ISSN: 2574-2701
Authors: Soyema Khatun*, Hyeonhwa Lee and MD Mahi Imam Mollah
Phenolic compounds are important products from secondary metabolism in plants. These cannot be synthesized in the human body and are mainly taken from plant source. Cereal grains are important sources of dietary polyphenols. Phenolic compounds are the main source of antioxidant that reduces the incidence of chronic diseases including heart disease, blood cholesterol, blood pressure, diabetic etc. Angiotensin-converting enzyme (ACE) inhibitors are medications that help to relax the veins and arteries to lower blood pressure. The aim of this experiment was to study the phenolic compounds identified in eight cereal grain (white rice, viscosity rice, brown rice, black rice, sticky rice, oatmeal, millet and sorghum) with their antioxidant and angiotensin-converting enzyme (ACE) inhibitory activity level. The phenolic content determined according to the Folin Ciocalteu’s method. Black rice contains maximum phenolic compound (94.90 mg Tannic acid equivalent/g of extract) that was statistically different from other cereal grains (p<0.05) but followed by oatmeal and sorghum (58.82 and 58.57 mg Tannic acid equivalent/g of extract respectively). Antioxidant activities were comparatively assessed by ABTS (2, 2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) free radical decolorization assay method. It was observed that maximum cereal grain has no antioxidant activity. Among eight cereal grain, only black rice, oatmeal and sorghum showed considerable free radical scavenging capacity by ABTS radical. Angiotensin-converting enzyme (ACE) inhibition rate was determined by using L-hippuryl-histidyl-leucine (HHL). Maximum angiotensin-converting enzyme (ACE) inhibitory activity was also found in black rice (66.80%) followed by oatmeal (48.62%) and sorghum (37.45%). It might be concluded that polyphenol content was closely related to antioxidant activity and angiotensin-converting enzyme (ACE) inhibitor activity. Black rice, oatmeal and sorghum can be used as functional food for their high phenolic content, antioxidant activity as well as angiotensin-converting enzyme (ACE) inhibitory activity against chronic diseases.
Keywords: Polyphenol; Antioxidant; Angiotensin-converting enzyme; Cereal grain
