Estudio de la transferencia de calor en la etapa de cocido en la elaboración de aceitunas verdes al estilo sevillano

Abstract

This article describes for the first time at the industrial level the temperature rise that occurs inside the processing tank during the lye treatment. Relationships between variables that define the lye treatment have been determined from the study of the thermal characteristics of this process. The initial temperature influences other variables of this treatment, such as its duration or the slope of the linear increase of temperature produced. The study estates that this generation of heat can be principally caused by the alkaline hydrolysis reactions that occur in the interior of the fruit and, to a lesser extent, by the dilution of sodium hydroxide solution with water present in the pulp of the olives.<br><br>En este artículo se describe por primera vez a nivel industrial el aumento de temperatura que se produce en el interior de los tanques de elaboración durante la etapa de cocido. A partir del estudio de las características térmicas de la etapa de cocido se han podido determinar relaciones entre las variables que definen el proceso. Se ha demostrado que la temperatura al inicio del tratamiento de cocido influye en otras de las características del proceso como la duración de éste o la pendiente del aumento lineal de temperatura durante la etapa. El estudio establece que esta generación de calor puede provenir principalmente de las reacciones de hidrólisis alcalina que ocurren en el interior del fruto y, en menor proporción, de la dilución de la solución de hidróxido de sodio con el agua presente en la pulpa de las aceitunas

Use of Artificial Vision during the Lye Treatment of Sevillian-Style Green Olives to Determine the Optimal Time for Terminating the Cooking Process

“…The evolution of the lye treatment curve, as seen in Figure 5, includes the following phases: the beginning of the process with a slow speed and reduced slope, which coincides with the filling of the tank with refrigerated lye [4] (in this phase, the olive skin is permeated by the action of caustic soda); the central phase with high speed and increasing temperature; the saturation phase due to lye consumption and the end of the alkaline pro-…”

“…The evolution of the lye treatment curve, as seen in Figure 5, includes the following phases: the beginning of the process with a slow speed and reduced slope, which coincides with the filling of the tank with refrigerated lye [4] (in this phase, the olive skin is permeated by the action of caustic soda); the central phase with high speed and increasing temperature; the saturation phase due to lye consumption and the end of the alkaline process with the addition of washing water. From this point on, it can be considered that the penetration speed of NaOH inside the olive decreases considerably and stops completely when the olives are poured into the fermentation brine.…”

“…These Sevillian-style green table olives [4] are made from olive varieties harvested in the stage before ripening, with the desired consistency and size; the heat transfer during its cooking has been studied [4] due to the costs of the energy involved in the treatment. These costs are currently rising; thus, optimizing them is in the interest of this industry.…”