Ellagic acid production by solid-state fermentation influenced by the inert solid supports
Ellagic acid and ellagitannins are defense phytochemicals and dietary polyphenols found in fruits and nuts and implicated with strong antioxidant, anticancer and antiatherosclerotic biological properties. Unfortunately, there are few reports on the bioconversion studies from ellagitannins to ellagic acid. The objective of the present work was to use of partially purified ellagitannins from pomegranate peels as inducers for production of ellagic acid by Aspergillus niger GH1 in solid-state fermentation on inert supports (perlite, polyurethane foam and nylon fiber). For total pomegranate polyphenols (TPP), two methodologies were compared. Higher recovery of TTP (70 g kg-1 peel) in a short time (2 h) were obtained by filtering through a muslin cloth followed by centrifugation at 3000 rpm for 15 min. Production of ellagic acid and ellagitannase enzyme were evaluated. Maximum ellagic acid production (231.22 mg g-1 TPP) at 24 h cultivation with an ellagitannase activity of 3213 U L-1 was obtained when using polyurethane foam as inert support. Polyurethane foam was the best solid support to produce high yields of ellagic acid production.