Edible films: transparent carriers for formulation and texture control

Edible packaging materials are now commercially available and increasingly used in product development, both in fine dining and in industrial R&D. Transparent edible films enable “disappearing” ravioli, clear canapés and edible cocktails, but they are also a practical platform for delivering controlled doses of flavours, actives and textures.

Beyond their visual appeal, these films behave as thin, water-sensitive polymer matrices whose mechanical and interfacial properties can be engineered and quantified. This makes them highly relevant to food scientists, process engineers and material specialists working on novel formats, portion control, and sustainable packaging concepts.

Material composition and functional behaviour

Edible film formulations such as those popularised in modernist cuisine are typically based on potato starch as the primary polysaccharide matrix, combined with soy lecithin as an emulsifier and surface-active component. The resulting material exhibits:

• Neutral flavour
• Paper-like thickness (tens of micrometres, depending on casting and drying conditions)
• High transparency, enabling “see-through” presentation
• Rapid dissolution in aqueous systems, but
• Limited solubility in oil or low-moisture environments

From a functional perspective, this means the film:

• Disintegrates quickly in high water activity systems (e.g. aqueous cocktails, sauces), providing a clean release of encapsulated ingredients.

• Remains intact in predominantly lipid or low water activity matrices, serving as a carrier or barrier layer.

The film can hold both liquid and solid inclusions, can be cut into arbitrary geometries (using die-cutting, laser cutting or simple mechanical cutting), and can be laminated to increase thickness, stiffness or fracture energy. Heat sealing allows the creation of sealed pouches or capsules, in a similar manner to conventional thermoplastic films, but within the constraints of food-safe temperature and time profiles.

Application concepts and formulation opportunities

Transparent edible films offer a controllable, thin-layer matrix for:

• Encapsulation and delivery of crèmes, honeys, dried fruits, oil suspensions or powders.
• Portion-controlled dosing of flavours, colours or functional ingredients.
• Structured layering where the film acts as a discrete interface between components.

Chefs have demonstrated their use as:

• Tortilla-like or taco shell-like carriers
• “Paper” cocktails and clear canapés
• Edible wrappers and cones

For R&D teams, the same principles can be extended to:

• Prototyping single-serve inclusions that dissolve in contact with saliva or beverages.
• Designing multi-phase assemblies where the film governs the timing of release or texture transition.
• Evaluating barrier behaviour in contact with oils or low-moisture components, where the film may act as a partial moisture or mass-transfer control layer.

Understanding dissolution kinetics, moisture uptake and mechanical response under controlled temperature and humidity is essential for scaling these concepts from kitchen trials to manufacturing.

Future directions in edible film packaging

Given their compositional flexibility and responsiveness to moisture, edible films are a candidate technology for:

• Edible primary packaging for snacks, single portions or inclusions that are further protected by a secondary, conventional pack.
• On-demand rehydrating systems, where the film provides structure until exposure to water or high humidity.
• Waste reduction strategies, where part of the packaging mass is designed to be consumed.

Their adoption will depend on demonstrating robust performance under realistic process and distribution conditions. This includes stability under mechanical handling, storage humidity cycles and temperature fluctuations, as well as consistent consumer sensory response.

Mechanical and interfacial characterisation

To integrate edible films into reliable products, their mechanical and surface properties must be quantified using appropriate test methods. Using a TA.XTplusC Texture Analyser, one can obtain:

• Tensile properties

  • Uniaxial tensile strength

  • Elastic modulus

  • Elongation at break

• Biaxial deformation response, more representative of real handling or inflation-type stresses
• Compression and puncture resistance, relevant for handling, filling and biting
• Adhesive and cohesive properties, including work of adhesion to substrates or between film layers

In addition to stress-strain behaviour, coating and adhesion characteristics are often critical. The film may be required to:

• Adhere to a food substrate to fix a coating or provide a glossy finish.

• Maintain cohesion under humidity changes without delamination.

• Deliberately minimise adhesion where easy release is required.

Example test configurations

Film Support Rig

Our Film Support Rig is used for biaxial tension measurements, where the film is clamped across an aperture and deformed out of plane. This configuration provides data on biaxial modulus, rupture force and energy to break, better reflecting deformation modes seen in applications such as filling, folding or inflation.

Miniature Tensile Grips

Our Miniature Tensile Grips are used for uniaxial tensile testing of small film strips. From the load-extension curve, tensile strength, modulus and elongation at break can be calculated. These parameters support optimisation of formulation (e.g. starch-to-lecithin ratio, plasticiser content, drying conditions) and process settings.

Additional tests of interest in a development environment may include:

• Adhesion/peel tests, quantifying the force required to detach the film from specific food substrates.
• Cyclic loading tests, to assess fatigue and resistance to repeated flexing.
• Environmental conditioning, where samples are equilibrated at defined relative humidity and temperature prior to testing to mimic storage conditions.

Implications for product development

By combining creative formulation with quantitative mechanical and interfacial testing, edible films can be engineered as predictable, functional materials rather than purely visual novelties.

Stable Micro Systems collaborates with the food sector to apply texture analysis and related measurement techniques to these films, supporting:

• Robust specification of mechanical properties.
• Objective comparison of alternative formulations and suppliers.
• Data-driven optimisation of processing conditions and shelf-life performance.

For scientists, engineers and R&D teams, edible films represent a practical platform where material science, texture analysis and product design intersect, enabling both innovative presentations and technically sound, reproducible products.