Valorization of the Olive Oil Production Residue: Healthy Ingredient for Developing High Value-Added Spread

This study focused on the development of a new olive-based product enriched with proteins, antioxidant compounds and functional properties, aiming at valorization of the olive residue from the typical olive oil extraction process. Olive oil was extracted using a patented cold pressing machine, resulting in a valuable source of bioactive compounds in the form of olive residue (pulp ~70%, pit- and skin-free). Conventional (solid: water ratio 1:4, 25 °C, 2 h) and HP-assisted (200 MPa, solid:water ratio 1/4, 10 min) de-bittering processes were carried out in order to remove oleuropein content (up to 50%) from olive residue, thus decreasing its bitter taste. The olive spread was prepared with olive residue (50%) and honey (25%), enriched with proteins (24.5%) from nuts. Quality parameters, nutritional attributes, microbiological analysis, phenolic compounds and oxidative stability as well as sensory evaluation of the olive spread were conducted during storage. Its shelf-life was estimated (prediction through accelerated tests) as 9.5 months when stored at 4 °C. The organoleptic evaluation showed that the proposed olive spread had a texture similar to peanut butter and could potentially be consumed as a health-promoting spread due to its high content of proteins (~10 g/100 g), crude fibers (>6 g/100 g) and essential fatty acids.

Integrated approach in treatment of solid olive residue and olive wastewater

Olive oil production processes breed two kinds of environmentally detriment waste by-products; the solid olive residue (SOR) and olive waste water (OWW) by-products. The current work aims to treat simultaneously both wastes in the same location. The solid olive residue was converted to activated carbon with pyrolysis at 600°C, followed by steam activation at 600, 700 and 800°C. The produced activated carbons were investigated by FTIR, SEM, BET surface areas analyzer and iodine number. The surface area increases with increasing stream activation temperature up to 800°C (1020 m2/g BET). However, steam activation at 700°C is most environmental and economically feasible, because increasing the activation temperature from 700 to 800°C increases the surface area only from 979 to 1020 m2/g. Activated carbon steam cured at 700°C shows high removal capacity of both polyphenolic compounds and COD of OWW. 95.5% of COD and 84.2% of polyphenolic compounds was removed after equilibrium with activated carbon for 2 hours at room temperature.

Green synthesis of silica nanoparticles from olive residue and investigation of their anticancer potential

Aim: To synthesize silica nanoparticles (SNPs) from olive residue with anticancer properties. Methods: SNPs were synthesized from olive residue ash (ORA). After characterization, cytotoxicity of the SNPs was assessed in vitro, with measurement of reactive oxygen species (ROS) levels. Results: The average diameter of the synthesized SNPs was 30–40 nm, and zeta potential analysis suggested they were stable. The synthesized SNPs were less cytotoxic than commercially available SNPs against fibroblast cells, and the cytotoxic effect on breast cancer cells was significantly higher compared with fibroblast cells. SNPs showed greater uptake into cancer cells where there was greater production of free radicals. Conclusion: SNPs synthesized from ORA have potential anticancer applications because they are more cytotoxic toward cancer cells than fibroblast cells.

Development and Analysis of the Novel Hybridization of a Single-Flash Geothermal Power Plant with Biomass Driven sCO2-Steam Rankine Combined Cycle

This study investigates the hybridization scenario of a single-flash geothermal power plant with a biomass-driven sCO2-steam Rankine combined cycle, where a solid local biomass source, olive residue, is used as a fuel. The hybrid power plant is modeled using the simulation software EBSILON®Professional. A topping sCO2 cycle is chosen due to its potential for flexible electricity generation. A synergy between the topping sCO2 and bottoming steam Rankine cycles is achieved by a good temperature match between the coupling heat exchanger, where the waste heat from the topping cycle is utilized in the bottoming cycle. The high-temperature heat addition problem, common in sCO2 cycles, is also eliminated by utilizing the heat in the flue gas in the bottoming cycle. Combined cycle thermal efficiency and a biomass-to-electricity conversion efficiency of 24.9% and 22.4% are achieved, respectively. The corresponding fuel consumption of the hybridized plant is found to be 2.2 kg/s.

Development and Analysis of the Novel Hybridization of a Single Flash Geothermal Power Plant with Biomass Driven sCO2-steam Rankine Combined Cycle

This study investigates the hybridization scenario of a single flash geothermal power plant with a biomass driven sCO2-steam Rankine combined cycle where a solid local biomass source, olive residue, is used as a fuel. The hybrid power plant is modeled using the simulation software EB-SILON®Professional. A topping sCO2 cycle is specifically chosen for its potential for flexible elec-tricity generation. A synergy between the topping sCO2 and bottoming steam Rankine cycles is achieved by a good temperature match between the coupling heat exchanger where the waste heat from the topping cycle is utilized in the bottoming cycle. The high temperature heat addition problem common sCO2 cycles is also eliminated by utilizing the heat in the flue gas in the bottoming cycle. Combined cycle thermal efficiency and biomass to electricity conversion efficiency of 24.9% and 22.4% are achieved, respectively. The corresponding fuel consumption of the hybridized plant is found as 2.2 kg/s.

Recovery of Residues from Olive Industry: Characterization of Simple and Acetylated Lignin

Lignin is a renewable material obtained in large quantities as a by-product of the olive industry. In this context, this study aims to examine lignin as macro-monomers in the synthesis of rigid polyurethane foam after chemical modification. Indeed, the lignin extracted from the olive residue is used by chemical treatment according to the organosolv process. Comparison by characterization of the single isolated lignin and the acetylated lignin according to the physicochemical analysisTGA, DSC, FTIR, C-13 NMR, 1-H NMR, and molar mass distribution (sec) shows its value as biomass capable of being transformed into polyol afterchemical modification. acetylation increases the weight and the number of molar masses by 25-50% was also determined. Acetylation has a greater effect on the short chains which are probably richer in free phenolic groups. Mass distribution analyzes reveal a relatively high molar mass in organosolv lignin moreover, polydispersity values are very high (20 >> 1). The characterization of spent olive cake reflects the interest of using this biomass as a source of renewable energy for the production of industrial polymers.