Do Best-Selected Strains Perform Table Olive Fermentation Better than Undefined Biodiverse Starters? A Comparative...

Area of Science:

• Food Microbiology
• Fermentation Science
• Oenology and Viticulture

Background:

• Lactobacillus pentosus is a key bacterium in table olive fermentation.
• Starter cultures are used to control fermentation and improve product quality.
• Biodiverse starters, like the undefined culture used here, are complex microbial communities.

Purpose of the Study:

• To characterize Lactobacillus pentosus strains for technological properties relevant to table olive fermentation.
• To compare the fermentation performance of selected strains against the original undefined starter and spontaneous fermentation.
• To evaluate the impact of different starters on fermentation parameters and table olive quality.

Main Methods:

• Isolation and characterization of 27 Lactobacillus pentosus strains from an undefined table olive starter.
• Assessment of technological properties including temperature, salt, pH, and olive leaf extract tolerance, acidifying ability, oleuropein degradation, and production of hydrogen peroxide and lactic acid.
• Comparative study of table olive fermentation using the original starter, selected strains, and spontaneous fermentation, analyzing texture profile and antioxidant activity.

Main Results:

• Two Lactobacillus pentosus strains with suitable technological properties were selected.
• The undefined starter culture demonstrated the most effective Enterobacteriaceae reduction, acidification, and olive debittering.
• Fermentation with selected strains resulted in the lowest antioxidant activity compared to other treatments.

Conclusions:

• Selected candidate strains did not guarantee superior fermentation performance compared to the original undefined, biodiverse starter mix.
• Biodiversity in starter cultures plays a significant role in achieving optimal table olive fermentation outcomes.
• The complexity of undefined starters may offer advantages over single-strain or limited-strain selections for certain fermentation processes.