Olive Harvesting Research Articles

Techno-economic and carbon footprint evaluation of anaerobic digestion plants treating agro-industrial and municipal wastes in North African countries

The agro-industrial activity, which is regarded as a pillar of the North-African economy, is responsible for generating considerable waste quantities. These byproducts can be treated through anaerobic digestion (AD), which offers various financial and ecological benefits over traditional waste disposal methods. However, the transition to this sustainable process is faced with several challenges due to the heterogeneity and seasonality of agro-industrial wastes. In this study, we proposed and evaluated three waste management strategies for treating agro-industrial wastes in large-scale AD plants conceived in specific North-African countries. These strategies involve co-digesting seasonal agro-industrial wastes, i.e., three-phase olive pomace (3POP), grape pomace, and orange peel, with the organic fraction of municipal solid waste (OFMSW) throughout the year (MS1); co-digesting the dominant agro-industrial waste (3POP) with OFMSW during the olive harvest season and mono-digesting OFMSW during the rest of the year (MS2); and co-digesting 3POP and OFMSW year-round by storing 3POP in cold storage facilities (MS3). The techno-economic findings show that the proposed AD plants would be profitable in Morocco and Algeria under both MS1 and MS2, with internal rate of return (IRR) values respectively reaching 10.8% and 18.4% under MS1 and 12.4% and 20.1% under MS2. In contrast, the conceived Tunisian plants would be financially feasible only if MS2 is adopted (IRR of 10.7%). Furthermore, the sensitivity analysis indicates that the economic performance of the proposed plants would mostly be affected by the biomethane selling price and capital cost. Additionally, the carbon footprint analysis suggests that the AD plants could, during their lifetime, reduce the CO2-eq emissions by 411, 208, and 26 Mt (under respectively MS1, MS2, and MS3) compared to the currently used waste disposal practices in the North African region.

Mathematical modeling of the effect of pH on 4-ethylphenol formation during two-phase olive pomace storage

Typically, two-phase olive pomace is stored during the peak of olive harvesting period, leading to the formation of malodorous compounds like 4-ethylphenol that are then released to the atmosphere during olive pomace drying prior to kernel oil extraction. The acidification of pomace prior to storage is an effective way of preventing the enzymatic process that leads to 4-ethylphenol formation from p-coumaric acid. In this work, experimental data were used to train a mathematical model that simulates the three-step process of 4-ethylphenol formation. The process includes the release of p-coumaric acid from the lignocellulosic material, p-coumaric acid decarboxylation to 4-vinylphenol, and finally, 4-vinylphenol reduction to 4-ethylphenol. Michaelis-Menten kinetics were used to describe the concentrations of the compounds with the addition of enzyme concentration inducibility and activity inhibition from pH. The trained model was able to predict the concentration of 4-ethylphenol as a function of time and storage pH, using only the initial concentrations of p-coumaric acid, 4-vinylphenol (intermediary product) and 4-ethylphenol. Such a model can be used to optimize an acidification scheme, adjusted to the expected storage duration at kernel oil extraction facilities and a set limit in the final 4-ethylphenol concentration.

Development of Olive Harvesting Machine by Shaking

Olive harvesting machine by shaking was developed and fabricated using local materials with required specifications. The developed elements were frame and hitch, gear assembly, input and transmission shafts, vibrating unit, connecting rod, limb clamp, and transmission system. This research work aimed to evaluate the developed olive harvester capable to perform harvesting operation in the proper time using the tractor as the available economic source of power. Measurements covered the properties of olive fruit, stem, and limb for five olive varieties: Agizi, Manzanillo, Picholine, Kalamata and Arbiquen. The developed harvester was tested at three levels of frequency; 3.3, 6.7, and 10 Hz, four levels of stroke; 40, 80, 120, and 160 mm, and three levels of shaking time 60, 120 and 180 s. Results indicated that the effective range to attach the clamp on the olive limb were 30 to 40% of limb length. The average value of the maximum bending stress affecting the limb and limb deflection were 16.5 MPa and 196.6 mm respectively. In addition, results have provided the suitability of the developed shaker to harvest olive fruit. The suitability of the developed machine was judged through the fruit removal percentage. The values of performance parameters of olive harvester were 10 Hz optimum shaking frequency, 120 mm of stroke, and 120 s of shaking time.

A novel co-processed olive tree leaves biomass for lead adsorption from contaminated water

Olive farming is one of the key agricultural activities in Jordan, where nearly 70% of the cultivated land in Jordan is covered with olive trees. Olive harvesting generates massive quantities of agricultural waste which will be an environmental burden if not managed properly. The present study introduces the use of novel co-processed biomass extracted from the olive tree leaves for the adsorption of lead from contaminated water. Several biomass co-processing techniques using different concentrations of sodium hydroxide, phosphoric acid, and the Dead Sea water were investigated and their effect on the removal efficiency was demonstrated. Moreover, the effect of several parameters on the adsorption efficiency including biomass particle size, solution pH, contact time, adsorbent amount, and lead ion concentration was explored. It was inferred that biomass co-processing enhanced the adsorption capacity of lead. It was also found that the adsorption efficiency increased with decreasing biomass particle size due to the increase in surface area. The highest lead removal was attained at an efficiency value of 70% for the 0.1 mm particle size and at a maximum adsorption capacity recorded at pH 5. The foregoing had a negatively charged biomass surface which, as such, favored the cationic adsorption (pHPZC values around 2.8–4.5). For lead biosorption, the process was a rapid process whereby most adsorption was observed within the first 20 min. Concurrently, there were no considerable changes in lead removal thereafter. Theoretically, this was attributed to the decrease in the available adsorption sites on the biomass surface. On the other hand, a continuous increase in the removal efficiency was recorded upon increasing the adsorbent amount. However, there was a continuous decline in the removal efficiency upon an increase in the initial lead concentration. The experimental data were fitted well with Langmuir isotherm (indicating a monolayer adsorption isotherm), while kinetic data showed the best fit with a pseudo-second-order kinetic model.

Noise Exposure in Olive Harvest Mechanization

The purpose of this study was to determine the daily noise exposure levels in olive harvesting and to evaluate its effects on employees' health. The sound pressure levels (dBA) at the ear level of the employees were measured during olive harvest operations performed by hand-held, self-propelled and tractor-driven machines. It was determined that equivalent sound pressure levels and daily personal noise exposure levels at the operator ear level were in the range of 74-88 dBA and 66-82 dBA, respectively. These values for other employees ranged from 71 to 81 dBA and 65 to 75 dBA. It was determined that the hand-held and tractor driven machines driven by internal combustion engines had higher noise parameters compared to other machines, and the lower exposure action value was exceeded in these machines. The study showed that the health and work efficiency of the employees could be adversely affected, due to prolonged exposure during olive harvest activities.

Crop year, harvest date and clone effects on fruit characteristics, chemical composition and olive oil stability from an Empeltre clonal selection grown in Aragon

BACKGROUNDIn this study, the effects of crop year, harvest date and clone on the fruit characteristics and chemical composition of Empeltre olive oils were evaluated. For this purpose, the weight and oil content of fruit and the fatty acid composition, polyphenol content and oxidative stability of the olive oil was analysed throughout ripening during three successive seasons.RESULTSThe weight and moisture in the fruit, as well as the fatty acids and polyphenol content in the olive oil, were mainly affected by crop year. In contrast, the stability was strongly influenced by the harvest date. Both factors had an influence on the fruit's oil content. The clone was not a substantial component in terms of variability, although the interaction with crop year was notable for some of the characteristics. The oil content increased significantly along with the harvest date and reached maximum values in the last period (44.9%). Conversely, stability and polyphenols decreased significantly (depending on the year, by 30–70%) from October to December, reaching the highest mean values between 1 October and 10 November (15.5 h; 500 mg caffeic acid kg−1). Oleic acid and monounsaturated/polyunsaturated fatty acids (MUFA/PUFA) did not show significant differences depending on the harvest date, but between years, with 2018 having the highest percentage of oleic acid (72.72%) and MUFA/PUFA (8.38).CONCLUSIONEarly harvesting of Empeltre olives would provide considerably more stable olive oils, regardless of the clone selected, with higher phenolic content. It would not affect the MUFA/PUFA ratio, mainly influenced by the crop year. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Separation and Determination of Biophenols in Olive Oil Samples Based on the Official Method of the International Olive Council and Commission Regulation (EU) No. 432/2012

The purpose of this study was to evaluate the key quality characteristics of olive oil with a main focus on the biophenolic content, its beneficial effects on health and the contribution of various quality characteristics to its health claims, as well as its influence from various parameters. Samples from different traditional oil-producing regions of Greece were initially examined for the most important quality parameters, such as the percentage of free acidity, the number of peroxides and the spectrophotometric investigation in the ultraviolet. The samples were then tested for their biophenolic content, expressed in milligrams of tyrosol, and its derivatives per 20 g of olive oil using the analytical technique high-performance liquid chromatography (HPLC). Then, the biophenol contents of the analyzed samples were compared based on the presented intensities in terms of the variety and the area of cultivation, the altitude, the type of cultivation, the extraction system in the mill and the time interval from olive harvest to oiling. Finally, according to the results, the content of biophenols in olive oil and its health claims were found to be influenced by the various parameters with which they were compared.

Vibration from Electric Hand-Held Harvesters for Olives

Olive harvesting is the most expensive cultivation operation in areas where full mechanization is not possible due to structural conditions such as low tree density, old trees, irregular spacing, and terraced fields, which are very frequent in many small Italian farms. Under these conditions the use of hand-held vibrating harvesters is quite wide spread, because they are capable of approximately three times the productivity of workers using manual harvesting methods. Unfortunately, the use of these machines exposes the operators to hand-arm vibration risk and acceleration values are affected by several factors, including harvester kinematics, rod material and geometry, and load conditions. In this study several models of electrical portable harvesters, obtained by combining six harvester heads and four rods (one telescopic), were tested under idling and load conditions, measuring acceleration values on the rod, near the hand positions. Assuming the use of the machinery for 4 h per day, the result is a level of daily vibration exposure A(8) for the most exposed hand ranging from about 11 to 40 m/s2, much higher than the daily exposure limit value of 5 m/s2 stated by the European Directive 2002/44/EC. With the same harvester head, reduction in vibration may be achieved by using carbon fiber rods rather than aluminum ones or by increasing the rod diameter. The most significant reduction is achievable by designing harvester heads whose kinematics inherently incorporate oscillation compensation.

Applying Solar Energy in the Combination of Solar Dryer with Olive Harvesting Machine to Reduce Energy Losses

In recent years, leveraging the amount of energy loss occurring in different fields of human activity has captured the attention of researchers. Harvesting and drying processes can be integrated in order to reduce energy losses. The present research work seeks to pinpoint the association between the harvesting and drying processes as well as to make optimal use of both processes so as to decrease the level of energy loss and apply the renewable energies to the food supply chain. The olive harvesting machine was designed and evaluated, and the olives harvested in the solar dryer were placed in the solar dryer as the input materials. To obtain the evaluation of the experimental tests’ purpose, Mari cultivar was used. Following this trend was the evaluation of the olive harvesting machine and its comparison with the manual harvesting method. Having separated the olives from the tree through use of the harvesting machine designed and made, a solar dryer was used to accommodate the olives in order to make the final examination concerning any damage to olives. Findings of the study indicated up to 92% separation of the olive fruits by the olive harvester. It was also found that there is a 29.47 harvest efficiency for the olive harvester. In addition, evaluation of the solar dryer emphasized that an increase in the temperature and velocity of the inlet air results in a rapid decrease in the olive moisture.

Evaluation of physicochemical, bioactive composition and profile of fatty acids in leaves of different olive cultivars

Olive leaves are agro-industrial residues resulting from pruning and / or olive harvesting, and are used in animal feed, as an organic fertilizer and as a source of compound extraction for various applications. This study aimed to carry out the physicochemical characterization, main bioactive compounds and the fatty acid profile of olive leaves from the cultivars Frantoio, Koroneike, Manzanilha, Arbosana and Arbequina. Proximal composition, pH, titratable acidity, minerals by MIP OES, bioactive compounds were determined by spectrophotometry, oleuropein and tocopherols by high performance liquid chromatography and the fatty acid profile by gas chromatography. The olive leaves had a high content of fibers and proteins, the predominant minerals were potassium and calcium, in addition the olive leaves had a high content of bioactive compounds, mainly flavonoids and carotenoids and the cultivar Koroneike had a higher content of oleuropein compared to the others. In relation to tocopherols, α-tocopherol stood out from the other tocopherols with the maximum concentration (63436.79 mg.100g-1) measured in the cultivar Arbequina. In view of the results found, it is concluded that olive leaves are sources of macromolecules, bioactive compounds and fatty acids, which can be extracted and applied in the most diverse areas.

Use of refrigerated cells for olive cooling and short-term storage: Qualitative effects on extra virgin olive oil

• Cooling slightly increases oxidative processes of olive fruit; • Cold storage of olives reduces the production of fusty -related volatile compounds; • Cooling of olive fruit can modulate the aroma profile of olive oil; • Container type does not affect olive oil quality for short periods of storage. In extra virgin olive oil production, the time between olive harvesting and milling is a critical period that must be carefully controlled to preserve oil quality. Particularly, several detrimental phenomena can emerge during storage. Hence, a key issue for producers is to optimize conditions to preserve the quality of fruit before milling. With this requirement in mind, we tested the effect of olive cooling and short-term cold storage on olive oil quality in two experiments. The first, baseline trial was run in the laboratory, and involved storing small batches of olives at 6°C and at 25°C for 16 h. Here, the aim was to simulate a situation with a high temperature difference. The second experiment was conducted at industrial scale, using a refrigerated storage cell. One batch of fruit was stored at 6.5°C for 16–18 h, while a control batch was stored at ambient temperature (13.5 ± 1°C). Finally, the effect of the surface/volume ratio (SVR) of the storage container was evaluated in a full factorial experiment. Although an effect of SVR on olive temperature was found, no significant differences were registered in oil quality. Short-term storage after cooling slowed metabolic processes, reducing hydrolysis of phenols and slowing the development of undesirable compounds. Furthermore, it supported oxidation, evidenced by higher concentrations of the oxidized form of polyphenols and higher production of lipoxygenase pathway compounds. The latter result suggests that this system could be successfully used to modulate the aroma profile of the produced olive oil.

Türkiye’nin Marmara Bölgesindeki Türk Zeytin Üreticilerinin İyi Tarım Uygulamalarını Benimsemesini Etkileyen Faktörlerin Belirlenmesi

This study was carried out with 63 farmers using good agricultural practices (GAP) in olive production in five districts of Balıkesir, Bursa and Tekirdag provinces located in the Marmara Region of Turkey by conducting a questionnaire survey. The farmers with GAP certificate produce either Gemlik (71.4%) or (28.6%) Ayvalık varieties. Survey forms were handed out to contract-based producers in November 2017 during olive harvest period. The data were evaluated using SPSS statistical program. The results showed that average size of farms producing olive oil with GAP are generally 60-65 decares (da) in size. The average age of olive producers is 58.7, who have been producing olives for an average of 39 years with an average GAP experience of 2.4 years. A positive relationship was evident between lower level of education and late adoption of GAP. The most important problem faced by growers was Verticillium wilting, followed by olive fly in recent years. The study revealed that the absence of a significant difference in the prices of olives and olive oils grown with or without GAP reduced the attractiveness of GAP production. Moreover, because of the lack of price policy in olives grown with GAP, olives are marketed along with conventionally produced ones in an equal conditions in the domestic market.

Mechanically assisted harvesting of dry and semi-dry dates of average to low quality

A large number of date palms in the world produce average to low quality dates that are used for processing into derivate or as animal feed and constitute an important source of sugar and energy; most of these dates are of the dry or semidry kind, so they can bear the shock of being harvested by shaking and dropping on the ground without losing their value. In order to evaluate the possibility of using hand carried electromechanical harvesters, of the type used for harvesting olives and other fruits, for collecting dates of Mech Degla and Deglet Noor varieties, preliminary field tests have been carried out at Biskra, in Algeria, with the use of two models of Italian olive harvesters, that were able to detach all fruits from a single bunch in a time ranging from 30 to 88 s, with a productivity in the range of 22.8 - 36.4 kg*min-1. These results are encouraging and allow for further investigation, even with a more complex experimental design, including adaptation of the equipment to the specific context.

Impact of Olive Harvesting Date on Virgin Olive Oil Volatile Composition in Four Spanish Varieties

AbstractThe unique sensory characteristics of extra virgin olive oil (EVOO) depend upon its volatile composition. This work investigates the impact of olive fruit harvesting time and growing location on the volatile composition of the obtained EVOO, on four typical Spanish olive varieties (Cornicabra, Picual, Castellana, Manzanilla Cacereña). Several growing locations within the Madrid region (Spain) are studied to assess the natural variability attributed to the environmental factors. Aroma compounds are analyzed by solid‐phase microextraction coupled with gas‐chromatography and mass spectrometry, and sensory analysis. A considerable different behavior is observed depending on the olive variety and ripening stage. Statistically significant differences are obtained for volatile compounds biosynthesized from the lipoxygenase pathway and other fatty acid metabolism routes, which results in significant differences in their aroma profiles.Practical applications: These results have practical applicability for the olive oil industry and regulatory bodies. For example, for protected designation of origin EVOOs the aroma profile needs to be consistent over different production lots. The outcome of this research is of interest to the olive oil industry to get a better insight into the expected variability and interactions among cultivars, small pedoclimatic differences within the same broader area, and the harvesting date on the sensory and volatile profile of the resulting EVOO.

Planting Systems for Modern Olive Growing: Strengths and Weaknesses

The objective of fully mechanizing olive harvesting has been pursued since the 1970s to cope with labor shortages and increasing production costs. Only in the last twenty years, after adopting super-intensive planting systems and developing appropriate straddle machines, a solution seems to have been found. The spread of super-intensive plantings, however, raises serious environmental and social concerns, mainly because of the small number of cultivars that are currently used (basically 2), compared to over 100 cultivars today cultivated on a large scale across the world. Olive growing, indeed, insists on over 11 million hectares. Despite its being located mostly in the Mediterranean countries, the numerous olive growing districts are characterized by deep differences in climate and soil and in the frequency and nature of environmental stress. To date, the olive has coped with biotic and abiotic stress thanks to the great cultivar diversity. Pending that new technologies supporting plant breeding will provide a wider number of cultivars suitable for super-intensive systems, in the short term, new growing models must be developed. New olive orchards will need to exploit cultivars currently present in various olive-growing areas and favor increasing productions that are environmentally, socially, and economically sustainable. As in fruit growing, we should focus on “pedestrian olive orchards”, based on trees with small canopies and whose top can be easily reached by people from the ground and by machines (from the side of the top) that can carry out, in a targeted way, pesticide treatments, pruning and harvesting.

An artificial neural network model to predict olive mechanical harvesting: a first approach based on metadata

An artificial neural network model to predict olive mechanical harvesting: a first approach based on metadata

DEVELOPMENT OF A PNEUMATIC OLIVE HARVESTER

A pneumatic olive harvester was developed and evaluated in this study. The components of the developed machine were the limb clamp, vibrating unit, control elements, main tube, air-pressured hoses, control valve, and power source. The measurements that related to the development of the harvester were fruit and limb damage, and some physical and mechanical properties of the olives fruit-stem system. The results demonstrated that the effectiveness of the developed machine to harvest olive fruits. The appropriateness of the developed machine was evaluated by some criteria: machine productivity, fruit removal, fruit damage, limb damage depth at the contact point with the clamp of the machine, breakage of shaken limb, and consumed energy. The suitable values of these criteria were achieved at 27 Hz frequency and 60 mm stroke.

Estimation of the Cooling Rate of Six Olive Cultivars Using Thermal Imaging

Bringing the olive harvest period forward leads to storing fruit in field temperatures that risk jeopardizing its quality. Knowledge about the bio-thermal characteristics of olives is crucial when considering their cooling, although published research on the subject is limited. In this work, the cooling rate of the fruit of six olive cultivars has been empirically determined by measuring the evolution of their low temperature under controlled conditions by thermal imaging. Based on these data, the cooling time needed to cool the fruit to 22 °C was estimated, considering the biometric characteristics of the individual fruit, a field temperature from 26 to 42 °C, and a room cooling temperature from −8 to −20 °C. The results showed differences among the cultivars and the need to further investigate the specific heat requirements for small varieties and the impact of the conduction factor on the heavier ones. The simulation suggests that between 2 min (for the light Arbequina and Koroneiki cultivars) and 5 min (for the heavier Verdial and Gordal cultivars) suffice to cool the fruit to the desired temperature with a room temperature of −16 °C. These results show the feasibility of developing technological solutions for cooling olives before their industrial processing with industrial applications such as cooling tunnels on individual fruit.

Combined Metabolome and Transcriptome Profiling Reveal Optimal Harvest Strategy Model Based on Different Production Purposes in Olive

Olive oil has been favored as high-quality edible oil because it contains balanced fatty acids (FAs) and high levels of minor components. The contents of FAs and minor components are variable in olive fruits of different color at harvest time, which render it difficult to determine the optimal harvest strategy for olive oil producing. Here, we combined metabolome, Pacbio Iso-seq, and Illumina RNA-seq transcriptome to investigate the association between metabolites and gene expression of olive fruits at harvest time. A total of 34 FAs, 12 minor components, and 181 other metabolites (including organic acids, polyols, amino acids, and sugars) were identified in this study. Moreover, we proposed optimal olive harvesting strategy models based on different production purposes. In addition, we used the combined Pacbio Iso-seq and Illumina RNA-seq gene expression data to identify genes related to the biosynthetic pathways of hydroxytyrosol and oleuropein. These data lay the foundation for future investigations of olive fruit metabolism and gene expression patterns, and provide a method to obtain olive harvesting strategies for different production purposes.

دراسة اقتصادية لأثر الحيازة الفدانية على الکفاءة الإنتاجية والاقتصادية لمحصول الزيتون فى محافظة شمال سيناء

Despite the importance of the olive crop in North Sinai Governorate, this crop is characterized by its low production efficiency in light of the high age of some of its trees, and the presence of local varieties characterized by low productivity, and the main problem of research is limited to the decrease in the cultivated area of ​​the olive harvest from about 52.8 thousand feddans in 2013, To about 35.5 thousand feddans in 2017, a decrease of about 32.8%. The research aims in general to study the effect of feddan holding on the productive and economic efficiency of olive farms in North Sinai Governorate, where the research used the descriptive analysis method to present the topics included in the research, in addition to the quantitative analysis method using some standard models such as multiple regression in its double logarithmic form. In estimating production functions, and in cubic forms in estimating cost functions, The study also relied mainly on primary data through a stratified random sample of 70 farms It is estimated that the fruitful area of ​​the olive harvest increases annually by a statistically significant amount of about 2.6 thousand feddans, which represents about 9% of the annual average, and on the productive indicators of the research sample farms, the average number of trees per acre is about 56 trees, and the general average productivity of the tree is about 81 kg / year, and the general average productivity per feddan was about 4.6 tons / year. The general average age of olive trees in the research sample was about 28.3 years. The general average of the holder's share was about 3.9 feddans It is also evident that the relative importance of the rent item is high among the fixed costs items, as well as the rented labor item, and organic fertilizer is among the variable costs items. It is evident that the first holding category farms (less than 3 feddans) achieved the highest rates of lost income, while the third holding category farms The lowest rates of lost income, which confirms the need for intensification and rationalization of the elements of production within this category. Regarding the profit margins, the results indicated that the general average of the net yield from the olive harvest amounted to about 14.4 thousand pounds, which is equivalent to about 3.1 pounds per kilogram of the crop. The general average of the return over the variable costs of the olive harvest was about 19.1 thousand pounds, which is equivalent to about 4.2 Pounds per kilogram of crop. The general average of the added value was about 17.9 thousand pounds With regard to economic efficiency, the results indicated that every pound spent on fixed and variable production costs achieves an added value of about 1.36 pounds. It was found that the farms of the third holding category for the olive harvest were superior to their counterpart in the first and second categories in profit margins, as well as indicators of economic efficiency. This indicates the importance of expanding olive cultivation to take advantage of the capacity savings in the short and long term.