Product overview
The Dough Inflation System enables the rheological properties of dough to be measured during biaxial stretching, which is the deformation in the cell wall material surrounding a expanding gas bubble during proof and baking. It provides a precise, digital measurement of dough expansion under conditions of strain and strain rate similar to those encountered in baking producing graphical and spreadsheet data for optimising recipes, proofing, shaping and baking conditions.
Why measure dough inflation properties?
Measuring dough inflation helps bakers to determine the quality of the dough, which traditionally was done by the tactile experience of hand kneading and stretching.
This modern technique is ideal for quality control and R&D supporting the development of superior baked products in the following ways:
- Optimising ingredients: Understanding dough inflation and monitoring what affects the dough’s rise can guide adjustments in the formulation or optimisation of flour blending or wheat choice. The conformity of incoming flour at the bakery can also be evaluated.
- Processing conditions: Dough inflation properties can inform the optimal conditions for mixing, proofing and baking, including time, temperature and humidity levels.
- Product development: For new products or variations, studying dough inflation is part of the R&D process to create baked goods with specific qualities and differentiation in the market. Wheats or flours can be classified according to their baking strength and the need for dough conditions for strengthening or weakening the dough can be assessed.
- Predicting final product characteristics: The way dough inflates is indicative of the final product’s volume, texture, and crumb structure. For example, in bread-making, proper inflation is crucial for achieving the desired lightness and porosity.
- Quality control: It helps in ensuring consistency in dough performance across different batches in the production process. Consistent inflation properties mean that the dough will behave predictably during processing and baking.
- Troubleshooting: If a final baked product is not meeting quality standards, analysing dough inflation can help identify issues in the fermentation or mixing process.
- Efficiency and cost: By understanding and controlling dough properties, manufacturers can reduce waste and improve the efficiency of the baking process, potentially lowering production costs.
Dough inflation properties are a key component of the science of baking, impacting the product’s commercial success and customer satisfaction.
Advantages of this system
(in comparison with alternative systems)
Testing of smaller samples is possible where sample quantity is limited
Temperature Chamber allows testing and sample storage at controlled proofing temperatures (up to 60°C) for optimised results
Provides traditional test capabilities with enhanced control over test parameters and comprehensive data analysis for advanced rheological evaluations
How the Dough Inflation System works
Samples are prepared to a specific thickness in a container which includes a central hole in its base. The sample is inflated by volume displacement of air using a piston driven by a Stable Micro Systems Texture Analyser. Pressure during inflation is measured by a pressure transducer and the volume of the inflating dough sheet is calculated from the displacement of the piston.
The system together with dedicated software, combines ease of use with automatic data collection and project based data analysis to provide traditionally recognised rheological measurements or customer-created parameters from pressure, volume and time data.
Traditional measurements
The Dough Inflation System provides traditional universally recognised measurements for tenacity, extensibility, elasticity, and baking strength (P, L, W and I.e. values) based on fundamental equations.
P (Y-axis): Tenacity – the maximum pressure (height of the peak) required during inflation of the sample. It is the capacity to resist deformation and at a given hydration it represents dough consistency e.g. whether the dough is hard or soft. It has also been claimed to be an indicator of dough tensile strength in the initial stage of deformation, related to the stiffness, shortness and tightness of the dough. Tenacity depends on water absorption capacity, protein quantity and quality, starch damage, fibres (pentosans, ash content).
L (X-axis): Extensibility – the length (mm) of the curve up to the point of rupture. It is a measure of how much the dough can be extended before it breaks and is related to the maximum volume of air that the bubble can contain. This value depends on protein quantity and quality and represents the dough’s gas retention capacity. It has a strong correlation with bread volume.
W (area under the curve): Baking strength – the deformation energy necessary to inflate the sample until rupture. This total area of the curve or total deformation energy value indicates dough baking strength and depends on protein quantity and quality, starch damage, enzymes, interactions. W is usually much larger for hard wheat flours than for soft wheat flours.
P/L: Configuration ratio of the curve or the maximum pressure required for deformation divided by the maximum amount of air that the bubble is capable of containing. It represents the balance of the elastic and viscous components of the dough. High P/L indicates a resistant and inextensible dough, while low P/L indicates a weak and extensible dough.
Ie: Elasticity index – represents the capacity of dough to stretch and return to its initial position when the stress ends. It compares pressure after 200 mL volume of air has been blown into the dough test piece or bubble versus the maximum pressure (P).
Additional measurements
The collected data allows flexibility in the acquisition and calculation of additional bespoke parameters either in pressure, volume or stress-strain terms. This allows for further discrimination and predictive tools to be defined.
Sample preparation
Mixing flexibility
We recognise that in practice bakeries are using a wide range of mixing bowl sizes and mixing blade types. You will want the flexibility to gain test results that correspond to the equipment and mixing preference you have in your facility. This is why we leave the dough preparation decisions up to you and take your testing from this stage onwards for optimum correlation.
Sample steps
1. Rolled dough cut and transferred to sample pot
2. Sample retained with 50mm ring and pressed to 2.67mm thickness.
3. Stack of 5 samples covered and allowed to rest.
4. Sample mounted onto inflation system ready to inflate.
Minimal manual handling
The pre-inflation procedure requires minimum handling of the dough when preparing samples – there is no contact of the sample when transferring to the Dough Inflation System.
Dough Cutter
Small Sample Set – for when sample size is limited
The Small Sample Set allows the option of preparation of much smaller samples with software calculations adjusted accordingly to measure the same parameters.
This requires less material which is especially beneficial when ingredients are in limited supply during certain stages of trials. It also allows for testing of dough behaviours in products where only a small amount of dough is used such as in cookie or mini pastry quality control.
For quality control, testing small pieces can also be a quick quality check without disrupting the larger batch, enabling continuous monitoring.
Small Sample Set
How to interpret your data
No single type of flour is inherently “better” than another; the suitability largely depends on the specific production process and the final product being made. For example, flour with lower tenacity (P value) might be ideal for making cookies or wafers, whilst a higher tenacity flour would be better suited for products like sliced bread or panettone.
The Dough Inflation System can help identify the key characteristics of dough that are best suited for the desired end product.
Typical value ranges
| Flour function | Inflation requirements | Typical P/L values | Typical W values |
| Strong elastic dough suitable for excellent bread making | High pressure (P) Long distance (L) to burst |
P/L < 0.9 | W > 170 |
| Extensible dough suitable for biscuit making and blending with strong wheat flours | Low pressure (P) and long distance (L) to burst W value is less critical | P/L < 0.55 | W 80 – 120 |
| Tough inelastic dough suitable only for animal feed | High pressure (P) and short distance (L) to burst | P/L 0.3 – 1.5 | W 60 – 140 |
Data display and presentation options
The test, display of the result and calculation of index values are fully automatic and provided in graphical, spreadsheet and report formats.
Designing your test method and analysis – the traditional or investigatory approach?
Alongside the traditional method for testing dough inflation properties the software provides users with a wide variety of alternative test setting options in order to provide a real-time graphical display from tests. For example, stress relaxation measurements can be obtained by inflating dough to a fixed volume and measuring collapse in stress with time.
Built in macros and spreadsheet facilities provide automated data collection and spreadsheet facilities of the traditional method parameters along with the tools to make any measurements you wish such as drum distance, Hencky strain, pressure ratios, areas, volume change and deformation energy between two chosen points as well as simple spot values.
Spreadsheets support a range of mathematical functions that enable results to be derived from the basic data. Charts are easily created to present spreadsheet results in a more convenient format thereby providing full analysis and presentation flexibility.
Standard dough inflation settings
Settings to allow inflation at a constant strain rate
Constant Strain Inflation Rate
The TA.XTplusC Texture Analyser has the unique option of continuously variable inflation speed, which allows tests to be performed at constant strain rates.
Because dough is viscoelastic, its rheological properties vary with both strain and strain rate. Therefore it is necessary to separate out the effects of strain and strain rate by keeping one constant whilst varying the other. As an option we provide a dough inflation test sequence where strain is varied and measured as the bubble inflates, and by continuously changing the speed at which the bubble is inflated, strain rate is kept constant.
Verification
Work at Reading University as part of a MAFF funded LINK project has shown that the stability of failure in single dough bubble walls is related directly to the extensional strain hardening properties of the dough, and that strain hardening plays an important role in the stabilisation of bubble walls during baking. Strain hardening measured at 50°C and constant strain rate for a number of commercial flours of varying quality using the TA.XTplusC Texture Analyser has been related to commercial breadmaking performance.
Optional testing accessories
Thermal Cabinet
Adding a thermal cabinet to a dough inflation system is necessary for several reasons:
Temperature control to 60C: Yeast activity and dough development are highly temperature-dependent. A thermal cabinet can provide a consistent and controlled environment, which is crucial for accurate dough inflation measurements.
Proofing optimisation: It allows for precise control of the proofing stage, ensuring that the dough reaches the ideal gas retention and elasticity before testing.
Testing under different conditions: A thermal cabinet can simulate various baking environments, allowing for testing under conditions that mimic different climates and seasons.
Material behaviour analysis: Understanding how dough reacts to temperature changes can help in analysing and adjusting the formulation for desired inflation properties.
Quality assurance: Maintaining the dough at specific temperatures can help in ensuring that the end product meets quality and safety standards.
Process standardisation: A thermal cabinet helps standardise the pre-testing conditions of the dough, which is essential for comparative analysis and research and development purposes.
Video Capture and Synchronisation System
Providing the option of video synchronisation in dough inflation testing offers significant advantages by adding a dynamic layer of analysis, enriching the data with visual insights and offering a multifaceted understanding of dough properties.
Visual analysis: It allows for a visual record of the inflation process, giving insights into the dough’s behaviour that may not
be captured by numbers alone, such as uneven expansion or surface tearing.
Correlation with data: Synchronising video with data helps in correlating visual cues with specific stages of the inflation process, making it easier to identify the exact moment when changes occur.
Research and development: For R&D, video can be used to observe the effects of different formulations or ingredients on the dough’s expansion and texture.
Communication tool: Video evidence can be a powerful communication tool, useful for reporting results to stakeholders, troubleshooting technical issues or for educational demonstrations/training purposes.
Innovation and improvement: Visual information can drive innovation by revealing unexpected behaviours, leading to improvements in dough formulations and processing techniques.
Additional Sample Set
Technical specification
|
Mechanical and performance |
|
| Piston diameter | 150mm |
| Pressure range | 0 – 27.7in H20 (68.95 mb/704 mm H20 (1Psi)) |
| Volume (theoretical) | 0-2032218 mm³ (2032 cm³) 2.3L |
| Weight | 5.7kg |
| Working temperature range | 10°C – 65°C |
| Flow rates are always received as speeds from the Texture Analyser and converted through the software. Flows can be input in cm³/minute or litres/minute. | |
| Minimum flow rate | 10.56cm³/min for a TA.XTplusC/HDplusC Texture Analyser (corresponding to 0.01mm/sec) |
| Maximum flow rate | 42240cm³/min (corresponding to vertical speed of 40mm/sec) |
|
Environmental conditions |
|
|
The equipment is designed for operation in typical indoor laboratory conditions |
|
| Temperature | 0°C to 40°C |
| Humidity | 0% to 90% RH non-condensing |
| Ingress protection rating | IP40 |
| Additional | |
| Power | Provided by Texture Analyser |
| Software languages | Language editor available for translation to Cyrillic languages |
| Exporting options | Excel, LIMS, USB |