Post harvest losses of Vitamin A in orange maize reduced with better storing methods


By Fredalette Uys | 2 August 2017

Scientists have found the health benefits of orange maize can be enhanced with almost 25% by using better post harvest storage methods.

According to the World Health Organisation (WHO) more than half of Zambian children aged between 6 months and 5 years suffer from Vitamin A deficiency due to poor diets.

Preventable blindness and night blindness, as well as the increased risk of disease and possible death are the leading effects caused by the deficiency.

Orange, red, and dark green fruit and vegetables contain the carotenoid pigment beta-carotene, one of the most important sources of pro-vitamin A, meaning the body converts the substance into Vitamin A.

Over longer periods, adding these vegetables to your diet is the best way to insure a sufficient intake of the nutrient. According to the WHO, cultivating a garden to grow fruit and vegetables is one of the best ways to tackle the deficiency.

As a short-term solution, the organisation HarvestPlus developed a bio-fortified orange maize variety through conventional breading methods with high levels of caretonoids, since maize is a staple for the largest part of Zambia’s population.

Study results

However, recent studies, by scientists from HarvestPlus, Stellenbosch University and International Maize and Wheat Improvement Center (CIMMYT),  done in Zambia show the positive impact of the biofortified maize is reduced by carotenoid loss during the storing of the maize and post harvest losses. Carotenoids are broken down by oxygen, high temperature and light during storage.

Maize farmers can generally lose about 30% of their maize harvest due to traditional storing methods, which include woven bags or self-constructed silo’s. This include losses to insects like weevils, rodents or fungi and the accumulation of poisonous mycotixins that pose health risks like cancer, to maize consumers.

Scientists found carotenoid levels are maintained better with improved maize storage methods, such as multilayer polyethylene PICS bags and metal silo’s where oxygen levels are kept low.