Estimated obligations for State research on peanuts, Federal-grant and non-Federal funds, fiscal year 1963

In addition there is a non-Federal research project in Oklahoma which covers more than 1 commodity. There is no information available as to amount of funds applied to this research on peanuts.

DESCRIPTION OF PROGRAMS

Breeding, quality, and cultural practices

Breeding for superior types and evaluation of fertilization and cultural practices. (Florida, Oklahoma, and Texas.)

Fertilization of peanuts with major and minor elements, studies on the development of rancidity, new varieties, use of supplemental irrigation in growing peanuts, characterization of substances in peanuts responsible for flavor and aroma, and effect of treatments on keeping quality. (Georgia.)

Breeding for variety improvement including the use of radiation techniques, influence of plant nutrition on productivity, and the productivity of peanut soils as influenced by crop sequence. (North Carolina.)

Soil-plant nutrient relationships. (Virginia.)

Diseases and insects

Research on soil-borne and other diseases of peanuts (Alabama, Georgia, North Carolina, Texas, Virginia); entomological studies on insects affecting peanuts (Virginia).

Engineering and other production research

Handling of peanuts during harvesting, curing, drying, and storage. (Georgia, Virgilia.)

Farm economics

Effect of Federal price support programs for peanuts on farm land values. (Virginia.)

Marketing

Chemical and physical properties during storage and their effect on market value, and fermentation products produced by fungi growing on a peanut sub(Alabama.)

strate.

SUMMARY OF CURRENT PROGRAM, SOUTHERN REGIONAL UTILIZATION RESEARCH AND DEVELOPMENT LABORATORY

PEANUTS PROCESSING AND PRODUCTS

Problem.-Peanuts constitute a major cash crop in the Southern States and are in surplus. Because of the high price of peanuts in the United States, peanuts are used almost exclusively (more than 80 percent of the crop) in foods such as peanut butter, confections, and roasted and salted nuts. New type food products and improvement in the quality and uniformity of existing products are needed to increase consumer acceptance and extend markets; the average per capita consumption has been rather stable since World War II. The increased trend toward mechanical harvesting has necessitated the use of artificial means for curing and drying peanuts, with the result that processed peanuts and peanut products do not always possess the same desirable flavor and physical properties as peanuts which have been cured slowly in the field. Information is needed as to the physical and chemical characteristics of those chemical constituents in peanuts which affect the properties of processed products as a basis for developing new or improved products and processing procedures. Fundamental studies of peanut protein and associated materials could similarly lead to the development of new concepts and new uses.

USDA PROGRAM

The Department has a continuing long-term program involving organic chemists, biochemists, and chemical engineers engaged in both basic and applied studies on peanuts and its products to increase consumer acceptance and extend markets for peanuts. Research to develop basic information on the chemical composition and properties of peanuts, its constituents, and processed peanut products is carried out at New Orleans, La. Fundamental investigations of peanut proteins and associated materials are conducted to form the basis for developing new concepts and perhaps new uses for peanuts and peanut proteins. Peanut constituents and their modification by processing that influence nutritive properties and consumer acceptance of processed peanut product are also studied. The Crops Research Division of ARS and several State Experiment Stations, including Georgia, Alabama, and Texas, cooperate in the research by providing samples of peanuts of known variety and of known growing, harvesting, and drying histories. Louisiana State University cooperates by conducting evaluation tests on selected peanut isolates. Research on new and improved food products, and improved processing technology for peanuts are conducted at New Orleans, La. In the food products work, emphasis is on obtaining a stable, defatted whole peanut (kernel) product of long shelf life, which also meets the requirements of taste, odor, color, texture, and appearance. Several industrial concerns specializing in peanut products cooperate by supplying deskinned peanuts and by evaluating the experimental products. The processing research consists of investigations of procedures for large scale production of defatted whole peanuts. Industrial concerns are cooperating in the determination of the necessary processing conditions for such operations as desolventization and roasting.

The Federal scientific research effort in this area totals 5.1 professional manyears. Of this number 4.1 is devoted to chemical composition and physical properties, 0.5 to new and improved food products, and 0.5 to new and improved processing technology.

The following line of work was terminated during the year: (1) Investigations to isolate, identify, and measure chemical constituents in peanuts which contribute to quality of processed peanut products (under chemical composition and physical properties).

RELATED PROGRAMS OF STATE EXPERIMENT STATIONS AND INDUSTRY

State experiment stations in 1961 reported a total of 2.2 professional man-years effort, divided among subheadings as follows: chemical composition and physical properties, 0.7; new and improved food products, 1.2; and new and improved processing technology, 0.3.

One State experiment station is investigating chemical composition and physical properties of peanuts as these relate to susceptibility of various strains of Spanish peanuts to rancidity development. Determination of phosphorus content, level of free fatty acids and susceptibility of oils to autoxidation has been made for peanuts of known geretic history and maturity in a search for means

of control at the genetic level. A second program includes a comprehensive investigation of the chemical composition of peanuts as composition is affected by environmental and agronomic factors. Flavor of peanuts is also being determined in an effort to rote any effects due to production practices or handling. Two main phases of work are underway on new and improved peanut food products. One phase is directed toward development of more dependable and efficient methods of curing peanuts which will yield peanut products of high quality and free of bitterness; the second seeks to determine the effect of various treatments (temperature, time, moisture, and storage conditions) upon the keeping qualities of peanuts and peanut products in common and refrigerated storage. In the latter study, the influence of variety, grade, and prestorage quality of peanuts on processing characteristics and on shelf-life of peanut products is also obtained.

Aroma and flavor characteristics of peanuts are developed from the basic constituents of raw peanuts by reaction at roasting temperatures. One station is conducting research on improved processing technology for peanuts by investigating the chemistry of the process of roasting peanuts and the effect of variations in roasting on the resulting product. It is expected that characterization of the substances responsible for the aroma and flavor of roasted peanuts will lead to identification of the precursors of flavor and aroma to be found in raw peanuts.

Industry and other organizations also conduct research of interest and value in this area. The estimated annual expenditures are equivalent to approximately 8 professional man-years. Of this total, about 6 man-years is by processors and 2 man-years by equipment manufacturers. For the most part food processors are engaged in improving peanut butter and peanut-containing confections. Research is directed toward improvements in the texture, appearance, and mouthing properties of peanut butter and in the stability, appearance, texture, and flavor of roasted or salted peanuts and of peanut-containing products. A limited amount of attention is being given to processing peanut oil for edible purposes and to peanut flour as a food constituent. There is limited effort on the part of the industry to develop fundamental information on peanuts either as a food item or as a potential raw material for industrial use. Frequently such information is sought from the Southern Utilization Research and Development Division by representatives of the industry. Information concerning problems of the peanut industry is exchanged through representatives of the National Peanut Council and of the industry at meetings of the Peanut Improvement Working Group. Some attention is given by equipment manufacturers to improving equipment for shelling and grading peanuts with respect to size and color, and for blanching and roasting.

REPORT OF PROGRESS FOR USDA AND COOPERATIVE PROGRAMS

A. Chemical composition and physical properties

1. Structural factors, properties, and reactions of the proteins.-Pioneering research in scientific fields involving seed proteins and associated substances was continued as a basis for development of new concepts and possibly new uses for these materials. Major areas of recent research have included studies of seed globulins, of their subcellular distribution, and of a specific group of seed proteins, the lipases.

Research on isolation and chemistry of seed globulins has shown that ultracentrifugation is sensitive to protein interaction and, therefore, is a relatively unreliable method for analyzing seed proteins. It has been found possible, however, to apply chromatography on DEAE cellulose and the new technique of zone-electrophoresis on cyanogum gel to the total proteins of the peanut. In both these instances these methods are much less subject to protein interaction and may be relied upon to reflect accurately the composition of mixtures and the progress of fractionation. With the aid of these two tools and by scaling up the process of chromatography, it has been possible to isolate a pure globulin from peanuts which has been named a-conarachin, and which is now being studied extensively for structure and composition. This globulin disappears from the peanut in the first few days of germination as shown by chromatography, and it is very sensitive to the environment-by simply changing ionic strength and pH molecular weights varying from 145,000 to 500,000 are obtained. In the presence of low concentrations of sodium dodecyl sulphate or concentrated urea, particles of molecular weights of less than 10,000 can be noted. This leads to the belief that the major primary unit is of low molecular weight, and that perhaps several types of primary units go in to make the final major structure.

One of the classical seed proteins, edestin from hempseed, has now been shown to be a mixture by cellulose chromatography at elevated temperatures.

This

procedure opens the way for_chromatography of insoluble proteins without resorting to extremes of pH. This procedure is being employed to isolate pure proteins from hempseed.

Two independent methods have been developed for subcellular fractionation of the contents of the peanut parenchyma cell. The first method which involves fractionation in the absence of water has resulted in obtaining protein-rich particles with protein concentrations up to 85 percent. These particles do not exhibit any enzymatic activity. However, protease activity has been found in the cell wall fraction, and hexokinase activity in a fines fraction. A second fractionation using concentrated sucrose and Carbowax solutions has demonstrated that about 75 percent of the protein of the peanuts are in subcellular particles, and are not released into solution in the presence of the aforementioned asomatic agents. Among these proteins is a-conarachin. A new approach has therefore been made available for studying the biological function of the major seed globulins which have been shown to be in subcellular particles-by isolating and studying the biochemistry of the particles themselves.

In the course of these studies, unique distributions of components have been found. For example, all of the phytic acid is found in a protein rich component (aleurone grains), as well as the greater proportion of magnesium and potassium. The major proportion of calcium is found in the cell walls and the major amount of sucrose and nucleic acids in the fines fraction (reticulum).

The mobilization of fat in oilseeds takes place rapidly in the early days of germination and is one of the important physiological processes for mobilization of energy to support the growth processes. The first step in the mobilization is lipolysis of the glyceride, or otherwise making available the acyl group for further metabolism. The proteins involved in this process have been investigated in two lines of research: (1) the study of lipolysis in resting seeds as observed in the castor bean; (2) study of the development of lipolytic systems in germinating seed. For the purpose of comparison, the castor bean was chosen for this study as well.

The study of the lipase in castor beans has resulted in the isolation of a particulate preparation which contains the acid lipase free of all substrate, and of most of the other proteins. This preparation is very active and quite stable. There seems to be evidence of two enzymes in this preparation: one with a maximum activity for triglycerides of C. saturated fatty acids and the other with maximum activity for glycerides of long-chain unsaturated fatty acids. One of the problems in understanding the catalysis of heterogeneous reactions involving water and insoluble material such as fat, is to find the means of bridging between the two in the catalytic action. Accordingly, one phase of the research has sought the removal of a factor from the enzyme which might perform this function. Success has been achieved in removing from the acid lipase a lipid material which acts as a cofactor for hydrolysis of triglycerides of long-chain fatty acids. This is the first time that a cofactor for a lipase has been reported. And this work has taken an exciting turn with the finding that a-tocopherol succinate can substitute or this lipid cofactor. This is the first time that an enzymatic role for tocopherols has been found.

The lipase of the resting castor bean is more typical of lipolysis in animal or plant adipose tissue than is the lipase of the gastrointestinal tract. Information on the properties of the castor bean lipase will therefore have general meaning, not only for plant tissue lipases, but possibly also for animal lipases. The fact that tocopherol is involved in lipase activity might even suggest a role for tocopherol in a field so far away from the original purpose of investigation as atherosclerosis.

The methods used to study the fatty acid content of serum lipids have been applied to the germinating castor bean. It has been shown that there is a sharp increase in fatty acid content up to 4 days of germination, following which the fatty acid content decreases sharply. This will be the basis for selection of ideal conditions for isolation of the lipase in the germinating seed.

2. Identification of factors influencing flavor, aroma, color, structure, and nutritive value of processed products.-In contract research at the University of Arizona, which is now terminated, investigations were continued to study the influence of processing on the composition and flavor of peanut products. The concentrations of free arginine, histidine, aspartic acid, lysine, proline, serine, and threonine were determined through the use of ion exchange methods for the roasted fat-free peanut flours for the 1957 and for the 1958 crops of the varieties Argentine, Florispan Runner, Fla. 302-12-B-28, Tennessee Red, and Dixie Runner. Arginine, histidine and lysine determinations were made on two varieties of peanuts from

the 1957 crop and on the five varieties of the 1958 crop in the "uncured, dried and refrigerated" treatment. The free alanine, aspartic acid, glutamic acid, glycine, proline, serine, cystine, threonine and valine were determined on the flour obtained from "uncured, dried and refrigerated," and for the "cured, refrigerated" for the 1957 and 1958 crops. Nonprotein, total and amino nitrogen, total sugar, and oil contents were also determined for all treatments for the five varieties.

The data for the free amino acids in the peanuts as determined by ion exchange methods and by microbiological methods were not in agreement. This points to the fact that microbiological methods may not be relied upon in the determination of free amino acids in plant extracts. Evidence for the reduction of the amino nitrogen in peanut proteins on the roasting of peanuts suggests that lysine may be affected by the roasting process. No clear-cut pattern of a relationship between the free amino acids in peanuts and the quality factors such as aroma, flavor, color and texture evolved from the studies. The wide variation in the intensity of the quality factors observed in the samples studied indicate that sampling of peanuts over wide geographical areas and growing conditions is essential for quality comparisons of varieties and for the ultimate correlation of quality factors and constituents of raw peanuts.

As an aid to better understanding and assessing the quality factors of processed peanut products, further in-house research was conducted on the isolation and characterization of chemical constituents in peanuts which might affect nutritive properties and consumer acceptance. The myotonic factor in peanuts has been concentrated 15,000-fold. Its physiological activity is lost on mild acid or alkaline hydrolysis. This material has been shown by paper chromatography to consist of two major components and at least one minor one. One of the crystalline materials isolated in the course of fractionation of the alcohol extract of de-oiled peanuts was identified as pinitol, a monomethyl ether of D-inositol. Investigations will be continued to identify the hemostatic factor and other crystalline products in the alcohol extract. The physiological tests on various peanut fractions are carried out in the Department of Zoology at Louisiana State University. (S4 1-87, S4 1-100).

B. New and improved food products

1. Defatted whole peanuts.-Research to develop defatted whole peanuts (kernels) as a new confection was conducted. Interest in defatted peanuts is due to several factors, including lower caloric value, possible increase in shelf life by minimizing oil rancidity, possible use by hemophiliacs to control bleeding, and opportunity for increased utilization of peanuts.

Roasted Virginia peanuts were solvent extracted with hexane to different levels of oil removal, and then desolventized. Some of the samples of defatted desolventized peanuts were salted, either by dipping in saturated salt solution at room temperature or preferably by dipping in water and sprinkling with salt. The wet peanuts were oven dried. The most acceptable product (salted or unsalted) proved to be the defatted peanuts with 81 percent oil removed. The peanuts have a good appearance, and their taste is considered acceptable even though it is not like that of the original roasted peanuts. Packaging of the product in metal cans, in either vacuum or in an atmosphere of nitrogen containing less than 2 percent oxygen, maintained the peanuts in good condition even after 1 year storage time. In cellophane-type packages, defatted peanuts tended to pick up excessive moisture within 30 days. Other types of flexible packaging are being investigated.

C. New and improved processing technology

1. Processing technology related to defatted peanuts.-Based on earlier laboratory experiments in producing defatted peanuts, pilot-plant runs were conducted to prepare large amounts of materials for taste and appearance evaluation, to obtain pilot-plant processing data for cost calculations, and to investigate practical methods of desolventization of the extracted peanuts and other processing steps. Fully roasted and one-half roasted Virginia peanuts were batch extracted with hexane for 23, 47, 71, 120, and 335 hours at room temperature to remove 38, 61, 71, 81, and 92 percent oil, respectively. The fully roasted peanuts with 81 percent of the oil removed have the best appearance. Low rates of extraction indicate that a batch method would be required for large-scale processing.

The extracted, solvent-wet peanuts were desolventized by (1) air drying followed by drying in a forced draft oven at 150° F. and then at 212° F., (2) direct drying in a force draft or vacuum oven at a low initial temperature of 150° to