Optimization of olive oil extraction from olive pomace using solvent extraction and response surface methodology analysis of oil yield

Abstract

The processing of olives to produce olive oil results in a significant by-product known as olive pomace (O.P.). This O.P. contains bioactive compounds that are beneficial to human health and well-being, making it a valuable resource. Various tests were conducted to extract the olive oil present in O.P. by employing a solvent extractor that used hexane as a suitable solvent. To extract olive oil from olive pomace, the study employed response surface methodology (R.S.M.) along with central composite design (C.C.D.). This enabled the development of a comprehensive experimental design approach. The study aimed to determine the optimal yield of oil by considering three factors: extraction time, solvent-solid ratio, and particle size. The results obtained from the R.S.M. helped identify the optimal values of these factors, which were found to be 120 min for extraction time, 30:1 for solvent-olive ratio, and 0.1 mm for particle size. These optimized values resulted in a maximum oil yield of 12%. It is concluded that the linear model was the best fit for the data, which was supported by the highest coefficient of determination (R2) value and a good match with the predicted value.