By-product Of Olive Oil Extraction Research Articles

Olive mill wastewater: From by-product to smart antioxidant material

Olive mill wastewater (OMWW) is a byproduct of olive oil extraction that represents a critical environmental concern due to its potential adverse effects on ecosystems. Given these premises, spray-dried microparticles were designed and developed using maltodextrins as carriers to encapsulate OMWW bioactive compounds. The microparticles were manufactured using an easily scalable and sustainable spray-drying process. The resulting microparticles were smooth, spherical, and exhibited a mean particle size of about 18 μm. The systems demonstrated notable antioxidant properties with a DPPH radical scavenging activity higher than 60 %, due to the polyphenolic compounds of OMWW (about 24 gallic acid equivalents per g of sample). In addition, the microparticles supported fibroblast and macrophage viability at concentrations up to 1 mg/mL. They also determined a 4-fold inflammation reduction in macrophages, improved collagen expression in fibroblasts, and modulated oxidative stress on aged fibroblasts. In conclusion, these microparticles could be considered as promising medical devices in wound healing, while offering a sustainable solution for valorizing OMWW.

Effect of partial substitution of wheat flour with freeze-dried olive pomace on the technological, nutritional, and sensory properties of bread

In the last years, olive pomace, a by-product of olive oil extraction, has shown great interest. The work aims to valorize the olive pomace of two Sardinian olive cultivars, Bosana and Semidana, by incorporating them into the formulation of functional baked products to improve their nutritional value. The freeze-dried pomace of the two varieties has been used to substitute the type 00 flour in percentages of 1, 2, and 3% (w/w). The olive pomace was characterized by macro-composition analysis, while the bread samples were characterized for their proximate, physical, technological, sensory characteristics and shelf life. The specific volume of fortified samples decreased significantly compared to the control, while antioxidant activity, and nutritional parameters were significantly improved using olive pomace. Moreover, fortified samples showed a reduction of browning and whiteness indices with respect to control. Textural profile analysis showed a firmer product, compared to the control, with higher levels of olive pomace which also positively affected the cell size distribution in the crumb. Sensorially, consumers were mostly appealed by the 1% levels of substitution of olive pomace, in particular that of the Bosana. Hardness of all samples increased significantly along 7 days of storage thus resulting in a shelf life of less than 3 days. Therefore, it can be concluded that the incorporation of olive pomace, especially at low levels (1%), into white bread significantly improves the nutritional and sensorial quality of bread without significantly affecting its technological properties.

Improving the Rheological Properties of Dough Obtained by Partial Substitution of Wheat Flour with Freeze-Dried Olive Pomace

Mediterranean countries are known for their high-quality olives and the production and consumption of olive oil. Olive pomace (OP), the major by-product of olive oil extraction, is receiving attention for its potential as a functional compound in food products, reflecting its physiology- and health-promoting attributes. This study assessed the physico-chemical characteristics of OP obtained from two Sardinian olive cultivars, Bosana and Semidana, and the effect of OP incorporation on the baking performance of wheat dough. We assessed the rheological parameters, pasting profile, and fermentation of doughs obtained through the partial substitution of wheat flour with OP at 0 (control), 1, 2, 3, and 5%. OP inclusion resulted in significant differences in the studied parameters compared with control samples. Positive effects included a decrease in development time, improved dough stability and storage, and superior loss modulus and gas retention capacity. Negative effects comprised an increase in dough resistance and a decrease in dough development height, gas production, gas retention, pasting profile, stickiness, and elasticity. These differences in the OP dough were due to the interactions between polyphenols and fibre with water and the starch–gluten matrix. This study found improvements in dough characteristics following the substitution of wheat flour with low percentages of OP, especially Semidana at 1%. Although higher percentages of OP would be associated with greater nutritional and health benefits, they resulted in a degradation of the dough’s attributes, producing a gluten-free-like matrix in the final product.

Effects of Dietary Enrichment with Olive Cake on the Thyroid and Adrenocortical Responses in Growing Beef Calves.

Agro-industrial by-products incorporated into livestock feed formulations can positively impact feed costs and promote a circular bio-economy. Italy produces significant amounts of olive cake (OC), a by-product of olive oil extraction, with the potential for incorporation into bovine diets. However, information on its effects on endocrine responses in growing beef calves is lacking. Forty-eight Limousines randomly allocated to dietary treatment (control or 10%-OC or 15%-OC inclusion) were segregated according to sex and body weight. Serum concentrations of TSH, thyroid hormones, and cortisol were measured on day 0, day 56, and at the end of the trial on day 147. Circulating TSH, total (T3, T4) and free (fT3, fT4) iodothyronines, and cortisol concentrations were all within the normal physiological ranges, with no significant effect imparted by diet. However, the diet × time interaction was significant for T3. The cortisol, T3, T4, and fT4 registered on day 147 were higher than those of day 56, and cortisol was higher in heifers than bulls. Final body weight was positively correlated with TSH and T3 and negatively with cortisol concentration. These findings suggest that the inclusion of OC at levels up to 15% in growing/finishing beef diets had no adverse effects on the calves' thyroid and cortical status.

Continuous Production of Dietetic Structured Lipids Using Crude Acidic Olive Pomace Oils.

Crude olive pomace oil (OPO) is a by-product of olive oil extraction. In this study, low-calorie structured triacylglycerols (TAGs) were produced by acidolysis of crude OPO with medium-chain fatty acids (caprylic, C8:0; capric, C10:0) or interesterification with their ethyl ester forms (C8EE, C10EE). These new TAGs present long-chain fatty acids (L) at position sn-2 and medium-chain fatty acids (M) at positions sn-1,3 (MLM). Crude OPO exhibited a high acidity (12.05-28.75% free fatty acids), and high contents of chlorophylls and oxidation products. Reactions were carried out continuously in a packed-bed bioreactor for 70 h, using sn-1,3 regioselective commercial immobilized lipases (Thermomyces lanuginosus lipase, Lipozyme TL IM; and Rhizomucor miehei lipase, Lipozyme RM IM), in solvent-free media at 40 °C. Lipozyme RM IM presented a higher affinity for C10:0 and C10EE. Lipozyme TL IM preferred C10:0 over C8:0 but C8EE over C10EE. Both biocatalysts showed a high activity and operational stability and were not affected by OPO acidity. The New TAG yields ranged 30-60 and the specific productivity ranged 0.96-1.87 g NewTAG/h.g biocatalyst. Lipozyme RM IM cost is more than seven-fold the Lipozyme TL IM cost. Therefore, using Lipozyme TL IM and crude acidic OPO in a continuous bioreactor will contribute to process sustainability for structured lipid production by lowering the cost of the biocatalyst and avoiding oil refining.

Health benefits of first and second extraction drum-dried pitted olive pomace.

Olive pomace (OP) is the main by-product of olive oil extraction. After pit and skin removal, OP pulp has high concentrations of dietary fiber and phenolics with high antioxidant capacity. This study evaluated mice health benefits of drum-dried pitted OP pulp obtained after first and second oil extraction. Fresh OP was steam blanched, then pits and skins separated in a pulper/finisher, and pulp drum-dried and milled. OP was characterized by proximate analysis, total soluble phenolics (TSP), individual phenolics, and dietary fiber. Drum-dried pitted OP from first and second extraction was formulated at 10% and 20% in a high fat mice diet. Low fat (5%) and high fat (18%) control diets were also used for comparison. First extraction OP had higher TSP than OP from second extraction. Hydroxytyrosol was the main phenolic in OP. Mice weight gain was lower for the four OP diets compared to high and low-fat control diets. Fecal protein was high for all OP diets, indicating poor protein retention in mice, possibly by phenolics binding of protein and enzymes. Liver weight and adipose tissue were lower in mice consuming the four high fat OP diets compared to high fat control diet. Also, there was no effect on blood glucose by OP in diets. Mice gut microbiota analysis indicated that Actinobacteria decreased in the OP diets compared to the two control diets while Bacteroidetes increased, indicating a positive correlation with reduced body fat and weight. Drum-dried pitted OP is a novel agricultural by-product with its bioactive compounds having the potential to be incorporated in feeds and foods providing health benefits. PRACTICAL APPLICATION: Drum-dried pitted olive pomace can be produced from first or second olive oil extraction byproducts to be used as a shelf-stable healthy food or feed supplement.

Polyphenols associated to pectic polysaccharides account for most of the antiproliferative and antioxidant activities in olive extracts

• Olive extracts rich in polysaccharides associated with polyphenols were obtained. • The extracts showed strong antioxidant and antiproliferative activities. • These activities were reduced when the phenols were removed by sodium chlorite. • Bleached extracts had a similar antiproliferative activity as citrus modified pectin. Extracts rich in pectic polysaccharides associated to polyphenols were obtained from alperujo, the by-product of olive oil extraction, by different thermal treatments and subsequent chemical treatments. The resulting “Pectoliv” extracts exhibited strong antioxidant activities and a high antiproliferative capacities in vitro against colon carcinoma Caco-2 and leukemia monocytic THP-1 cell lines. Bleaching of the extracts with sodium chlorite removed the phenolic compounds and significantly reduced antiproliferative and antioxidant activities, confirming that these were due mainly to the associated polyphenols present in Pectoliv. However, even after bleaching, these activities remained very similar to that of a commercial citrus modified pectin obtained by chemical treatment from citrus pectin, which has been implicated in cancer treatment and prevention. Thus Pectolivs have a high potential as antiproliferative or antioxidant agents.

Gas chromatography-mass spectrometry analysis andin vitrobiological studies on fixed oil isolated from the waste pits of two varieties ofOlea europaeaL.

Olive oil isolated from the fruits of theOlea europaeaL. is an important part of Mediterranean diet. It is known for its diverse biological actions. Furthermore, a little amount of fixed oil and other bioactive components can also be extracted from the olive seeds which are considered as byproduct of olive oil extraction. Therefore, this study was designed to analyze the fatty acid composition and to performin vitrobiological studies on fixed oil isolated from olive seeds. The fixed oil was isolated from the olive seeds of Syrian and Greek black olive fruits by using Soxhlet apparatus. The purity was checked by measuring its refractive index. Composition of two isolated oils and a commercially available virgin olive oil was determined by preparing their Methyl esters (FAME) followed by GC-MS analysis. Variousin vitroassay methods were used to investigate activities such as antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), cytotoxic activity by using Brine shrimps lethality bioassay and antimicrobial activity against two bacterial strains;Staphylococcus aureusandEscherichia coliby agar well diffusion method. GC-MS analysis revealed that the two isolated oils differ quantitatively in chemical composition with oleic acid identified as the major chemical constituent (62.6% and 73.56%). Both the fixed seed oils showed a concentration dependent DPPH radical scavenging activity ranging from 8 to 76% inhibition. The oils also exhibited excellent cytotoxic activity but no antimicrobial activity was observed. The chemical composition of the isolated fixed olive seed oil is found to be almost similar to the commercially available fruit olive oil. The fixed oil from the seeds of olive fruits possesses useful biological actions. Further studies are needed to isolate and quantify their bioactive constituents.

Olive Pomace in Diet Limits Lipid Peroxidation of Sausages from Cinta Senese Swine

In order to examine whether olive pomace (OP), the mean by‐product of olive oil extraction, can be included in the animal diet, its effect on the raw mixture and sausages made from meat from OP‐fed Cinta Senese swine is tested by comparing it with a diet supplemented with high oleic sunflower oil (SO) and a control diet (C). Proximate composition, pH, color, total culturable bacteria, lactic acid bacteria (LAB), and lipid oxidation are evaluated in both the raw mixture and sausages. The aroma profile is also evaluated in sausages. Olive pomace affected the fatty acid composition of the raw mixture and strongly limited the lipid peroxidation of sausages, probably due to the synergistic action of 3,4‐DHPEA and α‐tocopherol. Olive pomace selectively promotes LAB growth, and protected the raw mixture and sausages from discoloration. The diet also affected the content of volatile organic compounds thus enabling OP sausages to be distinguished from other sausages.Practical Applications: The protection of foods against lipid peroxidation is a very important aspect in terms of their quality. Achieving this naturally is a high priority for consumers, as there is an increasing demand for “low impact” and “environment‐safe” production processes. The approach proposed in the present study is aimed at meeting both these objectives. Our findings demonstrate that the inclusion of olive pomace in the swine diet effectively slowed down the lipid oxidation in the sausages. The strategy we propose also meets both economic and ecological goals. Olive pomace is the main by‐product of olive oil spinneret, and its re‐use in another spinneret is a cost‐effective way of improving the sustainability of the production process.Three different kinds of sausages are made. The experiment is aimed at studying the effect of olive pomace (OP) in controling the progression of lipid oxidation. OP have protected sausages against cholesterol oxidation, thus limiting the production of COPs (α‐hydroxycholesterol, α‐epoxycholesterol, and 7‐ketocholesterol). The most probable mechanism is attributable to electron or H+ donor properties of polyphenols contained in olive pomace.

Physico-chemical assessment of pomace exhausted and appreciation of their compostability in the delegation of Kalaa Kebira (Tunisia)

Olive pomace is the solid by-product obtained from the extraction of olive oil revealing serious environmental problems in all Mediterranean countries olive growing. Generally, that pomace can be valued, among others, as a source of organic matter (composting). In this perspective, we have addressed in this work to the quantitive and qualitative characterization (limited to certain physico-chemical parameters) of the solid by-product of olive oil extraction in the delegation of Kalaa Kebira (Sousse, Tunisia) while appreciating their compostability. The results showed that those olive residues are essentially dry, carbon-rich and CF, low in nitrogen. They can be used as compost by combining them with other available sources of plant originand/or animal such as manure of cattle, sheep or poultry (in varying proportions and responsible of the nature very heterogeneous and the variable quality) that can be applied to improve soil fertility and crop productivity.

Isolation and identification of minor secoiridoids and phenolic components from thermally treated olive oil by-products

The application of an industrial process based on the hydrothermal treatment of 160°C/60min of alperujo, a by-product of olive oil extraction, allows the formation of a liquid phase containing a high concentration of phenolic and secoiridoid compounds. Ethyl acetate was used to extract these phenolic compounds from the aqueous matrix. In this study, the isolation with polyamide and XAD resin allowed detection of the presence of phenolic compounds in minor concentrations. These minor phenols were several oleuropein derivatives that had not been identified in these phenolic extracts previously. The polar compounds, acteosides, secoiridoids, and flavonoids, that remain in the aqueous fraction after extraction with ethyl acetate were identified. We report the presence of known compounds and also detected a novel molecule in alperujo with a molecular weight of 408 whose structure was characterized for first time. This new secoiridoid glucoside was identified as 1-β-d-glucopyranosyl acyclodihydroelenolic acid.

Inhibitory and synergistic effects of natural olive phenols on human platelet aggregation and lipid peroxidation of microsomes from vitamin E-deficient rats.

This study explored the in vitro antioxidant and anti-platelet activities of hydroxytyrosol, hydroxytyrosol acetate, 3,4-dihydroxyphenylglycol and two phenolic olive extracts. These compounds and extracts were obtained from a new industrial process to hydrothermally treat the alperujo (160 °C/60 min), a by-product of olive oil extraction. The extracts and the purified compounds were obtained chromatographically using both ionic and adsorbent resins. The antioxidant activity was determined by measuring inhibition of human platelet aggregation and inhibition of lipid peroxidation in liver microsomes of vitamin E-deficient rats. The positive effect of the extracts on the inhibition of platelet aggregation is showed, being higher in the case of hydroxytyrosol acetate up to 38%, and for the first time, its synergist effect with hydroxytyrosol has been proved, obtaining more than double of inhibition. The phenolic extracts and the isolated phenols showed good results for inhibiting the lipid oxidation, up to 62 and 25%, respectively. A synergistic effect occurred when the hydroxytyrosol acetate and the 3,4-dihydroxyphenylglycol were supplemented by hydroxytyrosol. These results suggest the extract and these compounds obtained from a novel industrial process could be natural alternatives for the prevention of diseases related to cardiovascular disorder or oxidative damage.

Antioxidant Effects of Alperujo Extract (Arbequina and Frantoio Varieties) on MIN6 <i>β</i>-Cells Subjected to Stress with Glucose or H<sub>2</sub>O<sub>2</sub>

Alperujo, an antioxidant-rich by-product of olive oil extraction, could protect β-cells against oxidative damage. Our goal was to study the antioxidant effects of an alperujo extract (AE) on MIN6 β-cells challenged with glucose or hydrogen peroxide. MIN6 β-cells were challenged with glucose (100 mM) or H2O2 (0.15 mM), with or without AE (20 μM phenol). Reactive oxygen species, intracellular iron (Fe), insulin, glucose uptake, and mRNA gene expression of Uncoupling Protein-2 (UCP-2), Thioredoxin (TRDX), p47phox, and the ratio Bax/Bcl-2 were measured. ROS increased when the stressors were incubated with AE (p β-cells with AE tended to protect them against apoptosis, thereby enhancing insulin secretion.

Direct and residual effects on diuron behaviour and persistence following two-phase olive mill waste addition to soil: Field and laboratory experiments

Two-phase olive mill waste (TPOMW) is a by-product of olive oil extraction, contains up to 90% organic matter, and may be used as a soil amendment. In order to investigate the impact of TPOMW amendments to soil on the sorption-desorption, degradation, leaching, and persistence of the herbicide diuron, field and laboratory experiments were conducted on a representative olive grove soil. The soil was amended in the laboratory with TPOMW at the rates of 5% and 10%, and in the field with 30 and 60 Mg ha − 1 of TPOMW for seven years. Direct and residual effects were evaluated in the last year and two years after the last TPOMW field application (2005 and 2007, respectively). Significant increases in diuron sorption were observed with the greater amount of TPOMW in the laboratory and field-amended soils, mainly promoted by an increase in humic acid content, this process being more reversible in the laboratory than in the field amended soils. The TPOMW soil application only significantly increased the half-life of diuron in the laboratory amended soils, ranging from 8.5 days for the original soil to 32 days at the greater application rate. The TPOMW amendments significantly reduced the downward mobility of diuron, and reduced the amount of herbicide leached in the laboratory and field-amended soils, with a major residual decrease two years after the last waste addition since no herbicide leached through these amended-soil columns. In the field persistence study, TPOMW addition increased diuron retention mainly in the upper 30 cm of the soils, decreasing the herbicide's vertical movement through the amended soils. The residence time of diuron increased with increasing TPOMW rate, especially in the direct year (2005). The results revealed major changes in diuron's behaviour due to the different TPOMW loading rates and the transformation of the amendment during two years of biodegradation in the soil. This study has shown the usefulness of TPOMW for reducing groundwater contamination by pesticides for at least 24 months following its application.

Methods for Preparing Phenolic Extracts from Olive Cake for Potential Application as Food Antioxidants

Olive cake, the most important byproduct of olive oil extraction by the two-phase centrifugation system, was used to obtain phenolic extracts. The extracts were obtained using the two constituents of this waste, vegetative water and solid residue, to maximize the extraction of all phenolic compounds. Different extraction procedures were studied, a simple and rapid extraction procedure being developed from the solid residue using an accelerated solvent extractor (ASE). Afterward, the phenolic extracts were fractionated using semipreparative HPLC to study the antioxidant activity of the different components. The identification of the phenolic compounds was carried out with an ultraperformance liquid chromatograph coupled to tandem mass spectrometry equipment (UPLC-ESI-MS/MS). With this method, a complete list of the polyphenols from the extract was obtained. Finally, the antioxidant activity of the phenolic extracts and the isolated fractions was evaluated, showing great antioxidant capacities, between 3450 and 17900 micromol of Trolox equivalents/g of extract. With regard to the isolated fractions the most antioxidant were those that contained hydroxytyrosol and 3,4-DHPEA-EDA. The suitability of the solid residue extract obtained by the ASE procedure was demonstrated given the great range of phenolic compounds and the feasibility of production on an industrial scale.

Long-chain fatty alcohols from pomace olive oil modulate the release of proinflammatory mediators

Pomace olive oil is a by-product of olive oil extraction that is traditionally produced and consumed in Spain. The nonglyceride matter of this oil is a good source of interesting minor compounds, like long-chain fatty alcohols, which are present free or as part of waxes. In the present study, long-chain fatty alcohols were isolated from the nonglyceride fraction of pomace olive oil, and the composition was identified and quantified. The major components of long-chain fatty alcohols were tetracosanol, hexacosanol and octacosanol. We investigated the ability of long-chain fatty alcohols from pomace olive oil to inhibit the release of different proinflammatory mediators in vitro by cells involved in inflammatory processes. Long-chain fatty alcohols significantly and dose-dependently decreased nitric oxide production by RAW 264.7 murine macrophages stimulated with lipopolysaccharide. Western blot analysis showed that nitric oxide reduction was a consequence of the inhibition of inducible nitric oxide synthetase expression. Long-chain fatty alcohols also reduced tumor necrosis factor-α and prostaglandin E 2 production, although the potency of inhibition for the latter was lower. On the other hand, long-chain fatty alcohols significantly reduced thromboxane A 2 production in rat peritoneal neutrophils stimulated with the calcium ionophore A-23187. The reduction of eicosanoid release was related to the inhibition of phospholipase A 2 enzyme activity by long-chain fatty alcohols, reaching an inhibitory concentration 50% value of 6.2 μg/ml. These results showed that long-chain fatty alcohols may have a protective effect on some mediators involved in the inflammatory damage development, suggesting its potential value as a putative functional component of pomace olive oil.

Drying Characteristics of the Solid By-product of Olive Oil Extraction

Olive cake, the solid by-product of olive oil extraction, consists of pit and pulp of the olive fruit, and has significant oil content. Although the initial moisture content of olive cake is 44·78%±0·5 by weight (wet basis), the material has quite a high-energy content that enables it to be used for direct burning in bakeries and olive oil mills after sun drying in Turkey. When the latter manufacturing processes such as pomace oil production, bio-oil production by using thermal conversion processes were used, the effect of drying should be considered. Therefore, drying behaviour of olive cake in a cabinet type dryer was examined using heated ambient air at temperatures from 80 to 110°C and constant air velocity of 1·2 m s −1 in this study. In addition, the effects of sample thickness on the drying characteristics, drying time and energy quality of dried product were also determined. The experimental data was compared with values predicted by the Page model, and by the Henderson and Pabis model, good agreement being obtained with Page model. A diffusion model was used to describe the moisture transfer and the effective diffusivity at each temperature was determined. The effective diffusivity varied between 489·2 and 998·4 μm 2 s −1. The temperature dependence of the diffusivity coefficient was also described by the Arrhenius type relationship. The activation energy was found to be 26·71 kJ mol −1.