22 Analytical Testing
The purpose of analytical testing is to reduce the number of sensory panels needed by measuring sensory attributes with equipment and to measure attributes needed for product specifications. Analytical testing also can be used to determine shelf life and shelf stability parameters. Make a plan for analytical testing based on key product characteristics/attributes.
1. Determine what attributes of your food are most important for food safety, quality, and consistency.
- It is too expensive and time-intensive to test every attribute of a food product, but enough testing needs to be done to understand product characteristics and to maintain product safety and quality.
- Typically 4-6 analytical tests are run per new food product.
- Look at the Analytical Testing Equipment available in your food lab.
- Common Analytical Equipment
- Water Activity Meter
- Moisture Balance
- pH Meter
- Hunter Colorimeter
- Texture Analyzer – know what textural attribute you want to measure
- Bostwick Consistometer
- Ring Spread Test
- Brookfield Viscometer
- Seed Displacement
- Density (calculation)
- Next, determine the best way(s) to test the key product attributes.
- Discuss options with faculty as needed.
A Note on Microbial Testing – Often food labs do not have microbial testing capabilities and rely on available research and knowledge to set kill steps in-process and finished product specifications. If specific microbial testing is needed for a new product, teams can inquire with related food microbiological labs on campus to see if testing can be conducted.
2. Timing of Testing: Think through the timing of testing or when the product iterations that need to be tested will be made.
- The gold standard product will need to be compared with the scaled-up industrial product.
- Some in-process testing may be needed.
- Typically finished product testing is best when the product is fresh, but testing at the same time for each product is more important.
- Analytical testing also can be used for shelf-life testing and to compare the preparation or storage methods of a product.
3. Sample Amount Needed: When in doubt, more samples are better than fewer. Testing multiple batches is advised when possible, but we realize it is not always feasible with limited time and resources.
- At least three samples from the same batch or iteration are needed for testing such as viscosity, color, moisture, and water activity. This will help reduce variability across a batch.
- Seven to ten samples per batch or iteration are typically needed for texture analysis. More is needed if there is considerable variability of texture in the product (think crisp and crunchy products).
- Consider the sample available for testing and the order of testing when the sample amount is limited. Texture analysis typically needs whole product. Water activity, moisture content, and pH need homogenous and often mixed/ground product.
- More samples are almost always needed at the beginning of analytical testing to set test parameters. This is especially true for the texture analyzer because testing parameters will need to be set specific to your product.
4. Analytical Testing Plan: After working through steps 1-3, compile your testing needs into the table shown below. Edit the table as necessary for your product testing needs. Review your testing plan with faculty before you start.
|Product Characteristic||Testing Method/ Equipment||Testing Parameters||What the method actually tests||Number or Amount of Samples needed||Sample time (s)||Sample conditions|
|Ex. Chewiness||Texture Analyzer||3 Point Bend Rig + Knife||Downward force and distance||At least 10 per variable or iteration||Same day as baked – for gold standard and scale-up product. Test 1st (then use the broken product for other sampling)||Whole, 6-7 cm in diameter|