Evaluation of Dietary Fiber and Phenolic Compounds in Rice (Oryza sativa Linn.) and the Extracts from Rice Bran, Benjakul and Wild Betel Leaf Bush (Piper sarmentosum Roxb.)
Jansom C, MSc1, Pavasutti V, BSc2, Parklak W, PhD2, Lerdvuthisopon N, PhD3
Affiliation : 1 Research Office, Faculty of Medicine, Thammasat University, Pathumthani, Thailand 2 Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand 3 Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Background : The previous studies found that metabolic dysfunction in rats induced by high-fat feeding apparently subsides if they
were co-fed with either the water extract from rice bran or herbs, Benjakul (BWE) or Wild betel leaf bush (WWE). The extracts
contain a mixture of substances but carbohydrate was found as a majority. Therefore, the tentative active carbohydrates, dietary
fiber and phenolic compounds, were evaluated.
Materials and Methods : Dietary fiber was analyzed by AOAC Method 2009.1 and 2011.25 using the reagent kits. Phenolic compounds
were determined by the HPLC.
Results : The results showed that the possible active substances in RB, BWE and WWE were 2 kinds of soluble dietary fiber, the non-
precipitated and the precipitated fiber in 78% ethanol, since the combination of these 2 kinds of soluble dietary fiber were
approximately equal among the specimens (60.93+10.70 plus 55.56+5.33 mg/g rice; 72.72+1.36 plus 16.33+1.20 mg/g BWE;
104.38+0.54 plus 1.77+0.08 mg/g WWE). The content of phenolic compound, p-coumaric acid, tended to be equal among the
specimens as well (38.02+2.36 μg/g rice bran enzymatic extract; 38.92+2.49 μg/g BWE; 59.019+5.42 μg/g WWE).
Conclusion : The molecular weight of the soluble dietary fibers found in RB, BWE and WWE are similar to oligosaccharides those
known to be the prebiotics. The similar content of soluble dietary fiber concomitant with the similar ability to ameliorate the
metabolic syndrome in the animal studies. The other possible activity to ameliorate the signs of metabolic syndrome found in the
specimens is the antioxidant effect as due to p-coumaric acid in the extracts.
Keywords : Rice bran, Benjakul, Wild betel leaf bush, Dietary fiber, Antioxidant
