Starchy grains contain about 2.5% lipids while oil rich seeds contain much more (Aspinall and Greenwood 1965). Lipids can be degraded endogenously and via fungal invasion, both by oxidation and by hydrolysis, with lipoxygenases and lipases, respectively (Zeleny and Coleman 1938). Usually an increase in free fatty acids in the seeds is indicative of utilization by spoilage fungi. Indeed Magan et al. (1993) demonstrated that free fatty acid values for different spoilage fungi varied considerably with aw and temperature in in vitro studies with rape seed oil and with rape seed. Farag et al. (1985a,b) had earlier showed that fungal lipases degraded different classes of lipids by degrading triglycerides to mono/diglycerides and free fatty acids.
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