A diffusion model for a composite flat plate, consisting of a thin skin of thickness o, and a thicker flesh of thickness L, with constant flesh and skin effective diffusion coefficients (DF and DS) was successfully adjusted to the experimental data obtained during the debittering of green olives variety Arauco (also known as Criolla) at 15C, 20C and 25C and lye concentrations of 1.50%, 2.25% and 3.00% of NaOH. the DF values ranged between 1.64 × 10−10 and 9.20 × 10−10 m2/s, and increased with increasing temperature and lye concentration. the DS values ranged between 1.27 × 10−12 and 5.63 × 10−12 and also increased with increasing lye concentration and temperature. Activation Energies (Ea) of diffusion in the flesh and the skin were evaluated with an Arrhenius‐type relationship. the Ea values for the flesh were 93.2, 72.7 and 64.8 kJ/mol, and 92.7, 91.46 and 33.67 for the skin for lye concentrations of 1.50%, 2.25% and 3.00%, respectively.
RESUMENUn modelo simple del fenómeno de difusión que tiene lugar durante el proceso de desamarizado de aceitunas verdes de mesa.Se ha cuantificado el cambio en la concentración de sodio y calcio en la pulpa y en la lejía durante el tratamiento alcalino de aceitunas. La concentración promedio de sodio en la pulpa aumentó de 0,0045 a 0,395 meq Na/g mientras que la de calcio creció de 0,018 a 0,0252 meq Ca/g. La textura de las aceitunas disminuyó casi linealmente de 375 gf a 235 gf durante el tratamiento alcalino. Las aceitunas sufrieron una perdida de azúcares reductores del 25.9%. Se ha propuesto una hipotética y simplificada descripción de la dinámica de los cambios de carga iónica y el desenrrollamiento de las pectinas durante el desamarizado de las aceitunas. También se calculó el coeficiente efectivo de difusión para sodio y calcio usando un modelo de difusión para una placa compuesta. Los coeficientes resultaron en el orden de 10 -12 m 2 /s para la piel y 10 -10 m 2 /s para pulpa. En ambos casos el coeficiente de difusión de Na fue mayor que el de Ca.
PALABRAS CLAVE: Calcio -Carga iónica -Difusión -Sodio -Tratamiento alcalino de aceitunas verdes.
SUMMARYA simple model of the diffusion phenomena taking place during the debittering process of green table olives.The change in the concentration of sodium and calcium ions in the olive flesh and in the lye during the debittering process was quantified. The average concentration of Na increased from 0.0045 to 0,395 meq Na/g of olive flesh and the concentration of Ca increased from 0.018 to 0.0252 meq Ca/g of olive flesh. The firmness of the olives decreased almost linearly from 375 gf to 235 gf during the alkali treatment. The olives also suffered a 25.9% loss in their initial content of reducing sugars. A hypothetical simplified description of the dynamic of ionic charge changes and unwinding of the pectinic structure during the debittering process of green olives has been proposed. In addition, the A simple model of the diffusion phenomena taking place during the debittering process of green /s for the flesh. In both cases, the diffusion coefficients of Na were larger than the diffusion coefficients of Ca.
Effective diffusion coefficients were calculated in cherry flesh and skin. The fastest molecular movement is during the first hours of starting the process. Diffusivity of water and lactitol molecules is differential. Cherry skin acts as a barrier to the diffusivity of substances.
Time-variable average effective diffusion coefficients of sodium in the skin and flesh were determined using Macroscopic Mass Balances from experimental data obtained during debittering of green olives, variety Arauco at temperatures of 15, 20 and 25C and lye concentrations of 1.50, 2.25 and 3.00% of NaOH. The effective diffusion coefficient of sodium increased with treatment time at both surfaces of the skin, while it varied very little within the flesh, and in many cases, remained almost constant during the debittering process. In general, the diffusion coefficients determined in the present study were within an order of magnitude of 10 -10 m 2 /s for the flesh during most of the treatment time, while for the skin, they were of the order of 10 -12 m 2 /s for the initial treatment times. Macroscopic mass balances are a simple mathematical method that can be used in lieu of more common numerical techniques, to evaluate variable diffusion coefficients providing accuracy and greater detail of the whole phenomena.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.