Bioactive Compounds in Waste By-Products from Olive Oil Production: Applications and Structural Characterization by Mass Spectrometry Techniques.

Ramona Abbattista,Giovanni Ventura,Tommaso R I Cataldi,Cosima Damiana Calvano,Ilario Losito

doi:10.3390/foods10061236

Ramona Abbattista, Giovanni Ventura + Show 3 more

Open Access

https://doi.org/10.3390/foods10061236

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Abstract

In recent years, a remarkable increase in olive oil consumption has occurred worldwide, favoured by its organoleptic properties and the growing awareness of its health benefits. Currently, olive oil production represents an important economic income for Mediterranean countries, where roughly 98% of the world production is located. Both the cultivation of olive trees and the production of industrial and table olive oil generate huge amounts of solid wastes and dark liquid effluents, including olive leaves and pomace and olive oil mill wastewaters. Besides representing an economic problem for producers, these by-products also pose serious environmental concerns, thus their partial reuse, like that of all agronomical production residues, represents a goal to pursue. This aspect is particularly important since the cited by-products are rich in bioactive compounds, which, once extracted, may represent ingredients with remarkable added value for food, cosmetic and nutraceutical industries. Indeed, they contain considerable amounts of valuable organic acids, carbohydrates, proteins, fibers, and above all, phenolic compounds, that are variably distributed among the different wastes, depending on the employed production process of olive oils and table olives and agronomical practices. Yet, extraction and recovery of bioactive components from selected by-products constitute a critical issue for their rational valorization and detailed identification and quantification are mandatory. The most used analytical methods adopted to identify and quantify bioactive compounds in olive oil by-products are based on the coupling between gas- (GC) or liquid chromatography (LC) and mass spectrometry (MS), with MS being the most useful and successful detection tool for providing structural information. Without derivatization, LC-MS with electrospray (ESI) or atmospheric pressure chemical (APCI) ionization sources has become one of the most relevant and versatile instrumental platforms for identifying phenolic bioactive compounds. In this review, the major LC-MS accomplishments reported in the literature over the last two decades to investigate olive oil processing by-products, specifically olive leaves and pomace and olive oil mill wastewaters, are described, focusing on phenolics and related compounds.

Highlights

The production of high-quality olive oils implies the generation of vast quantities of solid residues and/or wastewaters that may have a great impact on terrestrial and aquatic environments because of their high phytotoxicity [1]
Depending on the techniques used for olive oil production, namely, on the type of horizontal centrifugation, the process most adopted to separate olive oil from olive paste obtained after malaxation, different by-products are obtained (Figure 1)
The results indicated that the addition of Olive Pomace (OP) in the mixture is beneficial in terms of environmental impact compared to that related to aggregates made with clay

Summary

Introduction

The production of high-quality olive oils implies the generation of vast quantities of solid residues and/or wastewaters that may have a great impact on terrestrial and aquatic environments because of their high phytotoxicity [1]. After a survey on the general features and the main applications reported so far for olive oil by-products, including olive leaves, pomace, and olive mill wastewater, with a special emphasis on the correlation between their content of high-added value compounds and their reuse, this review will focus on the literature concerning the use of MS techniques for the extended characterization of the most relevant bioactive compounds in these matrices. Olive leaves extracts may be used as additives to increase food shelf-life, safety and functionality for their antioxidant and antimicrobial features [23,24]. Their probiotic properties have been recently found to promote the Lactobacillus casei survival during cold storage of cheese [25]. The promising antimicrobial and antioxidant hallmarks of phenols contained in olive leaves by-products have led to produce bio-active films for food packaging by integrating olive leaf extract or powder in plastic polymers [44,45]

Olive Pomace and Olive Oil Mill Wastewater

C27 H30 O14 C12 H18 O11 C9 H16 O4 C29 H36 O16 C29 H36 O16 C30 H38 O16

H6 O4 C15 H10 O7 C20 H18 O11 C21 H20 O12 C21 H20 O11 C7 H12 O6

C29 H36 O15

Findings

Conclusions