Texture and antioxidant evolution of naturally green table olives as affected by different sodium chloride brine concentrations

Abstract

SUMMARY:The results on the evolution of the texture and antioxidant activity during the processing of naturally fermented green olives are reported in the present study. The olives were brined with two different NaCl concentrations, 4 and 7%. A puncture test and a texture profile analysis (TPA) test were carried out to evaluate texture, while the antioxidant activity was assessed in consideration of the loss of absorbance of a stable radical upon reaction with a polyphenolic olive extract. The puncture test revealed both an increase and decrease in peel and flesh hardness, respectively. The olives processed with 7% NaCl concentration showed higher peel hardness than olives brined with 4% salt. The texture profile analysis did not reveal any difference between the two salt concentrations used, but showed a decrease in the value of all parameters after 30 days of brining. The antioxidant activity of the polyphenolic extract decreased significantly during processing, with a major loss after the first 30 days of processing and was higher in the 7% brined olives, than the sample treated with 4% NaCl. KEYWORDS: Antioxidant activity; Natural Fermentation; Sensory analysis; Texture; Texture profile analysis; Tonda di Cagliari RESUMEN: Evolución de la textura y capacidad antioxidante de aceitunas de mesa procesadas al natural con diferentes concentraciones de cloruro de sodio. En este trabajo se presentan los resultados sobre la evolución de la textura y la actividad antioxidante durante el proceso de fermentación natural de las aceitunas verdes. Los frutos se colocaron en salmueras con dos concentraciones de NaCl del 4% y 7%. Se evaluó la textura mediante ensayo de perforación y mediante análisis de perfil de textura (TPA), mientras que la actividad antioxidante se evaluó considerando la pérdida de absorbancia de un radical estable tras la reacción con un extracto polifenólico de las aceitunas. El ensayo de perforación reveló un aumento de la dureza de la piel y una reducción en la dureza de la pulpa. Las aceitunas procesadas con una concentración de NaCl del 7% mostraron una dureza mayor que aquellas tratadas con sal al 4%. El análisis del perfil de la textura no reveló diferencias entre las dos concentraciones usadas de sal, pero mostró una disminución en el valor de todos los parámetros después del primer mes de salmuera. La actividad antioxidante del extracto polifenólico disminuyó significativamente durante el tratamiento, con una pérdida importante después de los primeros 30 días de tratamiento y fue más alto en las aceitunas del 7% en salmuera respecto a las muestras tratadas con el 4% de NaCl.

Effect of olive leaf extract combined with Saccharomyces cerevisiae in the fermentation process of table olives

“…These results partially differ from those of previous studies. Fadda et al (2014), by using natural fermentation on table olives, observed that the maximum force increased throughout the fermentation. Also, Romeo et al (2009) explained that the stability of table olive texture during fermentation is due to the salt concentration used.…”

Evolution of Bacterial Communities, Physicochemical Changes and Sensorial Attributes of Natural Whole and Cracked Picual Table Olives During Spontaneous and Inoculated Fermentation

“…Texture evaluation was estimated using a texture analyzer (Stable Micro Systems TA.XTplusC, Vienna Court, Lammas Road, Godalming, Surrey GU7 1YL, United Kingdom) following the method of Fadda et al (2014). The analysis applied to at least ten random olives.…”

Comparative Study on Chemical Composition of Green and Black Table Olives Brines of the Endemic ′′Sigoise′′ Cultivar: Recovery of high‐Added Values Compounds

“…With respect to the antioxidant properties of the olive, it is to be noted that they are conditioned by the fatty acid profile and the phenolic profile. In fact, the research works of Fadda, et al [47] have proved the main changes in the composition of black olives in brine.…”