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An original computer program was set up to predict and control olive paste malaxation in the range of temperature between 22 and 37 °C under exposure to air. The program consisted of four sections to solve the our previous literature time-temperature kinetics. It was able to predict both the apparent oil extraction yield and the relative variation of 3,4 DHPEA-EDA and sum of verbascoside diastereoisomers contents in steady and unsteady-conditions; it was also able to determine optimal malaxation time-temperature conditions to maximize the oil extraction yield and minimize the oxidative degradation of phenolic compounds. Simulation examples were carried out to test prediction potentiality. The malaxation treatments at low temperatures appeared preferable, since they seemed to be unaffected by time-temperature profiles under unsteady-state conditions. However, it seemed more difficult to identify optimal time-temperature conditions at a low temperature than at a high temperature in some operating states. [ABSTRACT FROM AUTHOR]

An original kinetic study of the transformation phenomena of phenolic compounds in olive paste was carried out at different malaxation time-temperature conditions under exposure to air, using Abencor lab equipment to process olives (Frantoio cv) of a known degree of ripeness. Empirical kinetic models and the relevant apparent kinetic constants were determined for the following significant indices: total phenolic compound content in waste water samples using the Folin-Ciocalteu method; verbascoside and β-OH-verbascoside contents in olive paste samples using HPLC; and 3,4-DHPEA-EDA contents in olive oil samples using HPLC. Two opposite phenolic compound transformation phenomena were proposed to explain the kinetic models: (i) enzymatic oxidative damage of phenolic compounds; (ii) physical and enzymatic release of phenolic compounds from cellular tissues. It was possible to propose a reference optimization chart to predict “selective” time-temperature conditions to maximize the apparent EVOO extraction yield while minimizing the degradation phenomena of phenolic compounds during malaxation. [ABSTRACT FROM AUTHOR]

An original kinetic study of both oil coalescence phenomena and potential extra virgin olive oil extraction yield (i.e. apparent Extractability Index) was carried out at different malaxation time-temperature conditions using Abencor lab equipment to process olives (Frantoio cv) of a known degree of ripeness. The apparent Extractability Index was modelled at every malaxation temperature by pseudo first-order kinetics, where the yield rate constant was temperature dependent following the Arrhenius equation ( k 0 = 7.50 10 7 min −1 ; Ea = 54512 J/mol). Oil droplet coalescence, which was expressed as a relative variation in the percentage of oil droplets with a diameter of >30 μm, proved to be an time-dependent phenomenon only; the pseudo zero-order kinetics modelling was statistically significant, where the coalescence rate constant was equal to 0.033 min −1 . The above kinetics were applied in order to propose a synoptic chart to predict the potential effect of malaxation in isothermal conditions on EVOO extraction yield. [ABSTRACT FROM AUTHOR]