Incorporation of ash during traditional black olive processing: Effects on
bioactive compounds and antioxidant activity

Introduction: In addition to the conventional styles of table olive processing, there are some ancestral methods rarely used for which data are almost limited. Table olive composition is closely related to the applied technique, which is responsible for significant modifications. Consequently, the choice of a suitable method should take into consideration several parameters, in particular the use of natural ingredients that preserve their quality. Hence, the purpose of this study was to determine the effects of the incorporation of ash during olive processing on the bioactive compounds and the antioxidant activity of three Algerian olive cultivars.

Methods: Harvested olives were prepared with two methods using dry salt and ash as ingredients. Spectrophotometric methods were used for the analysis of fresh and treated olive extracts.

Results: The results indicate that processing has a significant effect on the contents of the bioactive substances as well as antioxidant activity. The method using ashes showed a better yield. Significant increases were recorded in phenolic contents, as well as antiradical activity, reaching an inhibition rate of 80% in Chemlal olives treated with ash, alongside a hydrogen peroxide inhibition activity rate of 75%.

Conclusion: This investigation confirms the quality of products prepared with natural and inexpensive ingredients which preserve their nutritional characteristics.