From Farm to Table: Dr Nandi Nyamende Revolutionises Safety for Convenient Salads

In our fast-paced lives, the crisp convenience of a bagged salad or a container of pre-sliced fruit feels like a small win for healthy eating. However, there is a quiet, invisible vulnerability that begins the moment a vegetable or fruit is cut. Slicing through the natural skin of produce essentially opens a door, making the delicate inner tissues far more susceptible to rapid spoilage and the unwanted growth of germs. While these products are designed for ease, they require a level of scientific protection that most consumers never see.

Fresh-cut salads are convenient, but they’re vulnerable to spoilage and microbial growth once cut.

The Harsh Reality of Traditional Food Sanitisers

To keep this produce safe, many suppliers in South Africa currently rely on chlorine-based sanitisers to disinfect both whole and fresh-cut produce. While common, these chemicals come with heavy "baggage." Food scientist, Dr Nandi Nyamende points out that while we still use them, "in many developed countries, the use of chlorine at certain concentrations has been banned due to health and environmental concerns". She adds that these traditional cleaners can react with organic bits of soil or plant debris, losing their power exactly when they are needed most, and can even be corrosive to the machinery used to process our food. This approach is increasingly being questioned, highlighting a critical need for a cleaner, gentler way to protect what we eat. This is the research gap Dr Nyamende has been working to address by exploring electrolysed water as a safe, effective, and sustainable alternative cleaning method for our fresh produce.

Harnessing Nature’s Spark to Protect Our Food

Nandi’s PhD study focuses on a niche area: the quality and safety of fresh-cut and minimally processed produce, using activated water treatments (electrolyzed water) and modified atmosphere and humidity packaging. She explains, “If you’ve ever bought a bag of ready-to-eat salad or pre-cut fruit, that is exactly what I study.” While consumers increasingly look for these quick, convenient, and healthy food options, once produce is cut, it becomes far more vulnerable to spoilage and microbial contamination.

To address this, she uses a sophisticated approach that harnesses the properties of electrolysed water as a safe, effective, and sustainable food safety treatment. By applying electricity to change the properties of water, she creates a robust sanitiser that is remarkably environmentally friendly. "I combine these treatments with modified atmosphere and humidity packaging to preserve nutrients, extend shelf life, and maintain safety," she explains. Unlike harsh chemicals, this activated water eventually breaks back down into harmless substances, leaving no dangerous residues behind while creating a synergistic shield that locks in freshness.

Dr Nandi Nyamende studies the safety and quality of fresh-cut produce, exploring innovative treatments to keep it safe.

The most profound evidence of this technology's power appeared under the high-powered lens of a scanning electron microscope. When Nandi exposed common, dangerous bacteria like E. coli to this activated water, she watched as the germs suffered a total structural collapse, shrivelling and breaking apart. It was a true "aha" moment for her. Reflecting on the results, she says, "It provided visual, undeniable proof that electrolysed water doesn’t just inhibit these pathogens, but it physically destroys them at the cellular level". In contrast, bacteria exposed to ordinary water remained healthy and intact. This visual evidence proves that it’s possible to destroy harmful pathogens without relying on toxic chemicals!

Nandi’s study is the first of its kind to be conducted in South Africa, and the combination of these treatments is the first ever explored globally!

In the lab, Nandi works with electrolysed water solutions to develop safer alternatives to traditional chlorine-based sanitisers.

Building a Career on the Power of Science to Change Lives

This dedication to solving real-world problems is deeply rooted in Nandi’s own history, growing up in Matatiele and Mthatha in the Eastern Cape. Her upbringing taught her the value of resilience. She shares, "That foundation shaped who I am today... it gave me a deep appreciation for how knowledge, especially in science, can change lives". This drive led her through a rigorous academic path, eventually earning her MSc in Food Science and Technology from the Cape Peninsula University of Technology (CPUT) with high honours (cum laude), during which she published six research papers that laid the groundwork for the safer food systems she advocates for today. She then pursued a PhD in Food Science at the University of Stellenbosch, where she developed her pioneering research on safer cleaning treatments for fresh-cut produce.

Dr Nandi Nyamende celebrates her PhD from Stellenbosch University, marking a pioneering world-first study on safer fresh-cut produce treatments.

Leading the Charge from Academic Theory to Industry Action

Beyond her own research, Nandi is a dedicated educator who spent over three years as a lecturer in the Department of Agriculture at CPUT. During this time, she shared her expertise in subjects like Crop Protection, Plant Production, and Integrated Research, helping students bridge the gap between classroom theory and practical agricultural science. Her impact went beyond lecturing; she also successfully supervised an MSc student as a principal supervisor and mentored many others in the laboratory.

These experiences have reinforced her passion for education and her commitment to developing the next generation of researchers. She understands that one of the biggest challenges isn't just discovering a solution in a lab, but convincing a whole industry to change its long-standing habits. "What I enjoy most is the relevance," Nandi says. "Knowing that my work can directly contribute to safer, higher-quality food that reaches South African households is deeply motivating". For her, the work is only finished when these scientific breakthroughs actually reach the kitchen tables of families across the country.

Beyond the lab, Nandi emphasises sustainable practices and reducing food waste for a healthier environment.

A Scientist’s Vision for a Truly Zero Waste World

Nandi’s message to the public is a reminder that our food is the result of immense labour and precious resources. "When we throw away fresh produce, we’re not just wasting money; we’re wasting all the water, energy, and labour that went into growing it," she emphasises. By understanding the care and science that goes into keeping our food safe, we can learn to be more mindful consumers. Nandi believes that small actions, like storing our food properly and reducing waste, help protect the environment and ensure a healthier future for everyone.

Nandi’s mission resonates powerfully with the International Day of Zero Waste, a global call to eliminate the environmental toll of what we discard. Her research into extending shelf life is a direct contribution to this goal, as she works to prevent food from prematurely becoming waste. "I’d like to encourage us all to see waste differently," she urges, noting that keeping organic waste out of landfills is essential for solving environmental problems that affect us all. By finding cleaner ways to preserve our food, Nandi is helping us move toward a future where we value every resource and strive for a truly zero-waste world. “It would be great if packhouses in South Africa could move to implementing electrolysed water as a substitute for chlorine-based treatments,” she urges, leaving us with a clear challenge and a vision for a safer, more sustainable food industry.

Protecting our food and reducing waste , Dr Nandi Nyamende’s work ensures safer, longer-lasting fresh-cut produce.

Connect with Dr Nandi Nyamende on LinkedIn

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