Processing destoned olives by means of extracting adjuvants micronised food talc and depolymerising Cytolase 0 enzyme complex have been studied in the present work. This innovative processing technology increased the plant efficiency (amounts of olives processed per hour) by 20%, as well as the nutritional quality of the end product with respect to functional compounds. The oils showed higher contents of biophenols, aromas, and tocopherols. An intense and balanced flavor and a potentially higher stability and endurance to oxidation (shelf-life) was found. Contents of chloroplast pigments (chlorophylls, pheophytins, carotenes, and xanthophylls) appeared to be lower in comparison to conventional processing. The processing aids allowed to increase significantly the oil yields and to reduce the oil percentage in the byproducts. Traceability of the new products was still possible applying chemometric data analysis for discriminating between cultivars.

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This research paper reports on the concentrations of oleuropein in fruits of seven Italian olive cultivars. These oleuropein levels, during fruit growth and maturation, were monitored by taking olive samples from the same olive trees grown in Middle Italy. A novel high-resolution gas chromatography (HRGC) oleuropein quantification method and a new high-performance liquid chromatography (HPLC) method were developed. The olive fruits showed high contents of oleuropein, which were greatly influenced by the olive cultivar (genetic store) factor. The stage of fruit growth and maturation was another factor strongly affecting the contents of iridoid oleuropein in olive drupes, whatever the olive cultivar considered. Green olives had much higher concentrations of this biofunctional glucoside, which decreased regularly during fruit growth and ripeness. No differences were observed between the two developed oleuropein quantification methods, which gave, for all the olive cultivars, average values of fruit oleuropein contents that were not statistically different. These two reliable repetitive methods, noticeably the HPLC one (which also showed a lower running time), could be used for routine determination of oleuropein in olive drupes. We observed that, in general, olive cultivars having high oleuropein concentrations in the fruits were also characterized by marked oleuropein contents in the leaves.

In the present study, we considered the effects of several chemical treatments of three different olive residues (pomace) of diverse origins, which all involve H 2 O 2 . Diluted (40 vol) and concentrated (130 vol; 30% wt) H 2 O 2 was used alone or in combination with Fe sulfate (the Fenton system). The main goal was to oxidize the phenolic substances, as only a dephenolyzed sample can be safely used for applications like soil improvement or as biomass for biogas generation. The o-diphenols were always oxidized in higher amount than single phenols as demonstrated by data on tyrosol and hydroxytyrosol. The Fenton system appears to be a method that can oxidize the phenolic fraction, while leaving only a trace of residual H 2 O 2 inside the pomace. We also considered the effects of these oxidative treatments on the triglycerides. Linoleic acid was largely oxidized, although only in pomace with a low water content and in the presence of the Fenton treatment. Finally, the whole lignocellulose matrix of all of the pomaces was recovered at the end of treatment without any large changes, as shown by the IR spectra of oxidized samples.Practical applications: Modern two-phase olive-oil extraction systems have become widely used, and it can be expected that in the near future they will replace traditional extraction plants. Together with many advantages, they also have some disadvantages, such as a greater need for disposal of pomace. Such byproducts can be of value for re-use in soil improvement, as biomass for generation of biogas, as new ingredients for livestock feed, and as raw material for energy purposes (stone). Often these uses are hindered by the presence of low amounts of derivatives that can cause problems such as inhibition of the biochemical pathways involved. The high amounts of phenols and fatty acids in pomaces represent a serious problem for these supplementary uses. A phenol-free pomace would allow alternative uses and provide additional economic return from these by-products.

As energy systems transition toward renewable resources, anaerobic digestion (AD) is actually receiving growing attention. AD relies on biochemical methane potential (BMP) tests to determine the methane potential of by-products of carbonious nature. This investigation aims to understand how an oxidative treatment, like the Fenton reaction, influences the BMP, starting from solid residues of olive oil production, coming from the two-phase extraction systems (TPES). We compared two different olive pomaces (with and without stones), both from TPES. The Fenton treatment here proposed is able to produce three effects in the employed matrices: improving the speed of BMP decreasing the bacteriostatic effect of phenols, reducing the H2S content in the produced biogas (precipitating it as FeS) and enhancing the production of methane in the first four weeks of the test. Graphical Abstract