Olive mill wastewaters: quantitation of the phenolic content and profiling of elenolic acid derivatives using HPLC-DAD and HPLC/MS2 with an embedded polar group stationary phase

The date palm is one of the most economically important perennial plants of the North Africa and in Morocco, where it is extensively cultivated for food and many other commercial purposes. Palm trees are threatened by many pests such as Potosia opaca newly identified in Morocco, especially in Marrakesh and Errachidia regions. In addition, olive mill wastewaters (OMW) are an environmental problem in olive oil producing countries such as Morocco. Generally, these effluents are drained into ecosystems without any pre-treatment. To reduce their negative impact and to get benefits in particular from their high phenolic content, OMW were used as bio-insecticides in crude form. The results showed that crude OMW were effective to control this pest causing a weight loss similar to Cordus insecticide (17% vs. 15%) and mortality almost similar to Kemaban insecticide. OMW’s biocide potential was related principally to their high phenolic content. Based on HPLC analysis, ten phenolic molecules were identified, including two which were revealed as the major monomeric phenolic compounds in OMW, 0.248 g/L of hydroxytyrosol and 0.201 g/L of tyrosol. In this chapter, the potential use of OMW as bio-insecticides for the control of P. opaca in date palm is discussed.

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Exploiting Food-Grade Mesoporous Silica to Preserve the Antioxidant Properties of Fresh Olive Mill Wastewaters Phenolic Extracts

Antioxidants ◽

10.3390/antiox10091361 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1361

Author(s):

Federica Ianni ◽

Andrea Gagliardi ◽

Agnese Taticchi ◽

Maurizio Servili ◽

Nicola Pinna ◽

...

Keyword(s):

Mesoporous Silica ◽

Inclusion Complex ◽

Inclusion Complexes ◽

Total Phenolic Content ◽

Phenolic Content ◽

Antioxidant Properties ◽

Total Phenolic ◽

Olive Mill Wastewaters ◽

Olive Mill ◽

Phenolic Extracts

Fresh olive mill wastewaters phenolic extracts are of great interest as preservatives or fortifying ingredients but are characterized by limited stability. The purpose of this study was to use mesoporous silica to enhance their stability and preserve their antioxidant properties. The phenolic extracts were characterized for their composition by HPLC-DAD and included in a mesoporous matrix with or without a lipid coating. The inclusion complexes were characterized in terms of total phenolic content, radical scavenging capacity and in vitro antioxidative activity and cell compatibility. Besides, inclusion complex stability under different storage conditions (22 and 37 °C, 75% relative humidity, 1 month) was evaluated. The inclusion process was nearly quantitative and modified neither the total phenolic content nor the total antioxidant capacity. None of the inclusion complex concentrations assayed on the HT29 cell line showed toxicity. Moreover, HT29 cells treated with the inclusion complex exhibited a significant antioxidant effect, while the lipid coating impaired the antioxidant activity. The complexes without lipid were stable under all the investigated conditions, while the lipid-coated products were less stable under the more drastic conditions. Overall, inclusion complexes in mesoporous silica have suitable characteristics to be used for different applications, including food supplementation.

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Bioconversion of p-Tyrosol into Hydroxytyrosol under Bench-Scale Fermentation

BioMed Research International ◽

10.1155/2018/7390751 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

Zouhaier Bouallagui ◽

Sami Sayadi

Keyword(s):

Experimental Design ◽

Dry Matter ◽

Specific Productivity ◽

Bench Scale ◽

Olive Mill Wastewaters ◽

Rich Solution ◽

Olive Mill

Tyrosol hydroxylating Pseudomonas strain was previously isolated from olive mill wastewaters-irrigated soil. In the present work, experimental design was used to study the bioconversion of tyrosol in laboratory fermenters aiming at the recovery of the highest yields of hydroxytyrosol. The effects of biocatalyst loading and tyrosol concentration were studied. The bioconversion yield reached 86.9% (37.3 mM hydroxytyrosol) starting from a tyrosol concentration of 43 mM. Under these conditions, the specific productivity relative to the biocatalyst was 4.78 μM/min/g. The established model to predict bioconversion yield was validated in two bench-scale fermenters. At the downstream stage, the reaction product was recovered as a hydroxytyrosol rich solution after microfiltration and concentration under vacuum. Subsequent to this operation, hydroxytyrosol composition yielded 73.8% of the total dry matter.

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