Hydroxytyrosol is a very potent form of polyphenols that occurs naturally in the olive.
The aim of this study is to show that hydroxytyrosol is a powerful antioxidant that contributes to better stability and improves the shelf life and freshness of the product.

Results

Sensory evaluationstrong
The sensory evaluation shows no significant differences either during storage or between the samples.

Colour stabilitystrong
The colour of the samples does not develop or develops very slowly during storage. A very slight increase in red colour (a) is observed in samples with natural extract standardised into hydroxytyrosol. No influence of the yellow colour (b).

Oxidative stabilitystrong
The peroxide value measures the primary oxidation of fats. The peroxide value is given in milliequivalents of active oxygen per kilogram of oil (meq 02/kg).
A lower peroxide value indicates better oxidative stability of the product.

Conclusion
This comparative test clearly shows that hydroxytyrosol is very efficient in protecting fat in salad dressings from oxidation during storage and after opening the package.
Recommended use 840 ppm of the natural extract standardised to 3% hydroxytyrosol, which corresponds to 25 ppm hydroxytyrosol.