Subcritical water treatment to modify insoluble dietary fibers from brewer's spent grain for improved functionality and gut fermentability

Xueqian Su; Qing Jin; Yixiang Xu; Hengjian Wang; Haibo Huang

doi:10.1016/j.foodchem.2023.137654

Subcritical water treatment to modify insoluble dietary fibers from brewer's spent grain for improved functionality and gut fermentability

Food Chem. 2024 Mar 1:435:137654. doi: 10.1016/j.foodchem.2023.137654. Epub 2023 Oct 4.

Authors

Xueqian Su¹, Qing Jin², Yixiang Xu³, Hengjian Wang⁴, Haibo Huang⁵

Affiliations

¹ Department of Food Science and Technology, Virginia Polytechnic Institute and State University, 1230 Washington Street SW, Blacksburg VA 24061, USA. Electronic address: xueqians@vt.edu.
² School of Food and Agriculture, The University of Maine, 5763 Rogers Hall, Orono, ME 04469, USA. Electronic address: qing.jin@maine.edu.
³ Healthy Processed Foods Research Unit, United States Department of Agriculture, Agricultural Research Station, 800 Buchanan Street, Albany, CA 94710, USA. Electronic address: Yixiang.xu@usda.gov.
⁴ Department of Food Science and Technology, Virginia Polytechnic Institute and State University, 1230 Washington Street SW, Blacksburg VA 24061, USA. Electronic address: hewang@vt.edu.
⁵ Department of Food Science and Technology, Virginia Polytechnic Institute and State University, 1230 Washington Street SW, Blacksburg VA 24061, USA. Electronic address: huang151@vt.edu.

PMID: 37820401
DOI: 10.1016/j.foodchem.2023.137654

Abstract

Lactic acid (LA)-assisted subcritical water treatment (SWT) was applied to modify the insoluble dietary fiber (IDF) from brewer's spent grain (BSG) for enhancing its functionality and gut fermentability. Modified IDFs were thoroughly characterized for their chemical and structural properties. The results revealed that increasing the treatment temperature and LA concentration reduced hemicellulose content in IDFs from 38.4 % to 0.7 %, alongside a decreased yield (84.8 %-51.4 %), reduced particle size (519.8-288.6 μm), and more porous structure of IDFs. These modifications were linked to improved functionalities, evidenced by the highest water and oil holding capacity increasing by 36 % and 67 %, respectively. Remarkably, the highest glucose adsorption capacity increased by 6.5 folds. Notably, modified IDFs exhibited slower in-vitro fermentation, elevated short-chain fatty acids (SCFAs) production, and a higher proportion of butyrate in SCFAs. These findings highlight the potential of LA-assisted SWT in transforming BSG-derived IDF into a valuable functional food ingredient.

Keywords: Acetic acid (PubChem CID: 176); Brewer’s spent grain; Butyric acid (PubChem CID: 264); Functional properties; Hexane (PubChem CID: 8058); In-vitro fermentation; Insoluble dietary fiber; Inulin (PubChem CID: 24763); Lactic acid (PubChem CID: 612); Propionic acid (PubChem CID: 1032); Short-chain fatty acids; Subcritical water treatment.

MeSH terms

Adsorption
Dietary Fiber / analysis
Edible Grain / chemistry
Fatty Acids, Volatile* / analysis
Particle Size
Water Purification*

Substances

Fatty Acids, Volatile
Dietary Fiber