I'm devoted to Food Technology research. I like to study about future frontiers for improving sensory, nutritional and compositional properties of every day foods
Abstract Among the different kinds of marine sources, microalgae are a potential source of triacy... more Abstract Among the different kinds of marine sources, microalgae are a potential source of triacylglycerides which may contain high amounts of LC-PUFAs such as ω-3 fatty acids EPA and DHA. For the extraction of oil from microalgae, Sc-CO2 is regarded with interest being safer than hexane and offering a negligible environmental impact, a short extraction time and a petroleum-free final product. In such a contest, a mathematical model able to describe the kinetics of an SFE process was applied to the extraction with Sc-CO2 of lipids from Schizochytrium sp., a marine microalga characterized by a particularly high content of LC-PUFAs, and a very high concentration of DHA. The aim of this paper was to examine the effect of operating conditions on the kinetics of the SFE, on process yields and on the fatty acid composition of lipid extracts, also in comparison with the conventional extraction by percolation with n-hexane.
BACKGROUND Bread represents a significant share of food wastes worldwide, so the extension of bre... more BACKGROUND Bread represents a significant share of food wastes worldwide, so the extension of bread shelf life, together with innovative systems of waste treatment, might decrease the emissions by waste biomass degradation, extensive transportation, and storage necessities. In recent years, insects have been selected as a valuable tool for food waste treatment owing to their capability to transform low-value food waste into biomass with high nutritional value. Bakery wastes can be profitably used for this purpose. The object of this work was twofold: i) to measure the impact of flaxseed cake fortification on bread shelf life depending on the leavening agent (baker's yeast vs sourdough); ii) to evaluate the possible re-use of the stale bread fortified with flaxseed cake for Tenebrio molitor rearing. RESULTS Our results showed that the fortification seemed to slow down the hardening rate of bread, particularly if baker's yeast was utilized. Besides, the time necessary for mold appearance in sourdough bread doubled (from two to four days). The addition of flaxseed cake to the recipe determined an increase of its scrap consumption by T. molitor larvae. Besides, we observed a significant increase in the body mass of the T. molitor larvae fed with bread obtained with the brewer's yeast with respect to larvae fed with the sourdough. CONCLUSION Taken together, these preliminary data can indicate that sourdough bread fortified with 5% of flaxseed cake can represent a promising tool to reduce food waste and recycle bread scraps by a novel zero-waste approach. This article is protected by copyright. All rights reserved.
While in the last few years the use of olive cake and mill wastewater as natural sources of pheno... more While in the last few years the use of olive cake and mill wastewater as natural sources of phenolic compounds has been widely considered and several studies have focused on the development of new extraction methods and on the production of functional foods enriched with natural antioxidants, no data has been available on the production of a phenol-enriched refined olive oil with its own phenolic compounds extracted from wastewater produced during physical refining. In this study; we aimed to: (i) verify the effectiveness of a multi-step extraction process to recover the high-added-value phenolic compounds contained in wastewater derived from the preliminary washing degumming step of the physical refining of vegetal oils; (ii) evaluate their potential application for the stabilization of olive oil obtained with refined olive oils; and (iii) evaluate their antioxidant activity in an in vitro model of endothelial cells. The results obtained demonstrate the potential of using the refining wastewater as a source of bioactive compounds to improve the nutraceutical value as well as the antioxidant capacity of commercial olive oils. In the conditions adopted, the phenolic content significantly increased in the prototypes of phenol-enriched olive oils when compared with the control oil.
Journal of the American Society for Horticultural Science
Using mathematical equations that describe the 02 mass-transfer and the enzymatic oxidation of th... more Using mathematical equations that describe the 02 mass-transfer and the enzymatic oxidation of the organic substrates of apples (Malus domestica Borkh.), we developed a kinetic model to correlate fruit respiration rate with environmental oxygen partial pressure (PO2. The kinetic determinations were carried out at room temperature using apples stored at 3 to 4C for 11 to 19 weeks. Results show that: 1) the calculated value of the Michaelis-Menten constant related to the enzymatic oxidation of the respiratory substrate (Km = 2.1 ± 0.5.10-5 mol·kg-1) is close to that reported in the literature for cytochrome-c oxidase; 2) the located range of PO2 levels where 02 becomes the limiting factor in the respiration process (near 2.6 kPa at T = 20.5 ± lC) is close to those usually used on a commercial scale for controlled atmosphere storage.
With the aim to determine the infl uence of packaging in preserving the quality of wine, in this ... more With the aim to determine the infl uence of packaging in preserving the quality of wine, in this research project the chemical and sensorial evolution of a red wine stored in different packaging materials (glass bottles vs multilayer Tetrabriks®) has been evaluated over a period of 12 months. Furthermore, two different temperature levels (4 and 20 °C) for each packaging solution were maintained throughout the storage period. The results show how the characteristics of packaging could deeply affect wine quality as a function of the storage conditions used, and suggest that with their rational optimization the quality of red wine during storage can be kept and its shelf life extended. In this context, the kinetic characterization of the time evolution of some chemical compounds that can be assumed as indexes of wine oxidation rate could enhance the consumer's enjoyment during tasting. Under the adopted experimental conditions, the rate of wine aging was higher when the storage temperature increased. Furthermore, after 12 months of storage at room temperature, the glass bottles generally better preserved red wine from oxidation than multilayer Tetrabriks®.
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.
During grape crushing, the release in the liquid phase of oxidizing enzymes can reduce the concen... more During grape crushing, the release in the liquid phase of oxidizing enzymes can reduce the concentration of phenols which are natural antioxidants important for human health. On the contrary, in the following phases, related to the aging of wine, it is the slower chemical oxidation that causes the unwished degradation of the phenolic compounds. In spite of the wide literature on the field, kinetic evaluations which allow to quantify the extent of the phenomenon with temperature (30 and 45°C) are not yet available. To evaluate the phenol degradation kinetics, a model solution containing gallic acid which was subjected to both chemical and enzymatic oxidation was used. After determination of the kinetic equation able to describe the time reduction of the gallic acid concentration in the solution, the kinetic parameters related to the degradation curves and the oxidative process involved were calculated. In both the chemical and enzymatic oxidation experiments, an increase in the tempe...
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.
ABSTRACT For the extraction of oil from microalgae, which are recognised as an important renewabl... more ABSTRACT For the extraction of oil from microalgae, which are recognised as an important renewable source of bioactive lipids, supercritical CO2 is regarded with interest being safer than hexane and offering a negligible environmental impact, short extraction time and petroleum-free final product. A mathematical model, able to describe the kinetics of a supercritical fluid extraction (SFE) process, was applied to the recovery of oil from the cyanobacterium Spirulina (Arthrospira) platensis, characterised by a particularly high content in γ-linolenic acid (C18:3ω-6). In this paper, we examine the kinetics of the SFE and the effect of operating conditions on extraction yield and fatty acid composition of lipid extracts.
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.
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.
The study aimed at determining mathematical models able to describe the kinetics of substrates co... more The study aimed at determining mathematical models able to describe the kinetics of substrates consumptions (L-malate and D-glucose) and synthesis of end-products involved in malolactic and lactic fermentations promoted by Oenococcus oeni ML 34. The strain was added to aqueous solutions of L-malate or/and D-glucose and to a white wine. The time evolution of bacterial cells and concentrations of both substrates and final products were evaluated by mathematical equations based on a same kinetic approach which involved the introduction of a reduced number (five) of functional parameters characterised by a well identified biological meaning, namely bacterial charge, substrate consumption and accumulation of end-products.
Abstract Among the different kinds of marine sources, microalgae are a potential source of triacy... more Abstract Among the different kinds of marine sources, microalgae are a potential source of triacylglycerides which may contain high amounts of LC-PUFAs such as ω-3 fatty acids EPA and DHA. For the extraction of oil from microalgae, Sc-CO2 is regarded with interest being safer than hexane and offering a negligible environmental impact, a short extraction time and a petroleum-free final product. In such a contest, a mathematical model able to describe the kinetics of an SFE process was applied to the extraction with Sc-CO2 of lipids from Schizochytrium sp., a marine microalga characterized by a particularly high content of LC-PUFAs, and a very high concentration of DHA. The aim of this paper was to examine the effect of operating conditions on the kinetics of the SFE, on process yields and on the fatty acid composition of lipid extracts, also in comparison with the conventional extraction by percolation with n-hexane.
BACKGROUND Bread represents a significant share of food wastes worldwide, so the extension of bre... more BACKGROUND Bread represents a significant share of food wastes worldwide, so the extension of bread shelf life, together with innovative systems of waste treatment, might decrease the emissions by waste biomass degradation, extensive transportation, and storage necessities. In recent years, insects have been selected as a valuable tool for food waste treatment owing to their capability to transform low-value food waste into biomass with high nutritional value. Bakery wastes can be profitably used for this purpose. The object of this work was twofold: i) to measure the impact of flaxseed cake fortification on bread shelf life depending on the leavening agent (baker's yeast vs sourdough); ii) to evaluate the possible re-use of the stale bread fortified with flaxseed cake for Tenebrio molitor rearing. RESULTS Our results showed that the fortification seemed to slow down the hardening rate of bread, particularly if baker's yeast was utilized. Besides, the time necessary for mold appearance in sourdough bread doubled (from two to four days). The addition of flaxseed cake to the recipe determined an increase of its scrap consumption by T. molitor larvae. Besides, we observed a significant increase in the body mass of the T. molitor larvae fed with bread obtained with the brewer's yeast with respect to larvae fed with the sourdough. CONCLUSION Taken together, these preliminary data can indicate that sourdough bread fortified with 5% of flaxseed cake can represent a promising tool to reduce food waste and recycle bread scraps by a novel zero-waste approach. This article is protected by copyright. All rights reserved.
While in the last few years the use of olive cake and mill wastewater as natural sources of pheno... more While in the last few years the use of olive cake and mill wastewater as natural sources of phenolic compounds has been widely considered and several studies have focused on the development of new extraction methods and on the production of functional foods enriched with natural antioxidants, no data has been available on the production of a phenol-enriched refined olive oil with its own phenolic compounds extracted from wastewater produced during physical refining. In this study; we aimed to: (i) verify the effectiveness of a multi-step extraction process to recover the high-added-value phenolic compounds contained in wastewater derived from the preliminary washing degumming step of the physical refining of vegetal oils; (ii) evaluate their potential application for the stabilization of olive oil obtained with refined olive oils; and (iii) evaluate their antioxidant activity in an in vitro model of endothelial cells. The results obtained demonstrate the potential of using the refining wastewater as a source of bioactive compounds to improve the nutraceutical value as well as the antioxidant capacity of commercial olive oils. In the conditions adopted, the phenolic content significantly increased in the prototypes of phenol-enriched olive oils when compared with the control oil.
Journal of the American Society for Horticultural Science
Using mathematical equations that describe the 02 mass-transfer and the enzymatic oxidation of th... more Using mathematical equations that describe the 02 mass-transfer and the enzymatic oxidation of the organic substrates of apples (Malus domestica Borkh.), we developed a kinetic model to correlate fruit respiration rate with environmental oxygen partial pressure (PO2. The kinetic determinations were carried out at room temperature using apples stored at 3 to 4C for 11 to 19 weeks. Results show that: 1) the calculated value of the Michaelis-Menten constant related to the enzymatic oxidation of the respiratory substrate (Km = 2.1 ± 0.5.10-5 mol·kg-1) is close to that reported in the literature for cytochrome-c oxidase; 2) the located range of PO2 levels where 02 becomes the limiting factor in the respiration process (near 2.6 kPa at T = 20.5 ± lC) is close to those usually used on a commercial scale for controlled atmosphere storage.
With the aim to determine the infl uence of packaging in preserving the quality of wine, in this ... more With the aim to determine the infl uence of packaging in preserving the quality of wine, in this research project the chemical and sensorial evolution of a red wine stored in different packaging materials (glass bottles vs multilayer Tetrabriks®) has been evaluated over a period of 12 months. Furthermore, two different temperature levels (4 and 20 °C) for each packaging solution were maintained throughout the storage period. The results show how the characteristics of packaging could deeply affect wine quality as a function of the storage conditions used, and suggest that with their rational optimization the quality of red wine during storage can be kept and its shelf life extended. In this context, the kinetic characterization of the time evolution of some chemical compounds that can be assumed as indexes of wine oxidation rate could enhance the consumer's enjoyment during tasting. Under the adopted experimental conditions, the rate of wine aging was higher when the storage temperature increased. Furthermore, after 12 months of storage at room temperature, the glass bottles generally better preserved red wine from oxidation than multilayer Tetrabriks®.
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.
During grape crushing, the release in the liquid phase of oxidizing enzymes can reduce the concen... more During grape crushing, the release in the liquid phase of oxidizing enzymes can reduce the concentration of phenols which are natural antioxidants important for human health. On the contrary, in the following phases, related to the aging of wine, it is the slower chemical oxidation that causes the unwished degradation of the phenolic compounds. In spite of the wide literature on the field, kinetic evaluations which allow to quantify the extent of the phenomenon with temperature (30 and 45°C) are not yet available. To evaluate the phenol degradation kinetics, a model solution containing gallic acid which was subjected to both chemical and enzymatic oxidation was used. After determination of the kinetic equation able to describe the time reduction of the gallic acid concentration in the solution, the kinetic parameters related to the degradation curves and the oxidative process involved were calculated. In both the chemical and enzymatic oxidation experiments, an increase in the tempe...
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.
ABSTRACT For the extraction of oil from microalgae, which are recognised as an important renewabl... more ABSTRACT For the extraction of oil from microalgae, which are recognised as an important renewable source of bioactive lipids, supercritical CO2 is regarded with interest being safer than hexane and offering a negligible environmental impact, short extraction time and petroleum-free final product. A mathematical model, able to describe the kinetics of a supercritical fluid extraction (SFE) process, was applied to the recovery of oil from the cyanobacterium Spirulina (Arthrospira) platensis, characterised by a particularly high content in γ-linolenic acid (C18:3ω-6). In this paper, we examine the kinetics of the SFE and the effect of operating conditions on extraction yield and fatty acid composition of lipid extracts.
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.
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.
The study aimed at determining mathematical models able to describe the kinetics of substrates co... more The study aimed at determining mathematical models able to describe the kinetics of substrates consumptions (L-malate and D-glucose) and synthesis of end-products involved in malolactic and lactic fermentations promoted by Oenococcus oeni ML 34. The strain was added to aqueous solutions of L-malate or/and D-glucose and to a white wine. The time evolution of bacterial cells and concentrations of both substrates and final products were evaluated by mathematical equations based on a same kinetic approach which involved the introduction of a reduced number (five) of functional parameters characterised by a well identified biological meaning, namely bacterial charge, substrate consumption and accumulation of end-products.
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