Here is ListWare - the Digital Shelf Life Calculator

Animalia has launched ListWare, a shelf life calculator web tool for producers of ready-to-eat food products.

This is a web program that calculates the shelf life of ready-to-eat products based on the potential growth of the bacterium Listeria monocytogenes. The software is designed for food companies that produce ready-to-eat foods, meaning products that consumers do not heat before consumption. Examples include deli meats, sausages, burgers, meatballs, mayonnaise-based salads, and green salads.

ListWare aims to facilitate more affordable and straightforward risk assessments for the shelf life of ready-to-eat products. It provides safer food, reduces costs for food businesses, minimizes food waste, and promotes a more sustainable supply chain.

Ready-to-eat Food

The calculator helps in risk assessment and documenting the shelf life of ready-to-eat foods through predictive modeling. The bacterium Listeria monocytogenes poses a challenge in foods not heat-treated by consumers because the bacteria can grow at refrigerator temperatures and reach pathogenic levels during storage.

Healthy individuals can tolerate consuming some Listeria without getting sick, but those with weakened immune systems, pregnant women, children, and the elderly are more vulnerable. Authorities have set a legal limit of 100 colony-forming units (CFUs) per gram of product during the shelf life. Listeria growth is mainly influenced by pH, water activity, added growth inhibitors in the products, and storage temperature. Therefore, the growth rate of Listeria varies in different products.

Testing of Growth Rate

In the projects, the Veterinary Institute has tested the growth rate in many products with various packaging methods and additives. A total of 243 growth experiments have been conducted on 27 individual ingredients or composite products. Based on these results, statistical models have been created to predict the growth rate at different temperatures and other growth factors.

Simplifying Calculations

Food companies producing ready-to-eat products are responsible for risk assessment and determining the shelf life of their products. This can be done by testing products in a laboratory with the addition of Listeria or using predictive modeling. The ListWare program was developed by Animalia, the Veterinary Institute, Grilstad, Fatland, Matbørsen, Salatmestern, Mills, and Bama. Nortura and Orkla were also part of the initial project. The projects were funded by the Research Council and the companies.

ListWare is a user-friendly program available in Norwegian or English that is easy to use. The user selects a product from a menu, and suggested product characteristics such as ingredients, pH, water activity, carbohydrate content, and growth inhibitors like lactate and acetate are proposed. These suggestions are based on 1677 laboratory analyses, eliminating the need for users to analyze this themselves. However, values can be overridden. The user enters the packaging method and assumed storage temperature, and a growth curve for Listeria is calculated. The number of days it takes for Listeria growth to reach 100 colony-forming units per gram defines the Listeria shelf life. Users can print documentation for use in inspections and product development.

Significant Research Effort

The program can also be used for simulation to find ways to increase shelf life. This may involve adding acetate or lactate in varying amounts, changing to a different packaging method that inhibits Listeria growth, and adjusting pH and carbohydrate content. Increased shelf life can be calculated with a few keystrokes instead of conducting stress tests in the laboratory.

Behind these predictive models is substantial research work. Expertise has been gathered from Norwegian and European research environments specializing in Listeria and predictive modeling. The research has been published and accepted in scientific journals and presented at research conferences.