A HPLC method using an aqueous mobile phase containing the chiral ligand‐exchanger Cu II‐L‐valine complex at pH 5.5 with a polystyrene divinyl‐benzene copolymer column was used to resolve D‐malic acid in apple, pear, and Concord grape juices. D‐malic acid was detected and quantitated at 330 nm in less than 15 min per sample. The detection limit appeared to be 2 mg/100 mL D‐malic acid in 12 Brix juice, or 0.33% total malic acid in a typical apple juice containing 0.6 g/100 mL using the described procedure.
No takes yet. Share an insight, caveat, or question.
Eisele et al. (1990) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: