| dc.description.abstract | In this study, brown red rice was investigated for the change of total phenolic contents, total flavonoid contents, total anthocyanin contents, antioxidant capacity and ferulic acid profile after heat-moisture treatment. Brown red rice was soaked in water to obtain desired moisture contents (20%, 25%, 30%) and heat treated at two different temperatures (100oC and 120oC). Untreated brown red rice had highest total phenolic content (439.89±6.65 mg FAE/100g flour), total flavonoid content (43.84±3.81 mg RE/100g flour) and antioxidant capacity (89.49% DPPH scavenging). Total phenolic contents and total flavonoid contents of treated samples resulted in lower values compared untreated samples (P<0.05). Anthocyanins were unable to be detected from all samples (both treated and untreated samples). Significant loss (P<0.05) of DPPH scavenging capacity was recorded after treatment. Loss of phenolic compounds and antioxidant capacity was identified to be proportional to the moisture content. Higher temperature (120oC) was recognized to retained more phenolics and antioxidant capacity compared to 100oC. The ferulic acid profiles of untreated and treated brown red rice were determined by high-performance liquid chromatography (HPLC). The raw material contained 0.46±0.05 μg of ferulic acid/g, while the ferulic acid contents of treated samples ranged from 1.06±0.02 to 3.53±0.07 μg/g. These results suggest appropriate conditions for heat-moisture treatment on brown red rice to obtain the highest total phenolic contents, total flavonoid contents and antioxidant capacity.
Keywords: brown red rice, heat-moisture treatment, phenolic compounds, antioxidant properties. | en_US |
