Olive Cake Research Articles

Olive Cake as a Fuel: A Comparison with Lignite

Olive Cake as a Fuel: A Comparison with Lignite

Molecular modeling of cationic dyes adsorption on agricultural Algerian olive cake waste

In this research, the adsorption isotherms of Methylene Blue (MB) and Basic Yellow 28 (BY28) on agricultural Algerian olive cake waste (AAOCW) were modeled at molecular level using statistical physics and COSMO–RS theories. This molecular modeling aimed to demonstrate an alternative way to describe the interactions between dyes and adsorbents. The adsorption equilibrium isotherms of MB and BY28 on AAOCW were constructed at different temperatures. The statistical physics model was used to quantify the number of adsorbed dye molecules per site, the anchorage number, the receptor sites density, the adsorbed quantity at saturation, the concentration at half saturation and the molar adsorption energy. The COSMO–RS theory was used to quantify the interaction energies: Electrostatic, hydrogen bonding and Van der Waals. σ–Profile and σ–potential were calculated to show the ability of each of the two dyes to interact with every adsorbent site. It was demonstrated that statistical physics and COSMO–RS theories are confident ways to elucidate the interactions between dye molecules and adsorbent surface at a molecular level.

The impact of hydrothermal carbonisation on the char reactivity of biomass

Hydrothermal carbonisation (HTC) is an attractive biomass pre-treatment as it produces a coal-like fuel, can easily process wet biomass and wastes, and lowers the risk of slagging and fouling in pulverised fuel (PF) combustion boilers. One of the major factors in determining the suitability of a fuel as a coal replacement for PF combustion is matching the char reactivity and volatile matter content to that of coals, as these significantly affect heat release and flame stability. The char reactivity of wood and olive cake biocoals and their respective drop tube furnace chars have been studied using thermogravimetric analysis in comparison to other biomass fuels and high-volatile bituminous coal. It was found that HTC reduces the reactivity of biomass, and in the case of HTC of wood pellets the resulting biocoal has a char reactivity similar to that of high-volatile bituminous coal. Proximate analysis, X-ray fluorescence analysis, and textural characterisation were used to show that this effect is caused primarily by removal of catalytic alkali and alkaline earth metals. Subsequent torrefaction of the wood biocoals was performed to tailor their volatile matter content to match that of sub-bituminous and high volatile bituminous coals without major impact on char reactivity.

Kinetic study of thermal degradation of olive cake based on a scheme of fractionation and its behavior impregnated of metals

This research aims to provide a better knowledge of the thermal decomposition of the olive cake as well as this lignocellulosic material loaded, in a previous stage of biosorption, with heavy metals for its use in processes of energy recovery.Firstly, isolation of constituents of the olive cake was carried out. Then, experiments were performed by thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) under inert and oxidative atmosphere at a heating rate of 15 K/min for each isolated fraction. Next, adequate reactions schemes were proposed to find kinetic parameters. Validation of these schemes were verified by the goodness of fitting between experimental and simulated data. Also, some important combustion characteristics such as ignition and burnout temperatures were determined.With regard to the effect of metals, cadmium, copper, chromium, nickel and lead present in metal-loaded olive cake did not modify values of kinetic parameters which described the thermal decomposition processes.

Optimization of ultrasound-assisted extraction (UAE) of phenolic compounds from olive cake.

The use of ultrasound in ultrasound-assisted extraction (UAE) is one of the main applications of this technology in food industry. This study aimed to optimize UAE conditions for olive cake extract (OCE) through response surface methodology (RSM). The optimal UAE conditions were obtained with extraction temperature of 56°C, extraction time of 3min, duty cycle of 0.6s, and solid to solvent ratio of 3.6%. At the optimum conditions, the total phenolic compounds (TPC) content and antioxidant activity (AA) were measured 4.04mg/g and 68.9%, respectively. The linear term of temperature had the most effect on TPC content and AA of OCE prepared by UAE. Protocatechuic acid and cinnamic acid were characterized as the highest (19.5%) and lowest (1.6%) phenolic compound measured in OCE extracted by UAE. This research revealed that UAE is an effective method to extract phenolic compounds from olive cake. RSM successfully optimized UAE conditions for OCE.

Extra CO2 sequestration following reutilization of biomass ash

Although combustion ashes are usually used in soils, little attention is paid to the CO2 sequestration potential of this practice. The present study aims to quantify carbon sequestration as carbonate compounds in a tailored synthetic calcareous soil treated with biomass ash from a gasification power plant that uses olive cake. It is estimated that after ash amendment, 14.5g CO2 remained fixed per kg of fly biomass ash, 16.5g CO2 per kg of bottom biomass ash with plant cultivation and 19.7g CO2 per kg of bottom biomass ash without plant cultivation. This inorganic C fixation plus the organic (black) C contained in the ashes made the reutilization of ashes as K fertilizer a relevant practice due to its C resilience and rate, with a yearly C sequestering potential of ca. 8% of ‘Soil carbon 4 per mille’ goal, an initiative launched at the COP21.

Simulation of Olive Cake Combustion in a Fluidized Bed Burner

Simulation of Olive Cake Combustion in a Fluidized Bed Burner

Characterization of minerals content in olive cake and bakery wastes: application in animal nutrition and bio-fuel production

Olive cake and bakery wastes are considered as important feed ingredients that are incorporated at different levels in animal diets and can be used in bio-fuel production. Major nutrients of both feed ingredients have been characterized in the literature; however, minerals concentration and extent of variation have been overlooked. The importances of characterization of minerals content and extent of variation between different sources have a significant applications in feed industry and bio-fuel production produced from biomass pyrolysis reactions. The purpose of this study was to investigate minerals composition (Ca, Mg, K, Na, P and S) in olive cake and bakery wastes produced in Jordan and to discuss the results in relation to the average and the extent of variation with tabulated values mostly used in literature. Olive cake and bakery waste samples (twelve samples each) were collected from different olive mills and bakeries distributed in Jordan. Among all analyzed bakery wastes samples, Na had the highest average concentration (0.36%) and ranged from 0.02 to 0.67%, whereas, Mg had the lowest concentration (0.03%) and ranged from 0.01 to 0.05 %. Among all analyzed minerals in bakery wastes, Ca, K and S had the lowest CV% (16.62%, 16.57%, and 16.28%, respectively), whereas, Na had the highest CV% (69.51%). Among all analyzed olive cake samples, this study showed that K had the highest average concentration (0.75%) and ranged from 0.46 to 1.98 %, whereas, Na had the lowest concentration (0.02%) and ranged from 0.01 to 0.03 %. Among all analyzed minerals in olive cake samples, Ca had the lowest CV % (17.48%), whereas, K had the highest CV% (53.41%). It can be concluded from this study that the existed variation in minerals concentrations within the investigated by-products is necessary to recommend minerals supplementation strategies and have applied consequences on optimization bio-fuel production process.

Alternative Feeding in Iberian Pigs during Growth Period: Incorporation of Olive Cake in a Dry or Wet (silage) Form

Alternative Feeding in Iberian Pigs during Growth Period: Incorporation of Olive Cake in a Dry or Wet (silage) Form

Combustion characteristics of solid waste biomass, oil shale, and coal

ABSTRACTIn this study, a developed two-dimensional mathematical model was used to represent the physical model of the combustion process of olive cake and date seed, and solve the governing equations using finite-volume method. The simulation was performed using ANSYS/Fluent software in order to estimate maximum temperature, heating values and pollutants concentrations. The obtained results were compared with experimental results, and corresponding values of oil shale and coal. The experimental work of direct burning of olive cake and date seeds was performed using an existing circulated fluidized bed (CFB) unit.It was found that the adiabatic flame temperatures were 1380 K and 839 K for olive cake and date seed, and 2260 K and 1080 K for coal and oil shale, respectively. The experimental results showed that the maximum temperatures were 1126 K and 723 K for olive cake and date seed, respectively. The lower heating values were 19,500 kJ/kg and 16,400 kJ/kg for olive cake and date seed, and 29,000 kJ/kg and 7000 kJ/kg for coal and oil shale, respectively.Thus, biomass such as date seed and olive cake may be used as an alternative fuel in electrical power plants in olive- or date-producing countries, which may save 40% of fuel cost.

Nutritional value of crude and partially defatted olive cake in finishing pigs and effects on nitrogen balance and gaseous emissions

By-products from the food industry can be valuable ingredients in animal feeds. One example is olive cake (OC), generated in large amounts by the olive oil industry, which contains oil with a high proportion of oleic acid and polyphenols. An experiment was performed using pigs to determine the nutritional value of crude (COC) and partially defatted (PDOC) olive cake, and to evaluate their effect on nutrient balance, slurry properties and potential ammonia (NH3) and methane (CH4) emissions. Five experimental feeds were designed; a basal diet and another four diets produced by substituting 100 or 200 g/kg of the basal diet with either COC or PDOC. Thirty finishing male pigs (76.1 ± 4.2 kg initial BW) were used in the experiment (6 animals/treatment). After a 14-day adaptation period, faeces and urine were collected separately for 7 days to measure nutrient digestibility and the excretory patterns of nitrogen. Potential NH3 and CH4 emissions were measured in reconstituted slurry samples over 11 and 100 days, respectively. The dry matter (DM), crude protein (CP), cellulose, starch and energy coefficients of total tract apparent digestibility (CTTAD) were negative and linearly (P < 0.05) affected by OC inclusion level. However, the type of OC did not influence any of the digestion efficiencies studied. The energy digestibility of the ingredients tested, estimated by substitution, were 0.479 (±0.040, SEM) and 0.327 (±0.049) for COC and PDOC, respectively. Overall, the results indicate a digestible energy (DE) value from COC and PDOC that account respectively for around 80 or 60% of the DE provided by barley grain in pigs. Faecal content of cellulose, polyphenols and gross energy (GE) increased linearly with OC inclusion, whereas ash content decreased. The total N content of urine decreased linearly with OC inclusion, but benzoic and hippuric acid contents increased, which resulted in lower pH values for the OC diets. The ratio between faecal and urine N excretion decreased from 2.48 in the basal diet to 1.01 on average in the 200 g/kg OC diets. As a result, increasing both COC and PDOC levels in diets resulted in lower NH3 emissions per volume of slurry and in a lower biochemical CH4 potential. Although slurry excretion increased with OC inclusion, daily NH3 emissions still decreased with increasing OC inclusion. However, potential CH4 emissions per animal increased. A global perspective throughout the production chain is needed to assess the impact of including OC in pig diets on gaseous emissions.

UTILIZATION OF ALLZYME SSF TO IMPROVE THE NUTRITIVE VALUE OF OLIVE CAKE IN SHEEP

The objective of the current work was to study the effect of adding different level of allzyme SSF to olive cake based diet of sheep on the intake, digestibility and nutritive value. Twenty four Barki rams (average 40.0 ± 2.11 kg live body weight) at 2-3 years old were used in the experiment. Animals were randomly allocated to four groups (6 animal/group) in separate pens and offered the experimental diets . All animals were fed concentrate feed mixture (CFM) consists of 90 % olive cake, 7% molasses, 1% sodium chloride, 1.5 % Limestone, 0.5 % mineral. During this trial the experimental diets were offered at (85% CFM and 15% Barseem hay) .in which olive cake were treated with 0.5, 1.0 and 1.5% of the allzyme SSF in the diet, respectively, for D2, D3, and D4 groups in comparison with the control (D1, without enzyme addition). The results indicated that treating olive cake with allzyme SSF decreased its fiber content. Animals in D3 and D4 groups contained relatively similar content of dry matter (DM), crude protein (CP), fiber fractions and condensed tannins. The results indicated that palatability of olive cake was improved with allzyme SSF addition. The apparent digestibility of all nutrients were higher in D3 and D4 than that in D2 and the control group (D1). The highest TDN and DCP intakes were reported for sheep in D3 and D4 followed by D2 and then D1. Results showed that TDN and DCP values were increased with increasing the level of enzyme in the diets. The concentration of ruminal pH was decreased , while that of ammonia and volatile fatty acids were increased gradually from zero to 4 hours post feeding. No significant differences were found in serum total protein, albumin and globulin concentrations among sheep in the four treated groups. Blood concentrations of creatinine, glutamic pyruvic transaminase (GPT) and glutamic oxalacetic (GOT) were not affected significantly by Allzyme SSF addition. It could be concluded that using Allyzme SSF supplementation at levels 1.0 and 1.5% in sheep diets tended to improve the digestibility and the nutritive values of sheep diet.

Oxidative Status and Presence of Bioactive Compounds in Meat from Chickens Fed Polyphenols Extracted from Olive Oil Industry Waste

A study was carried out to determine the quality characteristics, antioxidant capacity, oxidative status, and consumer acceptability of chicken meat after dietary administration of a semi-solid olive cake, known as “paté” (pOC), in broilers. pOC is an olive oil industry waste rich in bioactive compounds, such as polyphenols, obtained by mechanical extraction from destoned olives. Two hundred and ninety-seven 22-day-old fast growing (Ross 308) female chicks were randomly assigned to three experimental grower-finisher diets. Each dietary group consisted of three replicates, each with 33 birds. The experimental treatments were: (1) basal control diet (C); (2) C diet supplemented with a low dose of pOC (82.5 g/Kg, L-pOC); and (3) C diet supplemented with a high dose of pOC (165.0 g/Kg, H-pOC). Chicken growth rate increased with increasing pOC concentration in the diet. Polyphenol analyses were performed through liquid-chromatography coupled to tandem mass spectrometry technique (LC-MS/MS). In meat of animals belonging to L-pOC and H-pOC groups, tyrosol and sulphate metabolites of hydroxytyrosol were detected. Meat quality parameters and proximate composition were not affected by the dietary treatment, whereas the antioxidant status and the oxidative stability of meat were positively affected, especially when the highest level of pOC was applied. These results demonstrate that pOC can be recommended in chicken diets to improve performance and meat oxidative status.

Effects of dietary partly destoned exhausted olive cake supplementation on performance, carcass characteristics and meat quality of growing lambs

In an experiment with 32 male growing Florina (Pelagonia) lambs, effects of replacing barley grain, sunflower meal and wheat bran with partly destoned exhausted olive cake (PDEOC) and soybean meal on productivity, carcass characteristics, meat chemical composition and meat fatty acid (FA) composition was determined. In the 56day experiment, lambs were randomly allocated into four dietary treatments (PDEOC0, PDEOC80, PDEOC160, and PDEOC240) of 8 lambs each and accommodated in individual floor pens. Lambs had an initial body weight (BW) of 16.7±1.81kg, and were fed one of four isonitrogenous (crude protein 162g/kg, dry matter − DM basis) and isoenergetic (net energy for gain 6.11MJ/kg, DM basis) concentrate mixtures ad libitum and alfalfa hay (0.2kg DM/lamb/day). The PDEOC was added to the concentrate mixture at inclusion levels (as mixed basis) of 0, 80, 160, and 240kg/t for treatments PDEOC0, PDEOC80, PDEOC160, and PDEOC240, respectively. No differences (P>0.05) occurred among PDEOC treatments in final BW (29.9kg), BW gain (0.24kg/day), DM intake (0.97kg/day), and feed conversion ratio (4.07kg DM intake/kg BW gain). Moreover, meat chemical composition and carcass characteristics were not affected (P>0.05) with increased PDEOC feeding, except for the fat color, fat firmness, wetness and overall acceptability of carcasses that linearly increased with increasing PDEOC supplementation. Oleic and palmitic acids were the predominant FA in intramuscular fat of all treatments. FA were not affected (P>0.05) with increased PDEOC feeding, except for the lauric acid which decreased (P=0.018), as well as the α-linolenic acid which increased (P=0.020). PDEOC supplementation, at levels up to 240kg/t of concentrate mixtures, in isonitrogenous and iso (net energy) energetic diets for growing lambs did not affect their performance and carcass characteristics, while it improved carcass qualitative traits.

Development of Phenol-Enriched Olive Oil with Phenolic Compounds Extracted from Wastewater Produced by Physical Refining.

While in the last few years the use of olive cake and mill wastewater as natural sources of phenolic compounds has been widely considered and several studies have focused on the development of new extraction methods and on the production of functional foods enriched with natural antioxidants, no data has been available on the production of a phenol-enriched refined olive oil with its own phenolic compounds extracted from wastewater produced during physical refining. In this study; we aimed to: (i) verify the effectiveness of a multi-step extraction process to recover the high-added-value phenolic compounds contained in wastewater derived from the preliminary washing degumming step of the physical refining of vegetal oils; (ii) evaluate their potential application for the stabilization of olive oil obtained with refined olive oils; and (iii) evaluate their antioxidant activity in an in vitro model of endothelial cells. The results obtained demonstrate the potential of using the refining wastewater as a source of bioactive compounds to improve the nutraceutical value as well as the antioxidant capacity of commercial olive oils. In the conditions adopted, the phenolic content significantly increased in the prototypes of phenol-enriched olive oils when compared with the control oil.

Phosphate removal by activated carbon–silica nanoparticles composite, kaolin, and olive cake

This work aimed to utilize four low-cost materials, namely activated carbon (AC), activated carbon–nanoparticle composite, kaolin, and olive cake, for phosphate removal. Batch mode tests were used to evaluate the performance of the adsorbents. The parameters affecting the adsorption process such as pH, initial concentration, mixing time, dosage, and temperature were studied. The obtained results showed that the removal efficiency of the adsorbents followed the order of: activated carbon–nanosilica > activated carbon > kaolin > olive cake. The addition of silica nanoparticles significantly enhanced the removal efficiency of activated carbon by 18.1% reaching a removal efficiency of 98% at 15wt% nanosilica loading. The adsorption isotherm data fitted well with Langmuir and Redlich–Peterson models with a correlation coefficient of >0.98, which indicates a monolayer homogenous adsorption. The fitness of the kinetic models was ranked as: pseudo-second-order > pseudo-first-order > intraparticle model. The calculated values of ΔH° = 23.4 kJ/mole, ΔS° = 0.11 kJ/mole, and ΔG = −7.4 to −11.8 kJ/mole indicated the endothermic and spontaneous nature of adsorption. The positive value of activation energy (17.66 kJ/mole) and the very low value of the sticking probability (2.4 × 10−4) suggest high indefinite sticking of the phosphate ions to the adsorbent surface. The removal efficiency increased with time, dosage, and temperature, while it decreased with the increase in the initial concentration at an optimum pH of 7. The obtained results buttressed the benefit of using silica nanoparticles to enhance activated carbon capacity for phosphate removal, while kaolin and olive cake provided lower removal.

Effect of mixed feeds containing different levels of olive cake on fattening performance, carcass, meat quality and fatty acids of lambs.

In this study, the effects of diet including different levels of olive cake were investigated on the fattening performance, blood parameters, certain slaughtering traits, and carcass quality of lambs. Thirty-six male lambs were used in the experiment. The lambs were randomly assigned to three groups with 12 lambs each. Groups included control, 12.5 and 25% olive cake (OC). The mixed feeds were offered ad libitum. All lambs were also allowed to consume alfalfa hay (83.8gDM/animal/day). The experiment lasted for a period of 56days. The effect of different levels of olive cake was not found different in fattening performance values of lambs in 0-56days (P>0.05). Carcass weight, pH, and yield were not different (P>0.05). While the values of color parameters, cooking loss, tenderness, and ether extract level of longissimus dorsi muscle (MLD) was not found different (P>0.05), it was determined that the levels of olive cake increased the water-holding capacity of meat (P<0.05). Furthermore, although the levels of olive cake were shown to decrease total n-3 and total saturated fatty acids (Σ SFA), they also increased total n-6, n-6/n-3 ratio, total monounsaturated fatty acids (Σ MUFA), and total polyunsaturated fatty acids (Σ PUFA) were not different (P>0.05).

The effects of feeding olive cake and Saccharomyces cerevisiae supplementation on performance, nutrient digestibility and blood metabolites of Awassi lambs

Throughout a 63day-period, thirty fat-tailed Awassi ram lambs were used to determine the influence of feeding olive cake (OC) and Saccharomyces cerevisiae (SC) supplementation on performance and blood metabolites. Intact male lambs with an average initial body weight (BW) of 25.0kg±1.91 were randomly assigned to 3 dietary treatments; lambs fed the conventional diet (CON; n=10; group 1) or OC containing diets (n=20). Within the OC diet, 10 of the lambs received a diet containing 150g/kg dietary dry matter (DM) OC (OC; group 2) and the other 10 received OC diet plus 0.5g/head/day SC (OCSC; group 3). Lambs were offered ad libitum access to the assigned diets until the end of the study. On day 0, 21, 42, and 63, lamb BW was measured before the morning feeding to evaluate average daily gain (ADG) and feed:gain ratio (feed efficiency). Additionally, on the same days, ten milliliters of blood were collected before feeding from the jugular vein and analyzed for blood metabolite concentrations and liver enzymes. With the exception of ether extract (EE) intake, which was greater (P<0.01) in OC containing diets than CON diet, no differences (P≥0.11) were observed in DM, crude protein (CP), neutral detergent fiber (aNDF) and acid detergent fiber (ADF) intakes among dietary treatments. Digestibility of DM, CP, aNDF and ADF decreased (P≤0.04) in OC and OCSC diets vs the CON diet. However, digestibility of EE increased (P<0.01) in OC containing diets over the CON diet. No significant differences were noticed in total gain, ADG and feed efficiency among dietary treatments. No differences were observed in serum content of urea N, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase among treatments. However, serum content of glucose tended to be greater (P=0.07) in the OC and OCSC groups than in the CON group. In all measured variables, SC supplementation did not show any differences over the OC diet alone. In summary, results of the current study indicate that feeding olive cake for growing Awassi lambs could replace the conventional feeds at 150g/kg of dietary DM; whereas Saccharomyces cerevisiae supplementation did not show any significant benefits.

Wastes from the olive oil production in sustainable bioremediation systems to prevent pesticides water contamination

Installation of biobed biopurification systems at farm level, traditionally composed of soil, peat and straw, to reduce point source contamination is difficult in some countries where peat is not environmentally or economically feasible. This study evaluates the use of local organic wastes from olive oil production such as wet olive cake and its vermicompost as substitutes of peat and olive tree pruning as substitute of straw to perform robust biobeds capable of removing mixtures of pesticides at high concentrations. Adsorption capacity of the novel biomixtures was comparable to or higher than traditional one. The biomixture with soil and olive tree pruning showed the highest pesticides adsorption, except for imidacloprid. The biomixture with soil, vermicompost and olive tree pruning showed dissipation efficiency of dimethoate, imidacloprid and oxyfluorfen (>73%) higher than traditional biobed. Meanwhile, the biomixture with soil and vermicompost was the alternative biomixture with the highest dissipation of diuron (54%) and tebuconazole (35%) but it was lower than traditional biomixture (59 and 47% for diuron and tebuconazole, respectively). The low dissipation of these compounds (<60%) is probably due to competitive and/or inhibitory phenomena between the pesticides in the mixture. Labile organic compounds from biomixture components such as water-soluble carbon constitute a more available carbon source for microorganisms that may counteracted the negative impact of high pesticide load on biomixture microbial populations, but they may have limited the pesticides dissipation. Novel biomixtures composed of olive oil mill waste may be a sustainable and less expensive alternative to traditional biomixture.

Effects of olive-cake supplementation on fatty acid composition, antioxidant status and lipid and meat-colour stability of Barbarine lambs reared on improved rangeland plus concentrates or indoors with oat hay plus concentrates

The effects of feeding system (indoor vs rangeland) and olive-cake (OC) supplementation (control vs supplemented) on fatty acid (FA) composition, lipid oxidation status and meat-colour stability were studied. Lambs were fed indoor with hay (OH) or reared on improved rangeland (RL). All lambs received concentrate at a rate of 400 g/head.day. Twenty-four 6-month-old Barbarine lambs with an average weight of 24.3 ± 1.1 kg were assigned into the following four groups: OH without OC, OH with OC, RL without OC and RL with OC. Supplemented groups received 280 g/day of OC. Lambs were reared for ~3 months and then slaughtered at 33 kg. Feeding lambs on rangeland increased proportions of polyunsaturated fatty acids (PUFA, P &lt; 0.05), n-3 PUFA (P &lt; 0.01) and long-chain n-3 PUFA (P &lt; 0.01) and decreased those of C16:0 and monounsaturated fatty acids (P = 0.052). Higher PUFA : saturated FA (SFA) (P &lt; 0.001) and lower n-6 : n-3 PUFA (P &lt; 0.01) ratios were found for RL lambs. The peroxidisability index was higher (P = 0.024) for RL lambs. Whereas, a lower malondialdehyde concentration (P &lt; 0.001) was found for meat of RL group after 5-day storage, because of a higher vitamin E concentration (P &lt; 0.001) and catalase activity (P = 0.002). Moreover, colour was more stable for meat of RL lamb. OC supplementation reduced only superoxide dismutase activity (P = 0.033) and did not have any effect on lipid peroxidation and colour stability. No interactions were noted between the feeding system and olive-cake supplementation. Meat lambs produced on rangeland had a healthier fatty acid composition. Lipids were more stable to oxidation than was meat produced indoor with hay and concentrate.