Soybean flakes (G. max) were gently supplied by IMCOPA (Araucária, Brazil). These were vacuum-packed in high-density
polyethylene bags, which were stored under refrigeration (−12 ◦C) before analyses. Fatty acid ethyl esters (ethylic biodiesel) containing 97.6% esters content (wt%) were produced as previously reported (Dagostin et al., 2015). The anhydrous (>99.8% v/v) and hydrated ethanol (96% v/v) of analytical grade were purchased from PANREAC (Barcelona, Spain). The chemicals were used as received, without further purification.