Exploring the effect of combined hydrothermal-microwave pretreatment operating conditions on canola oil expression

CORTESE, M.; PORTELA, G.; SANCHEZ, R.J.; FERNANDEZ, M. B.

Journal of Food Technology and Preservation

Allied Academies

Lugar: Londres; Año: 2017 vol. 1 p. 1 - 6

2591-796X

The effect of the combined hydrothermal-microwave (HT-MW) pretreatment operating conditions onthe oil extraction yield by cold pressing was evaluated, as well as its canolol and tocopherols content.Entire and broken canola seeds were subjected to hydrothermal pretreatment at differenttemperatures (110°C and 130°C), then they were irradiated in a microwave oven until reaching amoisture content of 6.5% (dry basis), that it is a safe storage moisture and it is adequate for thepressing process. Entire seeds exposed at a HT temperature of 130°C and microwaved for 2.98 minexhibited the best canola oil expression yield (34.9%, d.b) and the highest amount of canolol (533 μg/goil), maintaining the total tocopherol content invariant with respect to oil from samples subjected tothe other pretreatment operating conditions and from untreated seeds. However, individual tocopherolisomers presented different contents when varying pretreatment conditions, showing a differentialextraction due to the factors analysed (seeds granulometry/breakage and HT temperature).At the optimum conditions quality as means of acidity, peroxide index and p-Anisidine value weredetermined. Acidity index slightly increased due to the pretreatment and peroxide index significantlydiminished, being both value below the limits preestablished by the Alimentarius Codex. Meanwhile,p-Anisidine value notably increased, slightly affecting TOTOX value.