The physics of creating shelf-stable gummies

For gummy candies, texture might be more important than taste. It is disappointing to bite into a gummy expecting a burst of sweetness, only to be met by a hard, stale treat. Formulation and storage, both of which alter how the molecules in the candies link together, are vital to keeping gummies in good condition.

In AIP Publishing’s Physics of Fluids, researchers from Ozyegin University and Middle East Technical University conducted a series of experiments to explore how changing key parts of the gummy-making process affect the final product, as well as how the products behave in different storage temperatures. These results were used to identify the most shelf-stable combination for gummy candies.

The group adjusted a variety of inputs while making the gummies, from the glucose syrup-to-sucrose ratio to starch and gelatine concentrations. They sought to understand how these changes affected features like candy texture, moisture content and pH.

They then studied the resulting features of the candies before and after storage. Storage conditions vary from 10–30°C for 12 weeks or 15–22°C for a year.

These extensive combinations of procedures presented hurdles during the study, with the main challenge being a high number of parameters, according to author Suzan Tireki.

“We had eight different candy formulations, four different temperature conditions and two different storage times. Another challenge was to try to find a common model for all these eight formulations, as each of them behaved differently,” Tireki said.

Image credit: Suzan Tireki

To account for all the variables, the researchers used a statistical model to describe how each combination affected the quality parameters of the gummy. They explored the chemical crosslink distances — the length of bonds between molecules in the candy.

“The most innovative part of our study was investigating the texture of the gummy candies by estimating the average crosslink distances using the hardness data coming from texture profile analysis,” Tireki said.

The moisture content and pH, for example, were heavily dependent on the glucose syrup-to-sucrose ratio, whereas the gelatine content affected crosslink distances.

“Our most surprising finding was that hardness and average crosslink distance were not affected by the amount of starch,” Tireki said.

By identifying the most stable combinations for gummies, the shelf life can be extended and candy quality in different climates and across the industry can be improved.

The researchers next look to explore the role of plant-based formulations, mould shapes and packaging types.

Image credit: iStock.com/nadisja