Produce Quality & Safety

In many parts of South Africa, the huge demand for clean water in the fresh produce industry, together with other costs, force farmers to use all available water resources, including river water, often without any treatment. The fact that human pathogens can survive on fresh produce for extended periods of time, coupled with the presence of an unacceptably high microbial load in irrigation water, represent a potential microbiological hazard that could pose a food safety risk. In addition, unhygienically handled vegetables during pre-harvest, processing ,distribution and sale, especially for produce which are usually consumed raw, adds an additional potential contamination source within fresh produce supply. Furthermore, antimicrobial resistance has become one of the greatest public health challenges globally, with dissemination in clinical as well as agricultural settings. Next-generation risk analysis, including the whole genome sequencing (WGS) of foodborne pathogens, is essential to understanding the complexity of the food safety conundrum within any country and internationally. The determination of antibacterial resistance prevalence is essential in developing a full risk assessment required to determine the level of risk to human health.

Current projects in Produce Quality and Safety

Development of a fit-for-purpose water microbiological quality guideline for smallholder farmers and informal food traders

This project is funded by the Water Research Commission and predominantly focuses on irrigation water used in informal (smallholder) fresh produce farming systems. The occurrence, dissemination and characteristics of potential human pathogenic bacteria in the irrigation water and associated fresh produce from the selected small holder farms will be determined and a fit-for-purpose guidance document of microbiological quality criteria for vegetable crop production in informal (small holder farmers) supply chains will be established. With the use of WGS, information from the informal crop production systems can then be compared and linked with information from WGS on isolates in the water-plant-animal-food human health nexus of different sectors/ stakeholders/academic/reference laboratories.

All-inclusive One Health risk analysis for community health

The food safety “One Health” approach incorporates the three main interlinking facets of animal, plant and human health with the crosscutting facets of water and environment. With support from the DSI-NRF Centre of Excellence in Food Security, this project focuses on major antimicrobial resistant pathogens which have previously been identified as prevalent in the environment and informal food system. For an effective risk management system, hazard characterisation and a better understanding of the level of risk is needed. With the use of next generation tools in conjunction with the metadata from previous research within the group risk analysis and risk assessment will be done. The data required to execute this analysis include the available food within a community and its associated consumption patterns and processing/ preparation methods, the hazard analysis and hazard’s dose-response curve, and the anticipated health effects of the hazard when ingested by humans. Collectively this information will allow the modelling of the final estimate of risk.

Furthermore, assessment of emerging risks such as Cryptosporidium in ruminants, fresh produce and water in South Africa is an essential part food safety. The purpose of this study will therefore be to investigate the prevalence and risk factors associated with cryptosporidiosis in ruminants from small-scale farms and irrigation water and associated fresh produce to determine the continuum from available food in a community and the potential health burden. Integrating analysis of ruminants, fresh produce, and water quality and community health will enable an all-inclusive approach to “One Health” needed to address this complex problem.

From crops to food waste, how animal feed and the environment affect the gut microbiome and health of pigs

This research, funded by the South African Pork Producers’ Organisation (SAPPO), forms part of a multidisciplinary study that is in collaboration with Professor Este van Marle-Koster from the Department of Animal and Wildlife Sciences and the Genomics Research Institute (GRI) at the University of Pretoria and the AgriPhytoMicrobiome research group. This project aims to develop a “fit-for-purpose” industry staggered framework that reflects the current environment and animal health and safety status of the commercial pig industry in South Africa in terms of food safety compliance and excellence, and, provide a risk profile of the “feed-to-faeces” antimicrobial resistance levels in the microbiomes within the food production environment, followed by a comparative assessment of the small-scale farmer biosecurity and food safety risks.  This information can then be used to develop a more enabling food security framework for the country through targeted risk mitigations.

-- Updated March 2022 --