Prebiotic, Antipathogenic Bacteria and Hypocholesterolemia Properties of Fermented Rice Bran Extracts Derived from Black Rice and Germinated Brown Rice

Khaetthareeya Sutthanut; Patcharaporn Tippayawat; Sukanya Srijampa; Wisitsak Phoksawat; Pornchanan Vachirodom; Roongrawee Wandee

doi:10.3390/foods11223704

Prebiotic, Antipathogenic Bacteria and Hypocholesterolemia Properties of Fermented Rice Bran Extracts Derived from Black Rice and Germinated Brown Rice

Foods. 2022 Nov 18;11(22):3704. doi: 10.3390/foods11223704.

Authors

Khaetthareeya Sutthanut^{1

2}, Patcharaporn Tippayawat³, Sukanya Srijampa³, Wisitsak Phoksawat⁴, Pornchanan Vachirodom¹, Roongrawee Wandee¹

Affiliations

¹ Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
² Human High Performance & Health Promotion Research Institute: HHP&HP Research Institute, Khon Kaen University, Khon Kaen 40002, Thailand.
³ Department of Medical Technology, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
⁴ Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.

Abstract

Rice bran is a rich source of health-promoting nutrition and bioactive compounds; nevertheless, the properties of rice brans depend on cultivars, ages, and preparation methods, drawing the potential of raw materials for health benefits. Therefore, this research aimed to investigate the health-promoting properties of fermented rice bran extracts from cultivar black rice (H7F) and germinated brown rice (G13F), focusing on their prebiotic, antipathogenic bacteria activity and safety demonstrated in vitro and in vivo study models, respectively. Here, the screening of metabolites' change after rice bran fermentation by ATR-FTIR spectra revealed specific peaks corresponding to the composited components of protein, carbohydrate, and lipid. Then, in the in vitro study, the prebiotic capability of H7F and G13F extracts was demonstrated by a growth-promoting effect on Lactobacillus delbrueckii subsp. lactis under specific acidic conditions. Furthermore, antipathogenic bacterial activity against Escherichia coli and Staphylococcus aureus was presented at 25 mg/mL of MIC values and 50 mg/mL of MBC of both fermented rice bran extracts, eliminating the bacteria by interfering with the biofilm formation. For safety, an acute and chronic toxicity study using Wistar rats was conducted, in which changes in the body and organ weights, histopathology of organs, blood chemistry, and hematological parameters were observed after H7F and G13F treatment. Desirably, they showed no toxicity, with a significant reduction in blood cholesterol levels in the chronic treatment of H7F and G13F. Conclusively, the overall results evidenced the health benefits of H7F and G13F related to their prebiotic and antipathogenic bacteria properties and hypocholesterolemia potential with a high level of safety. Therefore, the fermented rice bran extracts were demonstrated as potential materials for the further development of functional ingredients and health products.

Keywords: antibacterial; black rice; ferment; germinated brown rice; prebiotic; rice bran; toxicity.

Abstract

Grants and funding