Manuel Moya - Academia.edu (original) (raw)

Papers by Manuel Moya

Agronomy

Olive tree pruning is an abundant and renewable lignocellulosic residue, which is generally burne... more Olive tree pruning is an abundant and renewable lignocellulosic residue, which is generally burned in the fields, causing economic costs and environmental problems. This lignocellulosic residue can be considered a suitable raw material for the production of a wide range of byproducts in a biorefinery context due to its high content of potentially fermentable carbohydrates. To take advantage of its sugar content, pretreatment is necessary to enhance the accessibility of the enzymes to the cellulosic fraction. The aim of this work is to obtain sugars contained in olive tree pruning as a substrate for the production of bioethanol by fermentation. Specifically, the production of fermentable sugars by sequential pretreatment with sulfuric acid and sodium hydroxide is studied. A two-factor rotatable composite central design temperature and catalyst concentration (H2SO4 and NaOH) has been generated, and response surface methodology has been used to discuss and optimize the responses. This ...

Journal of Food Engineering, 2018

Pomace is an oil mill byproduct and the raw material for extracting olive pomace oil. The pomace ... more Pomace is an oil mill byproduct and the raw material for extracting olive pomace oil. The pomace is stored several months in ponds until it is processed. Tests have been carried out in stored olive pastes, malaxated with and without different coadjuvants. These pastes have been equated to the oil mill pomace. Coadjuvants increase the water pH in 0.8 units. 89.5% of the initial oil is recovered from pastes without coadjuvant; 91.1% from pastes with calcium carbonate and 80.5% from pastes with talc. The free acidity is 1.9%, 2.6% and 2.1% respectively. The maximum amount of refined pomace oil is obtained when calcium carbonate is used and the minimum when talc is used. Moisten the adjuvants affects talc and calcium carbonate differently, although both of them easily releases the original micro-powder. Moisture does not affect the technological action of the coadjuvants or modify their physical characteristics.

European Journal of Lipid Science and Technology, 2019

Extra virgin olive oil; super high density orchard; maturity index; composition progress; irrigat... more Extra virgin olive oil; super high density orchard; maturity index; composition progress; irrigation † This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Linear β-1,3 glucan chain with occasional β-1,6 linkages. Depending on the harvesting period, its... more Linear β-1,3 glucan chain with occasional β-1,6 linkages. Depending on the harvesting period, its concentration can attain up to 30%.

Chemical Engineering Science, 1993

Ab&act-Experiments have kn carried out on the absorption of SO, into 1 M solutions of tribasic so... more Ab&act-Experiments have kn carried out on the absorption of SO, into 1 M solutions of tribasic sodium citrate in the temperature range 2040°C. A global mass-transfer coefficient that remains constant during the absorption process has been defined on the basis of the total SO, concentrations. A procedure has been developed for calculating the concentrations of the species involved in the absorption process. This is based on the assumption that the equilibria occur instantaneously, which allows a buffer opacity of 0.68 to be established regardless of temprature. It also allows the mass-transfer enhancement factor and, thus, the physical absorption coefficient, to be determined. In addition, a saline-effect parameter of-0.043 (regardless of temperature) was calculated using the equilibrium data.

Nanomaterials

The efficiency of Rhodotorula mucilaginosa 1S1 as an Ag(I) biosorbent and at the same time its ab... more The efficiency of Rhodotorula mucilaginosa 1S1 as an Ag(I) biosorbent and at the same time its ability to biosynthesize recoverable silver nanoparticles is evaluated. Kinetic, equilibrium and thermodynamic tests are carried out for 19 °C, 27 °C and 37 °C, from which the process is adjusted to a pseudo second-order kinetics and to the Freundlich model, while optimal operational conditions are determined at 27 °C. The thermodynamic study shows positive values for enthalpy (ΔH: 133.23 kJ/mol) and entropy (ΔS: 0.4976 kJ/(mol K)), while the Gibbs free energy (ΔG) value is 12.136 kJ/mol. For a metal concentration of 459 mg/L, a maximum biosorption capacity (qm) of 137.2 mg/g at 19 °C is obtained, while for 100 mg/L concentration a qm value of 60.44 mg/g is obtained at the same temperature. The mechanisms involved in the biosorption process are studied by infrared spectroscopy, X-ray diffraction and scanning and transmission electron microscopy, while the nanoparticle synthesis is evaluate...

Agronomy

Second-generation bioethanol is considered a suitable option for replacing fossil fuels. Agricult... more Second-generation bioethanol is considered a suitable option for replacing fossil fuels. Agricultural residues are being studied as feedstocks for sugar generation, which are in turn converted into ethanol. Among them, barley straw (BS) is a promising raw material, due to its high abundance, lignocellulosic composition and lack of other practical applications. Under these assumptions, the central aim of this study is to suggest an efficient bioethanol production scheme from BS at different levels of integration in co-fermentation with Escherichia coli SL100, including separate hydrolysis and co-fermentation (SHCF), simultaneous saccharification and co-fermentation (SSCF), and presaccharification and simultaneous saccharification and co-fermentation (PSSCF), using the water-insoluble solid (WIS) and slurry fractions obtained after steam explosion (SE) pretreatment. The best results in terms of ethanol yield were achieved following the SHCF process, using the WIS and the slurry as sub...

African Journal of Microbiology Research, Feb 28, 2009

... independent of the pollution level at the site of isolation (Table 2). Similar results were r... more ... independent of the pollution level at the site of isolation (Table 2). Similar results were reported by Baldrian and Gabriel (2002) who ... is a co-factor in numerous enzymatic processes and represents the third most abundant transition metal found in living organisms (Brandolini et al ...

Chemical engineering transactions, 2018

Barley straw is being considered a potential lignocellulosic raw material for fuel-ethanol produc... more Barley straw is being considered a potential lignocellulosic raw material for fuel-ethanol production. Ethanol production from lignocellulosic biomass consists in three main steps: pretreatment, enzymatic hydrolysis and fermentation. In order to improve the accessibility of the enzymes during enzymatic hydrolysis, a dilute phosphoric acid steam explosion pretreatment was applied. A three factor experimental design with temperature (160-200 oC), residence time (10 – 30 min) and phosphoric acid concentration (1 – 3 % w/v) as relevant factors was performed after a previous stage of overnight soaking. Once the pretreatment was done, both liquid and pretreated solids were separated by filtration and analysed. The pretreated solids were further subjected to enzymatic hydrolysis (S/L= 5 %, 50 oC, 150 rpm, 15 FPU / g substrate, pH = 4.8) and the released glucose was determined. Optimal pretreatment conditions were determined based on highest recovery of hemicellulosic sugars and minimum inh...

Food Chemistry, 2020

Olive leaves farmed from trees are valuable for the production of functional extracts. Nonetheles... more Olive leaves farmed from trees are valuable for the production of functional extracts. Nonetheless, olive leaves (containing thin branches), which are separated during olives cleaning in the mill, have received little attention. In this context, a multiple response optimization was performed to maximize at once the yield, total phenolic content, oleouropein and antioxidant activity obtained by ultrasound-assisted extraction of this low-cost byproduct. The optimum was achieved using the following operational parameters: solid-to-liquid ratio, 5.9%; ethanol concentration, 47%; extraction time, 50 min. This enabled to obtain an extract with both high level of oleuropein and antioxidant activity. Besides oleuropein, other minor phenolic compounds were characterized in the extract, which could contribute to the antioxidant activity as Pearson correlation suggested. After this extraction step, how the phenolic extraction affects the recovery/profile of other constituents was evaluated, looking for the integral valorization of this resource towards the zero-waste.

LWT, 2018

The aim of this work is to obtain a balanced commercial virgin olive oil (VOO) using response sur... more The aim of this work is to obtain a balanced commercial virgin olive oil (VOO) using response surface methodology at an industrial level under continuous working conditions. Thus, a factorial design was developed with three factors: sieve size of the hammer mill, temperature, and malaxing time. Forty different responses were modulated, including extraction efficiency, but with special attention to phenolic and volatile compounds because they are responsible for the taste and aroma of VOO. The conditions for malaxing were 22 and 32 °C for 60 and 120 min using 5 and 6 mm sieve sizes. After modeling the responses, the highest extraction efficiency was obtained at 32 °C and 120 min; similar conditions were necessary to obtain the maximum contents of chlorophyll, carotenoid, and phenolic compounds, but the maximum content of volatile compounds was obtained at 22 °C. Therefore, it has also realized a combined optimization of total phenolics and total volatiles.

Chemical Engineering Science, 2002

We studied the absorption of SO2 from mixtures with N2 into limestone slurries. The reactor used ... more We studied the absorption of SO2 from mixtures with N2 into limestone slurries. The reactor used was a stirred tank with an almost at gas-liquid interface of area 67:7 × 10 −4 m 2 at 400 rpm, operated in gas-phase continuous operation mode and batchwise for the slurry. The operating temperatures used were 20 • C and 40 • C, the content of limestone in the initial slurry was 1, 3 and 5 wt% and the volume fraction of SO2in the gas mixture at the inlet to the reactor ranged from 4% to 10%. We determined the overall gas-side SO2 transfer coe cient, obtaining values of 0.104 and 0:083 mol=s=m 2 =bar at 20 • C and 40 • C, respectively. By taking into account the individual gas-side SO2 transfer coe cient and estimating the enhancement factor, we were able to determine the thickness of the interfacial liquid ÿlm, 45 and 58 m at temperatures of 20 • C and 40 • C, respectively, and the SO2 physical absorption coe cient, 3:27 × 10 −5 and 4:01 × 10 −5 m=s at 20 • C and 40 • C, respectively. The results obtained are comparable with those reported in previous studies, both by ourselves and by other authors.

Food Chemistry, 2019

Olive leaves have become a promising source of phenolic compounds and flavonoids with high added ... more Olive leaves have become a promising source of phenolic compounds and flavonoids with high added value. Phenolic compounds and flavonoids are important sources of antioxidants and bioactives, and one of the processes used to effectively produce them is extraction via solvents, using aqueous ethanol solutions. To obtain the highest extraction yield per kg of biomass, olive leaves were extracted using a conventional technique (dynamic maceration) and an emerging technology, such as pressurized liquid extraction. Studies of the factors that influence these processes were performed: temperature, leaf moisture content, solvent/solid, and aqueous ethanol concentration were optimized using the central composite and Box-Behnken experiment designs. Pressurized liquid extraction resulted in more efficient oleuropein and luteolin-7-O-glucoside extraction than dynamic maceration. The operational conditions for maximizing the recovery of phenolic compounds and flavonoids and antioxidant capacity were determined to be 190°C, leaf moisture content of 5%, and aqueous ethanol concentration of 80%.

Molecules, 2021

Wild olive trees have important potential, but, to date, the oil from wild olives has not been st... more Wild olive trees have important potential, but, to date, the oil from wild olives has not been studied significantly, especially from an analytical point of view. In Spain, the wild olive tree is called “Acebuche” and its fruit “Acebuchina”. The objective of this work is to optimize the olive oil production process from the Acebuchina cultivar and characterize the oil, which could be marketed as healthy and functional food. A Box–Behnken experimental design with five central points was used, along with the Response Surface Methodology to obtain a mathematical experimental model. The oils from the Acebuchina cultivar meet the requirements for human consumption and have a good balance of fatty acids. In addition, the oils are rich in antioxidants and volatile compounds. The highest extraction yield, 12.0 g oil/100 g paste, was obtained at 90.0 min and the highest yield of phenolic compounds, 870.0 mg/kg, was achieved at 40.0 °C, and 90.0 min; but the maximum content of volatile compou...

Antioxidants, 2022

Refined olive oils (ROOs) are commonly enriched with synthetic antioxidants. Antioxidant extracts... more Refined olive oils (ROOs) are commonly enriched with synthetic antioxidants. Antioxidant extracts obtained from natural products can be used to improve the stability of these oils. In this study, ROOs were enriched through the addition of phenolic extracts from olive leaves (OLs) and exhausted olive pomace (EOP). In addition to replacing synthetic antioxidants with natural ones, this results in the valorization of these olive-derived biomasses. The most suitable method for mixing and enriching refined oils was probe-type ultrasonication using lecithin as the emulsifier. Thereafter, the change in the content of antioxidant compounds and the antioxidant capacity of the oils at 25, 35, and 45 °C were studied over 28 and 50 days of storage. The experimental results were fitted using a pseudo-first-order kinetic model. The oxidative stability index of the ROO enriched with a 2 g/L OL extract (70 h) was higher than that of a commercial ROO (46.8 h). Moreover, the oxidative stability index...

Food Chemistry, 2020

Olive leaves are an under valorized residue of olive tree pruning and olive fruit harvesting and ... more Olive leaves are an under valorized residue of olive tree pruning and olive fruit harvesting and that are usually removed by either burning or grinding and scattering them on fields. However, as plant material easily available, they may be used as raw material in biorefineries, or for the industrial manufacture of many diverse products, given their lignocellulosic composition. Like other lignocellulosic biomasses, the composition of olive leaves depends on cultivar and to know it is essential for an adequate use. Therefore, this work tackles a characterization analysis of the lignocellulosic fraction of some olive leaf cultivars, both commercial and wild. In general, the cultivars studied did not show large differences in their quantitative composition, except for the content of ethanolic extractives and cellulose of the commercial and wild cultivars. In addition, the high lignin content (around 15%) is remarkable.

European Food Research and Technology, 2020

Extra-virgin olive oil is basically used in food, but it can also be used as a source of high add... more Extra-virgin olive oil is basically used in food, but it can also be used as a source of high added-value components, such as oleocanthal and oleacein. Oleocanthal and oleacein are bioactive compounds with proven activities in the treatment of various diseases. By applying response surface methodology, oils of the Arbequina, Arbosana, and Koroneiki cultivars of super-intensive olive trees have been elaborated, under both irrigation and rainfed conditions. 289 oils have been obtained and 13 parameters per oil determined, which have been grouped into 221 models, that determine extraction performance, quality, and minor components of oils. The maximum extractable olive oil with the current technology is 89.0 ± 3.9%, with the rest remaining in the pomace. Oleacein is the component that most influences the antioxidant capacity of oils; its activity is 5.85 ± 0.33 µmol Trolox/mg. Irrigated Arbequina produces very aromatic oils. Rainfed Arbequina produces less aromatic (18.5 mg/kg of volatile) but with a higher content of phenolic compounds (514.4 mg/kg) oils. Koroneiki produces oils with a very high content of phenolic compounds but low in volatiles. For Koroneiki, the factors that maximize phenolic compounds are: rainfed crops, mill with 4.5 mm sieve, and malaxation at 40 °C for 30 min (1307.2 mg/kg of phenolic compounds, witch 500.0 mg/kg of oleacein, and 174.3 mg/kg of oleocanthal). A method to extract oleocanthal and oleacein from olive oils is proposed, as a way to develop new strategies to improve their functional properties.

Food Chemistry, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Molecules, 2019

Three factors for the extraction of extra virgin olive oil (EVOO) were evaluated: diameter of the... more Three factors for the extraction of extra virgin olive oil (EVOO) were evaluated: diameter of the grid holes of the hammer-crusher, malaxation temperature, and malaxation time. A Box–Behnken design was used to obtain a total of 289 olive oil samples. Twelve responses were analyzed and 204 mathematical models were obtained. Olives from super-intensive rainfed or irrigated crops of the Arbequina, Koroneiki, and Arbosana cultivars at different stages of ripening were used. Malaxation temperature was found to be the factor with the most influence on the total content of lipoxygenase pathway volatile compounds; as the temperature increased, the content of volatile compounds decreased. On the contrary, pigments increased when the malaxation temperature was increased. EVOO from irrigated crops and from the Arbequina cultivar had the highest content of volatile compounds. Olive samples with a lower ripening degree, from the Koroneiki cultivar and from rainfed crops, had the highest content ...

Agronomy

Olive tree pruning is an abundant and renewable lignocellulosic residue, which is generally burne... more Olive tree pruning is an abundant and renewable lignocellulosic residue, which is generally burned in the fields, causing economic costs and environmental problems. This lignocellulosic residue can be considered a suitable raw material for the production of a wide range of byproducts in a biorefinery context due to its high content of potentially fermentable carbohydrates. To take advantage of its sugar content, pretreatment is necessary to enhance the accessibility of the enzymes to the cellulosic fraction. The aim of this work is to obtain sugars contained in olive tree pruning as a substrate for the production of bioethanol by fermentation. Specifically, the production of fermentable sugars by sequential pretreatment with sulfuric acid and sodium hydroxide is studied. A two-factor rotatable composite central design temperature and catalyst concentration (H2SO4 and NaOH) has been generated, and response surface methodology has been used to discuss and optimize the responses. This ...

Journal of Food Engineering, 2018

Pomace is an oil mill byproduct and the raw material for extracting olive pomace oil. The pomace ... more Pomace is an oil mill byproduct and the raw material for extracting olive pomace oil. The pomace is stored several months in ponds until it is processed. Tests have been carried out in stored olive pastes, malaxated with and without different coadjuvants. These pastes have been equated to the oil mill pomace. Coadjuvants increase the water pH in 0.8 units. 89.5% of the initial oil is recovered from pastes without coadjuvant; 91.1% from pastes with calcium carbonate and 80.5% from pastes with talc. The free acidity is 1.9%, 2.6% and 2.1% respectively. The maximum amount of refined pomace oil is obtained when calcium carbonate is used and the minimum when talc is used. Moisten the adjuvants affects talc and calcium carbonate differently, although both of them easily releases the original micro-powder. Moisture does not affect the technological action of the coadjuvants or modify their physical characteristics.

European Journal of Lipid Science and Technology, 2019

Extra virgin olive oil; super high density orchard; maturity index; composition progress; irrigat... more Extra virgin olive oil; super high density orchard; maturity index; composition progress; irrigation † This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Linear β-1,3 glucan chain with occasional β-1,6 linkages. Depending on the harvesting period, its... more Linear β-1,3 glucan chain with occasional β-1,6 linkages. Depending on the harvesting period, its concentration can attain up to 30%.

Chemical Engineering Science, 1993

Ab&act-Experiments have kn carried out on the absorption of SO, into 1 M solutions of tribasic so... more Ab&act-Experiments have kn carried out on the absorption of SO, into 1 M solutions of tribasic sodium citrate in the temperature range 2040°C. A global mass-transfer coefficient that remains constant during the absorption process has been defined on the basis of the total SO, concentrations. A procedure has been developed for calculating the concentrations of the species involved in the absorption process. This is based on the assumption that the equilibria occur instantaneously, which allows a buffer opacity of 0.68 to be established regardless of temprature. It also allows the mass-transfer enhancement factor and, thus, the physical absorption coefficient, to be determined. In addition, a saline-effect parameter of-0.043 (regardless of temperature) was calculated using the equilibrium data.

Nanomaterials

The efficiency of Rhodotorula mucilaginosa 1S1 as an Ag(I) biosorbent and at the same time its ab... more The efficiency of Rhodotorula mucilaginosa 1S1 as an Ag(I) biosorbent and at the same time its ability to biosynthesize recoverable silver nanoparticles is evaluated. Kinetic, equilibrium and thermodynamic tests are carried out for 19 °C, 27 °C and 37 °C, from which the process is adjusted to a pseudo second-order kinetics and to the Freundlich model, while optimal operational conditions are determined at 27 °C. The thermodynamic study shows positive values for enthalpy (ΔH: 133.23 kJ/mol) and entropy (ΔS: 0.4976 kJ/(mol K)), while the Gibbs free energy (ΔG) value is 12.136 kJ/mol. For a metal concentration of 459 mg/L, a maximum biosorption capacity (qm) of 137.2 mg/g at 19 °C is obtained, while for 100 mg/L concentration a qm value of 60.44 mg/g is obtained at the same temperature. The mechanisms involved in the biosorption process are studied by infrared spectroscopy, X-ray diffraction and scanning and transmission electron microscopy, while the nanoparticle synthesis is evaluate...

Agronomy

Second-generation bioethanol is considered a suitable option for replacing fossil fuels. Agricult... more Second-generation bioethanol is considered a suitable option for replacing fossil fuels. Agricultural residues are being studied as feedstocks for sugar generation, which are in turn converted into ethanol. Among them, barley straw (BS) is a promising raw material, due to its high abundance, lignocellulosic composition and lack of other practical applications. Under these assumptions, the central aim of this study is to suggest an efficient bioethanol production scheme from BS at different levels of integration in co-fermentation with Escherichia coli SL100, including separate hydrolysis and co-fermentation (SHCF), simultaneous saccharification and co-fermentation (SSCF), and presaccharification and simultaneous saccharification and co-fermentation (PSSCF), using the water-insoluble solid (WIS) and slurry fractions obtained after steam explosion (SE) pretreatment. The best results in terms of ethanol yield were achieved following the SHCF process, using the WIS and the slurry as sub...

African Journal of Microbiology Research, Feb 28, 2009

... independent of the pollution level at the site of isolation (Table 2). Similar results were r... more ... independent of the pollution level at the site of isolation (Table 2). Similar results were reported by Baldrian and Gabriel (2002) who ... is a co-factor in numerous enzymatic processes and represents the third most abundant transition metal found in living organisms (Brandolini et al ...

Chemical engineering transactions, 2018

Barley straw is being considered a potential lignocellulosic raw material for fuel-ethanol produc... more Barley straw is being considered a potential lignocellulosic raw material for fuel-ethanol production. Ethanol production from lignocellulosic biomass consists in three main steps: pretreatment, enzymatic hydrolysis and fermentation. In order to improve the accessibility of the enzymes during enzymatic hydrolysis, a dilute phosphoric acid steam explosion pretreatment was applied. A three factor experimental design with temperature (160-200 oC), residence time (10 – 30 min) and phosphoric acid concentration (1 – 3 % w/v) as relevant factors was performed after a previous stage of overnight soaking. Once the pretreatment was done, both liquid and pretreated solids were separated by filtration and analysed. The pretreated solids were further subjected to enzymatic hydrolysis (S/L= 5 %, 50 oC, 150 rpm, 15 FPU / g substrate, pH = 4.8) and the released glucose was determined. Optimal pretreatment conditions were determined based on highest recovery of hemicellulosic sugars and minimum inh...

Food Chemistry, 2020

Olive leaves farmed from trees are valuable for the production of functional extracts. Nonetheles... more Olive leaves farmed from trees are valuable for the production of functional extracts. Nonetheless, olive leaves (containing thin branches), which are separated during olives cleaning in the mill, have received little attention. In this context, a multiple response optimization was performed to maximize at once the yield, total phenolic content, oleouropein and antioxidant activity obtained by ultrasound-assisted extraction of this low-cost byproduct. The optimum was achieved using the following operational parameters: solid-to-liquid ratio, 5.9%; ethanol concentration, 47%; extraction time, 50 min. This enabled to obtain an extract with both high level of oleuropein and antioxidant activity. Besides oleuropein, other minor phenolic compounds were characterized in the extract, which could contribute to the antioxidant activity as Pearson correlation suggested. After this extraction step, how the phenolic extraction affects the recovery/profile of other constituents was evaluated, looking for the integral valorization of this resource towards the zero-waste.

LWT, 2018

The aim of this work is to obtain a balanced commercial virgin olive oil (VOO) using response sur... more The aim of this work is to obtain a balanced commercial virgin olive oil (VOO) using response surface methodology at an industrial level under continuous working conditions. Thus, a factorial design was developed with three factors: sieve size of the hammer mill, temperature, and malaxing time. Forty different responses were modulated, including extraction efficiency, but with special attention to phenolic and volatile compounds because they are responsible for the taste and aroma of VOO. The conditions for malaxing were 22 and 32 °C for 60 and 120 min using 5 and 6 mm sieve sizes. After modeling the responses, the highest extraction efficiency was obtained at 32 °C and 120 min; similar conditions were necessary to obtain the maximum contents of chlorophyll, carotenoid, and phenolic compounds, but the maximum content of volatile compounds was obtained at 22 °C. Therefore, it has also realized a combined optimization of total phenolics and total volatiles.

Chemical Engineering Science, 2002

We studied the absorption of SO2 from mixtures with N2 into limestone slurries. The reactor used ... more We studied the absorption of SO2 from mixtures with N2 into limestone slurries. The reactor used was a stirred tank with an almost at gas-liquid interface of area 67:7 × 10 −4 m 2 at 400 rpm, operated in gas-phase continuous operation mode and batchwise for the slurry. The operating temperatures used were 20 • C and 40 • C, the content of limestone in the initial slurry was 1, 3 and 5 wt% and the volume fraction of SO2in the gas mixture at the inlet to the reactor ranged from 4% to 10%. We determined the overall gas-side SO2 transfer coe cient, obtaining values of 0.104 and 0:083 mol=s=m 2 =bar at 20 • C and 40 • C, respectively. By taking into account the individual gas-side SO2 transfer coe cient and estimating the enhancement factor, we were able to determine the thickness of the interfacial liquid ÿlm, 45 and 58 m at temperatures of 20 • C and 40 • C, respectively, and the SO2 physical absorption coe cient, 3:27 × 10 −5 and 4:01 × 10 −5 m=s at 20 • C and 40 • C, respectively. The results obtained are comparable with those reported in previous studies, both by ourselves and by other authors.

Food Chemistry, 2019

Olive leaves have become a promising source of phenolic compounds and flavonoids with high added ... more Olive leaves have become a promising source of phenolic compounds and flavonoids with high added value. Phenolic compounds and flavonoids are important sources of antioxidants and bioactives, and one of the processes used to effectively produce them is extraction via solvents, using aqueous ethanol solutions. To obtain the highest extraction yield per kg of biomass, olive leaves were extracted using a conventional technique (dynamic maceration) and an emerging technology, such as pressurized liquid extraction. Studies of the factors that influence these processes were performed: temperature, leaf moisture content, solvent/solid, and aqueous ethanol concentration were optimized using the central composite and Box-Behnken experiment designs. Pressurized liquid extraction resulted in more efficient oleuropein and luteolin-7-O-glucoside extraction than dynamic maceration. The operational conditions for maximizing the recovery of phenolic compounds and flavonoids and antioxidant capacity were determined to be 190°C, leaf moisture content of 5%, and aqueous ethanol concentration of 80%.

Molecules, 2021

Wild olive trees have important potential, but, to date, the oil from wild olives has not been st... more Wild olive trees have important potential, but, to date, the oil from wild olives has not been studied significantly, especially from an analytical point of view. In Spain, the wild olive tree is called “Acebuche” and its fruit “Acebuchina”. The objective of this work is to optimize the olive oil production process from the Acebuchina cultivar and characterize the oil, which could be marketed as healthy and functional food. A Box–Behnken experimental design with five central points was used, along with the Response Surface Methodology to obtain a mathematical experimental model. The oils from the Acebuchina cultivar meet the requirements for human consumption and have a good balance of fatty acids. In addition, the oils are rich in antioxidants and volatile compounds. The highest extraction yield, 12.0 g oil/100 g paste, was obtained at 90.0 min and the highest yield of phenolic compounds, 870.0 mg/kg, was achieved at 40.0 °C, and 90.0 min; but the maximum content of volatile compou...

Antioxidants, 2022

Refined olive oils (ROOs) are commonly enriched with synthetic antioxidants. Antioxidant extracts... more Refined olive oils (ROOs) are commonly enriched with synthetic antioxidants. Antioxidant extracts obtained from natural products can be used to improve the stability of these oils. In this study, ROOs were enriched through the addition of phenolic extracts from olive leaves (OLs) and exhausted olive pomace (EOP). In addition to replacing synthetic antioxidants with natural ones, this results in the valorization of these olive-derived biomasses. The most suitable method for mixing and enriching refined oils was probe-type ultrasonication using lecithin as the emulsifier. Thereafter, the change in the content of antioxidant compounds and the antioxidant capacity of the oils at 25, 35, and 45 °C were studied over 28 and 50 days of storage. The experimental results were fitted using a pseudo-first-order kinetic model. The oxidative stability index of the ROO enriched with a 2 g/L OL extract (70 h) was higher than that of a commercial ROO (46.8 h). Moreover, the oxidative stability index...

Food Chemistry, 2020

Olive leaves are an under valorized residue of olive tree pruning and olive fruit harvesting and ... more Olive leaves are an under valorized residue of olive tree pruning and olive fruit harvesting and that are usually removed by either burning or grinding and scattering them on fields. However, as plant material easily available, they may be used as raw material in biorefineries, or for the industrial manufacture of many diverse products, given their lignocellulosic composition. Like other lignocellulosic biomasses, the composition of olive leaves depends on cultivar and to know it is essential for an adequate use. Therefore, this work tackles a characterization analysis of the lignocellulosic fraction of some olive leaf cultivars, both commercial and wild. In general, the cultivars studied did not show large differences in their quantitative composition, except for the content of ethanolic extractives and cellulose of the commercial and wild cultivars. In addition, the high lignin content (around 15%) is remarkable.

European Food Research and Technology, 2020

Extra-virgin olive oil is basically used in food, but it can also be used as a source of high add... more Extra-virgin olive oil is basically used in food, but it can also be used as a source of high added-value components, such as oleocanthal and oleacein. Oleocanthal and oleacein are bioactive compounds with proven activities in the treatment of various diseases. By applying response surface methodology, oils of the Arbequina, Arbosana, and Koroneiki cultivars of super-intensive olive trees have been elaborated, under both irrigation and rainfed conditions. 289 oils have been obtained and 13 parameters per oil determined, which have been grouped into 221 models, that determine extraction performance, quality, and minor components of oils. The maximum extractable olive oil with the current technology is 89.0 ± 3.9%, with the rest remaining in the pomace. Oleacein is the component that most influences the antioxidant capacity of oils; its activity is 5.85 ± 0.33 µmol Trolox/mg. Irrigated Arbequina produces very aromatic oils. Rainfed Arbequina produces less aromatic (18.5 mg/kg of volatile) but with a higher content of phenolic compounds (514.4 mg/kg) oils. Koroneiki produces oils with a very high content of phenolic compounds but low in volatiles. For Koroneiki, the factors that maximize phenolic compounds are: rainfed crops, mill with 4.5 mm sieve, and malaxation at 40 °C for 30 min (1307.2 mg/kg of phenolic compounds, witch 500.0 mg/kg of oleacein, and 174.3 mg/kg of oleocanthal). A method to extract oleocanthal and oleacein from olive oils is proposed, as a way to develop new strategies to improve their functional properties.

Food Chemistry, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Molecules, 2019

Three factors for the extraction of extra virgin olive oil (EVOO) were evaluated: diameter of the... more Three factors for the extraction of extra virgin olive oil (EVOO) were evaluated: diameter of the grid holes of the hammer-crusher, malaxation temperature, and malaxation time. A Box–Behnken design was used to obtain a total of 289 olive oil samples. Twelve responses were analyzed and 204 mathematical models were obtained. Olives from super-intensive rainfed or irrigated crops of the Arbequina, Koroneiki, and Arbosana cultivars at different stages of ripening were used. Malaxation temperature was found to be the factor with the most influence on the total content of lipoxygenase pathway volatile compounds; as the temperature increased, the content of volatile compounds decreased. On the contrary, pigments increased when the malaxation temperature was increased. EVOO from irrigated crops and from the Arbequina cultivar had the highest content of volatile compounds. Olive samples with a lower ripening degree, from the Koroneiki cultivar and from rainfed crops, had the highest content ...