Effect of Supercritical CO₂ on Myrosinase Activity and Glucosinolate Degradation in Canola

Abstract

The effect of supercritical carbon dioxide (SC-CO2) extraction conditions (temperature, pressure, extraction time, and moisture content of the samples) on the myrosinase activity and glucosinolate hydrolysis in flaked and whole canola seeds was studied. Combined effects of high temperature (75 °C), pressure (62.1 MPa), and moisture (∼20% w/w) were necessary to achieve 90% enzyme inactivation in canola flakes in 3 h. Similar extraction conditions resulted in only 44% enzyme inactivation in whole canola seeds. Significant glucosinolate degradation was observed after 5 h of extraction of low moisture content (8.5% w/w) whole canola seeds. Glucosinolate degradation in canola flakes was minimal at all moisture levels studied. Therefore, myrosinase inactivation prior to SC-CO2 extraction of canola flakes may not be necessary. However, the presence of enzyme activity in canola extracted at low moisture or temperature should be taken into account for further utilization of meal. Keywords: Supercritical CO2; myrosinase; moisture; canola; glucosinolate

The contribution of high pressure carbon dioxide in the inactivation kinetics and structural alteration of myrosinase

“…Similarly, as prolonging the treatment time from 5 to 60 min at 22 MPa and 55 °C, it decreased from 60.74 to 18.18%. However, Dunford & Temelli (1996) investigated the inactivation of MYR exposed to supercritical CO 2 in canola flakes with 19% moisture content at 21.4, 41.4 and 62.1 MPa and 55 °C, no significant reduction of MYR activity was found. It was assumed that lower moisture content increased the resistance of MYR to supercritical CO 2.…”

Aqueous Extended‐Surfactant Based Method for Vegetable Oil Extraction: Proof of Concept

“…70, which is in the recommended range for oilseed extraction [31]. The oilseeds were then oven-dried at 104°C for 35 min to inactivate myrosinase enzymes, gossypols and other unfavorable compounds [31,32]. Moisture level in the oilseeds were determined by AOAC standard procedure (Method 925.40) [33].…”

Stability and activity of lipase in subcritical 1,1,1,2-tetrafluoroethane (R134a)

“…Chulalaksananukul et al [7] showed that the stability of immobilized lipase from Mucor mihei is always decreased after addition of water at temperature between 40 and 100°C. The combined eVects of high pressure, temperature and moisture content are even used to achieve inactivation of enzymes resulting in a lower seed quality [9]. The extent to which water content inXuences on stability of lipase depends on the hydrophobicity of the media, the immobilized supporter and the type of enzyme.…”