Physical and Chemical Changes during the Maturation of Gordal Sevillana Olives (Olea europaea L., cv. Gordal Sevillana)

Abstract

A series of physical and chemical changes occur as olives mature on the tree, and these changes are important for the production of oil and table olives. The aim of this study was to increase the understanding of the maturation process of Gordal Sevillana olives, to optimize harvest timing, and to determine the most appropriate harvesting and post-harvesting processing methods. During maturation, the olive size, flesh/pit ratio, and oil content increased, with a maximum oil content of 72 g kg(-1) (wet weight). Changes in the fatty acid composition are reported. Levels of both total sugars and total phenolic compounds slightly decreased over the maturation period; however, we observed that these compounds were continually being synthesized until full black maturity. The optimal harvest time for the production of Gordal Sevillana as Spanish-style green olives occurred immediately prior to the color change from green to turning color, at which point the sugar levels and flesh/pit ratio were at maximum levels.

An explanation for the natural de-bittering of Hurma olives during ripening on the tree

“…The concentration of oleuropein decreased significantly during ripening in Erkence olives during the two seasons, which was more pronounced from the first to the 5th-7th week, which is a pattern previously described for other olive varieties (Menz and Vriesekoop, 2010;Talhaoui et al, 2015) but not in Erkence fruit (Aktas et al, 2014a).…”

“…In addition, it has been suggested that the fungus named Phoma oleae could be involved in the hydrolysis of oleuropein (Panagou, 2006), although it is not the prevalent microorganism on the surface of Hurma olives (Sozvilen and Baysal, 2016). There are many sweet olive varieties such as Dhokar, Gordal/Sevillano and Trouba Thassos but all of them need post-harvest processing to make them palatable (Panagou, 2006;Menz and Vriesekoop, 2010;Rigane et al, 2011). In contrast, Hurma olives are currently consumed after harvesting without any brining process.…”

Changes in Total Phenol Content and Antioxidant Activity of Greek Table Olive Cultivar Amfissis during Maturation

“…Contrary, decrease of the content total phenolic during ripening of olive fruits for some cultivars of Italy observed by [14,[17][18][19]. In addition, decrease total phenols during ripening for some cultivars of Australian observed by [20].…”

Comparison of some chemical parameters of a naturally debittered olive (Olea europaea L.) type with regular olive varieties

“…There are increases and decreases in sugar concentrations throughout the sampling period. These changes are associated with the continuous synthesis of sugar during the ripening period and its use in the fatty acid biosynthesis (Menz & Vriesekoop, 2010). Although some studies reported a decrease in total sugar content during ripening (Ergönül & Nergiz, 2010;Menz & Vriesekoop, 2010;Nergiz & Engez, 2000) an increase in reducing sugar content was observed for Chemlali and Dhokar varieties in another study (Jemai et al, 2009).…”

“…These changes are associated with the continuous synthesis of sugar during the ripening period and its use in the fatty acid biosynthesis (Menz & Vriesekoop, 2010). Although some studies reported a decrease in total sugar content during ripening (Ergönül & Nergiz, 2010;Menz & Vriesekoop, 2010;Nergiz & Engez, 2000) an increase in reducing sugar content was observed for Chemlali and Dhokar varieties in another study (Jemai et al, 2009). While another study also reported an up and down trend for a certain olive variety (Uslu) as it was observed in our study a decreasing trend was reported for another variety (Nergiz & Ergonul, 2009).…”