The sweet science behind gummy candies
Who doesn’t love those colourful, fruity gummy sweets 🍬 with their perfectly chewy, bouncy texture? They might seem simple, but there’s a lot hidden behind that irresistible bite. Each gummy is created from a carefully balanced recipe of gelling agents, sugars, acids, flavourings, and colourings. These ingredients work together to achieve the perfect texture and taste. For example, the chewy, gummy-like texture of gummy candies is created through the perfect interplay of sugar and gelatin. But, even the smallest change, like switching up the type or amount of gelling agent, can totally transform the final product. Furthermore, manufacturers need to consider labelling and certification standards, such as Halal compliance, to meet consumer expectations. That’s why reliable and consistent monitoring of each ingredient is essential!
Why SEC fingerprinting matters
Size Exclusion Chromatography (SEC), also called Gel Permeation Chromatography (GPC), is a fast and reliable solution. The process of separating molecules based on their hydrodynamic size creates a unique molecular fingerprint 🖐🏼 for each gummy formulation. With just a simple fingerprint, the manufacturer can:
- Verify the type or source of gelling agents, for example to ensure Halal compliance
- Monitor batch consistency and catch any production deviations
- Detect storage-related changes to evaluate shelf life
- Check low-molecular-weight components like sugars for semi-quantitative assessment
In short, SEC fingerprinting helps manufacturers ensure that their gummies always comply with regulations and remain consistent, so that every bite is as perfect as the first! 😋
How column choice impacts SEC resolution
Choosing the right column is really important for how well SEC can separate and reveal detailed molecular fingerprints. To demonstrate this, porcine and bovine gelatin reference standards were analyzed using two setups. First a single Multipore SuperOH-P column and second a coupled pair of SuperOH-P 350 and SuperOH-P 150 columns. Both setups cover the same separation range from 100 to 1 000 000 Da, but the coupled columns doubles the separation length, which in theory means higher resolution. And in practice, it really does! The coupled columns showed a better separation between porcine and bovine gelatin (see Fig. 1), creating more detailed and distinctive molecular fingerprints🔍.
Fig. 1 Overlay chromatograms measured with DAD at 230 nm, 20 µL. Dark blue: porcine reference standard; red: bovine reference standard; solid line: measured with column A; dotted line: measured with column set B.
How to create reliable SEC fingerprints
Reproducible and reliable SEC fingerprints are essential for effective quality control. The first step? Consistent sample preparation. Using the same dissolution method, concentration, and filtration keeps your SEC runs reliable, since even the smallest variation can change peak shapes and affect fingerprint accuracy. Next, it's not just about the column. Your overall system setup matters, too. For example, using a combination of a Refractive Index Detector (RID) and a Diode Array Detector (DAD) makes it possible to measure sugars, acids and polymers in a single run. Finally, peak identification makes it complete. By analyzing individual standards based on the gummy’s ingredient list, peaks can be correctly assigned, producing fingerprints that reveal everything from gelatin to low-molecular-weight components like sugars and organic acids (see Fig. 2).
Fig. 2 Zoom overlay chromatograms measured with RID, 20 µL and column set B. Black: Katjes® Yoghurt Gums; turquoise: apple pectin diluted 1:10; dark green: preserving sugar 1:1 (sugar; citric acid; pectin; fully hydrogenated sunflower oil); dark blue: maltodextrin; pink: sodium potassium tartrate; yellow: potassium citrate; red: citric acid; purple: lactic acid; beige: lactose; orange: sucrose; green: glucose; grey: blank.
In addition, using a flow marker can help correct system-related errors, like flow rate fluctuations, preventing shifts in retention times that might affect peak assignment (for more details on the flow marker and its use in SEC, see VTN0043).
How SEC verifies gelatin sources
The origin of gelatin is essential for labeling and religious compliance, particularly for Halal-certified products, where porcine gelatin is not allowed. To show how useful SEC can be, we analyzed two gummy samples with identical ingredients but different gelatin sources. One containing porcine gelatin and the other bovine gelatin as gelling agent. The resulting SEC fingerprints showed clear differences in the gelatin peak region (see Fig. 3 and 4). The Haribo® Goldbears matched the porcine reference standard, while the Halal Haribo® Goldbears matched the bovine reference standard. This confirms that SEC can reliably distinguish gelatin types.
Fig. 3 Overlay chromatograms measured with DAD at 230 nm, 20 µL and column set B. Solid dark blue line: Haribo® Goldbears; solid red line: Halal Haribo® Goldbears; dotted dark blue line: porcine reference standard; dotted red line: bovine reference standard.
Fig. 4 Overlay chromatograms measured with RID, 20 µL and column set B. Solid dark blue line: Haribo® Goldbears; solid red line: Halal Haribo® Goldbears; dotted dark blue line: porcine reference standard; dotted red line: bovine reference standard.
Why low-molecular-weight components matter
Beyond polymers and biopolymers like gelatin, SEC fingerprints also reveal low-molecular-weight compounds, such as sugars and organic acids. While this method doesn’t replace fully validated HPLC analyses, it provides a fast and reliable way to screen and compare samples, supporting quality control and ensuring product consistency. For example, using the RID, which detects non-UV-active compounds, differences in sugar content become visible. The RID chromatograms of two samples showed a much higher sucrose peak in the preserving sugar compared to the Haribo® Goldbears, highlighting variations in their formulations (see Fig. 5).
Fig. 5 Zoom overlay chromatograms measured with RID, 20 µL and column set B. Black: sucrose 1mg/ml; blue: Haribo® Goldbears; green: preserving sugar 1:1 (sugar; citric acid; pectin; fully hydrogenated sunflower oil).
SEC is a powerful tool for product quality and process control, providing detailed fingerprints across a wide range of gummy candies. And the best part? This approach can be expanded and adapted for use with other suitable products!
If you're planning to set up or optimize your GPC/SEC workflow, feel free to contact us at sales@knauer.net. Stay tuned for more exciting insights into the GPC/SEC world in our “GPC/SEC Made Easy” series.
For more information on the technical details, you can refer to the upcoming application note VFD0195, which will be published soon.
For further information on this topic, please contact our author: wesolowski@knauer.net
[1] Burey P., Bhandari B., Rutgers R. P. G., Halley P. J. & Torley P. J. (2010). Confectionery Gels: A Review on Formulation, Rheological and Structural Aspects. International Journal Of Food Properties, Vol. 12 (1), 176 - 210.
