Optimización del proceso de extracción por fluidos supercríticos en la obtención de aceite de semillas de uva con el empleo de la metodología taguchi y superficie de respuesta

Abstract

The present research corresponds to a project to use the waste of the Peruvian Wine Industry used malbec grape seed as raw material to evaluate the opportunity to obtain enriched oil, as a potential proposal for both the pharmaceutical and food industries. In the initial stage, the physicochemical characterization of the raw material was performed, the results obtained were: humidity (11.4%), proteins (8.1%), ashes (2.5%), fats (11.5%) and carbohydrates (66.5%). In the second stage, preliminary extraction tests with supercritical fluids were carried out using liquid CO2 as a solvent. The following fixed operating parameters were established: average particle size (522.15 Μm), supercritical extraction time in steady state (30 minutes), supercritical extraction time in dynamic state (180 minutes) and CO2 outflow (5 ft3 / h). While the study parameters were: Extraction pressure (PSI) and Extraction temperature (ºC). The results were evaluated based on the yield (g oil obtained / g raw material x100%). Subsequently, the factors and levels that significantly influence (p <0.05) in the supercritical oil yield obtained using the Orthogonal Array L9 of the Taguchi methodology were determined. The factors were: Extraction pressure (PSI) and extraction temperature (ºC). The levels established for the pressures were: 2205-4410-6615 PSI and the temperatures were: 40-50-60ºC. The result indicated that both factors are significant and the best values with respect to the performance of the supercritical oil were obtained to: Pressure (6615 PSI) and temperature (60ºC) that were later optimized. In the next stage, we performed the optimization of the significant factors identified by applying the Response Surface Methodology, with a central composite design (4 factorial treatments, 4 axial treatments and 2 central point treatments). Determining that the optimum temperature was (68 ° C) and optimum pressure was (7655 PSI). The optimized oil had a yield of 8.14 percent. Finally, the physical-chemical characterization of the obtained supercritical oil was carried out, which consisted in determining the percentage ratio of the fatty acids present. Linoleic and oleic fatty acids are found in greater proportion: 64.9 percent and 21.8 percent, respectively. The establishment of optimal operating conditions, the use of supercritical fluid extraction technology and the use of industrial waste allow establishing the foundations of sustainable industrial processes that is important for the growth of the productive sectors of developing countries.