Showing papers by "Government of Extremadura published in 2018"

The effect of olive fruit maturation in Spanish style fermentation with a controlled temperature

Abstract: The influence of maturation of different olive fruit varieties and the effect of these olives fermented at room temperature in a spontaneous fermentation were studied. Also, table olives from Carrasquena variety harvested in two consecutive weeks in green stage of maturation, were fermented at different thermal temperature by heat transfer to the brine. Initially, an olive growth characterization was carried out. The largest variety was “Manzanilla Cacerena” and presented less texture and the lowest total phenolic and antioxidant activity. However, “Carrasquena” variety, which had the highest firmness, showed a slower size. The color index of “Manzanilla Sevillana” was rather higher than the color index of the other varieties. After fermentation process, the highest color index and free acidity in “Manzanilla Sevillana” table olive could be caused by the highest temperature of the brine achieved. In general, the varieties studied had a good texture during fermentation. On the other hand, the effect of thermal applications in table olive color was higher when the olives were harvested later and by thermal application. Finally, the effect of thermal application depended on initial maturation stage achieving an increase of phenols with determined temperatures and conditions.

Improvement of the Sterol and Triacylglycerol Compositions of Chemlali Virgin Olive Oils through Controlled Crossing with Mediterranean Cultivars.

Abstract: The chemical composition of extra virgin olive oils (EVOOs) from six new progenies, obtained through controlled crossings between the main Tunisian variety Chemlali and autochthonous (Chemcheli) and foreign cultivars (Sigoise, Coratina, Koroneiki, and Arbequina) used as pollen acceptor or pollinator, were compared with the EVOO of Chemlali cultivar known to be the main one cultivated in Tunisia as it is the most adapted to the arid climate. Several analytical determinations of major and minor components of EVOO were employed, especially triacylglycerol and sterol fractions. All the studied hybrid EVOOs showed an improvement in their chemical composition and stability by comparison with Chemlali EVOO. The main triacylglycerols were 1,2,3-trioleylglycerol (OOO), 2,3-dioleyl-1-palmitoylglycerol (POO), 2,3-dioleyl-1-linoleylglycerol (LOO) and 2,3-dioleyl-1-stearoylglycerol (SOO). β-sitosterol, Δ5-avenasterol and campesterol were the principal sterols in all samples. Cholesterol, stigmasterol, clerosterol and Δ7-stigmastenol were also found in all samples. Oil samples examined showed inter-variability between the studied cultivars. Results of discriminant and principal component analyses appear to prove that genetic origin of the raw materials has a great influence on the final composition of the oil; especially triacylglycerol and sterol compositions.