Effect of Solid-State Fermentation by Lactobacillus plantarum on the Cooking Quality, Microstructure, and Physicochemical Properties of Brown Rice

Brown rice (BR) is nutritious but difficult to cook, which limits its consumption. In this study, a novel processing technology, solid-state fermentation (SSF), is developed to improve the cooking quality of BR. After SSF treatment with Lactobacillus plantarum JYI-3913, BR hardness (821.20g) decreased by 36.91%, and its cooking time (19.69min) is reduced by 29.07% compared to untreated BR (1301.72g and 27.76min, respectively). In addition, some small gullies and holes appear on the BR grain cortex, and the connections between the starch particles become looser. Cellulose and hemicellulose in BR exhibit a certain degree of degradation. Furthermore, the molecular structures of BR starch granules are damaged; the long chains of amylopectin are partially broken; the crystal structure of starch is partially destroyed; gelatinization enthalpy is decreased; and the setback value of starch is decreased. All of these characteristics make the BR easier to cook, and the cooked BR presents an improved taste and slower retrogradation. The results show that applied SSF treatment improves the cooking quality of BR.