Vapour Sorption Isotherm Analyser

Categorized in: Water Activity

AquaLab VSA - the Total Product Moisture Anlayser

VSA - Emarketing pic.jpg

A moisture sorption isotherm shows the relationships between water activity and moisture content.

You can know just how much water you can add to a product and still be safe. You can even predict textural changes and determine the most stable point for your food product.

Using an isotherm, you can tinker with a recipe and predict how water activity will change as you change the formulation. You can predict how abuse conditions like high humidity will affect your products and your ingredients.

Other things you can do with an isotherm;

- Set QA/QC specifications

- Define critical control points

- Do packaging calculations

- Predict the effects of temperature abuse

- Determine monolayer value

- Maximize shelf life

- Determine when caking and clumping will occur

- Find glass transition and deliquescence points

- Predict protective coating/layer permeability

- Evaluate hygroscopicity

How do you measure an isotherm?

The AquaLab “Vapour Sorption Analyser” (VSA) allows you to measure both DDI (dynamic dewpoint) and DVS (equilibrium) isotherms.

AquaLab VSA can measure isotherms by constantly introducing saturated or dry air into the chamber (DDI), or it can control humidity at a specific level, raising and lowering RH when equilibrium has been reached (DVS).

Typical isotherms have limited usefulness because they're made from fewer than a dozen points. By contrast, the VSA uses the dynamic dewpoint method, which is:

• High-resolution - pinpoint critical product quality points
• Fast - 100 points in about 48 hours
• Automatic - put in a sample, press start, and walk away
• Easy to use - simple interface with user-controlled settings
• Complete - Generates sorption and desorption curves
• Data-rich - export data, graphs, and isotherm coefficients (GAB, BET, DLP)

VSA - Affordability

Costing 50-80% less than other moisture vapour sorption analysers, the AquaLab VSA can fit into an R&D budget. Its affordability results from the new approach Decagon Devices (manufacturer) has taken to DDI and DVS isotherms. The AquaLab VSA gets the same or better performance as other models, while putting isotherm technology within financial reach for customers.

The VSA – 10 facts you need to know

1: The VSA has replaced the AquaSorp (previous model by AquaLab)

2: The VSA is a stand-alone instrument

3: The VSA can connect to a pc

4: The VSA measurement temperature range is 15-60 degrees celcius – thus providing greater accuracy.

5: The VSA is easy to maintain.

6: The VSA is also a water activity instrument.

7: The VSA can generate DDI isotherms.

8: The VSA can generate equilibrium isotherms.

9: The VSA can generate both DDI and equilibrium isotherms on the one sample.

10: The VSA has a “stage interface” feature allowing users to run multiple isotherms by varying factors such as temperature, water activity, resolution etc for each stage.

Further information – webinar: Click here to view a one hour webinar regarding the VSA “10 facts” – presented by Brady Carter – Research Scientist at Decagon Devices, USA.

Examples – Applications of isotherms in the workplace

Click on the following examples to read more;

Example 1: Cakes - Make component mixing models

Example 2: Pecans - Set QA/AC specifications

Example 3: Milk powders - Define critical control points

Example 4: Sports drinks - Do packaging calculations

Example 5: Pet food - Predict the effects of temperature abuse