Research into how to trace fresh produce from farm gate to dinner table is hitting speed bumps.
However, organisers believe they can find a solution within a couple of years.
Being able top trace produce fast could be important in the event of a food scare.
The problem arose after a food-borne disease, Yersinia pseudotuberculosis, broke out in September 2014, making 334 people ill.
Researchers could not prove where the bug came from.
Popular belief settled on carrots and lettuces, and growers suffered economic losses as a result.
This incident followed Fonterra's nightmare false alarm over botulism and made many people in the food industry nervous.
Since then, the consultancy, AgriChain Centre, has started research into how to trace fresh fruit and vegetables.
AgriChain managing director Anne-Marie Arts said the research was challenging, because the fresh food industry had so many products from different sources.
The company has received money from the Ministry of Primary Industry's Sustainable Farming Fund to carry out the research.
It has had some success developing systems for tracing fruit packed in containers, such as punnets of strawberries.
Although it was proving harder to trace loose, unpackaged products, such as lettuces, there was a system that might work, Ms Arts said.
"We're using the internationally recognised GS1 barcode," she said.
"With GS1, produce could be scanned at ten points across the supply chain.
"With those ten supply-chain points, we could track that product very quickly."
However, food producers often put their own labels on products, which could make tracing harder.
Ms Arts said if she could prove traceability was practical, there would be extra impetus for growers and distributors to comply with a universal tracing system, such as GS1.