Phytochemical screening and antioxidant activity of raw and blanched ulam raja (cosmos caudatus) and selom (oenanthe javanica) / Nor Afifah Ahmad Shakir

Malaysians love to eat their “ulam” (especially ulam raja and selom) either raw or blanched with boiling water. Nevertheless, blanching the “ulam” might destroy some nutrients in them such as antioxidant content, phenolic content, beta-carotene content, and vitamin C content. The objective of this research is to determine the antioxidant (DPPH), total phenolic, beta-carotene, and vitamin C contents in fresh and blanched ulam raja (Cosmos caudatus) and selom (Oenanthe javanica). Ulam raja and selom were blanched in boiling water for 90 seconds and were used raw. In conclusion, there was a reduction of percentage inhibition of DPPH in ulam raja where raw ulam raja contained 69.34±2.4596 % and blanched ulam raja contained 57.05±9.1140 %. The same pattern showed by selom where raw selom contained higher percentage with 76.08±0.7356 % than blanched selom that contained 29.65±0.7366 %. Next, raw ulam raja contained higher total phenolic content than blanched ulam raja with 526.48±0.1488 mg/GAE g and 277.02±0.3207 mg/GAE g respectively. Meanwhile raw selom also contained higher total phenolic content than blanched selom with 680.82±0.2712 mg/GAE g and 606.23±0.1871 mg/GAE g respectively. Thirdly, beta-carotene content showed a lower content in raw ulam raja than blanched ulam raja with 0.0149±0.0539 mg/100 g and 0.0799±0.0005 mg/100 g. However, beta-carotene content in raw selom and blanched were similar in content and no reduction occurred with 0.0799±0.0005 mg/100 g. Finally, vitamin C content in raw ulam raja was higher in content than blanched ulam raja with 25.81±0.0816 mg/100 g and 12.90±0.5477 respectively. The similar pattern was portrayed as raw selom contained more vitamin C than in blanched selom with 63.59±0.9882 mg/100 g and 19.35±0.3696 mg/100 g.