IN VITRO BIODEGRADATION OF OLEUROPEIN BY LACTOBACILLUS PLANTARUM FSO175 IN STRESS CONDITIONS (pH, NaCl AND GLUCOSE)

Nabil Ghabbour,Abdeslam Asehraou,Houssam Abouloifa,Nour-Eddine Chihib,Reda Bellaouchi,Ennouamane Saalaoui,Yahya Rokni,Riadh Ben Salah,Zahra Lamzira

doi:10.15414/jmbfs.2020.9.4.769-773

Nabil Ghabbour, Abdeslam Asehraou + Show 7 more

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https://doi.org/10.15414/jmbfs.2020.9.4.769-773

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Abstract

The objective of this work is to study the oleuropein (OLP) biodegradation by a strain of Lactobacillus plantarum FSO175 under conditions (pH 4.5, NaCl 5% and glucose 1%), during 7 days of incubation at 30 °C, in modified MRS broth containing OLP as carbon source. The results obtained, by HPLC analyses, showed that the biodegradation of OLP by L. plantarum FSO175, is accompanied with increase of hydroxytyrosol (HT) content and acidity values. The yields of OLP degradation and HT accumulation are depending on carbon sources, stress conditions and time of incubation. So that, the drastic reduction in OLP biodegradation, obtained at pH 6.7 (trial B), decreased significantly (p

Highlights

Oleuropein (OLP), a secoiridoid glucoside naturally found in leaves and fruits of Olea europaea L., is the major natural phenolic compound responsible for the bitterness in the unripe olives (Othman et al, 2009)
The effectiveness of the strain L. plantarum FSO175 in OLP biodegradation leading to variable yields of HT production, revealed its promising perspectives as starter culture, under controlled stress conditions of pH 4.5 and NaCl 5%, allowing the production of green table olives rich of HT, the main antioxidant highly desired in foods
In presence of OLP, the glucose variation showed the same allure in presence or absence of pH 4.5 and/or NaCl 5%, but with lower concentrations of glucose, in this condition, the release of glucose linked to OLP and its biodegradation by L. plantarum FSO175 occurs

Summary

Introduction

Oleuropein (OLP), a secoiridoid glucoside naturally found in leaves and fruits of Olea europaea L., is the major natural phenolic compound responsible for the bitterness in the unripe olives (Othman et al, 2009). To reduce the bitterness and antimicrobial effects of OLP, industrial process for green olives is based on chemicals debittering with the alkali- treatment of fruits, followed by washings and brining to undergo a natural lactic fermentation process (Brenes et al, 1998). This chemical debittering leads to high losses in nutrient value of processed olives (Othman et al, 2009), and generates high amounts of spoiled fruits and alkaline waste waters (Kailis et al, 2007). The main objective of the present work was to study the biodegradation of OLP by L. plantarum FSO175, previously selected in our laboratory as OLP degrading strain, under the main stress factors (pH 4.5, NaCl 5% and glucose 1%) affecting the industrial green table olive process

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