| heal.abstract |
Olive fruits of the Greek variety ""Amfissis"" were stored under industrial conditions and the microorganisms of their microflora were isolated and identified. Selected molds of the microflora were screened for production of lipase and lipoxygenase, two enzymes that are known to contribute in the biogenesis of olive oil aroma compounds through the lipoxygenase pathway. Penicillium strain was identified as the most potent enzyme producer, the yields being 7300U/L for lipase and 6.8U/mg for lipoxygenase. Kinetic studies of enzyme production by Penicillium showed that lipase was mostly active at the beginning of growth, while lipoxygenase activity increased gradually and peaked at the end of growth. Next, the effect of the microflora on volatile biogenesis was evaluated by comparing the profiles of volatiles of virgin olive oil versus processed olive oil obtained by extracting olives that were processed by their natural microflora. The volatiles profile showed that the processed olive oil contained novel volatile compounds that could enhance its flavor, but also contained some off-flavor compounds that could reduce its organoleptic characteristics and thus its quality. Our results show that olive microflora can contribute to the biogenesis of olive oil volatile compounds and thus some of its members could potentially be used to enhance the aroma of olive oil compounds. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
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