The Use of β-Glucosidase Enzyme in Black Table Olives Fermentation

Abstract

Edincik-Su variety black olives, grown in Marmara region, were processed by three different debittering methods [fermentation with Lactobacillus plantarum (T I), fermentation with β-glucosidase enzyme + L. plantarum (T II), modified ripe-olive fermentation (T III)], and the effects of the applied methods on physico-chemical and sensory characteristics of fermentation media were investigated. The average salt concentrations of the brines were determined as 5.718, 5.769 and 4.825%, for T I, T II and T III, respectively. Salt content of T III was found lower than other treatments. TIII olives displayed the lowest acidity (0.270%) with the highest pH (5.96) depending on removal of most of the sugars and nutrients by lye treatment and following washings. The pH presented a sharp decrease, on the contrary to acidity, within the first days of fermentation in all treatments. The average reducing sugar concentrations of treatments were determined as 0.748, 0.692 and 0.441% for T I, T II and T III, respectively. Although the lowest oleuropein values were obtained in T III olives, the overall liking scores revealed that T II olives had higher organoleptic acceptability (as 27.9). T II and T III olives were found to be more typical to consumers. The correlations of the different sensory attributes with overall acceptability indicated that the panel was negatively influenced by bitterness and skin separation. It appears that the panelists preferred olives with a acidic/bitter taste and firm appearance.