Effect of Cooking Method on Vitamin C Loses and Antioxidant Activity of Indigenous Green Leafy Vegetables Consumed in Western Uganda.

Hellen W Kinyi,Conrad O Miruka,Michael Tirwomwe,Herbert Izo Ninsiima,Parise Adadi

doi:10.1155/2022/2088034

Hellen W Kinyi, Conrad O Miruka + Show 3 more

Open Access

https://doi.org/10.1155/2022/2088034

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Abstract

Indigenous green leafy vegetables are known to contain high levels of antioxidants and are recommended in the management of chronic diseases. However, their consumption has received lower patronage. This is partly attributed to farmers replacing the growing of indigenous green leafy vegetables with their exotic counterparts and scarce information on their nutritional benefits. This study explored the effect of cooking methods (boiling and steaming for 10 minutes) on the antioxidant activity of Amaranthus dubius, Solanum nigrum, and Curcubita maxima. Spectrometry was used to evaluate the reducing power and antihemolytic activity. Titration via the 2,6-indophenol method was used for measuring vitamin C and replacement titration for hydrogen peroxide scavenging activity. Cooking the vegetables by steaming or boiling caused up to 99% reduction in the vitamin C concentration of the cooked vegetables. The antioxidant activity of the cooked vegetables varied across the species assessed and cooking method used. Steaming retained and in some instances promoted the antioxidant activity of the vegetables. The study concludes that cooking by either steaming or boiling alters the antioxidant activity of indigenous vegetables.

Highlights

Organism’s cells can be damaged by highly reactive atoms known as free radicals [1, 2]
Consumption of fruits and vegetables is associated with a low incidence of these oxidative-stress related diseases and aging [7]. This protective action is attributed to antioxidant vitamins such as vitamin C, α-tocopherol, and β-carotene as well as phytochemicals such as flavonoids, isoflavones, flavones, anthocyanins, catechin, and isocatechin that have shown antioxidant activity both in vitro and in vivo [2, 8, 9]
The study was conducted at the Institute of Biomedical Research (IBR) of Kampala International University Western Campus

Summary

Introduction

Organism’s cells can be damaged by highly reactive atoms known as free radicals [1, 2]. Consumption of fruits and vegetables is associated with a low incidence of these oxidative-stress related diseases and aging [7] This protective action is attributed to antioxidant vitamins such as vitamin C, α-tocopherol, and β-carotene as well as phytochemicals such as flavonoids, isoflavones, flavones, anthocyanins, catechin, and isocatechin that have shown antioxidant activity both in vitro and in vivo [2, 8, 9]. In Africa, indigenous green leafy vegetables are major ingredients of soups and sauces that accompany carbohydrate staples They are known to contain high levels of carotenoids, vitamin C, iron, calcium, protein, flavonoids, and phenolics and recommended in the management of malnutrition, HIV/AIDS, diabetes, and high blood pressure [10, 11].

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