Mild Hydrothermal Stabilization: An Innovative Technology for Improving Whole‐Grain Rice Quality in West Africa and Elsewhere

ABSTRACT Background and Objectives Whole‐grain (brown) rice has superior nutritional quality but is prone to rancidity, primarily caused by endogenous lipases and oxidases. This study evaluated mild hydrothermal stabilization (MHS), comprising grain surface wetting, followed by short‐duration atmospheric‐pressure steaming, applied to two West African rice varieties. Rice was processed as mild hydrothermal stabilized paddy whole‐grain rice (MHS‐PWGR) and brown whole‐grain rice (MHS‐BWGR). Findings With both MHS‐PWGR and MHS‐BWGR, lipase activity was not detected after 10 min steaming. Peroxidase activity was not detected after 5 min steaming. MHS improved grain lightness compared with conventional parboiling, giving a golden‐yellow color. MHS‐BWGR maintained acceptable brown head rice yield and essential mineral content (Fe, Zn, and Ca), (quantified by XRF). Cooking time and cooked‐grain hardness were reduced, particularly in MHS‐BWGR. Conclusions Multi‐criteria decision analysis of the data identified 15 min steaming of MHS‐BWGR as the optimal treatment, combining undetectable enzymatic activity, good color, texture, and mineral quality. Significance and Novelty MHS has considerable potential as a simple and effective process for improving the shelf life and quality of whole‐grain rice. It can be readily deployed with slight modifications to existing parboiling systems already in West African small‐ and medium‐scale rice mills and elsewhere.