{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T12:20:31Z","timestamp":1783426831947,"version":"3.54.6"},"reference-count":34,"publisher":"IMR Press","issue":"2","license":[{"start":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T00:00:00Z","timestamp":1781481600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"North Dakota Corn Counsil","award":["FAR0038727"],"award-info":[{"award-number":["FAR0038727"]}]},{"name":"Higher Education Commission of Pakistan"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Front. Biosci. (Elite Ed)"],"abstract":"<jats:p>Background: The increasing demand for sustainable and high-quality protein sources has driven research into the efficient extraction and characterization of proteins from various plants and industrial by-products. Dried distillers grains with solubles (DDGS) is a rich source of protein with potential applications in food and animal feed; however, the structural and nutritional properties of DDGS require further elucidation compared with those of soy protein isolate (SPI). Methods: Thus, this study aimed to optimize protein extraction from DDGS using response surface methodology, yielding a protein yield of approximately 23%. The extracted proteins were characterized by proximate analysis, sodium dodecyl sulfate\u2013polyacrylamide gel electrophoresis (SDS-PAGE) to assess structural integrity, thermogravimetric analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, and amino acid profiling. Comparative analyses with SPI were conducted to evaluate their structural, thermal, and nutritional differences. Results: The optimized extraction conditions included a 2-hour extraction time, a solid-to-liquid ratio of 1:10, 1 M sodium hydroxide (NaOH), and 60% ethanol. The crude protein content increased significantly from 24.94% in raw DDGS to 65.21% in the isolate. SDS-PAGE revealed intact globular protein bands in SPI, whereas DDGS proteins showed fragmentation, likely due to denaturation and interactions with fiber. Thermal analysis indicated that DDGS proteins possessed higher heat resistance and thermal stability than SPI. Amino acid analysis demonstrated the superior essential amino acid profile of SPI, which was rich in leucine, lysine, phenylalanine, and etc. In contrast, DDGS proteins contained valuable amino acids, including glutamic acid, aspartic acid, and branched-chain amino acids, making the DDGS proteins suitable for ruminant diets. These structural and compositional differences reflect the respective suitability of these sources for food versus feed applications. Conclusions: This study highlights the effectiveness of optimized extraction techniques for isolating high-protein concentrates from DDGS and emphasizes the distinct characteristics of DDGS proteins compared with SPI. While SPI remains ideal for nutritional formulations requiring high purity and amino acid completeness, DDGS proteins offer a sustainable alternative for livestock nutrition, especially in ruminant diets. These findings support the broader utilization of DDGS as an economical and environmentally sustainable protein source.<\/jats:p>","DOI":"10.31083\/fbe47018","type":"journal-article","created":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T12:01:18Z","timestamp":1783425678000},"source":"Crossref","is-referenced-by-count":0,"title":["Optimization and Characterization of Dried Distiller Grains With Solubles as a Sustainable Protein Isolate"],"prefix":"10.31083","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-1400-1899","authenticated-orcid":true,"given":"Muhammad","family":"Haris","sequence":"first","affiliation":[{"name":"Department of Agricultural and Biosystems Engineering, North Dakota State University, Fargo, ND 58102, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2170-6128","authenticated-orcid":true,"given":"Ademola","family":"Hammed","sequence":"additional","affiliation":[{"name":"Department of Agricultural and Biosystems Engineering, North Dakota State University, Fargo, ND 58102, USA"},{"name":"Department of Environmental and Conservation Sciences, North Dakota State University, Fargo, ND 58102, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"16242","published-online":{"date-parts":[[2026,6,15]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","unstructured":"Abd El-Hac ME, Alagawany M, Fara MR, Dhama K. Use of maize distiller\u2019s dried grains with solubles (DDGS) in laying hen diets: trends and advances. Asian Journal of Animal and Veterinary Advances. 2015; 10: 690\u2013707.","DOI":"10.3923\/ajava.2015.690.707"},{"key":"ref2","doi-asserted-by":"publisher","unstructured":"Iram A, Cekmecelioglu D, Demirci A. Distillers\u2019 dried grains with solubles (DDGS) and its potential as fermentation feedstock. Applied Microbiology and Biotechnology. 2020; 104: 6115\u20136128.","DOI":"10.1007\/s00253-020-10682-0"},{"key":"ref3","doi-asserted-by":"publisher","unstructured":"Rausch KD, Belyea RL, Ellersieck MR, Singh V, Johnston DB, Tumbleson ME. Particle size distributions of ground corn and DDGS from dry grind processing. Transactions of the ASAE. 2005; 48: 273\u2013277.","DOI":"10.13031\/2013.17928"},{"key":"ref4","doi-asserted-by":"publisher","unstructured":"Buenavista RME, Siliveru K, Zheng Y. Utilization of distiller\u2019s dried grains with solubles: a review. Journal of Agriculture and Food Research. 2021; 5: 100195\u2013100195.","DOI":"10.1016\/j.jafr.2021.100195"},{"key":"ref5","doi-asserted-by":"publisher","unstructured":"Kim Y, Mosier NS, Hendrickson R, Ezeji T, Blaschek H, Dien B, et al. Composition of corn dry-grind ethanol by-products: DDGS, wet cake, and thin stillage. Bioresource Technology. 2008; 99: 5165\u20135176.","DOI":"10.1016\/j.biortech.2007.09.028"},{"key":"ref6","unstructured":"Cookman DJ. Protein extraction from distiller\u2019s grain [Master\u2019s thesis]. Iowa State University: Ames, Iowa. 2008."},{"key":"ref7","unstructured":"Dong Y, Li Q, Gao N, Chen X, Cheng Y, Lu J, et al. Optimization of protein extraction from DDGS using response surface methodology and the properties of the protein. In 2012 Fifth International Conference on Intelligent Computation Technology and Automation (pp. 242\u2013245). Zhangjiajie, Hunan, China. IEEE. 2012."},{"key":"ref8","doi-asserted-by":"publisher","unstructured":"Bezerra MA, Santelli RE, Oliveira EP, Villar LS, Escaleira LA. Response surface methodology (RSM) as a tool for optimization in analytical chemistry. Talanta. 2008; 76: 965\u2013977.","DOI":"10.1016\/j.talanta.2008.05.019"},{"key":"ref9","doi-asserted-by":"publisher","unstructured":"Bello I, Adeniyi A, Mukaila T, Hammed A. Optimization of soybean protein extraction with ammonium hydroxide (NH4OH) using response surface methodology. Foods. 2023; 12: 1515\u20131515.","DOI":"10.3390\/foods12071515"},{"key":"ref10","doi-asserted-by":"crossref","unstructured":"Kruger NJ. The Bradford method for protein quantitation. In Walker JM (ed.) The protein protocols handbook (pp. 17\u201324). Humana Press: Totowa. 2009.","DOI":"10.1007\/978-1-59745-198-7_4"},{"key":"ref11","unstructured":"Latimer GW. Official methods of analysis of AOAC International. 19th edn. AOAC International: Gaithersburg. 2012."},{"key":"ref12","doi-asserted-by":"crossref","unstructured":"Ismail BP. Ash content determination. In Nielsen SS, Ismail BP (eds.) Nielsen\u2019s food analysis laboratory manual (pp. 129\u2013131). Springer International Publishing: Cham. 2024.","DOI":"10.1007\/978-3-031-44970-3_15"},{"key":"ref13","doi-asserted-by":"publisher","unstructured":"He Z, Zhang H, Olk DC, Shankle M, Way TR, Tewolde H. Protein and fiber profiles of cottonseed from upland cotton with different fertilizations. Modern Applied Science. 2014; 8: 97\u2013103.","DOI":"10.5539\/mas.v8n4p97"},{"key":"ref14","doi-asserted-by":"publisher","unstructured":"Das D, Panesar PS, Saini CS. pH shifting treatment of ultrasonically extracted soybean meal protein isolate: effect on functional, structural, morphological and thermal properties. Process Biochemistry. 2022; 120: 227\u2013238.","DOI":"10.1016\/j.procbio.2022.06.015"},{"key":"ref15","unstructured":"Official methods of analysis of AOAC International. 21st edn. AOAC International: Gaithersburg, MD, USA. 2019."},{"key":"ref16","doi-asserted-by":"publisher","unstructured":"Smith EP, Rose KA. Model goodness-of-fit analysis using regression and related techniques. Ecological Modelling. 1995; 77: 49\u201364.","DOI":"10.1016\/0304-3800(93)E0074-D"},{"key":"ref17","doi-asserted-by":"publisher","unstructured":"Ekpenyong M, Antai S, Asitok A, Ekpo B. Response surface modeling and optimization of major medium variables for glycolipopeptide production. Biocatalysis and Agricultural Biotechnology. 2017; 10: 113\u2013121.","DOI":"10.1016\/j.bcab.2017.02.015"},{"key":"ref18","doi-asserted-by":"publisher","unstructured":"Ovando E, Rodr\u00edguez-Sifuentes L, Mart\u00ednez LM, Chuck-Hern\u00e1ndez C. Optimization of soybean protein extraction using by-products from NaCl electrolysis as an application of the industrial symbiosis concept. Applied Sciences. 2022; 12: 3113\u20133113.","DOI":"10.3390\/app12063113"},{"key":"ref19","doi-asserted-by":"publisher","unstructured":"Coelho TLS, Braga FMS, Silva NMC, Dantas C, Lopes J\u00fanior CA, de Sousa SAA, et al. Optimization of the protein extraction method of goat meat using factorial design and response surface methodology. Food Chemistry. 2019; 281: 63\u201370.","DOI":"10.1016\/j.foodchem.2018.12.055"},{"key":"ref20","doi-asserted-by":"publisher","unstructured":"Phongthai S, Lim ST, Rawdkuen S. Ultrasonic-assisted extraction of rice bran protein using response surface methodology. Journal of Food Biochemistry. 2017; 41: e12314\u2013e12314.","DOI":"10.1111\/jfbc.12314"},{"key":"ref21","doi-asserted-by":"publisher","unstructured":"Rosentrater KA, Zhang Y, Wrenn B. Impacts of ethanol production and drying conditions on the chemical, physical, and flowability properties of distillers dried grains with solubles. Frontiers in Bioengineering and Biotechnology. 2021; 9: 716634\u2013716634.","DOI":"10.3389\/fbioe.2021.716634"},{"key":"ref22","doi-asserted-by":"publisher","unstructured":"Sui X, Zhang T, Jiang L. Soy protein: molecular structure revisited and recent advances in processing technologies. Annual Review of Food Science and Technology. 2021; 12: 119\u2013147.","DOI":"10.1146\/annurev-food-062220-104405"},{"key":"ref23","doi-asserted-by":"publisher","unstructured":"Pahm AA, Pedersen C, Stein HH. Standardized ileal digestibility of reactive lysine in distillers dried grains with solubles fed to growing pigs. Journal of Agricultural and Food Chemistry. 2009; 57: 535\u2013539.","DOI":"10.1021\/jf802047d"},{"key":"ref24","doi-asserted-by":"publisher","unstructured":"Ayadi FY, Rosentrater KA, Muthukumarappan K, Brown ML. Twin-screw extrusion processing of distillers dried grains with solubles (DDGS)-based yellow perch (Perca flavescens) feeds. Food and Bioprocess Technology. 2012; 5: 1963\u20131978.","DOI":"10.1007\/s11947-011-0535-5"},{"key":"ref25","doi-asserted-by":"publisher","unstructured":"Ellepola SW, Choi SM, Ma CY. Conformational study of globulin from rice (Oryza sativa) seeds by Fourier-transform infrared spectroscopy. International Journal of Biological Macromolecules. 2005; 37: 12\u201320.","DOI":"10.1016\/j.ijbiomac.2005.07.008"},{"key":"ref26","doi-asserted-by":"publisher","unstructured":"Gorinstein S, Zemser M, Friedman M, Rodrigues WA, Martins PS, Vello NA, et al. Physicochemical characterization of the structural stability of some plant globulins. Food Chemistry. 1996; 56: 131\u2013138.","DOI":"10.1016\/0308-8146(95)00144-1"},{"key":"ref27","doi-asserted-by":"publisher","unstructured":"Yaqoob S, Cai D, Liu M, Zheng M, Zhao CB, Liu JS. Characterization of microstructure, physicochemical and functional properties of corn varieties using different analytical techniques. International Journal of Food Properties. 2019; 22: 572\u2013582.","DOI":"10.1080\/10942912.2019.1596124"},{"key":"ref28","unstructured":"Escolano-Casado G, Fern\u00e1ndez-Penas R, Fernandez-Sanchez JF, Gomez-Morales J, Mino L. Spectroscopic insights into the structural, surface and luminescence properties of Ca\/Tb substituted phosphates. Available at SSRN. https:\/\/ssrn.com\/abstract=5690793. (In preprint)"},{"key":"ref29","doi-asserted-by":"publisher","unstructured":"Alesaeidi S, Kahrizi MS, Ghorbani Tajani A, Hajipour H, Ghorbani M. Soy Protein Isolate\/Sodium Alginate Hybrid Hydrogel Embedded with Hydroxyapatite for Tissue Engineering. Journal of Polymers and the Environment. 2023; 31: 396-405.","DOI":"10.1007\/s10924-022-02635-7"},{"key":"ref30","doi-asserted-by":"publisher","unstructured":"Mingqiao C, Qinghua Y, Zhidan L. Development and Characterization of Soy Protein Isolate\/Xylose Film. International Journal of Polymer Science. 2024; 1673547.","DOI":"10.1155\/2024\/1673547"},{"key":"ref31","doi-asserted-by":"publisher","unstructured":"Tang CH, Chen Z, Li L, Yang XQ. Effects of transglutaminase treatment on the thermal properties of soy protein isolates. Food Research International. 2006; 39: 704\u2013711.","DOI":"10.1016\/j.foodres.2006.01.012"},{"key":"ref32","doi-asserted-by":"publisher","unstructured":"Chen N, Zhao M, Chassenieux C, Nicolai T. Data on the characterization of native soy globulin by SDS-PAGE, light scattering and titration. Data in Brief. 2016; 9: 749\u2013752.","DOI":"10.1016\/j.dib.2016.10.016"},{"key":"ref33","doi-asserted-by":"publisher","unstructured":"Xu W, Reddy N, Yang Y. An acidic method of zein extraction from DDGS. Journal of Agricultural and Food Chemistry. 2007; 55: 6279\u20136284.","DOI":"10.1021\/jf0633239"},{"key":"ref34","doi-asserted-by":"publisher","unstructured":"Jakobsen GV, Jensen BB, Knudsen KEB, Canibe N. Improving the nutritional value of rapeseed cake and wheat dried distillers grains with solubles by addition of enzymes during liquid fermentation. Animal Feed Science and Technology. 2015; 208: 198\u2013213.","DOI":"10.1016\/j.anifeedsci.2015.07.015"}],"container-title":["Frontiers in Bioscience-Elite"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.imrpress.com\/journal\/FBE\/18\/2\/10.31083\/FBE47018","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T12:01:58Z","timestamp":1783425718000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.imrpress.com\/journal\/FBE\/18\/2\/10.31083\/FBE47018"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,15]]},"references-count":34,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2026]]}},"alternative-id":["S1945-0494(26)02992-0"],"URL":"https:\/\/doi.org\/10.31083\/fbe47018","relation":{},"ISSN":["1945-0494","1945-0508"],"issn-type":[{"value":"1945-0494","type":"print"},{"value":"1945-0508","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,15]]},"article-number":"47018"}}