Bioactive compounds and antioxidant activity of rice bran fermented with lactic acid bacteria

ABSTRACT

Aims: Rice bran has been documented as a rich source of bioactive compounds such as gamma-oryzanol, phenolic acids, phytic acid, β-sitosterol and vitamin E, which offer beneficial health properties and confer antioxidant activity related benefits. The objective of this research is to evaluate the bioactive compounds content of fermented rice bran such as organic acids, ɣ-oryzanol, α- tocopherol and phenolic acids using three lactic acid bacteria (LAB), namely Pediococcus acidilactici, Lactococcus lactis and Pediococcus pentoseous in a solid state fermentation. Methodology and results: High performance liquid chromatography (HPLC) was used to analyze the concentration of the active compounds in rice bran. The most abundant organic acids detected in fermented rice bran samples were lactic acid and acetic acid, which showed significant improvement after fermentation. Fermentation of rice bran with P. acidilactici showed a two-fold increment in ɣ-oryzanol and α-tocopherol compared to unfermented rice bran. A higher concentration of ferulic acid was observed in rice bran fermented with P. acidilactici compared to other strains. Meanwhile, coumaric acid concentration in all fermented samples decreased significantly upon fermentation. Conclusion, significance and impact of study These results indicated that the fermentation with LAB could enhance certain bioactive compounds production and antioxidant activity of rice bran. Therefore, improved rice bran has the potential to be used as an ingredient in functional food and cosmetic formulation. Keywords Rice bran; bioactive compounds; fermentation, lactic acid bacteria; antioxidant activity