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ARS Home » Southeast Area » Raleigh, North Carolina » Food Science and Market Quality and Handling Research Unit » Research » Research Project #438432

Research Project: Improvement and Maintenance of Peanuts, Peanut Products and Related Peanut Product Flavor, Shelf Life, Functional Characteristics

Location: Food Science and Market Quality and Handling Research Unit

2021 Annual Report

1. Improve peanut flavor, flavor consistency and nutritional composition through integration of novel peanut genetic/genomic resources. 1A. Investigation of peanut composition using targeted and non-targeted analyses to identify compounds and metabolomic pathways of formation related to peanut flavor formation. 1B. Evaluate the flavor and quality characteristics of specific peanut varieties or breeding lines in cooperation with U.S. peanut breeders. 2. Identify commercially-viable bioactive compounds from raw/roasted peanuts and characterize their functional food attributes. [NP306, C1 PS1B] 2A. Evaluate peanut skins as an antimicrobial ingredient in livestock feed. 2B. Determination of the effectiveness of extracts from peanut skins as a natural antioxidant in preventing the onset of rancidity in peanut butter. 3. Enable the commercial use of whole high-oleic peanuts and/or by-products as a livestock (poultry, swine, and aquaculture) feed ingredient.

The United States peanut industry generates approximately $4.4 billion annually in economic activity. With a value of over one billion dollars at the farm level, the peanut crop ranks twelfth among USA food crops, grown on approximately 7,500 farms with 1.4 billion acres producing over five billion pounds of peanuts in the shell. In addition, the peanut industry is composed of producers, shellers, and manufacturers. These manufacturers produce peanut butter, candies, confections, bakery goods and ingredients for other foods, in addition to snack peanuts. The USA peanut industry is vibrant, but the private sector relies on the USDA-ARS to increase and expand markets through continual improvement of peanuts and peanut products across all segments of the industry, from farm to processors and consumers. This project is one of only two public research programs dedicated to improving the value of the crop by enhancing flavor, nutrition, and post harvest processing using modern food science technology. The specific objectives are: Objective 1, improvement of peanut flavor, flavor consistency and nutritional composition through integration of novel peanut genetic/genomic resources; Objective 2, the identification of commercially-viable bioactive compounds from raw/roasted peanuts and peanut processing waste materials and to characterize their functional food attributes; Objective 3, to enable the commercial use of whole high-oleic peanuts and /or bi-products as a livestock feed ingredient. This research will be accomplished using chemical and molecular biological techniques and methodology as well as sensory analytical techniques.

Progress Report
ARS scientists at Raleigh, North Carolina, believe with a value of over one billion dollars at the farm level, the peanut crop ranks as number twelve among United States food crops. In addition, the peanut industry is composed of producers, shellers, and manufacturers. ARS scientists at Raleigh, North Carolina are focused on addressing issues of flavor, nutrition, processing, and value-added products that are critical to delivering optimized peanut products across all peanut industry segments. Samples of peanuts from commercial warehouses were roasted based on previous research to a range of levels as distinguished by final roast color. Using gas chromatography coupled to time-of-flight mass spectroscopy, the volatile and semi-volatile compounds were identified. Due to COVID restrictions, the confirmation of the identities was not confirmed from authentic standards. Once complete, these compounds will be evaluated as contributors to distinct flavors that have been confirmed in the samples by descriptive sensory analysis. This information will used to prove the relationship between specific genes which produce the compounds and generation of peanut flavor. This information is a priority of the Peanut Foundation Genomic Initiative, Part II. Peanut skins were obtained by ARS scientists at Raleigh, North Carolina from a commercial blanching plant and incorporated into feed for laying hens over the course of three studies of 6 weeks each. The treatment groups were: (1) Non-inoculated conventional fed group; (2) Non-inoculated peanut-skin supplemented conventional fed group; (3) Orally inoculated with Salmonella group fed non-supplemented control diet; and (4) Orally inoculated Salmonella peanut-skin supplemented group. Eggs, drag swab, fecal, feed and water environmental samples were collected weekly and analyzed for microbial content. At termination, fecal content and tissue samples (intestine) were collected. Intestinal samples of the jejuna and ileum were processed using standard histological processing with H& E staining procedures. Growth performance was evaluated bi-weekly with weekly recorded body weight and feed intake. Mortality was recorded daily. A peer reviewed publication is being prepared. Peanut extract skin powder encapsulated with maltodextrin was prepared according to methodology developed previously to produce a free-flowing powder. The powder was incorporated into freshly prepared peanut butter at levels of 0, 0.5, 1.0, 1.5, and 2.0% (w/w). The maximum value of addition was based on the maximum that synthetic antioxidants are added to foods. Samples were portioned into glass jars, sealed, and stored in an incubator at 30°C. Samples were removed at 1-month intervals over the course of 6 months. The controls will be the samples at the time of preparation (zero time). Each sample was analyzed for fatty acid profiles, tocopherols, moisture, and peroxide value. In addition, samples were analyzed for the pentanal and hexanal using static headspace sampling with gas chromatography. The samples were evaluated by the descriptive panel maintained using the standard peanut lexicon. The ability of the additive to delay or prevent rancidity is being evaluated. A manuscript will be prepared and submitted bby ARS scientists at Raleigh, North Carolina to a peer reviewed journal. Uniform Peanut Performance Tests (UPPT). Samples of peanut varieties and breeding line currently in development were provided by participating USA peanut breeders in the UPPT for the crop year 2019. Samples were analyzed for total fat, total protein, moisture content, fatty acid and sugar profiles, tocopherol content and sensory characteristics after roasting by a trained descriptive sensory panel. Creation of the data set is still in progress as laboratory work was was delayed due to COVID restrictions. The data will be compiled and reported to the cooperators and to the program website at the USDA-ARS National Peanut Research Laboratory. Laying hen feeding trials consisting of laying hens (36-40 week) randomly assigned to one of five isonitrogenous (18% crude protein) treatment diets with 120 birds per treatment, 6 replicates/treatment and 20 birds/replicate: with the following treatment groups: (1) conventional control soybean meal + corn diet; (2) low level-unblanched high-oleic/normal-oleic peanut supplemented diet; (3) high level-high-oleic/normal oleic peanut meal supplemented diet; (4) oleic acid oil supplemented diet; (5) 4% peanut skin supplemented diet. Body and feed weights were recorded weekly. Daily shell eggs were collected and egg weights recorded from each hen. Weekly, shell eggs were analyzed for quality (yolk color DSM, albumen height, Haugh unit) and USDA grading. Egg yolk color, egg albumen, shell and vitelline membrane strengths were determined. Homogenous pooled egg samples were analyzed for total cholesterol, ß-carotene and 36 differing fatty acids. Production performance is being determined bi-weekly using the feed intake, egg production, and feed conversion ratio. A peer reviewed publication will be produced.

1. Phenotyping of the composition of a peanut chromosome segment substitution line (CSSL) population. Phenotyping of the composition of a peanut chromosome segment substitution line (CSSL) population was performed by ARS scientists at Raleigh, North Carolina. 122 lines had been developed with a small chromosomal segment from wild species with a spanish type cultivar. The effects of the wild introgressions on oil content, fatty acid composition, sugar profile and protein content on a subset of the CSSLs relative to the cultivated parent. The effect of introgressions on these lines are being used by Institute of Plant Breeding, Genetics, and Genomics at the University of Georgia to produce new sources of high oleic peanut polymorphisms. Such polymorphisms have the potential for use in further improving peanut oil quality.

2. An organic peanut production survey of peanut farmers in the Virginia-Carolina region. A survey of peanut farmers in the Virginia-Carolina region was conducted by ARS scientists at Raleigh, North Carolina, to gather information on the interest of organic peanut production. The demand for organic food sources has increased exponentially over the past decade. No organic sources of peanuts are available for the Virginia-Carolina region. The survey determined the price incentive needed to have farmers produce organic peanut crops. This information was provided to extension agents, farmers, and researchers to promote organic peanut production for the Virginia-Carolina region.

3. Awarded the 2020 ARS 12th Round-ARS Innovation. ARS scientists at Raleigh, North Carolina were awarded the 2020 ARS 12th Round-ARS Innovation Award Funding to determine the use of high-oleic peanuts and/or peanut skins as a value-added alternative feed ingredient for aquaculture to enhance the quality and/or nutritional composition of the meat produced. These results will support ARS national program research objectives with “expansion of market opportunities for agricultural products and waste by-products” (NP 216) and the “creation of new products” (NP 306) as value-added feed additives while promoting agricultural sustainability.

4. Awarded the 2021 U.S. Soybean Board Grant. ARS scientists at Raleigh, North Carolina, were awarded the 2021 U.S. Soybean Board Grant, “Expansion of US Soybean Market with the Utilization of Full-fat High-Oleic Soybean Meal in Poultry and Aquaculture Feed to Enrich Meat and Eggs for Human Consumption” and the NC Soybean Producers Association Grant, “Valuation for Differentiation of NC Soybean Meal in Poultry and Livestock Feed Formulation”. These studies aim to determine the economic impact and dietary effects of full-fat high-oleic soybean meal as an alternative feed ingredient for broiler chickens, layers, and striped bass. The results will support economic growth within the Soybean Industry and market expansion of high-oleic soybeans within the agriculture animal food production sector as a preferable feed ingredient, providing producers with extended shelf-life of high-oleic soybean meal, enhanced livestock performance, and nutritional enrichment of the commodities produced.

Review Publications
Lahiri, S., Reisig, D.D., Dean, L.L., Reay-Jones, F.P., Greene, J.K., Carter Jr, T.E., Mian, R.M., Fallen, B.D. 2020. Mechanisms of soybean host plant resistance against Megacopta cribraria (F.) (Hemiptera: Plataspidae). Environmental Entomology.
Gimode, D., Chu, Y., Dean, L.L., Holbrook Jr, C.C., Fonceka, D., Ozias-Akins, P. 2020. Seed composition survey of a peanut CSSL population reveals introgression lines with elevated oleic/linoleic profile. Peanut Science. 47:139–149.
Toomer, O.T., Sanders, E., Vu, T.C., Malheiros,, R.D., Redhead, A.K., Livingston, M., Livingston, K., Carvalho,, L., Ferket, P. 2020. The effects of high-oleic peanuts as an alternative feed ingredient on broiler performance, ileal digestibility, apparent metabolizable energy and histology of the intestine. Translational Animal Science. 4(3):txaa137.
Kaufman, A.A., Jordan, D.L., Reberg-Horton, S., Dean, L.L., Shew, B.B., Anco, D.J., Mehi, H., Taylor, S., Balota, M., Goodell, L., Allen, J.C., Brandenberg, R.L. 2020. Identifying interest, risks, and impressions of organic peanut production: A survey of conventional farmers in the Virginia-Carolina region. Crop, Forage & Turfgrass Management. 6(1):e20042.
Ucar, R.A., Perez Diaz, I.M., Dean, L.L. 2020. Content of xylose, trehalose and L-citrulline in cucumber fermentations and utilization of such compounds by certain lactic acid bacteria. Food Microbiology. 91:103454.
Ucar, R.A., Perez Diaz, I.M., Dean, L.L. 2020. Gentiobiose and cellobiose content in fresh and fermenting cucumbers and utilization of such disaccharides by lactic acid bacteria in fermented cucumber juice medium. Food Science and Nutrition. 8(11):5798-5810.
Butts, C.L., Dean, L.L., Hendrix, K., Arias De Ares, R.S., Sorensen, R.B., Lamb, M.C. 2021. Hermetic storage of shelled peanut using the purdue improved crop storage bags. Peanut Science. 48(1):22-32.