Preparing and packaging a ready-to-eat salad may look simple enough, but it involves more than cutting tomatoes and closing a lid. Each production step affects how the salad will look and taste – and how long it will retain these qualities. These steps include the cold or dry storage of ingredients, washing, acidification (the addition of a dressing) to preserve freshness, heating, packaging and finally storage and distribution.

The EU-funded SOPHY project is developing software for salad producers wishing to either adapt a recipe (to meet consumer demand on salt content or additives, for example) or develop new products. The online computer program, which is being tested, uses microbiological data-based mathematical models to estimate the quality, shelf life and safety of the new product.

Picturing bacterial growth

To use the tool, a producer would simply input data on a given production step. For example, for cold storage, the user must indicate temperature, storage time and the initial bacteria count. The software depicts the bacterial growth in the form of a graph. The user is able to see at which time the number of spoilage bacteria crosses the acceptable threshold, which means the end of the product’s shelf life.

The user will see if this particular recipe might favour the growth of pathogenic bacteria like Salmonella – and if so, which processing steps could stop this (such as heating a chicken breast or acidifying a deli-salad).

Importantly, the software also is also able to keep track of potential quality changes such as taste. After all, what would be the point of a new salad that is safe and has a long shelf life, but which tastes bad?

Balancing safety and flavour

Achieving the right acidity level is just one of the problems – faced regularly by the industry – that the software can be used to solve. While consumers tend to dislike bitter flavours, removing acidity increases the risk of bacterial growth.

“The software can help define a level of acidity that doesn’t affect taste but still allows an acceptable shelf life,” explains project coordinator Christine Jewan of ttz-Bremerhaven in Germany.

The software’s predictions cannot replace laboratory analysis, but can reduce the intensive shelf-life tests involved in product development – only the most promising recipes need be tested. This saves the developer time and money and cuts down on waste, thus increasing competitiveness, says Jewan.

The software has been developed using a range of model fresh cut and deli salads proposed by industrial project partners, including shrimp, meat, cheese and mixed leaf salads as well as tzatziki.

The project presented a first version of the software to a packed industry workshop in September 2014. The SOPHY team is now working on improvements based on the feedback received from participants. This includes, for example, how the results are visualised, usability of the software in general, and the inclusion of new ingredients.

While developed specifically with deli salads in mind, the SOPHY software can also be adapted for other packaged foods.

A first version of the software will be available by the time the project finishes in January 2015, says Jewan. The team is currently discussing how to take to then take it to the market.