Taguchi's methodology for determining optimum operating conditions in hydrothermal pretreatments applied to canola seeds

Abstract

The aim of the present work was to determine the optimum operating conditions in hydrothermal pretreatments applied to canola seeds. The effect of these pretreatments on the canola oil extraction yield and quality was evaluated. Samples were characterized by proximate analysis. Acidity and peroxide value were studied as parameters for the determination of oil quality. Seeds were exposed to direct steam contact in an autoclave. Pretreatments were carried out using different temperatures (100, 120 and 130 °C), exposition times (5, 15 and 30 min) and seed granulometry (ground seeds, with a particle size in a range from 0.420 to 1.000 mm; broken seeds, with a particle size ranging from 1.000 to 1.410 mm, and entire seeds). After each hydrothermal pretreatment, oil extraction was carried out by the Soxhlet method (hexane). The Taguchi method was followed in order to explore the optimum operating conditions by using an L9 experimental design, and select the most favourable levels of each variable. Initial oil content was 44.2% dry basis (db). The selected optimum experiment, using a temperature of 120 °C, a time of 5 min and broken seeds, generated an oil yield increase of 20% compared with non‐hydrothermally treated seeds, whereas quality parameters remained within the accepted values for trade standards.