Olive Oil Extraction Industry Research Articles

Unraveling the effect of phenolic extract derived from olive mill solid wastes on agro-physiological and biochemical traits of pomegranate and its associated rhizospheric soil properties

Agricultural waste management poses a significant challenge in circular economy strategies. Olive mill wastes (OMW) contain valuable biomolecules, especially phenolic compounds, with significant agricultural potential. Our study evaluate the effects of phenolic extract (PE) derived from olive mill solid wastes (OMSW) on pomegranate agro-physiological and biochemical responses, as well as soil-related attributes. Pomegranate plants were treated with PE at doses of 100 ppm and 200 ppm via foliar spray (L100 and L200) and soil application (S100 and S200). Results showed increased biomass with PE treatments, especially with soil application (S100 and S200). Proline and soluble sugar accumulation in leaves suggested plant adaptation to PE with low-level stress. Additionally, PE application reduced malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents. Higher doses of PE (S200) significantly improved net photosynthesis (Pn), transpiration rate (E), water use efficiency (WUEi), and photosynthetic efficiency (fv/fm and PIabs). Furthermore, PE treatments enhanced levels of chlorophylls, carotenoids, polyphenols, flavonoids, and antioxidant activity. Soil application of PE also increased soil enzyme activities and microbial population. Our findings suggest the beneficial impact of PE application on pomegranate agro-physiological responses, laying the groundwork for further research across various plant species and soil types to introduce nutrient-enriched PE as an eco-friendly biostimulant.

Social life cycle assessment of the olive oil industry: a case study in Guilan Province, Iran

AbstractOlive oil production has severe environmental consequences, including resource depletion, land degradation, carbon emissions, and waste generation. As a result, for over two decades, environmental life cycle assessment (ELCA) has been applied to the olive oil industry to identify environmental issues and reduce the environmental effects. However, little is known regarding the social sustainability of this industry. Social life cycle assessment (S-LCA) has been established as one of the most effective methodologies for assessing the social implications of products throughout their life cycles. Accordingly, based on the S-LCA approach, this study aims to assess the social impacts of the olive oil extraction industry in Roudbar County in Guilan Province in Iran, the major producer of olives and olive oil. The S-LCA model adopted in this paper is built in four major phases (UNEP/SETAC in Guidelines for social life cycle assessment of products, 2009): (1) Definition of Goal and Scope: outlines the intended use and the goal pursued and specifies the scope of the research. The research will then be defined to fulfill that purpose within any constraints. (2) Life Cycle Inventory analysis: is the phase at which data are collected, systems are modeled, and LCI results are generated. (3) Life Cycle Impact Assessment: a collection of steps to obtain data categorization, aggregation, and characterization based on performance reference points. (4) Life Cycle Interpretation: considers all important aspects of the research when drawing results, offering recommendations, and reporting. The findings suggested that the social conditions governing the olive oil extraction cycle in the study area are almost adequate. However, other categories of social impacts, such as cultural heritage, community development, and working conditions, were rated unsatisfactory by olive orchard workers and need improvement. Adopting the cause-and-effect chain in this study favors identifying specific indicators based on social issues in the study location. On the other hand, a scale-based assessment may result in the subjectivity of the results, which adds to the uncertainty. An impact-based assessment may be applied to analyze social impacts such as occupational health and safety, employment, pay, and benefits to get more credible social impact data. Consequently, integrating the scale-based approach with an efficient path-based method may improve its effectiveness.

A sustainable and highly efficient fossil-free carbon from olive stones for emerging contaminants removal from different water matrices

The olive stone is a large waste product of the olive oil extraction industry. The present study investigates developing activated carbon from olive stone waste (OSAC) to remove pharmaceuticals from water. Different temperatures and olive stone: KOH ratios were studied. The OSAC produced at 750 °C and 1:3 ratio was found to have the highest porosity and surface area and was tested in the adsorption process. Diclofenac and ciprofloxacin were selected as model contaminants. The adsorption process was optimized with regards to OSAC dosage, pH, temperature, and initial concentration of adsorbate. The OSAC was found to be effective for a wide pH range (2–11) with an optimum dosage of 1 g/L at 25 °C. The pharmaceuticals were almost completely removed in 75 min. The adsorption was endothermic and followed first-order kinetics with physical mechanisms such as electrostatic possibly being the main driver. The optimum conditions were applied to test the removal of diclofenac and ciprofloxacin in synthetic water, lake water (Lake Balaton, Hungary) and secondary wastewater for seven cycles. There was little difference between the removal of the tested water matrices highlighting the potency of OSAC as an adsorbent for pharmaceutical removal in industrial applications. The removal dropped from >99% for the first cycle to 20–30% for the seventh cycle.

Economical Olive Cultivation by Selection of Suitable Variety in Pothwar Region of Pakistan

Olive (Olea europaea) is very popular for producing premium quality edible oil, though it is the main crop of the Mediterranean region, playing a pivotal role in the economies of those countries. Its cultivation is increasing in other countries, including Pakistan, due to its wide adoptability and easy propagation technology. The very wide genetic variability of the plant is a reason for its popularity. Olive varieties behave differently in different climatic zones of the world. Pakistan has adopted various varieties for their cultivation in different olive production pockets. These studies were conducted in the Centre of Excellence for Olive Research & Training (CEFORT), Chakwal, to prioritize suitable olive varieties for Pakistan's economical olive oil business. The highest yield (2652 Kg/acre), Net Profit/acre (Rs. 271386), Oil Recovery/acre (331.7652Ltr.), and Oil income (331765.2) was observed in BARI Zaitoon-I while Average Oil Recovery (13.48%), Total Expenditure /Acre (61335.01) was observed in Arbiquina olive variety. BARI Zaitoon-1, BARI Zaitoon-2, Arbequina, and Koroneiki proved most suitable for cultivation in sub-mountainous areas of Pakistan. These varieties are recommended for olive cultivation in the Pothwar region due to their growth behavior, olive oil content, and good economic return. The difference in the fruit ripening period among these varieties results in the prolonged supply of raw material to the olive oil extraction industry.

Towards energy efficient scheduling in the olive oil extraction industry: Comparative assessment of energy consumption in two management models

• Energy Use Efficiency and Specific Energy in olive oil mill was evaluated. • Batch and continuous extraction processes were compared. • The Overall Equipment Effectiveness in batch and continuous olive mill was evaluated. • The energy consumed in the batch system is double that of the continuous one. • Batch system performance is nearly half of continuous one. Although olive oil is one of the most important food products throughout the Mediterranean region, the main consideration in configuring and operating extraction plants is still the quantity of crop that will be brought by the individual growers, who are often of small and medium size. On this basis, the common configuration is the batch processing line (Ba-PL) for small and medium capacities, with malaxers arranged in parallel, or in larger-capacity industrial mills, the arrangement of malaxers in series for simulation of continuous processing (Co-PL). A review of literature to date reveals that there have been no assessments of the energy use and scheduling strategies for these two processes, therefore the current study undertakes such assessment and comparison of the Ba-PL and Co-PL configurations, within a single mill facility. The results show that energy output for Ba-PL was 105,570.00 MJ day −1 based on inputs of 3212.76 MJ day −1 , while outputs from Co-PL reached 422,280.00 MJ day −1 from inputs of 6740.38 MJ day −1 . Given that the yield of oil is almost the same in the two processes, the Net Energy (NE) for Ba-Pl then results as 10,2357.24 MJ day −1 versus 41,5539.62 MJ day −1 for the Co-PL configuration, and moreover the later process is seen to achieve almost double the Energy Use Efficiency, at 62.65 versus 32.86 in Ba-PL. Finally, the Overall Equipment Effectiveness (OEE) analysis of performance for the two processes shows values of 93.1 % for the Co-PL configuration but only 51.2 % for Ba-PL, due mainly to dead times in throughput on the Ba-PL machinery, resulting in a 44.7 % decrease in the values for the Performance parameter. The conclusion is that to meet the needs of small producers, there must be new management approaches and improvement in the energy use for batch processing. Some strategies could be: – measure the oil content and moisture in input batches using rapid, non-destructive methods, so that homogeneous batches can be pooled before processing; – reduce dead time by developing automated systems for pumping the olive paste from the malaxers to the separation decanter; – even in the case that they are non-homogenous, consider pooling undersized batches so as to avoid mass flows far below the malaxer capacities. Throughout the Mediterranean, olive oil production using batch processing remains very substantial, therefore further studies are required for the identification and evaluation of solutions for optimising this process.

Continuous pulsed electric field pilot plant for olive oil extraction process

The olive oil extraction industry often uses unit-constructed processing lines lacking in the necessary efficiency and sustainability. The development of efficient processing lines is seen as crucial in obtaining higher product quality and extraction yields. In recent years, numerous researchers and companies have explored the possibilities of assistance from pulsed electric fields (PEF) technology as a mean of reducing processing time and increasing extraction yields from different food crops. The current article shows the application of PEF technology in olive oil extraction, and specifically it researches the results from application of PEF technology in a pilot plant of industrial-layout olive oil extraction process. The experimental methodology involves construction of a plant meeting specific functional and cost criteria, capable of delivering unipolar electric pulses with amplitude <10 kV, current <200 A and 3 kW maximum average power. The analyses then focalize on the assessment of the results from PEF assistance on oil extraction, particularly in terms of extractability from crop and enhancement of bioactive substances content. The proposed PEF unit was found to be easy to install within existing plants, flexible in control and capable of continuous operation. Operating at different pulse and power levels, the plant results in increased process efficiency and content of desirable substances.

Advanced oxidation processes at ambient conditions for olive oil extraction industry wastewater degradation

The olive mills are theoretically waste free plants, at the refined oil extraction units, a highly pollutant effluent is generated. In this work the performance of different AOPs in the same multiphase reactor was evaluated to minimize real oil extraction effluent environmental impact. In terms of COD removal, the combination of Fenton and Ozone reaction simultaneously, allows the highest reduction (58.5%) although the combination of Fenton followed by ozone at pH3 lead to a similar removal, about 54%. In what regards mineralization, Fenton peroxidation alone was the most efficient process leading to 53% of TOC removal. Fentońs process presents an interesting role in the effluent treatment. However, if one bears in mind phenolic content removal and toxicity abatement, the best results were obtained by Fenton peroxidation (pH 3) followed by ozonation (pH 9). The treatment processes selection should consider the target results as well as a suitable economic analysis.

Application of dry olive residue-based biochar in combination with arbuscular mycorrhizal fungi enhances the microbial status of metal contaminated soils

Biochar made-up of dry olive residue (DOR), a biomass resulting from the olive oil extraction industry, has been proposed to be used as a reclamation agent for the recovery of metal contaminated soils. The aim of the present study was to investigate whether the soil application of DOR-based biochar alone or in combination with arbuscular mycorrhizal fungi (AMF) leads to an enhancement in the functionality and abundance of microbial communities inhabiting metal contaminated soils. To study that, a greenhouse microcosm experiment was carried out, where the effect of the factors (i) soil application of DOR-based biochar, (ii) biochar pyrolysis temperature (considering the variants 350 and 500 °C), (iii) soil application dose of biochar (2 and 5%), (iv) soil contamination level (slightly, moderately and highly polluted), (v) soil treatment time (30, 60 and 90 days) and (vi) soil inoculation with Funneliformis mosseae (AM fungus) on β-glucosidase and dehydrogenase activities, FA (fatty acid)-based abundance of soil microbial communities, soil glomalin content and AMF root colonization rates of the wheat plants growing in each microcosm were evaluated. Biochar soil amendment did not stimulate enzyme activities but increased microbial abundances. Dehydrogenase activity and microbial abundances were found to be higher in less contaminated soils and at shorter treatment times. Biochar pyrolysis temperature and application dose differently affected enzyme activities, but while the first factor did not have a significant effect on glucosidase and dehydrogenase, a higher biochar dose resulted in boosted microbial abundances. Soil inoculation with F. mosseae favored the proliferation of soil AMF community and increased soil glomalin content as well as rates of AMF root colonization. This factor also interacted with many of the others evaluated to significantly affect soil enzyme activities, microbial abundances and AMF community. Our results indicate that the application of DOR-based biochar along with AMF fungi is an appropriate approach to improve the status of microbial communities in soils with a moderate metal contamination at short-term.

Reproductive parameters and weight gain of roosters fed with waste oil from olive culture

Waste oil from olive oil extraction industry was used, instead of soybean oil, in heavy roosters’ diet in order to evaluate birds’ reproductive parameters. A total of forty roosters were housed individually in boxes with 1.2 m². Two experimental diets were used: control diet, based on corn, soybean meal, and soybean oil; and test diet, where soybean oil was totally replaced by waste oil. In order to verify weight gain and feed intake, animals were individually weighed weekly. Seven semen collections were performed with fifteen-day interval. Reproductive variables analyzed sperm volume, motility, concentration, and morphology. No statistical difference (p &gt; 0.05) was observed between treatments at the different collection periods for the variables sperm volume, motility, and concentration. There was a statistically significant difference between treatments for body weight in periods three (p = 0.04), and seven (p = 0.04). Statistical differences (p = 0.01) were also observed between treatments for abnormal sperm morphology. Among collection periods, statistical difference was observed for motility (p = 0.00), and sperm concentration (p = 0.01). Total replacement of soybean oil by waste oil from olive oil extraction in young heavy roosters’ diets does not affect sperm volume, motility, and concentration; reduces defects in sperm tail, and promotes better weight gain control.

Potential therapeutic of olive oil industry by‐products in skin health: a review

SummaryOlea europaea L. is one of the most important fruit trees in the Mediterranean countries due to its products, olive oil and table olives. However, the olive oil extraction industry produces large amounts of by‐products, such as olive pomace, leaves and olive mill wastewater, which are considered harmful to the environment, having negative impacts on soil, aquatic and air ecosystems. The olive oil industry by‐products are a major ecological issue mainly due to their phenolic components, such as oleuropein, hydroxytyrosol and tyrosol. However, olive oil industry by‐products can be recovered, treated and studied for their health‐promoting properties, holding great potential for the cosmetic and pharmaceutical industries. Furthermore, the recovery and treatment processes contribute to an efficient waste management and sustainability of the olive oil industry, leading to important economic benefits. The phenolic compounds extracted and obtained from these by‐products present numerous health properties and can be used as antioxidant, photoprotector, anti‐inflammatory and/or antimicrobial agents in wellness and therapeutics of the skin. This review highlights issues related to olive oil industry by‐products and then proceeds to discuss how their beneficial biological activities make them reusable, particularly their high positive impact in treating skin disorders.

Optimisation of COD removal from the olive oil mill wastewater by combined electrocoagulation and peroxone process: modelling and determination of kinetic coefficients

ABSTRACT The olive oil extraction industry is one of the most extensive industries, especially in the Mediterranean region. The wastewater produced in this industry contains high concentrations of organic pollutants, resistant and toxic compounds that, if not treated, can threaten the health of the environment. In the present study, the optimisation of the combined process of electrocoagulation and peroxone using central composite design of the response surface methodology with the help of Design-Expert V.11 The parameters of current density (0.06–0.73 A dm−2) and reaction time (5–45 min) in the process of electrocoagulation and the parameters of hydrogen peroxide concentration (4–12 ml) and reaction time (10–90 minutes) in the peroxone process were investigated on the COD removal efficiency. The design results showed that the quadratic model was significant for both processes and was determined as the selected model. The optimal conditions determined by the software in the process of electrocoagulation were 0.5 A dm−2 and 34 minutes and in the peroxone process, concentration of hydrogen peroxide and the time were obtained 12 ml and 62 minutes, respectively. In these conditions, the COD removal efficiency of the processes was determined 79.8% and 52.8%, respectively. Under optimal conditions, in peroxone process ozone consumption was reduced to 0.88 mg per mg of removed COD. Also, according to the results of Pseudo-first-order kinetics, constant rate increases with increasing of hydrogen peroxide concentration. The results obtained in this study were confirmed the application of electrocoagulation process along with advanced oxidation of proxone for effective treatment of effluents of this industry and similar industries.

Olive oil extraction industry wastewater treatment by coagulation and Fenton’s process

The treatment of olive mill wastewater is a problem that still does not have an effective solution. In order to minimize this problem, there has been an improvement in the olive oil production process, moving from three-phase processes in oil mills to two-phase processes, and integrating the later with the oil extraction industry with n-hexane. This improvement does not totally solve the olive mill wastewater problem on its own, it only releases the olive mills from the environmental burden and concentrates the problem in the oil extraction industry. In this study it was proposed a treatment of a real effluent from an olive oil extraction industry, using the Fenton’s process integrated with coagulation. Different coagulant loads were studied to achieve the best conditions for this process. For the Fenton’s process, the loads of iron and hydrogen peroxide were optimized. The main evaluation parameters present in this study were chemical oxygen demand (COD), biodegradability and toxicity. Regarding the toxicity of the treated effluent, tests were performed on Aliivibrio fischeri.The studied effluent has a dark color, with an organic load of about 50 g L−1 of COD and high toxicity, with 9% of biodegradability. Coagulation process was studied with a single addition of coagulant (80 mg L−1) leading to 12.5 % ​​COD removal, while the combination of 20 mg L−1 plus 20 mg L−1 allows a COD reduction of 15 %. With the best conditions for coagulation (double phased addition of a total of 40 g L−1 of coagulant) integrated with the Fenton reaction (4 g L−1 of hydrogen peroxide, 2 g L−1 of iron (II) at pH 3 with 60 min of reaction) was possible to achieve about 45 % of COD removal. This allowed to increase the biodegradability, to a ratio higher than 40 %, for further biological treatment application to definitively treat the effluent.

OLIVE MILL WASTEWATER (OMW) TREATMENT BY HYBRID PROCESSES OF ELECTROCOAGULATION/CATALYTIC OZONATION AND BIODEGRADATION

The olive oil extraction industry is one of the most polluting wastewaters from the food industry, which is considered an important economic activity in the world. The environmental effects of olive wastewater are related to chemical and organic loading, which is resistant to biodegradation processes. The purpose of this study was to determine the efficiency of combined electrocoagulation, catalytic ozonation, to reduce organic load and improve the biodegradability of olive oil sewage. The present study was experimental on a laboratory scale and was done at a batch reactor on actual olive wastewater. The electrocoagulation process was performed using Fe electrodes at a current density of 0.73, 0.5, 0.05..dm... The optimal conditions for the electrocoagulation process were obtained at a flow rate of 0.5 ..dm. for 45 min reaction time, so that the removal efficiency of TOC, COD, and turbidity was 75, 80 and 94%, respectively. Then the treated wastewater under these optimal conditions entered the catalytic ozonation process (COP) reactor. In the COP process, the TOC and COD concentrations reached 105 and 210 mg/L after 90 min (44% and 56% removal). Eventually, the effluent was introduced into the biology*ical reactor and the removal efficiency of COD and TOC were investigated. So, the amount of TOC and COD decreased from 105 and 210 mg/L to 22.3 mg/L and 37 mg/L, respectively. As a result, the overall efficiency of the EC/COP/SBR system in removing COD and TOC was 98.4% and 97.2%, respectively. The combination of these processes is very effective in comparison with other processes for the treatment of olive sewage.

Brinell indentation behavior of the stainless steel X2CrNi18-9: Modeling and experiments

Stainless steel X2CrNi18-9 plays an important role in many industrial fields, namely in the agro alimentary industry based on its corrosion resistance. Meanwhile, its mechanical and tribological resistance still presents a challenge. In the olive oil extraction industry, the stainless steel X2CrNi18-9 presents a complex damage mechanism under concentrated load. In the present study, a Brinell indentation test was carried out on the stainless steel X2CrNi18-9 under a load range between F = 10 N and F = 613 N. A three-dimensional finite element (FE) model has been elaborated in order to simulate and understand the mechanical response under this specific concentrated load given by the Brinell test. The mechanical behavior of stainless steel has been described by the Johnson-Cook elasto-plastic model and its damage mode by the Johnson-Cook failure model. The main experimental and numerical results show a stress concentration in the border and in the center of the indents throughout the indentation tests caused by the plastic deformation. The SEM investigations show typical indents increasing in size with increasing load and a pile-up phenomenon as a result of a large E/Y ratio (Young's modulus/yield stress). The elaborated FE numerical model of the Brinell indentation test shows a very satisfactory correlation to the experimental test results.

Day-ahead economic optimization of energy use in an olive mill

This article presents an economic case study on biomass and power dispatch focused on the olive oil extraction industry. A method is proposed to minimize the energy cost associated to olive oil production. This is realized through load shaping and optimal selection of the destination of subproducts and wastes. The mill and the loads linked to the extraction process are modeled using the energy hub concept, and an Economic Model Predictive Control (EMPC) based power and biomass dispatcher is introduced. The control strategy has been simulated over different scenarios to validate the optimization scheme.

Evaluation of an aerobic treatment for olive mill wastewater detoxification

Olive mill wastewater (OMWW) is a by-product of the olive oil extraction industry. Its dumping creates severe environmental problems in the Mediterranean countries. The phytoxicity of OMWW is due to the phenolic substances and is evaluated through a genotoxicity method. An aerobic treatment of OMWW was conducted during 45 days. Different concentrations of raw and treated OMWW were tested using the Vicia faba micronuclei test. Results showed that raw OMWW induced significant micronuclei formation at 10% of OMWW dilution. At 20% of dilution, no mitosis was recorded. The 45 days aerobic treatment OMWW showed an important decrease in the genotoxicity and also in the toxicity that was observed at 10% and 20% OMWW dilution. This could be correlated with the biodegradation of 76% of the total phenols. Indeed, qualitative analysis by high performance liquid chromatography shows the disappearance of the majority of phenolic compounds after 45 days of treatment. This study was completed by an agricultural test with V. faba plant. Data showed significant growth yield of 36.3% and 29.9% after being irrigated with 5 and 10 t/ha, respectively. These results supported the positive role of aerobic treatment on OMWW and their capacity to ameliorate the agronomic potential of these effluents.

Treatment of crude olive mill wastewaters by osmotic distillation and osmotic membrane distillation

Olive oil extraction industry is a very important economic activity in the entire Mediterranean basin. The olive mill wastewaters (OMWs) are seasonally produced with large volumes of toxic and polluting wastewaters. Amongst other organic constituents, crude OMW contain high concentrations of phenolic compounds up to 10g/L that make, along with the high organic load, OMW hardly biodegradable and phytotoxic. In this study attempts are made using osmotic distillation (OD) and osmotic membrane distillation (OMD) processes for OMW treatment and concentration of polyphenols present in OMW without any pre-treatment. These non-destructive processes were carried out using microporous polytetrafluoroethylene (PTFE, Gelman) membranes of different pore sizes (TF200, TF450 and TF1000). Calcium chloride was used as an osmotic agent in the permeate membrane side. The results show that the PTFE membranes exhibit reasonable permeate fluxes (2.9–4.2L/hm2) and a high retention of the phenolic compounds in the feed membrane side. The obtained concentration factor of phenolic compounds was up to 1.2 after 280min of crude OMW processing by OD. When using OMD with a temperature difference of 20°C and a mean temperature of 30°C, this concentration factor reached a value up to 1.9 after 30h of operating time using the membrane TF200. All used PTFE membranes exhibit a high fouling resistance since the reduction of the water permeate flux after OMW experiments did not exceed 5%. OD and OMD using PTFE membranes are promising alternative technologies for the treatment and concentration of crude OMW for further valorisation and recovery of their phenolic compounds.

SBR treatment of olive mill wastewaters: dilution or pre-treatment?

The olive-oil extraction industry is an economically important activity for many countries of the Mediterranean Sea area, with Spain, Greece and Italy being the major producers. This activity, however, may represent a serious environmental problem due to the discharge of highly polluted effluents, usually referred to as 'olive mill wastewaters' (OMWs). They are characterized by high values of chemical oxygen demand (COD) (80-300 g/L), lipids, total polyphenols (TPP), tannins and other substances difficult to degrade. An adequate treatment before discharging is therefore required to reduce the pollutant load. The aim of the present paper was to evaluate performances of a biological process in a sequencing batch reactor (SBR) fed with pre-treated OMWs. Pre-treatment consisted of a combined acid cracking (AC) and granular activated carbon (GAC) adsorption process. The efficiency of the system was compared with that of an identical SBR fed with the raw wastewater only diluted. Combined AC and GAC adsorption was chosen to be used prior to the following biological process due to its capability of providing high removal efficiencies of COD and TPP and also appreciable improvement of biodegradability. Comparing results obtained with different influents showed that best performances of the SBR were obtained by feeding it with raw diluted OMWs (dOMWs) and at the lowest dilution ratio (1:25): in this case, the removal efficiencies were 90 and 76%, as average, for COD and TPP, respectively. Feeding the SBR with either the pre-treated or the raw dOMWs at 1:50 gave very similar values of COD reduction (74%); however, an improvement of the TPP removal was observed in the former case.

Two by‐products of the olive oil extraction industry as oleic acid supplement source for Iberian pigs: effect on the meat's chemical composition and induced lipoperoxidation

The objective of the present study was to evaluate the effect of two by-products of the olive oil extraction industry-olive soapstocks and olive-pomace oil-as added fat sources into feed concentrates, in two different rearing systems (free-range complemented with concentrates and intensive rearing with concentrates) on the chemical composition and oxidative stability of Iberian pig meat. No differences in the chemical composition, colour and fatty acid composition of gluteobiceps m. were found due to added fat source. However, the feeding system had a significant effect on protein (P < 0.05), γ-tocopherol (P < 0.05), colour (P < 0.01) and fatty acid composition of gluteobiceps m. Neither added fat source nor the feeding system had an effect on the malondialdehyde content. The addition of olive soapstock or olive-pomace oil as fat sources into concentrates did not influence meat composition or fatty acid profile. However, there are differences in the fatty acid composition of meat from Iberian pigs as a result of the production system used.

Improved soil quality after 16 years of olive mill pomace application in olive oil groves

This report shows notable improvements of soil physical, chemical, and biological properties after long-term soil application of olive mill pomace compost. About four million tons of olive mill pomace is produced annually in Andalusia, Spain. Olive mill pomace is a main by-product of the olive oil extraction industry. Composting is a promising strategy to manage the huge volume of this potentially environmentally harmful pomace. Converting olive mill pomace into a useful soil amendment in semiarid Mediterranean areas of olive oil farms, characterized by low organic matter content and subjected to progressive degradation, would be valuable. There is actually no data on the long-term effects of composted olive mill pomace application on soil physicochemical and biochemical properties. However, this information is needed to encourage the composting of this pomace. Here, a field study evaluated soil fertility and soil capacity to degrade organic compounds after the application of composted olive mill pomace. Olive groves received compost annually for 3, 4, 9, and 16 years. Soils were sampled and compared to olive groves without compost application. Soil physico-chemical properties and soil enzyme activities such as acid phosphatase, β-glucosidase, protease, invertase, and dehydrogenase, were analyzed. Our results show that soil organic matter, nitrogen, available phosphorus, cation exchange capacity, aggregate stability, and exchangeable potassium were between 1.4 and 3.3 times higher in the compost-treated farms. Soil enzyme activities in soils treated with compost was between 180% and 420% higher than in untreated soils. Moreover, there was a clear trend of increasing soil fertility and enzyme activities with years of compost application. Here, we conclude that the addition of composted olive mill pomace to olive groves markedly improved soil quality.