Addition of ‘Chetoui’ olive leaf extract to reduce acrylamide in Californian-style black olive

Abstract

To improve food quality, the use of olive leaf extracts has been an emergent strategy that needs to be study in different scenarios. Certain local olive varieties are waiting to be discovered as potential by-product sources, in which a Tunisian variety named ‘Chetoui’ can be pointed out. The use of this variety at different tree ages to elaborate olive leaf extracts (OLE) in different solvents has been the main procedure to study during this assay. Different OLE concentrations were prepared in order to evaluate its effect in contaminants such as acrylamide. Adult ‘Chetoui’ OLE presented a richer phenolic content that is younger homonym. Principal phenols like hydroxytyrosol, tyrosol, oleuropein and luteolin-7-O-gluvoside presented higher levels for both tree ages. In terms of extractants, the most effective was Methanol, having concentrations for oleuropein, hydroxytyrosol and Luteolin-7-O-glucoside of 175331, 32433 and 10688 mg 100 g−1 respectively. Hexane was the least successful solvent, having no concentration for plenty of the phenols. Acrylamide concentration was deeply affected for the OLE presence for every extract concentration, being OLE (1:10) and OLE (1:10 + HTy) the additions with a better performance followed by OLE (1:100). A sensory analysis was performed finding out that OLE (1:100) was the most appealing for the consumer when adding it to table olives. The current research attempts to discover new applications for local varieties, using by-products to enhance oxidized black table olives added value. Finally, market products would become healthier, safer and with better quality to be released in the food industry.