Chemical parameters and antioxidant activity of turning color natural-style table olives of the Sigoise cultivar

C. Romero,E. Medina,F. Ait Chabane,P. Rovellini,A. Tamendjari

doi:10.3989/gya.0559201

C. Romero, E. Medina + Show 3 more

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https://doi.org/10.3989/gya.0559201

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Abstract

A chemical characterization of turning color table olives of the Sigoise variety was made through their processing as natural-style. Polyphenols, sugars, tocopherols, fatty acids, and antioxidant activity in the olives were monitored throughout the elaboration process. Oleuropein, salidroside, hydroxytyrosol 4-glucoside, rutin, ligustroside and verbascoside showed a decrease of 16.90-83.34%, while hydroxytyrosol increased during the first months of brining. Glucose was consumed by 90% due to the metabolism of the fermentative microbiota. The tocopherol content remained stable during the process and only the α-tocopherol decreased. The fatty acids were not affected. The loss in antioxidant compounds resulted in a decrease in the percentage of DPPH radical inhibition from 75.91% in the raw fruit to 44.20% after 150 days of brining. Therefore, the turning color natural table olives of the Sigoise variety are a good source of bioactive compounds.

Highlights

Table olives are elaborated from the fruit of olive tree (Olea europaea L.) and they are considered the most popular fermented vegetable in the Mediterranean countries
This study has characterized the main compounds, in particular, polyphenols, sugars, fatty acids and tocopherols, in the turning color table olives elaborated as natural-style of the Sigoise cultivar
The total polyphenol content decreased as the process progressed, except for the hydroxytyrosol, which increased at the beginning of brining and decreased

Summary

Introduction

Table olives are elaborated from the fruit of olive tree (Olea europaea L.) and they are considered the most popular fermented vegetable in the Mediterranean countries. The production of table olives in Algeria is estimated at 293000 tons (IOC, 2020) and represents 10% of worldwide production. The fruits contain a small amount of proteins (12%) and sugars (2.6-6%). This composition depends on several factors, such as the type of cultivar and the ripening stage (Boskou et al, 2014). Polyphenols are the most relevant and represent the 1-3% of the fresh pulp weight. Oleuropein is the major phenolic compound and is responsible for the bitter taste, which makes the fresh fruit inedible (Kiai and Hafidi, 2014)

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