Location: Food Science and Market Quality and Handling Research Unit
2019 Annual Report
Accomplishments
1. Profiles of secondary metabolites in raw and roasted peanuts. A non-targeted metabolomics study was used by ARS scientists in Raleigh, North Carolina, to evaluate raw and roasted peanuts of the runner and virginia market types. Pathways analysis was performed to determine the source of the compounds identified from the composition of the starting materials. Various statistical models were used to evaluate the data. Using the information, targeted analyses were performed to determine the actual content of certain metabolites. From this study, valuable information was obtained about the composition of peanuts and compounds that serve as precursors to roasted peanut flavor and nutrients. This study will be important to peanut breeders needing to identify genetic markers for certain traits and components to increase the sustainability and value of the USA peanut crop.
2. The flavor and nutritional composition of peanuts is dependent on the maturity of the peanut kernel and can vary with market type. The peanut is an indeterminate flowering plant. As such, peanut pods on the plant are not all at the same level of maturity at harvest. The degree of maturity affects the peanut composition in that lipid levels, fatty acid profiles, protein and carbohydrate levels all change as the peanut matures. These factors impact the flavor and texture of roasted peanuts. ARS scientists in Raleigh, North Carolina, evaluated the composition of peanuts from each of the four market types, runner, virginia, spanish and valencia, and determined the impact that maturity has one each. This information will provide growers with parameters to follow to insure optimum quality. Processors will be able to use the information to select growing areas and market types to suit their end use.
3. Waste peanut skins produce a functional food ingredient. Utilization of waste peanut skins from peanut blanching plants was made by extracting the skins with an aqueous solvent mixture and spray drying the extracts with maltodextrin to produce a free-flowing powder with reduced bitter flavor. ARS in Raleigh, North Carolina, produced a powder that was incorporated into flavored coating mixes. The coating mixes were used to make flavor peanuts that had similar or higher antioxidant values than fruits such as strawberries and blueberries due to the phenolic compounds present in the new functional ingredient. The antioxidant and consumer perception studies were published in a peer reviewed journal. USA Producers of peanut products such as roasted peanut and peanut butter produce hundreds of thousands of pounds of this material annually that currently disposed of as waste material or low-grade animal feed. This research shows practical application of food processing waste material to produce a value-added food ingredient which can provide human health benefits.
4. Chemical composition of entries in the 2018 Uniform Peanut Performance Tests. Peanut cultivars from the 2018 Uniform Peanut Performance Tests were evaluated for chemical and sensory characteristics. Samples from five USA peanut breeders were submitted to ARS scientists in Raleigh, North Carolina, after processing by ARS scientists in Dawson, Georgia. The breeders are cooperators from universities, private corporations and other ARS units. Samples were analyzed for moisture, total lipid, fatty acid profiles, sugars, and tocopherols using established methods. The flavor characteristics of the samples after dry roasting were evaluated by the descriptive sensory panel maintained by the Unit. The results were reported to participants in the program and are available to other interested parties on demand so that the information can be used by the cooperators and others in the peanut industry for the suitability of new cultivars for growing areas and food processing.
Review Publications
Klevorn, C.M., Dean, L.L., Johanningsmeier, S.D. 2019. Metabolite profiles of raw peanut seeds reveal differences between market-types. Journal of Food Science. 84(3):397-405. https://doi.org/10.1111/1750-3841.14450.
Toomer, O.T., Hulse-Kemp, A.M., Dean, L.L., Boykin, D.L., Ramon, M., Anderson, K.E. 2019. Feeding high-oleic peanuts to layer hens enhances egg yolk color and oleic fatty acid content in shell eggs. Poultry Science. 98:1732-1748. https://doi.org/10.3382/ps/pey531.
Toomer, O.T., Vu, T.C., Pereira, M., Williams, K. 2019. Dietary supplementation with peanut skin polyphenolic extracts (PSPE) reduces hepatic lipid and glycogen stores in mice fed an atherogenic diet. Journal of Functional Foods. 55:362–370. https://doi.org/10.1016/j.jff.2019.02.041.
Toomer, O.T. 2018. A comprehensive review of the value-added uses of peanut(Arachis hypogaea) skins and by-products. Critical Reviews in Food Science and Nutrition. 30:1-10. https://doi.org/10.1080/10408398.2018.1538101.
Christman, L.M., Dean, L.L., Bueno-Almeida, C., Weissburg, J.R. 2018. Acceptability of peanut skins as a natural antioxidant in flavor coated peanuts. Journal of Food Science. 83(10):2571-2577. https://doi.org/10.1111/1750-3841.14323.
Christman, L.M., Dean, L.L., Allen, J.C., Feng Godinez, S., Toomer, O.T. 2019. Peanut skin phenolic extract attenuates hyperglycemic responses in vivo and in vitro. PLoS One. 14(3):e0211459. https://doi.org/10.1371/journal.pone.0214591.
Lima, H.K., Vogel, K., Wagner-Gillespie, M., Hubble, C., Dean, L.L., Fogelman, A.D. 2018. Nutritional comparison of raw, holder pasteurized and shelf-stable human milk products. Journal of Pediatric Gastroenterology and Nutrition. 66(5):649-653. https://doi.org/10.1097/MPG.0000000000002094.
Perrin, M.P., Pawlak, R., Dean, L.L., Christis, A., Friend, L. 2018. A cross-sectional study of fatty acids and brain derived neurotrophic factor (BDNF) in human milk from lactating women following vegan, vegetarian, and omnivore diets. American Journal of Clinical Nutrition. pp. 1-10. https://doi.org/10.1007/s00394-018-1793-z.
Toomer, O.T., Livingston, M.L., Wall, B., Sanders, E., Vu, T.C., Malheiros, R., Livingston, K.A., Carvalho, L.M., Ferket, P.R. 2019. Meat quality and sensory attributes of meat produced from broiler chickens fed a high oleic peanut diet. Poultry Science. 98(10):5188-5197. https://doi.org/10.3382/ps/pez258.
