fumaric acid. It is a reversible reaction with equilibrium at
approximately 80% of L-malic acid at 30C (Presecˇki et al.
2007). L-Malic acid production has also been performed by
purified enzymes that were entrapped in hydrogels (Marconi
et al. 2001) or immobilised within membrane reactor
(Presecˇki et al. 2009).