Gummy hardness over time is a common challenge in the supplement industry, caused mainly by moisture loss and starch retrogradation. As a gummy sits, water molecules migrate to the surface and evaporate, creating a drier, harder matrix. If the gummy contains starch or certain hydrocolloids, the starch molecules can recrystallize—a process called retrogradation—which stiffens the texture. Temperature fluctuations and low-humidity storage accelerate these changes. To build a gummy that stays soft for two years, you need to control moisture retention, inhibit crystallization, and protect against environmental factors. It's not impossible.
So how do you fix it? Here’s the approach:
Key Formula Adjustments
- Moisture Stabilizers: Use humectants like glycerin or sorbitol at levels exceeding 15-20% of the formula. These bind water tightly and slow evaporation, keeping the gummy chewy.
- Prevent Retrogradation: Replace or reduce high-amylose starches with modified starches or maltodextrin. A blend of pectin and a low-amylose starch (e.g., waxy maize) significantly reduces hardening over time.
- Optimize Gelling Agents: Pectin-based gummies are less prone to hardening than gelatin-based ones. Go with a high-methoxy pectin with a rapid-set formulation for a stable, resilient gel network.
- Add Plasticizers: Ingredients like vegetable oil or medium-chain triglycerides (MCTs) at 0.5-2% help improve flexibility and reduce brittleness without affecting stability.
Processing and Packaging Controls
Deposition and Drying
Control the drying process carefully. Deposit gummies at a consistent temperature (e.g., 80-90°C) and cool them in a low-humidity environment to prevent surface moisture loss. Don't rush it. Avoid over-drying in starch molds; residual moisture levels of 12-15% by weight are often ideal for texture retention.
Packaging as a Barrier
Use high-barrier packaging films (e.g., metallized PET or aluminum foil laminates) with <0.1 g/m²/day water vapor transmission rates. Include a desiccant pack (e.g., silica gel) to absorb any moisture in the headspace. Seal packages under nitrogen to minimize oxidation and moisture migration.
Accelerated Stability Testing
To validate your design, conduct stability studies at 40°C/75% relative humidity for six months. Test hardness weekly using a texture analyzer (e.g., TA.XTPlus). If hardness increases by more than 10%, adjust humectant or gelling agent levels. For a two-year shelf life, aim for less than 15% change in hardness after the equivalent accelerated period.
At KorNutra, we stick to these principles. We never speculate on medical benefits or make health claims, focusing instead on production excellence. By combining careful ingredient selection, precise processing controls, and robust packaging, it's possible to deliver a gummy that stays soft, chewy, and identical in texture for two years. If you’re developing a product with such requirements, our team can help tailor the formulation to achieve this stability without compromising other quality parameters.