A recent economic analysis estimated that food loss and waste (FLW) in South Africa are estimated at 9.04
million tonnes per year, or 177kg per capita per year.
This accounts for an estimated R61.5 billion – equivalent to about 2.1% of the national gross domestic
product – in financial losses (2012 figures). Reducing food loss and waste is essential in a world where the
number of people affected by hunger has been rising steadily since 2014, and tonnes of edible food are lost or
wasted every day in different food value chains.
Globally, around 14% of food produced is lost between harvest and retail, while an estimated 17% of total global
food production is wasted – 11% by households, 5% in food service, and 2% in retail, according to the ![]()
United
Nations.
The day is aimed at prioritising efforts and initiatives to cut FLW to enhance efficient use of natural resources,
mitigate climate change, and support food security and nutrition, thereby contributing to the UN’s
Sustainable Development Goals.
Dr Honest Machekano, Lecturer in the Department of ![]()
Zoology and Entomology at the ![]()
University of Pretoria,
said it is important to separate food loss and waste. “Whichever food value chain you look at, food loss
occurs from the point of crop maturity up to wholesale market, whereas food waste refers to a decrease in
the quantity or quality of food suitable for human consumption as a result of decisions and actions by
retailers, food service providers and consumers post–wholesale.”
With the ![]()
Food and Agriculture Organisation of the United Nations reporting that about 11% of global food
waste occurs at household level, this indicates that more work needs to be done at this level. The reasons for
food loss and waste vary depending on the specific value chain, but the main reasons include lack of effective
storage capacity, lack of awareness and information, poor transportation systems, poor food budgeting
techniques, and lack of policy support. At household/ individual level, reasons for food waste include poor
storage, unplanned meals, poor cooking decisions, food overstocking, improper cooking, cooking too much,
and attitude.
“My research focuses on stored product protection, specialising in reducing food loss and waste in stored
cereal and pulse grain,” Dr Machekano said. “The need to effectively store grain for prolonged periods is not
only overemphasised under the current pandemics and global instability-related delivery restrictions, but
also climate change–related limitations in the availability of reliable, productive seasons.”
One of his projects focusses on creating a low–cost, climate–smart metal silo tailored for small–scale farmers
in South Africa. “Through investment in such research UP plays a leading role in addressing storage deficits at
grassroots level, creating awareness on FLW and generating knowledge that can be used as a basis for future
national food policy adjustments to mitigate FLW,” he said.
Insect pests are one of the major causes of food loss through grain damage. Entomologists work to find
economic and safe ways of reducing insect damage on grain without compromising grain quality. Warm
temperatures increase insect movement, mating and feeding, which means climate warming in sub-Saharan
Africa has led to increased grain damage and loss due to high insect populations and increased feeding
activities.
“In my research, I use the adage ‘It takes a thief to catch a thief.’ If insects use climate to proliferate, why not
use the same ‘climate’ at lethal levels to kill the insects? To do this, some knowledge gaps need to be filled.
For example, what are the lethal thermal thresholds of stored product pests at each extreme side of the
temperature scale? How long should the insects be exposed to the extreme temperatures for 90%
mortality?”
These are the types of questions that Dr Machekano tries to answer in his laboratory every day. “That
information is critical to ‘catch the thief’ by developing low–cost, low-capacity, climate–smart storage systems
customised for small–scale farmers. There are also many commercially available products that kill insect pests
through reduction in oxygen and an increase in carbon dioxide. Other efficacious/ repellent indigenous plants
are also available, but their effectiveness needs to be confirmed by science-based evidence.”
As the world commemorates ![]()
the International Day of Awareness of Food Loss and Waste Dr Machekano says
it’s important to not only focus on FLW reduction. “We must also focus on securing investment in futuristic
post–harvest technologies for effective storage, particularly in rural areas where food insecurity is a fiscal
responsibility.”
