Phytochemicals in commonly consumed foods in malawian diets

Authors

DOI:

https://doi.org/10.31989/ffhd.v12i10.976

Abstract

Background: Plant foods, as functional foods, provide not only the essential nutrients needed to sustain life, but also bioactive compounds (phytochemicals) for health promotion and disease prevention.

Objective of the study: The aim of this research was to screen phytochemicals in commonly consumed fruits and vegetables in Malawi. The effect of processing vegetables on phytochemicals was also evaluated.

Methods: The potential of some commonly consumed fruits and vegetables in their raw and cooked forms as natural source of phytochemicals was evaluated in both aqueous and methanol extracts. These fruits and vegetables were screened for alkaloids, saponin, tannins, flavonoids, quinones, coumarins, terpenoids, steroids, glycosides and anthocyanins, total flavonoids content (TFC) and total phenol content (TPC) using standard procedures. TPC and TFC were also analyzed using spectrophotometric methods.

Results: Almost all the phytochemicals screened were found in some of the studied fruits and vegetables, with indigenous fruits and vegetables having the most, except for glycosides and anthocyanins. TPC in fruits ranged from 715.08mgGAE/g to 21,119.66mgGAE/g, while TFC ranged from 44.10mgQE/g to 434.74mgQE/g in vegetables. TPC of uncooked vegetables ranged from 522.22 mgGAE/g (pumpkin leaves) to 33, 684.66 mgGAE/g (ntoriro), while in cooked vegetables it ranged from 135.93 mgQE/g (bonongwe) to 6817.86 mgQE/g (chisoso). Overall, indigenous vegetables showed higher TPC values in comparison to exotic vegetables. It was also observed that processing of vegetables affected total phenolic compounds differently. In some vegetables, TPC values increased with cooking (pumpkin leaves, bonongwe and chisoso), while in others (cabbage, Chinese and rape) it decreased.

Conclusions: The results show that fruits and vegetables can serve as a cheap source of natural antioxidants that could help fight non-communicable diseases, such as hypertension, diabetes, and cancer. As might be expected, a single fruit or vegetable doesn’t contain all the necessary phytochemicals. Therefore, an intake of a mixture of fruits and vegetables is recommended for maximum benefit as functional foods.

Keywords: Phytochemicals, fruits, vegetables, total phenolic content, non-communicable diseases

Author Biography

  • David Tryson Tembo, MALAWI UNIVERSITY OF BUSINESS AND APPLIED SCIENCES

    Born on 27 September 1974, David Tryson Tembo is a holder of a Doctor of Philosophy, PhD (University of Leeds, United Kingdom, 2017), Master of Science, MSc (University of Malawi, 2008) and Bachelor of Education Science, BEDs (University of Malawi, 2001). His PhD research study focused on Characterization of Phytochemicals in Functional Foods and Herbal Medicines using state of the art analytical techniques including 1H NMR, HPLC, LC-MS and GC-MS.

    David has over 21 years of research and teaching experience both Face to Face as well as ONLINE obtained from different Universities in United Kingdom (University of Leeds and Sheffield Hallam University) and Malawi (Kamuzu University of Health Sciences, Chancellor College and Malawi University of Business and Applied Sciences) as well as High Schools (Leeds East Academy, UK), Kamuzu Academy and Saint Andrews International High School, Malawi). David has supervised over 65 postgraduate and undergraduate research students at the University of Leeds, UK, Sheffield Hallam University, UK and University of Malawi (MSc and BSc).

    Some of his key Research Students include Dr Thom Msika (PhD, 2021) and Fred Masumbu (PhD student 2022), Kamuzu University of Health Sciences (KUHES). Dr Tembo has examined several PG students including PhD within Malawi (Dr Frank Ngonda, 2021) and United Kingdom (Andy Fang, 2015). David Tembo has a number of research articles in Peer reviewed high impact factor Journals. Teaching skills and experience were obtained from first professional degree, Bachelor of Education Science (BEDs with merit, University of Malawi, 2001) and United Kingdom (University of Leeds and Sheffield Hallam University, 2012 to 2017). Proficient in both oral and written English. Highly computer literate (Word, Excel and PowerPoint) including several statistical packages (SPSS, GENSTAT and R Commander) necessary for data processing, analysis for manuscripts and report writing. David is Christian, and Church Elder (Mount Pleasant Church, Blantyre Synod) and likes site seeing, watching football and tennis during free time.

Published

2022-10-07

Issue

Section

Research Articles