Location: Methods and Application of Food Composition Laboratory
2025 Annual Report
Objectives
Objective 1: Determine the impact of post-harvest processing (freezing, canning, and storage), industrial processing, and cooking (boiling, steaming, and microwaving) on carbohydrates (sugars, oligomers, starch, and fiber) in foods and bioaccessibility in the GI tract.
Sub-objective 1: Determine the effects of post-Approach:harvest handling, industrial processing, and cooking on carbohydrates and evaluate the impact of analysis methodologies.
Sub-objective 2: Evaluate the impact of industrial food processing and home cooking on the bioaccessibility of carbohydrates using the INFOGEST digestion model with modifications.
Sub-objective 3: Physical analysis of RS motifs and DF.
Objective 2: Determine the effects of dietary interventions in dairy cattle on the composition of milk.
Objective 3: Evaluate nutrient profiles of leafy vegetables grown under controlled environmental agriculture conditions (CEA).
Sub-objective 1: Modulation of growth conditions (light, water, nutrient delivery) to increase production and nutrient quality.
Sub-objective 2: Research staple foods grown under different saline environments to identify salt-tolerant cultivars with similar or better nutritional traits.
Approach
The concentration and variability of conventional and emerging nutrients impacted by genetics, environment and production, processing, and preparation in food and agriculture systems are integral to research in human nutrition. Targeted research on production, processing, and preparation and emerging analytical methodology will provide crucial information on compounds of public health importance, significantly expanding our understanding of food composition. Carbohydrates are critical in shaping microbiome and immune system health, but components can be altered by processing and preparation and dramatically change functionality. New analytical methods and biomimetic digestion systems are needed to cross-validate classic analytical methods and investigate the impact of the 3Ps on digestion and bioaccessibility assessed from a whole food/meal perspective. In addition to carbohydrates, the impact of production practices on milk lipids will be investigated with respect to forage, soil health, milk volume, and bovine microbiome. The effect of covering crops that promote soil and animal health and productivity and methane-reducing seaweed forage on milk lipid quality will be investigated. The impact of management and environmental factors (drought, soil salinity, radiation) on the nutritional quality and marketability of leafy greens from controlled environment agriculture (CEA) using variable nutrient delivery systems will be studied. Nutrient and phytochemical analyses will assist in the selection of cultivars with improved nutritional traits and higher crop yields. Research on soil salinity, nutrient composition, and plant growth will support the identification of salt-tolerant cultivars for crop farmers in drought-affected/water-stressed croplands. This will support agricultural and human nutrition research, dietary guidance and consumer awareness.
Progress Report
In support of Objective 1, research on the impact of post-harvest processing (freezing, canning, and storage), industrial processing, and cooking (boiling, steaming, and microwaving) on carbohydrates (sugars, oligomers, starch, and fiber) in foods and bioaccessibility in the gastrointestinal (GI) tract continued.
In support of Sub-objective 1, ARS researchers at Beltsville, Maryland, conducted in vitro digestion experiments using the INFOGEST model: 1) to test the digestibility of potato starch; and develop microscale sample clean-up (desalting and protein removal) and preparation procedure and 2) to evaluate the effects of cooking on carbohydrates in sorghum. The fiber content was determined in different wheat fractions (bran, germ, and endosperm) and compared with optimized methods in raw and processed foods. The impact of genetics and location on metabolite profiles of dry beans collected from different regions of the U.S. was investigated through collaboration with scientists from Fargo, North Dakota.
In support of Sub-objective 2, INFOGEST was implemented and validated internally using selected foods with different matrices. Various technical issues were resolved, operational modifications were made, and a standard operating procedure (SOP) was developed. External collaboration with an industrial partner for cross-validation of INFOGEST results was initiated. Modifications to include small intestinal microorganisms and their metabolites in the small intestinal phase are on-going in collaboration with ARS researchers in Wyndmoor, Pennsylvania. As a cost-saving initiative, the possibility of using human saliva in oral phase digestion was explored. Several experiments were conducted on different types of food/food products to evaluate: 1) the effects of cooking and industrial processing on carbohydrates, carotenoids and flavonoids in spinach; for comparative purposes, the effects of cooking and industrial processing on flavonoids were also measured in spinach; 2) the disintegration and dissolution of L-methylfolate in dietary supplements; 3) the fate of dietary nitrate/nitrite in gastrointestinal tract using selected dietary supplements as testing models. Carotenoids, flavonoids, and L-methylfolate were analyzed in-house, and carbohydrates and nitrate/nitrite were analyzed in collaborators’ labs. A quantification method using relative response factors was developed to more accurately quantify carotenoids in foods.
In support of Sub-objective 2, uncooked grains, pulses, and beans store energy as starch in microscopic semicrystalline granules that we cannot digest without cooking. This is type 2 resistant starch (RS2). When cooked, the crystals swell in a process called gelatinization, which makes starch digestible, but as it cools, it recrystallizes to form type 3 resistant starch (RS3). Texture preferences result in most grains not being completely gelatinized; consequently, a portion of RS2 remains. Foods that have been cooled and reheated should contain mixtures of both RS2 and RS3, though current official methods are not able to distinguish between these resistant starch species. X-ray diffraction (XRD) allows for the detection and semi-quantitative analysis of RS species due to distinct diffraction patterns. Further, while official methods require the use of the foods “as consumed,” there is no consensus preparation method. In collaboration with the Sorghum Checkoff Board located in Lubbock, Texas, ARS researchers at Beltsville, Maryland, have developed a reproducible method for cooking sorghum that produces standardized palatable food suitable for home preparation. This material was also analyzed by XRD to demonstrate semi-quantitatively the content of RS2 remaining. These samples were subjected to INFOGEST, and the remaining resistant dextrins and soluble dietary components were analyzed by size-exclusion chromatography with refractive index detection. These preliminary results are being used to develop a more extensive sample set comparing whole-grain preparation to pearled sorghum for total available carbohydrate content using official methods.
In support of Objective 2, ARS researchers at Beltsville, Maryland, developed an improved method for detection of short chain fatty acids, common metabolites of bacterial fermentation and components of dairy milk. The method used mass spectrometry (MS) for confirmation of analyte identities. Additionally, in collaboration with Virginia State University in Petersburg, Virginia, they used the SCINet computer cluster for the ‘big data’ analysis of Dairy Grand Challenge milk samples. Results for triacylglycerol standards were obtained by quantification of bovine milk samples using the new program. The quantification results were then provided to a USDA collaborator for statistical treatment. Different sources of variability and the relative amounts of each type of variability were identified. The variability due to individual cows, the cow’s breed, and the diet fed was statistically significant.
In support of Objective 3, Sub-objective 1, light intensity is a crucial factor impacting the cost-efficiency of controlled environment agriculture (CEA). Glucosinolates are important phytochemicals in Brassica vegetables for many health benefits, including anti-cancer, anti-inflammatory, and cardiovascular protection. ARS researchers at Beltsville, Maryland, combined non-targeted and targeted metabolomic methods with molecular networking analysis to determine the composition of broccoli microgreens cultivated under different photosynthetic photon flux densities (PPFD) with white light-emitting diodes (LEDs), and an additional far-red (FR) light supplement. The analysis identified 28 glucosinolates and 23 phenolic compounds, with a targeted quantification of 12 glucosinolates. The results showed that FR light supplementation significantly increased total glucosinolate content compared to white light-only treatments, while similar glucosinolate levels were found across the different white light intensities. These findings provide valuable insights for optimizing LED light intensity to enhance glucosinolate accumulation in broccoli microgreens, thus promoting more efficient energy use in CEA.
In support of Sub-objective 2 ARS researchers at Beltsville, Maryland, are currently investigating the effect of salinity on metabolic profiles of several pepper cultivars using targeted metabolomics that determines the variations in secondary metabolites such as flavonoids and capsaicinoids.
ARS researchers at Beltsville, Maryland, and Riverside, California, completed investigating the variations in phytochemical content of two tomato cultivars (‘Jaune Flamme’ and ‘Red Pear’) using targeted and untargeted metabolomic approaches with advanced mass spectrometric techniques. Results showed that there was no significant impact of salinity in both cultivars based on the limited phenolic compounds analyzed. The total free amino acid concentrations increased with salinity as compared to the control.
Accomplishments
1. Impact of light source and intensity on controlled environment agriculture (CEA). Light intensity is a crucial factor impacting the cost-efficiency of CEA. Glucosinolates are important phytochemicals in Brassica vegetables for many health benefits including, anti-cancer, anti-inflammatory, and cardiovascular protection. ARS researchers at Beltsville, Maryland, combined non-targeted and targeted metabolomic methods with molecular networking analysis to determine the composition of broccoli microgreens cultivated under different photosynthetic photon flux densities (PPFD) with white light-emitting diodes (LEDs), and an additional far-red (FR) light supplement. The analysis identified 28 glucosinolates and 23 phenolic compounds, with a targeted quantification of 12 glucosinolates. The results showed that FR light supplementation significantly increased total glucosinolate content compared to white light-only treatments, while similar glucosinolate levels were found across the different white light intensities. These findings provide valuable insights for optimizing LED light intensity to enhance glucosinolate accumulation in broccoli microgreens, thus promoting more efficient energy use in CEA. Many warm weather fruits and vegetables currently imported from hot-weather countries can be cultivated in CEA environments across the United States. Research in this area promotes the nutritional independence of the American food system and is vital to American farmers.
Review Publications
Bukowski, M.R., Goslee, S.C., Barthet, V.J. 2025. Longitudinal cohort study of canola composition demonstrates changes in the climate and the food system are decreasing the essential fatty acid content of canola. The American Journal of Clinical Nutrition. 121(2):304-314. https://doi.org/10.1016/j.ajcnut.2024.11.021.
Pinaffi-Langley, A.C., Nguyen, H.M., Whitehead, D., Roseland, J., Heydorn, K.C., Wu, X., Pehrsson, P.R., Hays, F.A., Hord, N.G. 2024. Nitrate and nitrite quantification in U.S. vegetable-based baby foods and infant formula via ozone chemiluminescence. Journal of Food Composition and Analysis. 137. Article 106902. https://doi.org/10.1016/j.jfca.2024.106902.
Singh, J., Tareq, F.S., Luthria, D.L. 2024. Comparative investigation of untargeted and targeted metabolomics in turmeric dietary supplements and rhizomes. Foods. 14(1). Article 7. https://doi.org/10.3390/foods14010007.
Li, Y., Shahkoomahally, S., Yang, T., Chen, P., Zhang, M., Sun, J. 2025. Metabolomics and molecular networking approach for exploring the effect of light intensity and quality on the chemical profile and accumulation of glucosinolates in broccoli microgreen. Journal of Agriculture and Food Chemistry. 73(10):6281-6291. https://doi.org/10.1021/acs.jafc.4c12826.
Singh, J., Metrani, R., Kumar Jha, D., Crosby, K.M., Jifon, J.L., Ravishankar, S., Brierley, P., Leskovar, D.I., Turini, T.A., Guan, W., Luthria, D.L., Patil, B.S. 2025. Metabolomic profiling of novel muskmelon cultigens reveals regional variations in fruit composition across four distinct U.S. growing locations. Foods. 142. Article 107470. https://doi.org/10.1016/j.jfca.2025.107470.
Islam, N., Krishnan, H.B., Slovin, J.P., Li, Z., Tareq, F., Luthria, D.L., Natarajan, S.S. 2025. High-resolution mass spectrometry approach for proteomic and metabolomic analyses of fast neutron-mediated high-protein soybean seeds. Journal of Agricultural and Food Chemistry. 73(11):6993-7002. https://doi.org/10.1021/acs.jafc.5c00375.
Lee, E.Y., Li, Y., Wu, X., Qin, J., Zhang, Y., Gao, B., Slavin, M., He, X., Yu, L. 2025. Chemical composition of coriander (coriandrum sativum. l) extract and its ability in reducing the risk of sars-cov-2 infection and scavenging radicals. ACS Food Science and Technology. 5(6):2215-2224. https://doi.org/10.1021/acsfoodscitech.5c00088.
Blumberg, K., Mckillop, K.A., Pehrsson, P.R., Fukagawa, N.K. 2025. Call to action: A need for community-driven minimum information standards for food composition data. The American Journal of Clinical Nutrition. 122(3):703-711. https://doi.org/10.1016/j.ajcnut.2025.06.027.