Response-Surface-Methodology-Based Optimization of High-Quality Salvia hispanica L. Seed Oil Extraction: A Pilot Study

Abstract

Featured Application: The present results provide the optimal conditions (size of the restriction die, pressing temperature, and duration of dry heat exposure) to extract chia seed oil via the screw press method. Chia seeds play an important role in human health and nutrition since they contain dietary fiber, lipids, protein, polyphenolic compounds, and polyunsaturated fatty acids. The present study aimed to evaluate the yield and quality of chia seed oil (extracted using the screw press method) in terms of total phenolic content, acid, and peroxide levels. A central composite design was used to optimize the extraction procedure, and the response surface methodology was used to assess the results. The restriction die size of 1 cm, pressing temperature of 53 °C, and no dry heat were the optimal conditions for extracting the desired quality of chia seed oil according to the predicted response surface methodology model. The conditions were evaluated and a 29.47% yield was achieved, with a TPC of 2.20 µg GAE/g of oil, acid content of 0.96 mg KOH/g of oil, and peroxide content of 2.87 mEq/Kg of oil. The extraction process exceeded 45.10 min. Antioxidant activities of 19.21 μg TE/g of oil (ABTS radical scavenging activity), 5.69 μg TE/g of oil (DPPH radical scavenging activity), and 186.68 μg CE/g of oil (nitric oxide free radical scavenging activity) were observed. The fatty acid composition of the chia seed oil samples is also reported herein. We report the optimal conditions for extracting oil from local cultivar chia seeds, thus helping to analyze changes in the composition and impact due to geographical differences in oil quality. The extracted chia seed oil could be utilized for functional foods, cosmetics, and pharmaceutical applications.