Solving an unexpected haze in fruit juice

One of our clients were asked to investigate why a batch of clear fruit juice had developed an unwanted haze. Here is how we approached their issue.

 

 

The challenge

 

A beverage manufacturer had noticed a haziness in a batch of fruit drinks during a quality assessment. After immediately quarantining the suspect products, they asked RSSL to investigate the problem.

 

 

Expert analysis

 

Our analytical team focused on identifying the haze, as this would help to explain why or how it had been formed and appropriate steps could then be taken to resolve the issue.

Several analytical techniques were used to gather data and build a profile of the haze. We began by examining the beverage sample at a higher magnification using light microscopy. This showed that the haze appeared to be dispersed throughout the liquid, although when left to settle it coalesced.

 

We then isolated the haze material and, after examining it again using light microscopy, determined that it comprised of extremely small and fine particulate material.

 

Further analysis with Fourier Transform Infrared (FT-IR) spectroscopy showed that the sample demonstrated a correlation with a protein/polyphenol spectra, which is the most common source of haze production in this type of beverage.

The result

 

Based on these findings, we confirmed the haze was formed by a protein-polyphenol reaction resulting from the presence of minute metallic particles in the liquid. This contamination was subsequently traced back to corrosion within the filling line in the manufacturing plant itself.  Once repaired, the haze problem was resolved. The client also disposed of the affected batches. 

 

Resolving urgent beverage issues

 

Concerned about unexpected haze in your liquid products? Our rapid and conclusive analytical tests mean you can be confident they will reach consumers with the required clarity, shelf life and quality. Find out more by clicking the link below.

Need to contact us? Get help or ask us a question