G. Andrich - Academia.edu (original) (raw)

Papers by G. Andrich

American Journal of Analytical Chemistry, 2012

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2 ), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and ScCO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pretreatments carried out on the used substrate; flow rate of ScCO 2 ; working conditions adopted (temperature, pressure and then ScCO 2 density).

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2 ), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and Sc-CO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pretreatments carried out on the used substrate; flow rate of Sc-CO 2 ; working conditions adopted (temperature, pressure and then Sc-CO 2 density).

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and Sc-CO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pre-treatments carried out on the used substrate; flow rate of Sc-CO 2 ; working conditions adopted (temperature, pressure and then Sc-CO 2 density).

Over the last two decades, most of Italian vines have produced grapes with higher sugar to total ... more Over the last two decades, most of Italian vines have produced grapes with higher sugar to total acid ratios, greater concentrations of phenols and aromatic compounds and greater potential wine quality. As a consequence, the musts obtained by these grapes are more difficult to process because of the risk of slowing or stuck of fermentation. With the aim of describing the time evolution of the sugars bioconversion during alcoholic fermentation, the kinetics of the D-glucose and D-fructose degradations, promoted by two yeast strains (Saccharomyces cerevisiae (strain C) e Saccharomyces bayanus (strain B)), was investigated using synthetic media, added or not with ethanol. The concentrations of both the substrates and the products of the sugars conversions, as well as the number of viable cells of yeasts, were determined as a function of the alcoholic fermentation time and the related kinetics constants determined. If the reaction medium contained high concentrations of both glucose and fructose, the strains showed significant different fermentatory ability. In these conditions a stuck of fermentation occurred and the remaining sugar was only fructose (strain C) or prevailing fructose (strain B). If the reaction medium contained only glucose as substrate, the strain C seemed more efficient while the kinetics behavior changed completely in presence of only fructose. On the basis of the information collected using this kinetic approach, it would be possible to develop technical data sheets, specific for each yeast strain, useful to choose the optimal microbial strain as a function of the different operative conditions. Moreover the kinetic constant of hexose conversion could be adopted as bio-markers in selection and breeding of wine yeast strains having a lower tendency for sluggish fructose fermentation.

South African Journal of Enology and Viticulture, 2016

In the cellar, slow and stuck fermentations occurring during winemaking are often successfully so... more In the cellar, slow and stuck fermentations occurring during winemaking are often successfully solved by the addition of yeast strains like Saccharomyces bayanus. The kinetic behaviour shown by S. bayanus during alcoholic fermentation was investigated using a mathematical model previously tested for S. cerevisiae, in order to show which of the six functional parameters of the model differed significantly with the yeast population. Although some parameters (hexose fractions converted to ethanol and glycerol) did not change, the kinetic constant related to the inactivation rate of the yeast population showed by S. cerevisiae assumed a value significantly higher (approximately 50-fold) than that observed for S. bayanus, while this latter population was ten times less affected by ethanol than S. cerevisiae. Although no remarkable differences could be found between the ability shown by the two yeast populations to convert hexoses (D-glucose and D-fructose), the tolerance for ethanol accumulation changed strongly. The conversion rate of these two hexoses by S. bayanus was affected less (about ten thousand-fold) by ethanol than that of S. cerevisiae.

Grasas y Aceites, 2016

SUMMARY: The use of solid carbon dioxide (dry ice) as a cryogen is widespread in the food industr... more SUMMARY: The use of solid carbon dioxide (dry ice) as a cryogen is widespread in the food industry to produce high quality wines, rich in color and perfumes. The direct addition of carbon dioxide to olives in the solid state before milling represents a fundamental step which characterizes this innovative extraction system. At room temperature conditions solid carbon dioxide evolves directly into the air phase (sublimation), and the direct contact between the cryogen and the olives induces a partial solidification of the cellular water inside the fruits. Since the volume occupied by water in the solid state is higher than that in the liquid state, the ice crystals formed are incompatible with the cellular structure and induce the collapse of the cells, besides promoting the diffusion of the cellular substances in the extracted oil, which is thus enriched with cellular metabolites characterized by a high nutraceutical value. Furthermore, a layer of CO 2 remains over the olive paste to preserve it from oxidative degradation. The addition of solid carbon dioxide to processed olives induced a statistically significant increase in oil yield and promoted the accumulation of tocopherols in the lipid phase, whereas a not significant increase in the phenolic fraction of the oil occurred. RESUMEN: Dióxido de carbono sólido para promover la extracción del aceite de oliva virgen extra. El uso de dióxido de carbono sólido (hielo seco) como criogénico está muy extendido en la industria alimentaria para producir vinos de alta calidad, ricos en color y perfumes. La adición directa de dióxido de carbono en estado sólido a las aceitu-nas antes de la molienda representa el paso fundamental que caracteriza este innovador sistema de extracción. En condiciones ambientales el dióxido de carbono sólido evoluciona directamente en la fase de aire (sublimación), y el contacto directo entre el criógeno y las aceitunas induce una solidificación parcial del agua celular dentro de los frutos. Dado que el volumen ocupado por el agua en el estado sólido es mayor que en el estado líquido, los cristales de hielo formados son incompatibles con la estructura celular e inducen el colapso de las células, además de pro-mover la difusión de las sustancias celulares en el aceite extraído, que así, por lo tanto, se enriquece con metabolitos celulares que se caracterizan por un alto valor nutracéutico. Además, una capa de CO 2 , permanece sobre la pasta de aceitunas para preservar de la degradación oxidativa. La adición de dióxido de carbono sólido a las aceitunas pro-cesadas indujo un aumento estadísticamente significativo en el rendimiento de aceite y promueve la acumulación de tocoferoles en la fase lipídica, mientras que produce un incremento, no significativo, de la fracción fenólica del aceite.

International Symposium on Postharvest Handling of Fruit and Vegetables, 1989

Italian Journal of Food Science

Eight malolactic bacterial strains were isolated through enrichment cultures kept at 10°C from di... more Eight malolactic bacterial strains were isolated through enrichment cultures kept at 10°C from different Tuscan wines. Six strains were identified as Oenococcus oeni by ARDRA and species- specific PCR. Two strains were tentatively assigned to L. brevis. A kinetic approach was used to assess their activity at 25° and 10°C. All strains induced a remarkable conversion of L-malate at 25°C. Four strains showed a measurable fermentative activity at 10°C, among which L. brevis LB2 gave a significant conversion of L-malate. The kinetic activity of this strain appears to be un- affected by the components dissolved in wine.

American Journal of Analytical Chemistry, 2012

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2 ), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and ScCO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pretreatments carried out on the used substrate; flow rate of ScCO 2 ; working conditions adopted (temperature, pressure and then ScCO 2 density).

Agrochimica -Pisa-

To verify the effect induced by pre-fermentative cryomaceration on the total amounts and mass tra... more To verify the effect induced by pre-fermentative cryomaceration on the total amounts and mass transfer rates of different groups of phenols (anthocyanins, procyanidins, non-flavonoid phenols and total phenolic compounds), Sangiovese grapes were processed following two winemaking protocols which differed from each other only in the addition or not of solid carbon dioxide to the crushed grapes. The time evolutions of the concentrations of the various phenolic compounds in the must/wine are described as function of only two functional parameters (the kinetic constant and the maximum extractable amount) by introducing kinetic equations. A significant difference of anthocyanins concentration in the cryomacerated wine compared to the traditional one was observed due to the fact that a more efficient extraction occurred and because CO2 protected wines against oxidation.

2006 First International Symposium on Environment Identities and Mediterranean Area, 2006

ABSTRACT The cold maceration of grapes allows one to produce wines characterised by a deep colour... more ABSTRACT The cold maceration of grapes allows one to produce wines characterised by a deep colour and an aromatic profile strongly connected to its zone of production as well as to the variety of grapes employed (typical wines). The temperature reduction could be obtained using an heat exchanger or by direct addition of a cryogen (CO2,liquid and/or CO2,solid, N2,liqiud) to the grapes crushed. Because of the very low temperature of the cryogen (T Lt 0degC), its contact with berries induces the cellular crash which promotes the later liberation of cellular components (phenols, mannoproteins, sugars, aromatic compounds) in the liquid phase. Moreover, the high cryogen content of the gaseous phase should limit remarkably the oxidation of phenolic and aromatic compounds. Some grapes parcels coming from the same vineyard were cold macerated using an heat exchanger or by addition of CO2,solid, to verify the existence of compositional differences between wine coming from different macerations. The experimental results seem to underline cellular crash is able to improve the extraction of coloured and aromatic substances so to produce wines characterised by typical flavours and organoleptic characteristics.

2006 First International Symposium on Environment Identities and Mediterranean Area, 2006

This paper reports an automatic apparatus to sample and to dilute samples of must/wine coming fro... more This paper reports an automatic apparatus to sample and to dilute samples of must/wine coming from a fermentor utilised in winemaking, to describe the evolution of composition of must/wine during alcoholic fermentation. This new analytical apparatus would allow to individuate rapidly when a reduction of rate or a stuck of fermentation could take place. After an accurate description of the apparatus used, preliminary results connected to its calibration are also reported and discussed. As the evolutions of experimental data collected using this new apparatus do not differ significantly from those obtained by traditional way, the suitability of this new analytical system was tested.

Postharvest Biology and Technology, 1998

To evaluate the temperature dependence of the constants involved in a mathematical model relating... more To evaluate the temperature dependence of the constants involved in a mathematical model relating the aerobic respiration rate of Golden Delicious apples to the P O 2 of the surrounding atmosphere, O 2 consumption (r O 2 ) and CO 2 production (r CO 2 ) rates were measured at four temperatures (21, 16, 6 and 1°C) and five partial pressures of O 2 (0, 3, 5, 10 and 21 kPa), while P CO 2 was maintained close to zero. The cellular oxidation of the respiratory substrate was expressed as a function of dissolved O 2 by a Michaelis-Menten-like equation. The maximum rate of O 2 consumption (k 2 ) increased linearly with temperature and the Michaelis constant K M decreased according to Arrhenius' equation. The activation energy calculated for k 2 (DE 2 /R=5097°K − 1 ) is very close to that found using a different theoretical approach (DE 2 /R= 5447°K − 1 ). The temperature dependence of these constants made it possible to individuate a mathematical model able to calculate, as a function of the P O 2 , the aerobic respiration rate expected for Golden Delicious apples stored between 0 and 20°C when a P CO 2 value close to zero was maintained.

European Journal of Lipid Science and Technology, 2005

Marine microalgae are recognised as an important renewable source of bioactive lipids with a high... more Marine microalgae are recognised as an important renewable source of bioactive lipids with a high proportion of polyunsaturated fatty acids (PUFA), which have been shown to be effective in preventing or treating several diseases. For the extraction of oil from microalgae, ...

Potato by-products contain phenolic compounds with antioxidant properties considered relevant to ... more Potato by-products contain phenolic compounds with antioxidant properties considered relevant to prevent some human diseases. These natural antioxidants can be also extracted and used in food industry to prevent the decay by peroxidation of lipid bearing foods. The recovery of these compounds requires however the use of mild extraction technologies, in order to preserve the antioxidant power. In such a contest, the extraction with supercritical CO2 coupled with ethanol (EtOH) as co-solvent is of potential interest. This paper reports the experimental protocol followed, together with the kinetics of the extraction, the knowledge of which allows the optimization of working parameters and the determination of the process yields. Results obtained show that the proposed mathematical model is able to describe the extraction kinetics and that high percentages of EtOH (≥ 50 %) need to obtain the extraction of whole polyphenolic pull.

European Journal of Lipid Science and Technology, 2001

Sunflower (Helianthus annuus L.) seed represents an important source for edible oil and its prote... more Sunflower (Helianthus annuus L.) seed represents an important source for edible oil and its protein fraction is also recognised as valuable for human consumption when suitably purified from polyphenols, which negatively affect colour and nutritional value. On this basis, a main ...

American Journal of Analytical Chemistry, 2012

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2 ), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and ScCO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pretreatments carried out on the used substrate; flow rate of ScCO 2 ; working conditions adopted (temperature, pressure and then ScCO 2 density).

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2 ), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and Sc-CO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pretreatments carried out on the used substrate; flow rate of Sc-CO 2 ; working conditions adopted (temperature, pressure and then Sc-CO 2 density).

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and Sc-CO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pre-treatments carried out on the used substrate; flow rate of Sc-CO 2 ; working conditions adopted (temperature, pressure and then Sc-CO 2 density).

Over the last two decades, most of Italian vines have produced grapes with higher sugar to total ... more Over the last two decades, most of Italian vines have produced grapes with higher sugar to total acid ratios, greater concentrations of phenols and aromatic compounds and greater potential wine quality. As a consequence, the musts obtained by these grapes are more difficult to process because of the risk of slowing or stuck of fermentation. With the aim of describing the time evolution of the sugars bioconversion during alcoholic fermentation, the kinetics of the D-glucose and D-fructose degradations, promoted by two yeast strains (Saccharomyces cerevisiae (strain C) e Saccharomyces bayanus (strain B)), was investigated using synthetic media, added or not with ethanol. The concentrations of both the substrates and the products of the sugars conversions, as well as the number of viable cells of yeasts, were determined as a function of the alcoholic fermentation time and the related kinetics constants determined. If the reaction medium contained high concentrations of both glucose and fructose, the strains showed significant different fermentatory ability. In these conditions a stuck of fermentation occurred and the remaining sugar was only fructose (strain C) or prevailing fructose (strain B). If the reaction medium contained only glucose as substrate, the strain C seemed more efficient while the kinetics behavior changed completely in presence of only fructose. On the basis of the information collected using this kinetic approach, it would be possible to develop technical data sheets, specific for each yeast strain, useful to choose the optimal microbial strain as a function of the different operative conditions. Moreover the kinetic constant of hexose conversion could be adopted as bio-markers in selection and breeding of wine yeast strains having a lower tendency for sluggish fructose fermentation.

South African Journal of Enology and Viticulture, 2016

In the cellar, slow and stuck fermentations occurring during winemaking are often successfully so... more In the cellar, slow and stuck fermentations occurring during winemaking are often successfully solved by the addition of yeast strains like Saccharomyces bayanus. The kinetic behaviour shown by S. bayanus during alcoholic fermentation was investigated using a mathematical model previously tested for S. cerevisiae, in order to show which of the six functional parameters of the model differed significantly with the yeast population. Although some parameters (hexose fractions converted to ethanol and glycerol) did not change, the kinetic constant related to the inactivation rate of the yeast population showed by S. cerevisiae assumed a value significantly higher (approximately 50-fold) than that observed for S. bayanus, while this latter population was ten times less affected by ethanol than S. cerevisiae. Although no remarkable differences could be found between the ability shown by the two yeast populations to convert hexoses (D-glucose and D-fructose), the tolerance for ethanol accumulation changed strongly. The conversion rate of these two hexoses by S. bayanus was affected less (about ten thousand-fold) by ethanol than that of S. cerevisiae.

Grasas y Aceites, 2016

SUMMARY: The use of solid carbon dioxide (dry ice) as a cryogen is widespread in the food industr... more SUMMARY: The use of solid carbon dioxide (dry ice) as a cryogen is widespread in the food industry to produce high quality wines, rich in color and perfumes. The direct addition of carbon dioxide to olives in the solid state before milling represents a fundamental step which characterizes this innovative extraction system. At room temperature conditions solid carbon dioxide evolves directly into the air phase (sublimation), and the direct contact between the cryogen and the olives induces a partial solidification of the cellular water inside the fruits. Since the volume occupied by water in the solid state is higher than that in the liquid state, the ice crystals formed are incompatible with the cellular structure and induce the collapse of the cells, besides promoting the diffusion of the cellular substances in the extracted oil, which is thus enriched with cellular metabolites characterized by a high nutraceutical value. Furthermore, a layer of CO 2 remains over the olive paste to preserve it from oxidative degradation. The addition of solid carbon dioxide to processed olives induced a statistically significant increase in oil yield and promoted the accumulation of tocopherols in the lipid phase, whereas a not significant increase in the phenolic fraction of the oil occurred. RESUMEN: Dióxido de carbono sólido para promover la extracción del aceite de oliva virgen extra. El uso de dióxido de carbono sólido (hielo seco) como criogénico está muy extendido en la industria alimentaria para producir vinos de alta calidad, ricos en color y perfumes. La adición directa de dióxido de carbono en estado sólido a las aceitu-nas antes de la molienda representa el paso fundamental que caracteriza este innovador sistema de extracción. En condiciones ambientales el dióxido de carbono sólido evoluciona directamente en la fase de aire (sublimación), y el contacto directo entre el criógeno y las aceitunas induce una solidificación parcial del agua celular dentro de los frutos. Dado que el volumen ocupado por el agua en el estado sólido es mayor que en el estado líquido, los cristales de hielo formados son incompatibles con la estructura celular e inducen el colapso de las células, además de pro-mover la difusión de las sustancias celulares en el aceite extraído, que así, por lo tanto, se enriquece con metabolitos celulares que se caracterizan por un alto valor nutracéutico. Además, una capa de CO 2 , permanece sobre la pasta de aceitunas para preservar de la degradación oxidativa. La adición de dióxido de carbono sólido a las aceitunas pro-cesadas indujo un aumento estadísticamente significativo en el rendimiento de aceite y promueve la acumulación de tocoferoles en la fase lipídica, mientras que produce un incremento, no significativo, de la fracción fenólica del aceite.

International Symposium on Postharvest Handling of Fruit and Vegetables, 1989

Italian Journal of Food Science

Eight malolactic bacterial strains were isolated through enrichment cultures kept at 10°C from di... more Eight malolactic bacterial strains were isolated through enrichment cultures kept at 10°C from different Tuscan wines. Six strains were identified as Oenococcus oeni by ARDRA and species- specific PCR. Two strains were tentatively assigned to L. brevis. A kinetic approach was used to assess their activity at 25° and 10°C. All strains induced a remarkable conversion of L-malate at 25°C. Four strains showed a measurable fermentative activity at 10°C, among which L. brevis LB2 gave a significant conversion of L-malate. The kinetic activity of this strain appears to be un- affected by the components dissolved in wine.

American Journal of Analytical Chemistry, 2012

To allow an easy individuation of the more suitable working conditions (temperature, pressure, fl... more To allow an easy individuation of the more suitable working conditions (temperature, pressure, flow rate, etc.) to be adopted to carry out the extraction of food grade oils from different substrates by supercritical CO 2 (Sc-CO 2 ), a simplified kinetic approach has been introduced. This kinetic model was utilised to describe supercritical fluid extraction (SFE) of oil by Sc-CO 2 not only from seeds (sunflower, soybean and rape) but also from microalgae (Nannochloropsis sp., Schizochytrium sp. and Spirulina (Arthrospira) platensis) characterised by a lipid fraction with a high proportion of polyunsatured fatty acids (C20:5ω-3; C22:6ω-3; C18:3ω-6). Thanks to the high affinity occurring between oil and ScCO 2 it was possible to introduce a simplified kinetic model able to describe the time evolution of oil extraction from substrates which deeply differ for biochemical and biophysical characteristics. Moreover the synergistic utilisation of the kinetic model introduced and of the Chrastil's equation, allowed to predict the time evolution of oil extraction as a function of the: substrate used; amount of its fat content; mass of substrate charged inside the extractor; possible pretreatments carried out on the used substrate; flow rate of ScCO 2 ; working conditions adopted (temperature, pressure and then ScCO 2 density).

Agrochimica -Pisa-

To verify the effect induced by pre-fermentative cryomaceration on the total amounts and mass tra... more To verify the effect induced by pre-fermentative cryomaceration on the total amounts and mass transfer rates of different groups of phenols (anthocyanins, procyanidins, non-flavonoid phenols and total phenolic compounds), Sangiovese grapes were processed following two winemaking protocols which differed from each other only in the addition or not of solid carbon dioxide to the crushed grapes. The time evolutions of the concentrations of the various phenolic compounds in the must/wine are described as function of only two functional parameters (the kinetic constant and the maximum extractable amount) by introducing kinetic equations. A significant difference of anthocyanins concentration in the cryomacerated wine compared to the traditional one was observed due to the fact that a more efficient extraction occurred and because CO2 protected wines against oxidation.

2006 First International Symposium on Environment Identities and Mediterranean Area, 2006

ABSTRACT The cold maceration of grapes allows one to produce wines characterised by a deep colour... more ABSTRACT The cold maceration of grapes allows one to produce wines characterised by a deep colour and an aromatic profile strongly connected to its zone of production as well as to the variety of grapes employed (typical wines). The temperature reduction could be obtained using an heat exchanger or by direct addition of a cryogen (CO2,liquid and/or CO2,solid, N2,liqiud) to the grapes crushed. Because of the very low temperature of the cryogen (T Lt 0degC), its contact with berries induces the cellular crash which promotes the later liberation of cellular components (phenols, mannoproteins, sugars, aromatic compounds) in the liquid phase. Moreover, the high cryogen content of the gaseous phase should limit remarkably the oxidation of phenolic and aromatic compounds. Some grapes parcels coming from the same vineyard were cold macerated using an heat exchanger or by addition of CO2,solid, to verify the existence of compositional differences between wine coming from different macerations. The experimental results seem to underline cellular crash is able to improve the extraction of coloured and aromatic substances so to produce wines characterised by typical flavours and organoleptic characteristics.

2006 First International Symposium on Environment Identities and Mediterranean Area, 2006

This paper reports an automatic apparatus to sample and to dilute samples of must/wine coming fro... more This paper reports an automatic apparatus to sample and to dilute samples of must/wine coming from a fermentor utilised in winemaking, to describe the evolution of composition of must/wine during alcoholic fermentation. This new analytical apparatus would allow to individuate rapidly when a reduction of rate or a stuck of fermentation could take place. After an accurate description of the apparatus used, preliminary results connected to its calibration are also reported and discussed. As the evolutions of experimental data collected using this new apparatus do not differ significantly from those obtained by traditional way, the suitability of this new analytical system was tested.

Postharvest Biology and Technology, 1998

To evaluate the temperature dependence of the constants involved in a mathematical model relating... more To evaluate the temperature dependence of the constants involved in a mathematical model relating the aerobic respiration rate of Golden Delicious apples to the P O 2 of the surrounding atmosphere, O 2 consumption (r O 2 ) and CO 2 production (r CO 2 ) rates were measured at four temperatures (21, 16, 6 and 1°C) and five partial pressures of O 2 (0, 3, 5, 10 and 21 kPa), while P CO 2 was maintained close to zero. The cellular oxidation of the respiratory substrate was expressed as a function of dissolved O 2 by a Michaelis-Menten-like equation. The maximum rate of O 2 consumption (k 2 ) increased linearly with temperature and the Michaelis constant K M decreased according to Arrhenius' equation. The activation energy calculated for k 2 (DE 2 /R=5097°K − 1 ) is very close to that found using a different theoretical approach (DE 2 /R= 5447°K − 1 ). The temperature dependence of these constants made it possible to individuate a mathematical model able to calculate, as a function of the P O 2 , the aerobic respiration rate expected for Golden Delicious apples stored between 0 and 20°C when a P CO 2 value close to zero was maintained.

European Journal of Lipid Science and Technology, 2005

Marine microalgae are recognised as an important renewable source of bioactive lipids with a high... more Marine microalgae are recognised as an important renewable source of bioactive lipids with a high proportion of polyunsaturated fatty acids (PUFA), which have been shown to be effective in preventing or treating several diseases. For the extraction of oil from microalgae, ...

Potato by-products contain phenolic compounds with antioxidant properties considered relevant to ... more Potato by-products contain phenolic compounds with antioxidant properties considered relevant to prevent some human diseases. These natural antioxidants can be also extracted and used in food industry to prevent the decay by peroxidation of lipid bearing foods. The recovery of these compounds requires however the use of mild extraction technologies, in order to preserve the antioxidant power. In such a contest, the extraction with supercritical CO2 coupled with ethanol (EtOH) as co-solvent is of potential interest. This paper reports the experimental protocol followed, together with the kinetics of the extraction, the knowledge of which allows the optimization of working parameters and the determination of the process yields. Results obtained show that the proposed mathematical model is able to describe the extraction kinetics and that high percentages of EtOH (≥ 50 %) need to obtain the extraction of whole polyphenolic pull.

European Journal of Lipid Science and Technology, 2001

Sunflower (Helianthus annuus L.) seed represents an important source for edible oil and its prote... more Sunflower (Helianthus annuus L.) seed represents an important source for edible oil and its protein fraction is also recognised as valuable for human consumption when suitably purified from polyphenols, which negatively affect colour and nutritional value. On this basis, a main ...