Effect of dry salting on flavonoid profile and antioxidant capacity of Algerian olive cultivars

Abstract

SUMMARY:This study investigated the changes in the flavonoid profile and antioxidant capacity of five olive cultivars after dry salting. The antioxidant activity was determined using ferric reducing ability power (FRAP), oxygen radical absorbance capacity (ORAC), and β-carotene bleaching assays. The results showed that the effects of dry salting on the analyzed parameters were significant (P<0.05). It caused a decrease in total flavonoids with a loss rate of 55%. The HPLC analysis of extracts revealed the presence of four flavonoids: rutin, luteolin-7-glucoside, cyanidin-3-glucoside and cyanidin-3-rutinoside. Among the studied cultivars, Azeradj was characterized by high levels of flavonoids. Concerning the antioxidant activity, diverging results were obtained using different antioxidant assays. Overall, the dry salting induced a reduction in the antioxidant activity with variable values depending on the cultivar. Among the used methods, high correlations were found between flavonoid contents and the FRAP assay.KEYWORDS: Antioxidant activity; Cultivar; Dry salting; Flavonoid; HPLC; Olive RESUMEN: Efecto de la salazón en seco sobre el perfil de flavonoides y la capacidad antioxidante de cultivares Argelinos. En este estudio se investigó los cambios en el perfil de flavonoides y la capacidad antioxidante de cinco cultivares de olivo después de una salazón en seco. La actividad antioxidante se determinó mediante los métodos FRAP (Ferric ion Reducing Antioxidant Power), ORAC (capacidad de absorción de radicales de oxígeno) y ensayos de blanqueo de β-caroteno. Los resultados mostraron que los efectos de la salazón en seco en los parámetros analizados fueron significativos (P<0,05). Esto causó una disminución en los flavonoides totales con una tasa de pérdida del 55%. El análisis por HPLC de los extractos reveló la presencia de cuatro flavonoides: rutina, luteolina-7-glucósido, cianidina-3-glucósido y cianidina-3-rutinósido. Entre los cultivares estudiados, Azeradj se caracteriza por altos niveles de flavonoides. En cuanto a la actividad antioxidante, se obtuvieron resultados divergentes utilizando diferentes ensayos antioxidantes. En general, la salazón en seco indujo una reducción en la actividad.

GC‐MS olfactometric and LC‐DAD‐ESI‐MS/MS characterization of key odorants and phenolic compounds in black dry‐salted olives

“…(2010) also examined commercial Greek table olives for their oleuropein and hydroxytyrosol content and found compounds with concentrations of 800 mg kg −1 and 350 mg kg −1 respectively in the Throuba Thassos variety debittered in dry salt . Soufi et al . investigated the changes in the flavonoid profile of five olive cultivars after dry salting.…”

Investigation and quantification of the potential antioxidant, inflammatory, and antibacterial bioactive molecules of the extracts of Algerian black and green table olive brine

“…EOGM had the highest concentrations of polyphenols (1884.66 mg GAE/kg) and ortho-diphenols (271.39 mg CAE/mL) whereas EOGB had the lowest concentration of polyphenols (1746.5 mg GAE/kg), and EOBM had the lowest concentration of ortho-diphenols (Table 1). The phenolic content of olives decreases during ripening (Soufi et al, 2016). Diversity in phenolic content is due to the influence of cultivar, ripening, and processing method.…”

Neuritogenic Activities of Various Kappaphycus alvarezii Extracts in Hippocampal Neurons

“…This condition might have caused the release of compounds responsible for neuritogenic activities from the tissue. Soufi, Romero, Motilva, Gaya, and Louaileche (2016) reported that salting decreased the antioxidant activity of olive because of the loss of flavonoid compounds. Salting of Ulva rotundata with 25% NaCl and storing at RT decreased the yield of ulvan extraction (Robic et al, 2007).…”