Corn lipoxygenase

Hurt (101) has partially separated two isoenzymes from dry bean seeds Phaseolus vulgaris, variety Golden Wax)—one with a pH optimum near neutrality, the second at pH 9.0. Corn germ apparently contains two isoenzymes, one active near neutrality, described by Gardner and Weisleder (36), the other active at pH 9, demonstrated by Veldink et al, 102), As more sensitive methods are applied, isoenzymes of lipoxygenase will become more commonly recognized. 

Wang and Johnson (2001) processed normal soybeans and several types of genetically enhanced soybeans with four extraction methods. The genetically enhanced soybeans were high-oleic with 79.2% oleic acid, low saturated fat with 8.4% total saturated fatty acids, low-linolenic with 3.1% linolenic acid, lipoxygenase-free, and an experimental line of high-cysteine soybeans. The fatty acid compositions of some of these soybeans are compared to oil from commodity soybeans (Table 6.6). Comparisons of fatty acids of soybeans to corn oil, canola, and lard are also given in Table... 

Lipoxygenase enzyme can oxidize polyunsaturated fatty acids into position-specific hydroperoxides that may be decomposed to produce various degradation products, such as aldehydes, alcohols, ketone, and hydrocarbons. These compounds influence the flavor quality of several foods rich in unsaturated fatty acids such as fish [90] and corn [91]. 

The lAA oxygenase was further purified to free it of peroxidase and lipoxygenase since there are reports in which both enzymes can oxidize organic molecules using fatty acid as the co-oxidant [6,14]. Corn scutellum was used as the source of enzyme since this tissue gave the highest initial specific activity [up to 80 pmol h mg protein" ]. 

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