African Journal of
Food Science

  • Abbreviation: Afr. J. Food Sci.
  • Language: English
  • ISSN: 1996-0794
  • DOI: 10.5897/AJFS
  • Start Year: 2007
  • Published Articles: 924

Article in Press

Effect of sautéing and boiling on antioxidant activity and phytochemicals content of selected traditional vegetables consumed in Malawi

Joseph Y. Issa, Arnold N. Onyango, Anselimo O. Makokha and Judith K. Okoth

  •  Received: 27 October 2021
  •  Accepted: 01 December 2021
Traditional vegetables are potential rich sources of health promoting phytochemicals and bioactive compounds. Previous studies have shown that cooking methods may have different effects on the phytochemical properties of fresh vegetables. This study evaluated the effects of boiling and sautéing on the total phenolic content (TPC), total flavonoid content (TFC), total carotenoid content (TCC) and 2, 2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity of five traditional vegetables from Malawi; namely : Amaranth, jute mallow, drum stick, black jack and sweet potato leaves. The ranges of TPC, TFC and TCC in the raw dried vegetables were (0.98-3.89g GAE/100g), (0.90-2.87g QE/100g) and (1,708-15,041.59µg/100g) respectively. Boiling decreased TPC significantly (p<0.05) in all the vegetables except jute mallow while sautéing decreased TPC in all the vegetables except amaranth. Sautéing increased TFC in drum stick and jute mallow leaves but reduced TFC in black jack and sweet potato leaves. Boiling either increased or retained TCC in all the vegetables while sautéing had negative impact on TCC of most vegetables except for jute mallow and drum stick leaves. Both boiling and sautéing decreased the antioxidant activity of all the vegetables except jute mallow where boiling increased its antioxidant activity. Sautéing reduced the antioxidant activity of most of the vegetables more than boiling. The study demonstrates that boiling and sautéing have significant impact on the phytochemicals and DPPH radical scavenging activity of the vegetables. Boiling had negative impact on phenolic content of most of the vegetables while sautéing had positive influence on flavonoid content of most of the vegetables. Both boiling and sautéing negatively affected the DPPH radical scavenging activities of all the vegetables except jute mallow.

Keywords: Traditional vegetables, sautéing, boiling, phytochemical properties, DPPH