Electronic Acidity Tester | The Olive Oil Source

Electronic Acidity Tester

Source: The Olive Oil Source
December 31, 2003

We have had a tremendous interest in a new hand held acidity and peroxides tester. The tester requires only micro liter amounts of sample to produce results in minutes using a colorimetric method. The rugged 12 volt machines use low cost pre-measured disposable reagents and pipettes and do away with test tubes. The basic model checks acidity and peroxides while the premium one also checks saponified matter ("soaps") and polyphenols. The larger machine has a printer to document measurements on paper tape.

There are several reasons to measure olive oil acidity and peroxides. Most companies want their oil certified by local or international bodies. Certification requires passing organoleptic (taste, smell) and chemical parameters. Acidity testing in California for California Olive Oil Council certification is currently done at certified independent labs. It is uncertain if producers would be allowed to test their own oil for certification if they had the equipment. Requiring independent labs discourages fraud, although it is only the honor system which prevents tampering with the sample sent to the lab. While lab fees are not exorbitant for most producers, shipping samples and waiting for results is a bother.

Having one's own tester allows for some interesting experimentation. Producers can test the effect of olive variety, ripeness, harvest method, time to milling, milling method and pest infestation on acidity and peroxides. Different oil batches could be blended to optimize acidity for submission for certification. Planting decisions could be changed depending on results.

Producers may want to test oil in storage for freshness. Olive oil makers are becoming concerned with how their product is treated after it enters the retail chain. Oil could be pulled off the shelf to make sure it has not been improperly handled. Tins or tinted glass may be necessary for some retail segments depending on results.

Those owning commercial mills could more easily provide customers with an acidity determination for every batch of olives put through. Experimentation with different grinders and malaxation times could be facilitated by such a tester.

Checking olive oil acidity using standard lab equipment is straightforward but time consuming and messy. Titration burettes must be set up, reagents made and checked for freshness, drops counted and mixing performed consistently. There can be operator to operator differences in interpretation of results.  Then there is the cleanup; "doing the dishes" afterward. 

The machines have a sensitivity of  .05% oleic acid and .5mEO/Kg peroxides. They run on 12v. and come with a 120v adapter.

For more information call The Olive Oil Source.