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 the data are almost limited. Olive table composition is closely related to the applied technique, which is responsible for significant modification. Consequently, the choice of a suitable method should take into consideration several parameters, in particular the use of natural ingredient that preserve their quality; hence, the purpose of this study is 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 via two methods using the dry salt and ash as an ingredient. Spectrophotometric methods were performed 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 phenolics contents, as well as antiradical activity reaching an inhibition rate of 80% in Chemlal olives treated with ash; hydrogen peroxide inhibition activity was at a rate of 75%.

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