Estimated reading time: 6 minutes
Food loss and waste is one of the silent catastrophes of global agriculture. Although it does not grab headlines like climate change, natural disasters such as droughts and floods, or rising food prices, its impact is just as devastating.
Stellenbosch University recently released information from a doctoral study by Dr Ikechukwu Opara with emphasis on post-harvest food waste which leads to higher fresh produce retail prices, affecting thousands of South African households. The study identifies possible solutions like machine learning for post-harvest losses and waste in practical, day-to-day operations at fresh produce markets.
Loss in the export value chain
This situation automatically prompts the question of how South African fresh produce, which is destined for overseas markets, is affected by logistical shortcomings in the value chain.
Food loss and waste often occur incrementally in the export value chain, starting in the orchard and culminating in the market. Ngcebo Parton Khumalo, research and development manager at the Perishable Products Export Control Board (PPECB), leads research focussed on cold-chain logistics and citrus quality under climate stress. In this article, he updates readers on the trials conducted by the PPECB over the past two years on the topic of food loss and waste.
“One of the consequences of food loss and waste is the reduction of farm income, thus threatening long-term sustainability of the industry,” he says. “The increase in food loss and waste is contributing to higher food prices.”
Where food loss occurs
Food loss and waste is often misconstrued as food that ends up in the bins of a household. The sad reality is that a significant share of the loss occurs even before the fruit reaches the consumer. According to research by the PPECB, some loss occurs in the orchard, and the extent of this loss is variable depending on several factors including fruit type, production conditions, prevailing weather conditions, etc.
Research conducted by the PPECB found that sunburn in the orchards of litchi fruit has been considerably high in the Malelane region during the years of monitoring by the PPECB. Insect stings on fruit, poor colour and injuries are some of the other losses reported in litchi orchards. Similar orchard losses were observed on mango orchards in the Hoedspruit area.
The packhouse is the second sector in the fruit-monitoring value chain. Here, fruit must not only meet the minimum quality and phytosanitary standards but also comply with specific market specifications set by the intended customer. This results in further culling in the packhouse, often for similar defects identified in the orchard, but with much stricter criteria, as the fruit is prepared for export.
The PPECB also does final product inspection for export markets and may reject fruit that falls short of the minimum export standards. Fruit that passes the PPECB inspection is then exported to the market. Additional losses can occur during this stage of the value chain, as reflected in fruit-arrival quality reports at the destination markets. These losses vary depending on many factors such as handling practices in storage facilities, the type of fruit, and the duration of storage. Highly perishable fruit like mangoes and berries may suffer significant losses during this stage. At this point new disorders, such as postharvest pathological infection and progressive physiological breakdown, may emerge, which may not have been present in the earlier stages of the value chain.
Combatting loss with technology
While several plausible solutions exist to curb food loss and waste, this article does not exhaust these options.
Orchard losses can be reduced by adopting more scientific production techniques such as climate smart agriculture and precision farming. These production techniques ensure responsible and optimum use of resources, resulting in better fruit quality and fewer orchard losses. The use of shade netting further reduces losses in the orchard, particularly weather-related damage such as sunburn, wind, and hail. In trials conducted by the PPECB, it was observed that litchi fruit grown under shade netting had less sunburn and better overall quality than fruit from an open orchard.
In the packhouse, modern scientific grading and sorting systems, which eliminates human error in the sorting process and allows good quality fruit to be sent to the market, assists in reducing further losses down the value chain.
Cold chain management is the next critical step to optimise quality once fruit has been passed for export. Modern cold storage facilities continuously monitor and adjust air and product temperatures to ensure optimal conditions throughout storage. The PPECB also plays a crucial role in monitoring the cold chain and will issue a pre-cooling certificate and/or carrying temperature instruction when the cold chain management complies to the relevant standards and requirements. Containers have modern cooling, ventilation and gas management systems that allow optimum airflow and fruit cooling, thus prolonging fruit quality. The containers also have advanced temperature monitoring systems including remote-management systems that allow real-time adjustments to maintain ideal temperatures. Furthermore, the modern containers can be used as controlled-atmosphere units, regulating gas composition to further prolong shelf life.
Temperature monitoring technology has advanced to include real-time portable temperature loggers to add a second layer of temperature monitoring. Real-time loggers and container remote monitoring can be used to ensure the fruit is kept at the best temperature to preserve quality. Some loggers even include artificial intelligence capabilities to analyse storage temperature and predict fruit quality, which is a risk mitigation tool.
The PPECB recently tested a quality-prediction model – originally developed in the United States for strawberries – on blueberries. The application uses complex algorithms to predict fruit quality at any stage of the export value chain. These algorithms consider temperature excursions and other factors to determine how much a fruit’s shelf life has been reduced. This is a significant development in quality control, as fruit with a shorter shelf life can be prioritised on arrival in the market, thus reducing further loss. Such techniques give you visibility of fruit quality at any stage of the fruit export process. However, while promising, this model is still at the testing phase and would need further validation and refinement.
Conclusion
Total elimination of food loss in the export value chain would be an unrealistic ambition, because fruit is a living product that continues to degrade over time. However, significant reductions in food loss and waste are achievable. The future lies in smarter systems with improved artificial intelligence technologies, enhanced data collection and interpretation, and stronger collaboration between players in the value chain. While much work remains to be done, the progress already made is worth acknowledging and building upon. – Carin Venter, Plaas Media
For more information on research conducted by the PPECB, please send an email to Ngcebo Parton Khumalo at NgceboPK@ppecb.com
