Olive Oil Extraction Research Articles

Alteration of haematological and antioxidant parameters in common carp ( Cyprinus carpio ) fed olive ( Olea europea ) leaf extract after exposure to Danitol ®

The present study aimed to assess the benefits of dietary olive (Olea europea) leaf extract (OLE) on haematological, biochemical and antioxidant parameters in the blood and livers of common carp (Cyprinus carpio) exposed to the pesticide Danitol®. Four treatments were carried out: (a) fish fed the control diet for 37 days (control); (b) fish fed the control diet for 30 days, followed by 7 days of exposure to 0.05 mg/L Danitol®; (c) fish fed the E1 diet for 30 days, followed by 7 days of exposure to 0.05 mg/L Danitol® (1 g/kg OLE); and (d) fish fed the E2 diet for 30 days, followed by seven days of exposure to 0.05 mg/L Danitol® (2 g/kg OLE). Exposure to Danitol® significantly decreased red blood count (RBC), haematocrit, haemoglobin, plasma and hepatic catalase (CAT), and superoxide dismutase (SOD) activities. However, the pesticide increased plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and plasma and hepatic malondialdehyde (MDA) contents. The RBC showed lower resistance against hypotonic osmotic shock, as established by the osmotic fragility test. OLE administration restored the changes caused by Danitol®, of which the most pronounced effects were observed in the fish fed 2 g/kg OLE. We may conclude that Danitol® exposure causes oxidative stress, yet provide protection against numerous adverse effects through the supplementation of olive oil extract (OLE), resulting in a higher red blood cell count.

Innovation in traditional foods: A laboratory experiment on consumers’ acceptance of extra-virgin olive oil extracted through ultrasounds

The use of ultrasounds for the extraction of extra-virgin olive oil is an emerging technology capable of improving both the efficiency of the process and the quality of the final product. However, this technology has not been introduced yet on the market mostly because of the uncertainty about consumers’ acceptance. This study aimed to investigate consumers’ preferences towards extra-virgin olive oil obtained through ultrasound-assisted extraction. For this purpose, a laboratory experiment was performed by combining sensory evaluation and experimental auction to elicit consumers’ willingness-to-pay under different information scenarios. The results of the study suggested that extra-virgin olive oil extracted through ultrasounds may be, generally, accepted by consumers. Whilst, no empirical evidences emerged to support the hypothesis that consumers are also willing to pay a premium price for such innovative product.

Olive mill wastewater treatment and valorization by extraction/concentration of hydroxytyrosol and other natural phenols

Olive mill wastewater (OMW) is a by-product generated from olive oil extraction systems. It contains high concentrations of organic compounds mainly phenols which cause environmental problems for the ecosystem, such as soil contamination and water pollution. Therefore, treatment of OMW is very much needed. Some of the naturally present chemicals in OMW have a positive economic value. In this investigation, liquid/liquid extraction using ethyl acetate (EA) as a solvent to recover such valuable compounds was investigated. Several parameters were studied namely, time of extraction, pH, EA/OMW volumetric ratio, and initial concentration of total phenols. Based on UHPLC analysis, hydroxytyrosol (HT) was the most abundant phenol in EA extracts from OMW. Many other phenols (tyrosol, oleuropein, p-coumaric acid, syringic acid, and 4-hydroxybinzoic acid) were also identified. Percentage recovery of HT reached 62 % after 2 h of extraction, at an EA/OMW ratio of 2/1 (v/v) and a pH of 2. Distribution coefficient of HT in EA was evaluated and was found to be around 0.8. The above process is envisioned to ultimately produce clean water which may be used in irrigation or in olive mills in a sustainable way. In addition, the extract is expected to have a high economic value.

Partial De‐Stoning of Olive Paste to Increase Olive Oil Quality, Yield, and Sustainability of the Olive Oil Extraction Process

AbstractStone recovery in the olive oil extraction process can be an opportunity to increase both incomes and environmental sustainability. To this aim a new partial de‐stoning machine (called Moliden) is installed at the first stage of an olive oil extraction plant to investigate its influence on the quality and sustainability of the extraction process. Quantitative and qualitative results are compared with those achieved using a conventional extraction process. Despite the 60% of stone recovered, no significant differences are registered for oil yield and extractability. A high‐quality biomass is recovered by the partial de‐stoner machine, belonging to A1 class quality when compared to the standard of the wood pellet, with the only exception of the moisture content. The partial de‐stoning also improves the extra virgin olive oil (EVOO) quality in terms of hydrophilic phenols resulting in an enhancement of bitter and pungent sensory notes and most of all provides a beneficial effect for human health.Practical Applications: The new concept of partial de‐stoner machine proposed in this work allows reducing the equipment employed in the extraction process of olive oil, since it consists of two sections: crushing and de‐stoning. When compared with a standard unit, which recover pits from pomace, it provides a higher quality stone to be used as a biomass fuel. This leads to economic benefits for the millers and has a significant impact on the environmental sustainability of the process.

Comparative study on different incorporation of olive oil and dill extract in fresh cheese

In the present study, a comparative analysis was undertaken on the possibilities of using olive oil in fresh spreadable cheese either emulsified or encapsulated. The changes in titratable acidity, active acidity and total Lactococcus count were recorded continuously throughout the storage period. At the end of the storage period, Lactococcus count in the samples with encapsulated oil were found to be slightly higher (7.7 and 7.8 log CFU.g-1 respectively) in comparison with the control sample (7.5 log CFU.g-1 ). A significantly higher content (P < 0.05) of unsaturated fatty acids (56.88 g per 100 g fatty acids) and a lower peroxide value of extracted fat (0.35 meqO2.kg-1 ) were found in the fresh spreadable cheese samples with 4% (w/w) encapsulated olive oil and extract of dill used as antioxidant in an amount of 0.003% (v/v). The addition of antioxidant (dill extract) further reduced oxidation process and enhanced cheese functionality. The sensory profile of the fresh cheeses, containing encapsulated oil, was better compared to the sensory profile of the products prepared with directly added olive oil (with or without added antioxidant).

Development of a modified malaxer reel: Influence on mechanical characteristic and virgin olive oil quality and composition

Malaxation represents a critical and deeply studied step of the virgin olive oil extraction process due to its influence on yield and quality. Nonetheless, few experimental works have been focused on the mechanical aspects of the malaxer machine itself, with the aim of increasing its performance. In this framework, we investigated the effects of design changes of the rotating parts of the malaxer machine on the oil yield and on the virgin olive oil quality, antioxidants and volatile compounds.The modified reel determined a significant increase in extraction yield, respect to the traditional one, as a consequence of the decrease in consistency index of the olive paste. By the qualitative point of view the extracted oil could be categorized as extra virgin. However, malaxer modification brought to a decrease of the antioxidants and an increase of the oxidative phenomenon, as showed by volatiles originated from oxidative degradation and by the enzymatic activities in olive paste. Nonetheless, the outcomes suggested that a possible reduction of malaxation time by the modified reel could be useful to increase the work capacity and to possibly preserve oil quality.

Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion

This work addresses for the first time the study of olive stone (OS) biomass pretreatment by reactive extrusion technology using NaOH as the chemical agent. It is considered as a first step in the biological conversion process of the carbohydrates contained in the material into bio-based products. OS is a sub-product of the olive oil extraction process that could be used in a context of a multi-feedstock and multi-product biorefinery encompassing all residues generated around the olive oil production sector. OS biomass is pretreated in a twin-screw extruder at varying temperatures—100, 125 and 150 °C and NaOH/biomass ratios of 5% and 15% (dry weight basis), in order to estimate the effectiveness of the process to favour the release of sugars by enzymatic hydrolysis. The results show that alkaline extrusion is effective in increasing the sugar release from OS biomass compared to the raw material, being necessary to apply conditions of 15% NaOH/biomass ratio and 125 °C to attain the best carbohydrate conversion rates of 55.5% for cellulose and 57.7% for xylan in relation to the maximum theoretical achievable. Under these optimal conditions, 31.57 g of total sugars are obtained from 100 g of raw OS.

Antioxidant quantification in different portions obtained during olive oil extraction process in an olive oil press mill.

Different antioxidant compounds are generally transferred from olives to olive oil during the production process. This work characterized the principal total bioactive compounds (tocopherols and phenols) in olives, olive oil and by-products of four cultivars grown in Calabrian areas (southern Italy), considering the effect of harvesting period. Antioxidant capacity, total and individual phenolic compounds were also analysed. Drupes, olive paste, pomace and olive wastewater showed similar phenolic compounds, while olive oil possessed a different composition, suggesting that phenols are not only transferred from drupe to oil, but also they change during oil production. Tocopherols varied among cultivars and harvesting period: generally, they were more abundant in samples produced in the first harvesting period. Qualitative and quantitative differences in phenolic composition and antioxidant activity were significantly found among cultivars in all the matrices. The highest amount of total phenolic antioxidants ended up in olive wastewater with variability due to the olive cultivar, while only a small part of them finished in the oil. This work shows evidence that the availability of bioactive compounds in different portions from the olive oil extraction belong to different varietal origins. In particular, new information was acquired on Ottobratica Calipa, a new olive clone, that produced an olive oil with an interesting antioxidant amount. © 2020 Society of Chemical Industry.

Environmental life cycle assessment of different biorefinery platforms valorizing olive wastes to biofuel, phosphate salts, natural antioxidant, and an oxygenated fuel additive (triacetin)

Olive agro-industry is a chemical- and energy-intensive agricultural activity and given its large scale globally is faced with serious challenges from the sustainability perspective. On the other hand, different by-products and residues generated are not generally used and end up as wastes. Therefore, it is of crucial importance to design and implement innovative platforms based on circular bioeconomy and zero-discharge principles to enhance the sustainability features of the olive supply chain system. In light of that, the present study was aimed at designing and experimentally scrutinizing two olive agro-biorefinery scenarios against the conventional olive oil production system (i.e., olive/olive oil production, including olive cultivation and oil extraction). The first agro-biorefinery system included olive cultivation and oil extraction from fruit and pomace for edible use. Moreover, the remaining pomace post-oil extraction was used as an animal feed. The second agro-biorefinery system included olive cultivation, olive oil extraction, olive pomace oil extraction, and its conversion into biodiesel. In addition, crude biodiesel glycerol was also valorized into two different phosphate salts and an oxygenated fuel additive (namely triacetin), while olive oil leaves were converted into a natural antioxidant for biodiesel. The performance of the natural antioxidant against the most promising synthetic antioxidant used by the biodiesel industry (i.e., propyl gallate) was also investigated. The developed scenarios were environmentally compared using the IMPACT 2002+ method. Overall, both developed agro-biorefineries outperformed the conventional system in terms of all four endpoint damage categories. Compared to the conventional olive oil production system, the production of 1 ton of olive oil in the first and second agro-biorefinery systems was associated with 10.62% and 4.08% saving in climate change damage category, 6.73% and 11.21% saving in primary energy consumption, and 12.01% and 1.55% saving in damage to human health. In addition, the implementation of the circular bioeconomy approach in olive oil production led to 31.28% and 26.38% saving in ecosystem quality damage category for Sc-2 and Sc-3, respectively. Overall, the weighted endpoint damage categories of olive oil production could be saved by 12.27% and 4.49% if respectively, the first and second agro-biorefinery scenarios were used. These findings revealed that through the transition from linear economy-oriented olive agri-food system to a bioeconomy-oriented olive agro-biorefinery, not only a wide spectrum of value-added bioproducts could be achieved, but also the environmental impacts per each ton of olive oil produced could be mitigated.

Virgin Olive Oil Extracts Reduce Oxidative Stress and Modulate Cholesterol Metabolism: Comparison between Oils Obtained with Traditional and Innovative Processes.

This study was aimed at demonstrating the substantial equivalence of two extra virgin olive oil samples extracted from the same batch of Coratina olives with (OMU) or without (OMN) using ultrasound technology, by performing chemical, biochemical, and cellular investigations. The volatile organic compounds compositions and phenolic profiles were very similar, showing that, while increasing the extraction yields, the innovative process does not change these features. The antioxidant and hypocholesterolemic activities of the extra virgin olive oil (EVOO) phenol extracts were also preserved, since OMU and OMN had equivalent abilities to scavenge the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals in vitro and to protect HepG2 cells from oxidative stress induced by H2O2, reducing intracellular reactive oxygen species (ROS) and lipid peroxidation levels. In addition, by inhibiting 3-hydroxy-3-methylglutarylcoenzyme a reductase, both samples modulated the low-density lipoprotein receptor (LDLR) pathway leading to increased LDLR protein levels and activity.

Study of the influence of technological coadjuvants on enzyme activities and phenolic and volatile compounds in virgin olive oil by a response surface methodology approach

Although the use of technological coadjuvants during virgin olive oil extraction helps in maximising the process efficiency, it could influence the characteristics of the final product. So far, why this happens is still not understood. In this context, an influence on the biochemical activities occurring during the malaxation step was supposed, and this hypothesis was verified by a response surface methodology approach. The effect of two independent variables, namely malaxation temperature and amount of coadjuvant, on polyphenol oxidase, peroxidase and lipoxygenase activities as well as on the corresponding phenolic and volatile compounds of the oils was studied. Calcium carbonate enhanced the activities of oxidases leading to a reduction of phenolic compounds, which were negatively correlated with the coadjuvant usage. Micronized natural talc behaved the opposite but had a general weaker influence, often overcome by that of mixing temperature. A significant shift of the olive paste pH toward that optimal for oxidases enzymes was highlighted under the use of calcium carbonate. The findings evidenced a “side effect” of the use of technological coadjuvants in the context of virgin olive oil extraction.

New Liquid Source of Antioxidant Phenolic Compounds in the Olive Oil Industry: Alperujo Water

The current management of alperujo as the main solid by-product from the two-phase olive oil extraction system has led to the appearance of a new liquid effluent that until now was treated together with the alperujo itself. The composition and antioxidant properties of its bioactive components at different depths of the pond were studied using colorimetric and HPLC with UV and MS detectors, DPPH, reducing power and rancimat. The concentration of suspended solids varied between 1.71 and 8.49 g/L, total fat was between 0.74 and 1.47 g/L, and total phenols were found between 3.74 and 4.11 g/L, which included hydroxytyrosol, 3,4-dihydroxyphenylglycol and tyrosol as the main phenols. Two types of extracts were obtained through two industrial systems with ethyl acetate and by chromotography, with an average content in total sugars of 2.1% and 3.16%, total phenols of 17.9% and 28.6% and hydroxytyrosol of 51.5 and 79.0 mg/g of extract, respectively. The activity presented by the chromatographic extract was higher in terms of free radical sequestering capacity, reducing power and the inhibition of lipid oxidation. Obtaining bioactive extracts would improve the formulation of food with natural components and at the same time would be the first step in a biorefinery to improve the management of the new effluent.

Synthesis of Dacus Pheromone, 1,7-Dioxaspiro[5.5]Undecane and Its Encapsulation in PLLA Microspheres for Their Potential Use as Controlled Release Devices

Olive fruit fly Dacus oleae is a well-known pest infecting the bark of olive fruit, leading to reduction of extracted olive oil properties. Among chemicals proposed for Dacus oleae population control, pheromone 1,7-dioxaspiro(5.5)undecane (DSU), Dacus pheromone, is considered as a promising agent, which is added in several traps. However, all proposed systems manage to sufficiently deliver DSU for only two weeks. Furthermore, an additional problem is the limited available amount of pheromone to use in such systems. To overcome this, in the present study, a novel synthetic procedure of DSU is described, including only five steps. Intermediate products were studied by High Resolution Mass Spectroscopy Electrospray Ionization (HRMS-ESI) (m/z), while the resulting DSU was further characterized by 1H and 13C-NMR. Synthesized DSU was further encapsulated in poly(L-lactic acid) (PLLA) microparticles in three different concentrations; 5, 10 and 20% w/w. Its successful incorporation was studied by FT-IR, XRD and differential scanning calorimeter (DSC) while two procedures, liquid extraction and solid phase microextraction, followed by GC-MS analysis, was used for quantification of pheromone to microparticles. It was found that microparticles loading was over 85% for all three formulations. Its release showed a prolonged profile for microparticles containing 20% w/w DSU, lasting four weeks, while the quantity of DSU released reached 100%. These microparticles could be appropriate to control Dacus oleae population.

The effect of particle size, temperature and residence time on the yields and reactivity of olive stones from torrefaction

Abstract Olive stones obtained as a by-product from olive oil extraction in combination with the favourable climate in Mediterranean countries are value-added feedstocks for the energy sector due to low moisture content ( 20 wt. %), suitable calorific value ( > 18.7 MJ kg−1 as received) and high bulk density (about 750 kg m−3). The torrefaction process at Arigna Fuels with high energy efficiency of (above 90%) improves biomass properties for conversion to a high-value fuel for use in solid fuel stoves. This study reports the effect of moisture content, organic composition, inorganic matter, particle size, heat treatment temperature and residence time on product yields, O2/CO2 reactivity, calorific value, composition and thermal conductivity value of torrefied olive stones. Results showed that both lignocellulosic content and ash composition equally influenced the reactivity of torrefied material. For the first time, time-of-flight secondary ion mass spectrometry (ToF-SIMS) showed that the structure of torrefied material from small olive stone particles contains more cellulose than lignin when compared to large grains. Importantly from a technological standpoint, the lower heating values of torrefied olive stones (21.8 MJ kg−1) [1] from a small scale reactor were within the range of values for torrefied woodchip briquettes containing high starch binder content which was an energy increase of ≈ 15% when compared to the raw feedstock. The results showed that olive stones of particle size ≤ 2 mm produced during torrefaction at 270 °C for 30 min are the most suitable material and conditions for briquetting due to high solid yield, low reactivity and low thermal conductivity values. These conditions are recommended for the pilot plant operation using olive stones from the Mediterranean region.

Application of response surface methodology (RSM) for the optimization of supercritical CO2 extraction of oil from patè olive cake: Yield, content of bioactive molecules and biological effects in vivo.

The two-phase technology for olive oil extraction generates large amounts of patè olive cake (POC), a by-product that is rich in bioactive health-promoting compounds. Here, response surface methodology (RSM) was used to maximize supercritical-CO2 oil extraction from POC, while minimizing operative temperature, pressure and time. Under the optimal parameters (40.2°C, 43.8MPa and time 30min), the oil yield was 14.5g·100g-1 dw (~65% of the total oil content of the freeze-dried POC matrix), as predicted by RSM. Compared with freeze-dried POC, the oil contained more phytosterols (13-fold), tocopherols (6-fold) and squalene (8-fold) and was a good source of pentacyclic triterpenes. When the biological effects of POC oil intake (20-40µL·die-1) were evaluated in the livers of BALB/c mice, no significant influence on redox homeostasis was observed. Notably, a decline in liver triglycerides alongside increased activities of NAD(P)H:Quinone Oxidoreductase 1, Carnitine Palmitoyl-CoA Transferase and mitochondrial respiratory complexes suggested a potential beneficial effect on liver fatty acid oxidation.

Modified Rotating Reel for Malaxer Machines: Assessment of Rheological Characteristics, Energy Consumption, Temperature Profile, and Virgin Olive Oil Quality.

The properties of food products are the result of changes produced in raw materials as a result of process treatments. In the olive oil extraction process, these changes can be observed as differences in quality, nutritional characteristics, taste, and flavor, and are especially due to the time and temperature of the malaxation phase. These parameters are closely related to the mechanical design of malaxer machines. In this study, a new reel model for malaxer machines was designed. The new model was incorporated into an industrial malaxer machine and experimental tests were carried out to study the effects of two different reel designs (modified and unmodified profile) on the rheological characteristics of olive paste, the energy consumption of the plant, and the temperature profile inside the machine. The main commercial parameters of the produced olive oil were studied, as well as the extraction yield and the extraction efficiency of the plant. The malaxer machine equipped with the modified reel showed better homogenization of the paste, which led to improved heat exchange and rheological properties. The results of this study showed that a specific modification of the rotating reel can improve the performance of the malaxer in terms of improving the viscosity of the paste, 127,157.67 (mPa sn) for the malaxer with the modified reel at the beginning of malaxation, reaching a final value of 64,626.00 (mPa sn) at the end. The unmodified malaxer showed an initial viscosity coefficient of 133,754.00 (mPa sn) and a final value of 111,990.67 (mPa sn). This led to a reduction in malaxing times, an increase in the work capacity of the plant, and a reduction in total energy consumption and slowed down the oxidative phenomena responsible for the decrease in the quality of olive oil.

Effect of olive ripening degree on the antidiabetic potential of biophenols-rich extracts of Brava Gallega virgin olive oils

The diet management is imperative to anticipate risk factors that favour the development of diseases; indeed, the intake of virgin olive oil could be an alternative natural source of α-glucosidase enzyme inhibitors, which delay the digestion rate of carbohydrates. Consequently, the impact of diabetes mellitus (DM) could be diminished.Extra Virgin Olive Oils (EVOO) were elaborated from Galician autochthonous variety ‘Brava Gallega’ with olives selected at three different degree of ripeness (ripening index, RI: 1.4, 3.0, 5.5) in order to assess the effect of maturation on overall chemical composition, sensory quality, and enzyme inhibition.The phenolic profile of the EVOOs determined by LC-ESI-IT-MS exhibited quantitative differences as ripening advanced; for example oleocanthal, tyrosol, luteolin and apigenin concentrations were higher in the overripe olive oil (RI 5.5). Anyway, the phenolic extracts (from every tested RI) were more active than acarbose. In particular, those obtained from the most mature olives displayed the most powerful inhibitory activity (IC50 value of 143 µg of dry extract/mL). In addition, the significant effect of these compounds (i.e. luteolin, apigenin, tyrosol and oleocanthal) on the inhibitory activity of the olive oil extracts was demonstrated. Our results suggest that, regardless of RI, the inhibitory activity of ‘Brava Gallega’ olive oils could represent a valuable strategy for reinforcing the health claim of olive oil for phenolic compounds.

Sustainable Environmental Management and Valorization Options for Olive Mill Byproducts in the Middle East and North Africa (MENA) Region

Cultivation of olive trees and olive oil production have been considered as a legacy for the Mediterranean region. This custom represents a very important benefit for many nations in terms of wealth and health. However, huge amounts of by-products and waste are generated during olive oil production. This represents a serious environmental impact on land and water bodies if not properly handled. Olive oil extraction generates two waste streams, a solid waste called pomace and olive mill wastewater (OMWW), which has been considered as highly pollutant and phytotoxic waste. These wastes have high disposal costs and predominantly generated from small-scale enterprises that have limited financial resources to treat them properly before discharge to the environment. Besides being a serious environmental problem, OMWW has potential economic value that remains to be utilized such as: fertilizers, valuable antioxidants agents and fatty acids needed in human diet. Also, Olive pomace is a valuable renewable energy source with an energy density of 23 MJ/kg and has become an inexpensive alternative for fossil fuels. Aiming at adding value to the olive production sectors and potential valorization options for byproducts in the MENA region, international practices applied in olive mills wastes management’s and treatment methods used in major oil producing countries are presented.

Utilization of Olive Oil Processing Waste Composts in Organic Tomato Seedling Production

Olive oil byproducts show differences according to the olive oil extraction systems, which are called olive mill solid wastes, olive oil wastewater and olive oil wastewater sludge. Three different kinds of composts, including two-phase and three-phase olive mill solid wastes, and olive oil wastewater sludge were produced with separated dairy manure, poultry manure, and straw. The composts obtained from two-phase and three-phase olive mill solid wastes and olive oil wastewater sludge were named as two-phase, three-phase, and water sludge composts, respectively. They were separately enriched by rock phosphate and potassium salt. These composts were mixed with peat in a ratio of 0%, 25%, 50%, 75%, and 100% (v/v). Tomato seeds were sown in all mixtures on 3 February 2016. All the seeds were sown into 2 trays and each plug included 2 replicates. The trays were left in a germination room for 3 days, then moved to a heated greenhouse which is specialized for growing seedlings, and the seedlings were grown there for 3 weeks. The results showed that increasing compost ratios in the growing medium and also the enrichment of the growing medium increased organic matter content, electrical conductivity, and macro and micro nutrient concentrations. The germination period lasted longer with increasing compost ratios. The shoot length was lower at a compost ratio of over 50% excluding water sludge compost, which reacted to over 75%. The highest plant dry weights were obtained in the plants grown on the media with compost ratios of 50%, 25%, and 25% for water sludge compost, enriched two-phase compost, and enriched three-phase compost, respectively. We concluded that the composts obtained from two-phase and three-phase olive mill solid wastes and olive oil waste water sludge can be used without any need of enrichment and a ratio of 25% was found appropriate in most of the measured properties.

Optimization of the extraction of phenolic compounds from olive pomace using response surface methodology

ABSTRACT Extraction of olive oil gives rise to large quantities of pomace and liquid effluents, since on average only 21% of the weight of the olive corresponds to oil, the remaining 79% consists of water, bark, pulp and stone. With the intention to make available new forms of use of this residue, this research was proposed, with aimed to optimize the extraction of phenolic compounds from olive pomace resulting from oil extraction using methanolic extracts. The analysis of phenolic compounds (TPC) and the evaluation of the antioxidant activity (AA) were performed by spectrophotometry, and the individual phenols were carried out by LC-ESI-qTOF-MS. The data were evaluated by the application of the response surface methodology (RSM). The condition that promoted the highest TPC in an extract was using 40% methanol, 70 °C and 180 minutes (extract 7). The highest AA was in the extract obtained with 40% methanol, 45 °C and 180 minutes (extract 5). The highest individual phenol sum (IPS) was in the extract with 80% methanol, 45 oC and 180 minutes (extract 6). Therefore, it is possible to conclude that the RSM was an interesting tool to measure the best conditions for extraction of phenolic compounds from olive pomace.