Hydrolysis of Oleuropein by Lactobacillus plantarum Strains Associated with Olive Fermentation

Abstract

Oleuropein (Chemical Abstracts Service registry number 32619-42-4), a bitter-tasting secoiridoid glucoside commonly found in leaves of the olive tree as well as in olives (Olea europaea L.), was found to be hydrolyzed by the j-glucosidase (EC 3.2.1.2.1) produced by oleuropeinolytic LactobaciUlus plantarum-type strains. Three strains, designated B17, B20, and B21, were isolated from the brine of naturally ripe olives not treated with alkali. These strains were rod-shaped forms, grown at a pH 3.5 limit, and tolerated 1% oleuropein and 8% NaCl in the growth medium. The 0-glucosidase produced hydrolyzed 5-bromo-4-chloro-3-indolyl- ,-D-glucopyranoside as well as oleuropein. The presence of 2% glucose in the medium inhibited activity by 40 to 50%, depending on the bacterial strain. Chromatographic analysis of the trimethylsilyl derivatives of the products obtained after 7 days of incubation at 30°C of strain B21 showed all the hydrolysis products of oleuropein, i.e., aglycone, iridoid monoterpen, and 3,4-dihydroxyphenylethanol (hydroxytyrosol). Oleuropein and its aglycone after 21 days of incubation decreased to trace levels with the simultaneous increase in concentration of ,-3,4-dihydroxyphenylethanol.

The olive oil oxygen radical absorbance capacity (DPPH assay) as a quality indicator

“…The evaluation of ORAC was conducted on some olive oil pure phenolic compounds and free fatty acids. The phenolic compounds used were: caffeic acid (Merck, Darmstadt, Germany), gallic acid (Merck), oleuropein (Extransynthese, Genay, France), aglycon [10] and hydroxytyrosol (Cayman, MI, USA). The free fatty acids used were oleic acid (Fluka, Buchs, Switzerland), stearic acid (Fluka), palmitic acid (Fluka) and linoleic acid (Fluka).…”

Study of the anti‐lactic acid bacteria compounds in table olives

“…Several research groups have reported that strains of Lactobacillus plantarum (Ciafardini et al, 1994) and Lactobacillus pentosus (Servili et al, 2006) are able to degrade the bitter glucoside oleuropein and it was assumed that these lactic acid bacteria (LAB), which are responsible for a proper olive fermentation, produce the enzyme ß-glucosidase during olive brining that catalyses the rupture of the glycosidic bond of the oleuropein moiety (Ciafardini & Zullo, 2000).…”

Ripe Olives Storage Liquids Reuse During The Oxidation Process

“…Hydroxytyrosol originates from acidic hydrolysis of oleuropein as suggested by Brenes et al (1993) . In this case, there was no lactic acid formation during storage and hydrolysis of oleuropein could not be due to the enzymatic activity of lactic acid bacteria (Ciafardini et al, 1994).…”