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Food Lipids: Chemistry, Nutrition, and Biotechnology

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Figure 50 Hydration of linoleic acid monoepoxides to vic-diols by epoxide hydrolase.<br />

Biochem North America, Inc., Franklinton, N.C., USA, <strong>and</strong> Olease, Biocon (US)<br />

Inc., Lexington, KY, USA) at 30% moisture <strong>and</strong> 50�C for 6 hours followed by drying<br />

<strong>and</strong> expelling gave 90–93% recovery of oil as compared with 72% recovery of the<br />

controls not treated with the enzymes (354).<br />

Enzyme-assisted expeller process is now a commercial process for partial oil<br />

recovery from rapeseed (356). In the commercial process the oil release is substantially<br />

enhanced <strong>and</strong> the resulting rapeseed cake with a superior nutritional value is<br />

preferred in a number of animal feeds.<br />

Enzyme-assisted pressing for the production of virgin grade olive oil has also<br />

been reported (107,353).<br />

Enzyme pretreatment followed by solvent extraction for enhanced oil recovery<br />

has been used for melon seeds (357) <strong>and</strong> rapeseed (358). Incubation of autoclaved<br />

<strong>and</strong> moistened rapeseed flakes (30% moisture) with carbohydrases for 12 hours,<br />

followed by drying to 4% moisture <strong>and</strong> extraction with hexane, resulted in 4.0–4.7%<br />

enhancement of oil extraction with the different enzyme preparations in the following<br />

order: mixed activity enzyme > �-glucanase > pectinase > hemicellulase > cellulase<br />

(358). A disadvantage of the process is a rather long incubation time.<br />

Since the earlier publication of Lanzani et al. (359) on rapeseed, sesame seed,<br />

sunflower seed, soybean, <strong>and</strong> peanut, several reports have appeared on enzyme pretreatment<br />

followed by aqueous extraction for enhanced oil recovery from coconut<br />

(352,360–363), corn germ (352,364), avocado (365,366), olives (352,367,368), mustard<br />

seed <strong>and</strong> rice bran (369), Jatropha curca seeds (370), <strong>and</strong> cocoa beans (371).<br />

Enzyme-assisted aqueous extraction has been extensively studied on rapeseed using<br />

the mixed enzyme preparation SP-311 (Novo) <strong>and</strong> found to yield an oil with low<br />

Table 10 Approximate Composition (%) of Cell Wall Polysaccharides of<br />

Some Oil-Bearing Materials<br />

Polysaccharide Rapeseed Coconut Corn germ<br />

Pectic substances 39 —

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