Location: Food Science and Market Quality and Handling Research Unit
2023 Annual Report
Objectives
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.
Approach
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 researchers Raleigh, North Carolina, believe that with a value of over 1 billion dollars at the farm level, the peanut crop ranks as second only to soybeans in terms of oilseed value. In addition, the peanut industry is composed of producers, shellers, and manufacturers. ARS researchers in 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.
Under Objective 1A samples of peanut cultivars from two of the four market types were obtained from cooperators in North Carolina, Virginia, Georgia, Oklahoma and Texas. The samples were high quality, raw, unblanched (skins on), shelled peanuts for human food uses of the Spanish and Valencia market types. Samples of the runner market types were also obtained to serve as controls. The samples were blanched (skins removed) and sized. The samples were analyzed in the raw state for nutritional content (protein, moisture, total fat, fatty acid profiles, free and total amino acid profiles, sugar profile, tocopherols). Samples were then roasted, and descriptive sensory analysis was performed by the trained sensory panel composed for ARS scientific personnel. This information is needed for comparison of the Spanish and Valencia market types with other market types to increase their use in USA peanut products.
Under Objective 1B samples of peanut cultivars in development for seed release during the crop year 2021 were evaluated by ARS researchers in Raleigh, North Carolina. The samples were grown in the United States by public plant breeders participating in the Uniform Peanut Performance Trials and sent to the USDA-ARS National Peanut Research Laboratory (NPRL) at Dawson, Georgia. After shelling and sizing at NPRL, the samples were forwarded to ARS researchers in Raleigh, North Carolina. The samples were analyzed for total fat, total protein moisture content, fatty acid and sugar profiles and tocopherol content. In addition, the samples were roasted, and the sensory characteristics were determined by a trained sensory panel. The data set was processed and reported to the cooperators and to the program website at the USDA, ARS, NPRL.
In regards to Objective 2A salmonella is the leading cause of bacterial foodborne zoonoses in humans. Thus, the development of strategies to control bacterial pathogens in poultry is essential. Peanut skins, a waste by-product of the peanut blanching industry, contain polyphenolic compounds possessing antimicrobial properties. ARS researchers in Raleigh, North Carolina, evaluated peanut skins as antibacterial feed additives in the diets of broiler chickens. One hundred and sixty male hatchlings were assigned to 4 treatments: 1) Peanut skin diet (PS) without inoculation with Salmonella Enteritidis (SE), 2) Peanut skin diet with SE inoculation, 3) Control diet without SE inoculation (CON), and 4) Control diet with SE inoculation (CONSE). The ileal microbiota was determined. The cecal microbiota of the broilers fed the PS diets were characterized and compared to the CON diets.
In regards to Objective 2B it was completed in 2022. Peanut skins and extracts of peanut skins were incorporated into ground peanut paste to evaluate the possible antioxidant/anti-rancidity properties of this peanut processing waste material. Some lipid oxidation was delayed over the course of the 6-month shelf-life study. The resulting changes in flavor, texture, and color were considered to be negative effects of the peanut skins and their extracts as functional food additives.
Under Objective 3 the publication for the poultry feeding trials performed in the previous year was prepared and published. Design of the aquaculture study was started.
Accomplishments
1. Phenotyping the composition of African peanut cultivars. Phenotyping of the chemical composition of peanut cultivars from cooperators at the Senegal Institute of Agricultural Research (ISRA) at Theis-Escale, Senegal and the National Agricultural Research Organization-National Semi-Arid Resources and Research Institute (NARO-NaSARRI) at Soroti, Uganda was performed by ARS researchrs in Raleigh, North Carolina. These lines have been developed specifically for optimal growth in the environments and soil types of these production areas in Africa in cooperation with the Feed the Future Innovation Laboratory at the University of Georgia and USAID. The nutritional information from the study is being used by the growers to select the best cultivars for their growing conditions for increased food stability and high-quality nutrition for their populations.
2. Sweet potato processing waste has applications as poultry feed. North Carolina is a major producer of sweet potatoes in the USA. An ARS researcher in Raleigh, North Carolina, evaluated the incorporation of sweet potato processing waste into feed for layer hens. The addition at levels of 4% were compared to additions of high oleic peanuts at 8% and controls without these additives. Egg quality was not significantly diminished by the additives. The addition of sweet potato processing waste resulted in an increase in the orange color of the egg yolks. A producer of sweet potato puree can redirect processing waste material to the poultry feed market.
3. Determination of precursor compounds to roasted peanut flavor. The maintenance and possible increase of roasted peanut flavor is an important element to be considered when developing new peanut cultivars. In the current global market, USA peanuts command the highest prices due to their superior flavor and quality. A comprehensive study by ARS researchers in Raleigh, North Carolina, of the changes in peanut composition during roasting and the identification of the conditions to produce the optimal roasted peanut flavor in runner peanuts identified the free amino acids that serve as precursors to compounds formed that have roasted peanut flavor correlations was done. These identifications give peanut plant breeders specific compounds to match with molecular markers for peanut flavor improvement.
4. Inshell high oleic peanuts are a viable poultry feed ingredient. ARS researchers in Raleigh, North Carolina, determined that nonfood grade inshell peanuts may have higher value applications beyond the use for the production of oil. Unshelled peanuts added to rations for laying hens reduced protein digestibility for the birds but did not affect egg laying performance or body weight when compared to control rations without peanuts or rations contained shelled peanuts. Peanuts unsuitable for human food can be added to poultry feed without the expense of removing the shells.
Review Publications
Marsh, A., Azcarate-Peril, M., Aljumaah, M., Neville, J., Perrin, M.T., Dean, L.L., Wheeler, M.D., Hines, I.N., Pawlek, R. 2023. Fatty acid profile driven by maternal diet shapes the composition of human breast milk microbiota. Frontiers in Microbiomes. 1:1041752. https://doi.org/10.3389/frmbi.2022.1041752.
Maharjan, P., Rahimi, A., Harding, K.L., Vu, T.C., Malheiros, R., Oviedo, E.R., Mian, R.M., Joseph, M., Dean, L.L., Anderson, K.E., Toomer, O.T. 2023. Effects of full-fat high-oleic soybean meal in layer diets on nutrient digestibility and egg quality parameters of a white laying hen strain. Poultry Science. 102:102486. https://doi.org/10.1016/j.psj.2023.102486.
Fritz, K.R., Dean, L.L., Hendrix, K., Andres, R.S., Newman, C.S., Oakley, A.T., Clevenger, J.P., Dunne, J.C. 2022. Flavor quality and composition of accessions resources in the North Carolina State University peanut breeding program. Crop Science. 62:1880-1890. https://doi.org/10.1002/csc2.20774.
Harding, K.L., Vu, T.C., Wysocky, R., Joseph, M., Malheiros, R., Anderson, K.E., Toomer, O.T. 2023. The effect of feeding a sweetpotato and/or high-oleic peanut diet on layer performance and the quality and chemistry of eggs produced. International Journal of Poultry Science. 22(1):73-83. https://doi.org/10.3923/ijps.2023.73.83.
Harding, K.L., Malheiros, D.M., Vu, T.C., Wysocky, R., Malheiros, R.M., Anderson, K.E., Toomer, O.T. 2022. Effect of feeding whole-in-shell peanuts and high-oleic peanuts to laying hens on ileal nutrient digestibility. International Journal of Poultry Science. 21(4):166-173. https://doi.org/10.3923/ijps.2022.166.173.
Harding, K.L., Malheiros, D.M., Vu, T.C., Wysocky, R., Malheiros, R.M., Anderson, K.E., Toomer, O.T. 2022. Effect of feeding sweet potato and/or high-oleic peanuts to laying hens on ileal nutrient digestibility. International Journal of Poultry Science. 21(4):174-180. https://doi.org/10.3923/ijps.2022.174.180.
Weissburg, J.R., Johanningsmeier, S.D., Dean, L.L. 2023. Volatile compound profiles of raw and roasted peanut seeds of the runner and virginia market-types. Journal of Food Research. 12(3):47-68. https://doi.org/10.5539/jfr.v12n3p47.
Mohebpour, D.A., Dean, L.L., Harding, R.O., Hendrix, K. 2023. Effects of peanut skin extracts on the shelf life of unstabilized peanut butter. Peanut Science. 50(1):8-21. https://doi.org/10.3146/0095-3679-501-PS22-8.
