A substantial portion of this loss and waste occurs during harvesting, transportation and marketing in the form of handling problems and inadequate infrastructure.

We are agri-food systems specialists who have studied food waste both at the farm level and further along the chain towards consumers. For example, I (Opara) have found that for pomegranates, 15.3% to 20.1% of the harvest is lost at the farm (for several reasons, but mainly sunburn and cracks) and 6.74% to 7.69% at the packhouse (as a result of superficial injuries and missorted fruits from the farm).

Another study (Opara) measured post-harvest waste at a produce market. This ranged from 0.68% to 1.26%.

The research confirms that food waste is partly due to inadequacies or failures in the cold chain, especially during summer when temperatures are high, affecting the physical quality of fresh produce. A cold chain is a temperature-controlled supply chain that keeps perishable products safe and fresh.

Better cold storage would reduce waste.

Impact of seasons on fresh produce waste

My (Opara) recent study set out to assess the magnitude and seasonal variations of postharvest waste at the wholesale level using a case study of a fresh produce market in Gauteng province, South Africa. The study used the historical fresh produce waste data of the market over three years (2021 to 2023).

The results show that fresh produce is affected by seasonal heat and humidity, which affect the physical quality and consumer acceptability of fresh produce. Fresh produce is marketed and sold on claims of its freshness.

High temperatures typically result in increased moisture loss. If that’s uncontrolled, the produce deteriorates and can’t be sold or safely eaten. Across the seasons in South Africa, temperatures and humidity levels vary considerably.

Much of the fresh produce waste occurs during summer, often requiring improvement in handling, storage and maintaining the cold chain to preserve quality.

The study shows that about 9,124 to 17,969 tonnes, which is about 0.68% to 1.26% of the supplied fresh produce, are discarded annually at the fresh produce market. Much of it is a result of high temperatures during summer, which is a period when cold storage facilities are stretched the most due to high demand.

Cold chain for food security

That’s why an efficient cold chain system and storage is so important. Cold chain systems involve a sequence of supply chain processes that are temperature-controlled, aimed at managing the temperature of perishable items from the moment they are harvested until they reach store shelves. This can involve storing fresh produce under shades immediately after harvesting, and insulating them from heat or direct sunlight through refrigeration throughout the supply chain.

This regulation slows down biological deterioration and spoilage. The cold chain is crucial for extending the shelf life of fruits and vegetables by ensuring optimal transport, storage and sales conditions. Maintaining a consistent cold chain preserves food quality and enhances safety, reducing the risk of foodborne diseases. This increases the availability of fresh produce and helps keep prices affordable for consumers.

Solutions to reduce fresh produce waste

One key to solving food waste problems in the country is investment in cold chain facilities. The wholesale markets in South Africa are formalised and the cold chain system is advanced compared to many sub-Saharan African countries. But more investments are needed in cold chain logistics, packhouses and storage, especially at the National Fresh Produce Markets, which serve as storage, distribution and wholesale hubs.

Small-scale farmers and packhouse operators need financial help to build refrigeration infrastructure, especially for first-mile cooling, and temporary storage before fresh produce is processed for the market. One instrument is blended investment: a mix of public funds and private capital. This approach attracts private investors as public money takes the first financial hit if an investment fails, thereby protecting private investors. It can drive innovation and investment in the food system.

Collaboration between research institutions and industry will aid in measuring food loss and waste effectively, enabling evidence-based decision-making to reduce food waste.

In addition to these solutions, studies elsewhere in the world have shown that integrating AI could enhance cold chain systems to reduce waste, improve food quality, lower costs and increase access to nutritious foods.

AI enhances the efficiency of the cold chain system. The national fresh produce markets can benefit from the automation and efficiency of AI integration to monitor cold storage temperatures. Advanced algorithms can help manage cold storage demand using real-time data and predictive modelling to balance energy use, cut costs and keep temperatures stable, especially during periods of high demand. This would minimise waste and ensure fresh produce reaches consumers in good condition.

A collective effort from farmers, cold chain operators, transport and logistics, research institutions and the government is vital. South Africa must focus not just on food production but on preserving what is produced through improved cold chain infrastructure.

Written by Ikechukwu Opara, Postdoctoral Research Fellow, Stellenbosch University and Frederic Isingizwe, Research Scientist - eResearch Office, University of the Western Cape

This article is republished from The Conversation under a Creative Commons license. Read the original article.