Antioxidant activity and biological evaluation of olive pomace extract

Olive oil and its derivatives for promoting performance, health, and struggling thermal stress effects on broilers

Olive oil (OL) production is the most significant agro-industrial business and has a high impact on the economy of numerous Mediterranean countries. However, OL extraction results in massive amounts of byproducts, including a solid residue (olive cake or olive pomace) and an aqueous stage (olive mill wastewater), which have serious environmental effects due to their hazardous nature and excessive organic content. Despite these byproducts causing environmental pollution, they can be applied for animal feeding. According to the literature, OL or its derivatives have been used to promote broiler performance, feed utilization, and health status in broilers as growth promoters or protein sources. Furthermore, using OL and its derivatives could improve heat resistance in stressed broilers via struggling thermal stress effects. In this framework, we highlighted the use of OL and its byproducts in broiler feeding to promote performance and health status. Additionally, the role of these byproducts and OL in combating thermal stress is investigated for sustainable strategy and promoting circular economy in broiler industry.

Temperature-Dependent Olive Pomace Extraction for Obtaining Bioactive Compounds Preventing the Death of Murine Cortical Neurons

High-pressure and temperature extraction (HPTE) can effectively recover bioactive compounds from olive pomace (OP). HPTE extract obtained by extracting OP with ethanol and water (50:50 v/v) at 180 °C for 90 min demonstrated a pronounced ability to preserve intracellular calcium homeostasis, shielding neurons from the harmful effects induced by N-methyl-d-aspartate (NMDA) receptor (NMDAR) overactivation, such as aberrant calpain activation. In this study, the extraction temperature was changed from 37 to 180 °C, and the extracts were evaluated for their antioxidant potency and ability to preserve crucial intracellular Ca2+-homeostasis necessary for neuronal survival. Additionally, to verify the temperature-induced activity of the extract, further extractions on the exhausted olive pomace were conducted, aiming to identify variations in the quality and quantity of extracted phenolic molecules through HPLC analysis. The results revealed a significant increase in bioactive compounds as a function of temperature variation, reaching 6.31 ± 0.09 mgCAE/mL extract for the extraction performed at 180 °C. Subsequent extraction of the exhausted residues yielded extracts that remained active in preventing calcium-induced cell death. Moreover, despite increased antiradical power, extracts re-treated at 180 °C did not display cell protection activity. Our results indicate that the molecules able to maintain physiological Ca2+-homeostasis in murine cortical neurons in conditions of cytotoxic stimulation of NMDAR are wholly recovered from olive pomace only following extraction performed at 180 °C.

A Comprehensive Optimization of Ultrasound-Assisted Extraction for Lycopene Recovery from Tomato Waste and Encapsulation by Spray Drying

This study aimed to extract bioactive compounds from tomato waste through ultrasound-assisted extraction (UAE), using ethanol as solvent. Process optimization was carried out by a central composite design of 33 runs for response surface modelling, simultaneously analyzing the effect of temperature (T), time (t), volume (V), liquid-to-solid ratio (L/S), amplitude (A), the pulser duration (on), and their interaction. The best conditions found by the desirability method (T = 65 °C, t = 20 min, L/S = 72 mL/g, A = 65%, on = 33 s, V = 90 mL) were experimentally verified, leading to the production of an extract with interesting properties (total carotenoids of 1408 ±14 µglycopene equivalents/g, lycopene yield of 1536 ± 53 µg/g, 36.1 ± 0.9 µgtrolox equivalents/g as antiradical power). Due to the instability of lycopene, the extract encapsulation by spray drying was undertaken using inulin and maltodextrins as coating agents. The evaluation of wall material composition provided high product recovery (73%), a high content of encapsulated compared to superficial lycopene (15.3 ± 2.9 and 0.30 ± 0.02 µg/g), and a product with good water solubility. The novelty of this work concerned the simultaneous study of the effect and interdependences of the UAE parameters, and the use of inulin to enhance the properties of microparticles.

Antimicrobial and cytotoxic activity to human colon adenocarcinoma cell lines (HT-29) potential of olive oil extraction residue

In the Olive drupe (Olea europaea L.) oil extraction process, 80% of the volume generated is waste (bagasse). Advancing the expansion of the olive oil market, it is necessary to develop alternatives that, in addition to adding value to industrial waste, also reduce possible environmental damage. Our study aimed to understand the antimicrobial and Cytotoxic activity potential of the residues from the extraction of olive oil from the blend of the varieties Arbequina and Arbosana. The extract shows cytotoxic activity, inhibiting about 75% of cancer cells in the human colon at a concentration of 0.15 mg of Gallic Acid equivalent (GAE)/mL. The effectiveness of the extract against microorganisms often associated with foodborne diseases and food decomposition has also been discovered, without compromising the microorganisms responsible for fermentation. Thus, this study provides future perspectives for the use of active ingredients extracted from the residue from the extraction of olive oil.

Treatment of table olive processing wastewaters using novel photomodified ultrafiltration membranes as first step for recovering phenolic compounds

Table olive processing wastewaters (TOPW) have high salt concentration and total phenolic content (TPC) causing many environmental problems. To reduce them, ultrafiltration (UF) was applied for treating TOPW. However, NaCl, which is the main responsible of salinity in TOPW, and phenols are small molecules that cannot be separated by conventional UF membranes. They have serious problems caused by fouling, which can be overcome using membrane modification techniques. For these reasons, photomodification may be an effective technique to obtain a stream rich in TPC due to the changes in membrane surface properties. UV-modification in the presence of two hydrophilic compounds (polyethylene glycol and aluminium oxide) was performed to achieve membranes with high reductions of organic matter and to keep the TPC as high as possible. Commercial polyethersulfone (PES) membranes of 30 kDa were used. Surface modification was evaluated using FTIR-ATR spectroscopy and membrane performance was studied by calculating the rejection ratios of colour, chemical oxygen demand (COD) and TPC. Results demonstrated that UF is a useful pre-treatment to reduce organic matter from TOPW, obtaining a permeate rich in TPC. PES/Al2O3 membranes displayed superior antifouling properties and rejection values, keeping high the TPC (>95%). Therefore, UF using modified membranes is an appropriate and sustainable technique for treating TOPW.

Kinetic and Isotherm Modelling of the Adsorption of Phenolic Compounds from Olive Mill Wastewater onto Activated Carbon

The adsorption of phenolic compounds from olive oil wastewater by commercial activated carbon was studied as a function of adsorbent quantity and temperature. The sorption kinetics and the equilibrium isotherms were evaluated. Under optimum conditions (8 g of activated carbon per 100 mL), the maximum sorption capacity of activated carbon expressed as mg of caffeic acid equivalent per g of activated carbon was 35.8 at 10 °C, 35.4 at 25 °C and 36.1 at 40 °C. The pseudo-second-order model was considered as the most suitable for kinetic results, and Langmuir isotherm was chosen to better describe the sorption system. The results confirmed the efficiency of activated carbon to remove almost all phenolic compound fractions from olive mill effluent. The preliminary results obtained will be used in future studies. The carbohydrate fraction of this upgraded residue could be employed to produce bioethanol, and adsorbed phenolic compounds can be recovered and used in different industries.

Apigenin inhibits the TNFα-induced expression of eNOS and MMP-9 via modulating Akt signalling through oestrogen receptor engagement

Apigenin is a naturally occurring plant flavone with strong anti-oxidant and anti-inflammatory activity. While the anticancer properties of Apigenin have been extensively studied, little is known about its effects on endothelial dysfunction. We investigated the effects of Apigenin in EAhy926 endothelial cells exposed to TNFα by evaluating the expression of eNOS and MMP-9, two key molecules in endothelial dysfunction. MMP-9 activity was measured by gel zymography. Western blot analysis was performed to analyze eNOS expression and signal transduction. Treatment with Apigenin (50 μM) counteracted the TNFα-induced expression of eNOS and MMP-9 and the TNFα- triggered activation of Akt, p38MAPK and JNK signalling suggesting that multiple signalling pathways are involved in mediating the protective effects of Apigenin on endothelial function. To better understand the molecular mechanisms underlying the protective effects of Apigenin, we used a pharmacological approach with specific inhibitors. The use of an Akt inhibitor mimicked the inhibitory effects of Apigenin on eNOS and MMP-9 expression, suggesting that eNOS and MMP-9 induction by TNFα depends on Akt activation. The TNFα-induced expression of MMP-9 was also affected by the JNK inhibitor SP600125. No effect on eNOS and MMP-9 expression was observed in the presence of the p38MAPK inhibitor SB203580 or the ERK 1/2 inhibitor PD98059. Pretreatment with 'classic' (ERα and ERβ) or 'non classic' (GPR30) oestrogen receptor (ER) inhibitors (ICI182,780 and PTX, respectively) counteracted the ability of Apigenin to decrease the TNFα-triggered activation of the Akt pathway. Consistently, the use of both ER inhibitors reversed the inhibitory effects of Apigenin on the TNFα-induced expression of eNOS and, to a lesser extent, MMP-9. We can conclude that Apigenin exerts its inhibitory effect on the TNFα-induced expression of eNOS and MMP-9 through the Akt signalling inhibition generated by ER activation. Oestrogen signalling has been implicated in protection from cardiovascular disease. Therefore, having regard to its ability to bind to ERs, Apigenin may be considered an oestrogen-like molecule to potentially be used against the onset and progression of vascular diseases associated with endothelial dysfunction.