Evaluation of Physiochemical, Phytochemicals, Antioxidant, Micronutrients Properties of Bangladeshi Crude and Commercial Rice Bran Oil

Abstract

Rice bran oil was extracted by product of milling of <i>Oryza sativa </i>seeds. The focus of the study was to determine the physiochemical, phytochemicals, micronutrients and antioxidant potentiality of rice bran oil and effect of refining process. The oil is extracted from bran of three popular rice varieties (BRRI-28, BRRI-29, Rajvogh) of Bangladesh. The acid value, peroxide value, iodine value and saponification value of extracted oils were observed in the range of 14.03-16.82 mgKOH/g, 26.68-34.50 meqO<sub>2</sub>/kg, 71.61-84.70 gI<sub>2</sub>/100g and 175.13-180.26 mgKOH/g respectively. Atomic absorption spectrophotometric method was used for determination of micronutrients. The concentrations for copper, zinc, iron and chromium were found to comprise between 0.03-0.25, 0.25-0.39, 17.97-64.47 and 0.96-4.87 ppm respectively. It was observed that BRRI-29 showed the greatest DPPH radical scavenging activity with the IC<sub>50</sub> value of 187.55µg/ml, followed by BRRI-28 (IC<sub>50</sub>- 284.04), Rajvogh (IC<sub>50</sub>- 325.56) and refined oil (IC<sub>50</sub>- 465.12). All the samples acted upon nitric oxide free radical according to following order- BRRI-29 (IC<sub>50</sub>- 286.4)> BRRI-28 (IC<sub>50</sub> -416.81) >Rajvogh (IC<sub>50</sub> -453.95)> refined oil (IC<sub>50</sub>- 557.86).All the extracted and refined oils were found to have considerably good antioxidant activity in a dose dependent manner. The extracted oils were found to contain more phenolic and flavonoid content than refined oil that serve as antioxidants. Some literatures show that, RBO contains tocotrienol and oryzanol which absent in soybean oil which regarded to be the best in perspective of antioxidant potentiality and categorize rice bran oil as promising edible oil. Comparative to crude bran oil commercial refined oil were lower in these parameters which shows the effect of refining process. Further investigation should be conducted on animal model (in vivo study) for safe human consumption. The knowledge would be useful in recommending various ways of using the oil in food industry, as well as in households.