How to measure "browning" in Fruit Juices Follow

FAQ: "I have a client who wants to measure the degree of 'browning' in fruit juice concentrates.  The browning can occur due to overheating the juice concentrates, caramelizing the sugars. They can see it when they dilute the juice to working strength. Can you advise on how to measure this browning effect?"

If this browning effect can be seen at working strength Brix level, an L* lightness difference should be able to measure it.

Standardize the UltraScan VIS in TTRAN Large Area of View, UV Filter Nominal using a 10 mm cell + distilled water.

Read it back the cell + distilled water as a PQ Performance Qualification step with L* = 100, a* = 0, b* = 0 expected.

Then read L*, a*, b* D65/10 of working strength juice samples rated by the customer as being "good color" and those "with browning" or caramelization.

Average readings from multiple samples in each group.

There should be a distinct difference in the average L* lightness value between the group allowing a limit tolerance to be established when caramelization with processing has occurred.