) and viscosity (28,000-100,000+ cps) as the pH was adjusted from 4.5 to 9.5. Consistencies of the products ranged from that of salad dressing (low percent suspensions, or acid pH) to that of mayonnaise (high percent, or basic pH). These data were utilized to derive a multiple regression model to predict optimum use of cottonseed proteins in emulsions of varying consistencies. A coprecipitated isolate containing greater than 94% protein was prepared from a blend of cottonseed and peanut flours. Amino acid content of the co-isolate reflected that of the protein in the two flours of the composite. The co-isolate has lower gossypol level and improved color and functional properties than a cottonseed protein isolate. Storage protein isolate of cottonseed suspended in aqueous solution and heated with constant stirring forms a texturized product; the quality of the product depends on heat, pH, salt, and the quantity of nonstorage proteins. Protein and amino acid content of meat products were improved by the addition of the texturized protein of cottonseed.

Determination of total gossypol at parts-per-million levels

The official AOCS method Ba 8-78 for total gossypol has been modified by introduction of two clean-up steps. These steps reduce sample blanks and also substantially increase the concentration of dianilinogossypol available for spectrophotometric measurement. An improved method of correcting sample absorptions for blanks, which reduces the possibility of over or under compensation, and criteria for judging the quality of the results have been added. With these modifications, the method is more than adequate for grading glandless cottonseed under Rule 112 of the National Cottonseed Products Association. As little as 1 ppm can easily be measured in sound cottonseed samples. The method is not universally applicable to mixtures that may contain TG, but the criteria of quality should permit identification of samples to which it is not applicable and, hence, prevent reporting of inaccurate TG concentrations. Additional modifications for use with foods and other complex mixtures are suggested.