Zero Hunger (SDG 2), Good Health & Well-being (SDG 3)
Phytochemicals in commonly consumed foods in Malawian diets
Victoria Ndolo 1 , Margaret Maoni* 1 , Bonface Mwamatope 2 , David Tembo 3 1 University of Malawi, Department of Human Ecology, Zomba, Malawi 2 Lilongwe University of Agriculture and Natural Resources, Lilongwe, Department of Basic Sciences, Malawi 3 Malawi University of Business and Applied Sciences, Department of Physics and Biochemical Sciences, Blantyre, Malawi Phytochemicals have been associated with a reduction in the risks of developing non-communicable diseases and hence promoting health due to high antioxidant activity, especially when consumed in the average human diet. Fruits, vegetables, and cereals are among the most important sources of phytochemicals in the human diet. Phytochemicals include phenolics, alkaloids, nitrogen-containing compounds, saponins, terpenoids, organosulfur compounds and carotenoids. The aim of this research was to screen phytochemicals in commonly consumed fruits and vegetables and examine the effect of processing vegetables on phytochemicals. Fresh fruits and vegetable samples were collected or purchased from forest, homestead farms, markets from three regions of Malawi. Indigenous and exotic fruit samples included, Parinari Curatellifolia (mobola plum) Strychnoscocculoides (monkey oranges), and Musa acuminate (bananas) Adansonia digitate (Baobab), Ziziphus mauritiana (Indian plum) and Tamarindus indica (tamarind). Indigenous and exotic vegetables included, Bidens pilosa (black jack) and Amaranths hybridus (pigweed), Galinsoga parviflora (Gallant soldier), Brassica napus L and,rape, Brassica rapa (Chinese cabbage) and Brassica oleracea var.botrytis (Cauliflower). Aqueous and methanolic crude extracts were screened for alkaloids, saponin, tannins, flavonoids, quinones, coumarins, terpenoids, steroids, glycosides and anthocyanins) for both raw and cooked forms using standard procedures. Total flavonoids content (TFC) and total phenol content (TPC) were also determined using spectrophotometric methods. Almost all phytochemicals screened were found in some of the fruits and vegetables, with indigenous fruits and vegetables having the most, except for glycosides and anthocyanins. In water extracts, saponins, tannins, flavonoid, quinones, coumarins, terpenoids were more available in most indigenous fruits, rather than the exotic fruits. In methanolic extracts, tannins, flavonoid, coumarins and terpenoids were the most present in indigenous fruits (IFTs). The differences are attributed to more polar phytochemicals in indigenous fruits. For vegetables, in methanolic extracts, tannins, flavonoids, quinones and coumarin were the most available in both indigenous and exotic vegetables. TPC in fruits ranged from 715.08 mgGAE/g to 21,119 .66 mgGAE/g, while TFC ranged from 44.10 mg QE/g to 434.74 mg QE/g. 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). Largely, indigenous vegetables showed higher TPC values compared to exotic ones. It was also observed that processing of vegetables affected total phenolic compounds differently. In some vegetables TPC values increased with cooking in pumpkin leaves, bonongwe and chisoso while it decreased in cabbage, Chinese and rape vegetables. The studied fruits and vegetables represent a good source of a variety of phytochemicals for many Malawians. Hence, they are a potential functional food and can serve as an inexpensive source of natural antioxidants, which could help in the fight against non-communicable diseases such as hypertension, diabetes, and cancer which are currently on the increase in Malawi. The results show that a single fruit or vegetable does not contain all the phytochemicals and that processing can either increase or decrease their content. Therefore, intake of a mixture of fruits and vegetables is recommended to maximize their health benefits.
P23
© The Author(s), 2023
Made with FlippingBook Learn more on our blog