A simple “smart food label” can accurately and instantly assess the freshness of food and determine if it has gone off. This helps reduce food waste and eliminate kitchen waste. Although this patented technology previously missed an opportunity for commercialisation, the launch of HK Tech 300, an innovation and entrepreneurship programme of City University of Hong Kong (CityUHK), prompted the research team to establish the start-up “ZenxTag”. They subsequently received a seed fund of HK$100,000 and angel fund investment of HK$1 million from HK Tech 300, enabling them to transform their research findings into a marketable label to help the food industry monitor food quality.
Unique detection technology: Label changes colour with food freshness
Food is essential to life, and food safety is paramount. ZenxTag’s smart food label uses technology to provide a food safety solution. In previous years, Professor Michael Lam Hon-wah, currently an Adjunct Professor in the Department of Chemistry at CityUHK, and his research team developed a “chemical sensing technology”. It can detect biogenic amines – highly volatile nitrogen-containing compounds produced when proteins break down during food spoilage. The team received a patent for the invention.
Miss Giselle Tsz-wing Chow, one of the co-founders of ZenxTag, is a member of Professor Lam’s team. She is also an alumna and a research assistant in the Department of Chemistry at CityUHK. She explained that high-protein foods, such as meat, seafood and soy products, can produce biogenic amines when stored in an inappropriate environment, at an improper temperature, or for an extended period. This can cause allergic reactions, such as vomiting, headaches or fainting. Higher concentrations of biogenic amines also indicate higher levels of bacteria in the food.
ZenxTag’s smart food label technology is based on a metal complex that reacts rapidly to biogenic amines. Combined with chemical molecular sensing technology, the label changes colour according to the concentration of biogenic amines, indicating the degree of freshness of the food. Green means the food is fresh and suitable for consumption; grey-brown suggests the food should be consumed quickly; and orange indicates spoiled food that should not be eaten. The label can be attached to the outside of food packaging without direct contact with the food.
High accuracy, low cost labels
“In the past, food inspectors or consumers could rely only on the best-before date, or their own senses by looking, touching or smelling the food to judge its freshness, based on its appearance or colour,” explained Giselle. While there are similar solutions in the market for the detection of biogenic amines, they generally rely on pH-induced reactions as the basis for detection, which can be easily affected by various factors in the food production process, including acidic additives or other chemicals. “Our chemical molecular sensing technology reacts only to biogenic amines, making it more accurate and reliable than other solutions,” she stressed.
In terms of cost, she pointed out that traditional testing relies mainly on laboratories to carry out bacterial content tests, which can cost thousands of dollars each. ZenxTag’s labels, in contrast, cost less than a dollar each, are disposable and can complete the test in a matter of seconds.
HK Tech 300 provides entrepreneurial support
The journey from laboratory to production line for ZenxTag’s smart food labels has not been without its challenges. Giselle recalled that while companies had previously shown interest in their technology, they preferred to buy the labels directly rather than the technological solution. “At that time, the team realised that we needed to set up a company to commercialise the product, but the innovation and technology environment back then was not as supportive of investment or start-ups as it is today, making it difficult to succeed,” she said.
It wasn’t until an event at which industry representatives visited university research projects that the team’s research was recognised again. Someone suggested they join the HK Tech 300 programme. They received seed funding from HK Tech 300 in 2021, officially launched ZenxTag in 2022, and later that year received angel fund investment of HK$1 million from HK Tech 300.
The company’s scientific research technology benefited considerably from the efforts of its predecessors, but setting up a start-up still presented many challenges. Giselle recalls that at the beginning of her entrepreneurial journey, she was just a 24-year-old university graduate, who had never paid taxes. Fortunately, HK Tech 300 provided entrepreneurial support and training. “Our team previously focused on studies and research, but running a business requires an understanding of accounting, taxation, contracts and working with other companies,” said Giselle. “So it was not clear how we could get support by just joining a start-up programme. The training and mentoring sessions provided by HK Tech 300 taught us how to write a business plan and make a presentation, which makes it easier for investors to understand our technology and products.”
With the incubation support of HK Tech 300, the company was eventually able to launch a product prototype. The programme gave them the opportunity to network with different industries, and they were selected for the Hong Kong Science and Technology Parks Corporation’s IDEATION programme.
Trial application in hotel restaurants to reduce food waste
So far, ZenxTag doesn’t have a large-scale production line, but they’ve started to tap into the market gradually, including trials in the restaurants of local Hong Kong hotels. “Leftover food from hotel buffets is collected and turned into meal boxes for the needy. They plan to invest in additional technology to prove that the food is still edible, thereby avoiding waste,” said Giselle. Other caterers can also use the labels to understand the exact condition of ingredients and decide the order in which they are used. For example, if the label is starting to change colour, they can use that batch of ingredients first, thus reducing kitchen waste.
The team’s smart food label is now in its fifth generation. In the future, they will continue to research and expand the technology to test alcohol, vegetables and other items. They also plan to incorporate Internet of Things technology to help manage food logistics, providing real-time information on food freshness and stock levels. In the long term, they hope to develop a production line to mass-produce the labels and expand into the mainland Chinese and Southeast Asian markets, making the technology widely available.
This research article originated from CityUHK HK Tech 300 Start-up Stories.