Can the secrets of gummy candy improve 3D-printed foods?

Their finding could have implications for the ability to enhance food texture to develop superior lab-produced foods.

To tackle these questions and explore the intersection where science and culinary artistry merge, Interesting Engineering (IE) interviewed the study's lead author, Assistant Prof. Dr. Suzan Tireki. 

Why gummy candies?

"Gummy candies are sophisticated and very good model foods to study quality changes since there are many options of formulations with different ingredients," Tireki told IE. "Especially polymers such as gelatin and sweeteners such as glucose syrup.

She highlighted that food texture is a complicated area to investigate, particularly if a formulation or recipe includes an edible polymer. The situation also becomes more complex if you have several of these polymers in the same recipe.

"When you check the food market worldwide, you see many, many types of gummy candies with different recipes and textures," she added. "However, when you check the literature, there are very few studies regarding these candies."

Specifically, her team noticed a lack of studies that examined changes to essential quality parameters, such as texture, with different formulations. 

"We describe gummy candies as food gels formulated with polymers like gelatin, starch, or pectin," Tireki told IE. 

She explained that gelatin and starch play an important role as gelling agents in food. These gelling agents create connections, known as crosslinks, which are responsible for the stability, texture, and mouthfeel of the final food item.

"If you stabilize these crosslinks, you see a phase transition, meaning that you are changing the texture and forming a gel because you have polymers in the formulation," she said.

Tireki pointed out that gel formation is a crucial process in candy production. It's important to create the right gel texture during manufacturing, and ensure this remains intact for the entire shelf-life of the product.

"Therefore, if you can estimate the texture via the distance of these crosslinks in the candies and track it through the storage, you can have a good idea of the stability of your food gel," she highlighted. 

The importance of 'crosslinks'

Tireki's team examined various factors in the creation of crosslinks, such as the ratio of glucose syrup to sucrose, and the concentrations of starch and gelatin in the mix. "We prepared eight different candy recipes with different amounts of gelatin, starch, glucose syrup, and sugar," she said.

These could then be used to determine the impact of any modifications, at the molecular level, on important attributes like candy texture, moisture content, and pH.

The candies were also examined under different storage conditions. These encompassed a range of temperatures and times, from 10 to 30 degrees Celsius over 12 weeks, as well as 15 to 22 degrees Celsius for a year. A statistical model was used to describe how different combinations affected the quality of the gummy candies.

According to Tireki, the study's most innovative aspect involved examining the candies' texture by estimating the average crosslink distances using data on hardness obtained from texture profile analysis.

"Our most surprising finding was starch concentration did not affect the hardness and average crosslink distance value, although it is one of the most used polymers in the formulation of gummy candies," she revealed.

Improving 3D-printed foods 

Tireki emphasized that compared to other food product categories, the number of studies focusing on gummy candies is relatively low. This can be attributed to the complexity of the gummy candy-making process and the wide variety of ingredients used in different gummy candies.

"There are also some best practices in the industry; however, there aren't many scientific substantiations and reasonings for these best practices available for the professionals in the industry," she told IE.

She further pointed out that the fast-paced nature of the industry, aimed at quickly delivering products to consumers, leaves limited time for in-depth research into these complex topics.

"Furthermore, like our study, long-term studies mean additional costs to the industry," she said. 

"We believe that the food industry, especially the sugar confectionery industry, will benefit from our findings in their quality, standardization, and research and development studies as we provide valuable information on these complicated topics, making them more accessible to industry."

"Our findings and especially our approach could be used for improved 3D-printed foods in the future," she added.

Tireki highlighted that for their study, her team utilized simple cubic-shaped molds. While advancements in 3D printing technology offer numerous options for creating gummy candies with various shapes, colors, and even layers, adopting a similar approach to their study could serve as a valuable starting point.

While using 3D printing technology can enhance the visual appeal of food products, Tireki outlined it can also introduce additional complexities, particularly when it comes to achieving the desired texture and mouthfeel. 

The intricacies of creating the perfect texture become even more complicated when working with polymers and attempting to adjust various machinery parameters during the 3D printing process.

"Those who select the right polymers, make a good formulation, and overcome equipment and parameter challenges will be successful in developing 3D-printed food products," Tireki concluded. 

By uncovering the role of polymers such as gelatin and starch in creating the perfect chewiness, food scientists may now have a better idea of how to improve many lab-produced foods.