Screening South African potato, tomato and wheat cultivars for five carotenoids

Charlotte S Mashaba,Eugenia Barros

doi:10.4102/sajs.v107i9/10.507

Abstract

In South Africa malnutrition is of great concern. Vitamin A deficiency is one of the leading causes of infections as a result of micronutrient malnutrition. Although supplementation and food fortification programmes exist, these either are not available or are unaffordable to communities in remote rural areas. The selection of crops that are naturally rich in provitamin A (β-carotene) and other carotenoids that can be recommended to small-scale farmers for breeding and for food production, could be an effective way to address vitamin A deficiencies and associated diseases. The aim of this study was to profile two cultivars each of potato, tomato, bread wheat and durum wheat, which are highly consumed crops in South Africa, for their carotenoid content using high-performance liquid chromatography. To this effect, reliable extraction and quantification of five carotenoids – lutein, zeaxanthin, canthaxanthin, β-carotene and lycopene – were performed for these crops. Lutein and zeaxanthin were found to be the major carotenoids in potato, whilst lycopene was the major carotenoid in tomato. In durum wheat, only lutein and zeaxanthin were identified whilst bread wheat contained lutein, zeaxanthin and β-carotene. The methodology used proved to be robust and suitable to screen a large number of potato, tomato and wheat cultivars for their carotenoid content.

Highlights

Malnutrition, in general terms, is the medical condition caused by improper or inadequate nutrition
In South Africa, malnutrition is responsible for up to 50% of the deaths of children that are admitted to hospital.[3]
Vitamin A plays a role in maintaining the surface linings of the eye and digestive, urinary and respiratory tracts; it plays a role in bone growth and cell division and it helps regulate the immune system, which assists in preventing and fighting off infections.[7,8,9,10]

Summary

Introduction

Malnutrition, in general terms, is the medical condition caused by improper or inadequate nutrition. Β-carotene is more efficiently converted to vitamin A than any other carotenoid.[6] β-carotene, β-cryptoxanthin, lycopene and lutein have been linked to a 50% reduction in the risk of women developing breast cancer, whilst lycopene is associated with a reduced risk of coronary heart disease.[11,12,13] Lutein and zeaxanthin have been suggested to play a protective role against cataracts and age-related macular degeneration, the leading cause of irreversible vision loss and blindness, especially in the elderly.[14] The mechanisms by which carotenoids act on the body to prevent or slow down diseases have not yet been fully elucidated but have been strongly linked to their antioxidant properties, their ability to scavenge free radicals that can cause a great deal of damage to human cells.[12,15]

Objectives

Methods

Results

Conclusion