Effect of subcritical water flash release processing on buckwheat flour properties

Authors: Plumier, Benjamin; Kenar, James - Jim; Felker, Frederick; Moser, Jill; Singh, Mukti; Byars, Jeffrey; Liu, Sean

Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2022
Publication Date: 12/21/2022
Citation: Plumier, B.M., Kenar, J.A., Felker, F.C., Moser, J.K., Singh, M., Byars, J.A., Liu, S.X. 2023. Effect of subcritical water flash release processing on buckwheat flour properties. Journal of the Science of Food and Agriculture. 103(4):2088-2097. https://doi.org/10.1002/jsfa.12399.
DOI: https://doi.org/10.1002/jsfa.12399

Interpretive Summary: Common buckwheat, a valuable gluten free grain, is a rich source of useful components such as antioxidants, phenolics, and dietary fiber that can provide health benefits to consumers. However, many of these components are trapped within its cellular structure and not readily digestible. Modifying buckwheat flour to improve the availability of components is a logical approach to improve nutritional benefits and consumer acceptance. Aqueous dispersions of buckwheat flour treated at various combinations of high temperature, pressure, and reaction times were found to increase soluble dietary fiber content, up to 40 %, shift soluble and insoluble dietary fiber ratios, and decrease the viscosity of buckwheat flour dispersions. The treatments differently affected the microstructure of particles, flour color, total phenolic content, and antioxidant activity depending on the reaction conditions. These findings demonstrate the changes in the functional properties of buckwheat flour with each treatment and allow food manufacturers to identify treatments that enhance buckwheat attributes for desired food applications.

Technical Abstract: Common buckwheat (Fagopyrum esculentum) is a rich source of bioactive components known to have beneficial health effects. However, many of these components are trapped within its cellular structure and not readily bioavailable. In this study, subcritical water flash (SCWF) release processing treatments in a batch reactor at 120, 140, and 160 °C and hold times of 0, 15, and 20 min were examined to improve the total phenolic content (TPC) and antioxidant activity of buckwheat flour. Changes in physicochemical, functional, and structural properties such as soluble and insoluble dietary fiber, color, water holding capacity, and viscosity due to the SCWF treatments were also determined. Reaction at 160 °C and 0 min hold time increased TPC by 42 % and antioxidant activity 120 %. Treatment of flour at 120 °C and 30 min hold time increased soluble fiber content 40 % relative to the control while water holding capacity of the 120 °C and 0 min hold time was improved (26.5 %) to 8.11 ± 0.21 g H2O/g sample. These results demonstrate SCWF can positively alter buckwheat flour attributes and serve as the basis to develop ready-to-eat foods and spreads with improved health benefits.