Progress in table olive debittering: Degradationin vitro of oleuropein and its derivatives byLactobacillus plantarum

Oleuropein, a bitter‐tasting secoiridoid glycoside present in olive leaves and fruit ( Olea europaea L.), is hydrolyzed by oleuropeinolytic Lactobacillus plantarum strains. The work reports the results of a gas‐chromatographic study of the oleuropein derivatives released by incubation with L. plantarum B21, isolated from table olive brines, and by L. plantarum ATCC 8014. Process kinetics indicate that the bacterial strains initially hydrolyze the oleuropein by means of β‐glucosidase action with formation of an aglycone (the first observable intermediate compound). In a second step, this derivative, by means of esterase action, gives rise to 2‐(3,4‐dihydroxyphenyl) ethanol (identified) and elenolic acid (not identified).