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Dorota Witrowarajchert - One of the best experts on this subject based on the ideXlab platform.
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ultrasound assisted Osmotic dehydration of organic cranberries vaccinium oxycoccus study on quality parameters evolution during storage
Food Control, 2018Co-Authors: Malgorzata Nowacka, Urszula Tylewicz, Silvia Tappi, Lorenzo Siroli, Rosalba Lanciotti, Santina Romani, Dorota WitrowarajchertAbstract:Abstract Cranberries are appreciated for their high amount of antioxidants such as flavonoids, anthocyanins, phenolic acids, carotenoids and vitamins. However, due to their sour and tart taste they request to be processed into sweeter dried fruits in order to be acceptable for the consumers. The aim of this work was to analyse the effect of ultrasound assisted Osmotic dehydration on mass transfer parameters and on quality characteristics during storage of cranberries. Ultrasound Treatment was performed at the frequency of 21 kHz for 30 min in three Osmotic solutions - 61.5% sucrose, 30% sucrose with an addition of 0.1% of steviol glycosides and 40% trehalose on cut in half cranberries. Afterwards, the cranberry samples were subjected to Osmotic dehydration process at 40 °C for 72 h. The osmodehydrated samples both with or without ultrasound pre-Treatment were collected and stored at 10 °C in climatic chamber in microperforated plastic bags (PLA) for 8 weeks. The weight reduction, dry matter, water activity, colour, and microbiological analysis were performed after 1, 2, 4 and 8 weeks of storage. The obtained results indicated that ultrasound application significantly affected the mass transfer parameters during Osmotic Treatment, as well as it did the type of Osmotic solution used. Thermal analysis showed variations in sugar melting temperature and enthalpy as a result of Osmotic Treatment and storage. During the storage, lower weight loss and higher lightness were observed in US pre-treated samples. The sample that preserved the best chemico-physical and microbiological characteristics during storage was the one treated with 61.5% sucrose solution, due to its lowest water activity.
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influence of power ultrasound on the main quality properties and cell viability of Osmotic dehydrated cranberries
Ultrasonics, 2018Co-Authors: Malgorzata Nowacka, Aleksandra Fijalkowska, Magdalena Dadan, Artur Wiktor, Urszula Tylewicz, Marco Dalla Rosa, Dorota WitrowarajchertAbstract:The aim of the study was to investigate the effect of ultrasound Treatment in two Osmotic solutions, carried out at different time, on some physical properties, antioxidant activity and cell survival of cranberries. Ultrasound Treatment was conducted at 21kHz for 30 and 60min in liquid medium: 61.5% sucrose solution and 30% sucrose solution with 0.1% steviol glycosides addition. Some samples before the ultrasound Treatment were subjected to cutting or blanching. The results showed that dry matter content and concentration of the dissolved substances increased during ultrasound Treatment in Osmotic solution, however higher value was observed for Treatment in 61.5% sucrose solution and for longer time. Water activity and volume of cranberries did not change after the ultrasonic Treatment. Combined Treatment led to colour and antioxidant activity alterations as well. A cell viability of whole and cut samples decreased after 60min of Osmotic Treatment and completely lost in the blanched samples.
Patrick Gervais - One of the best experts on this subject based on the ideXlab platform.
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Sequence of occurring damages in yeast plasma membrane during dehydration and rehydration: Mechanisms of cell death
Biochimica et Biophysica Acta:Biomembranes, 2007Co-Authors: Hélène Simonin, Laurent Beney, Patrick GervaisAbstract:Yeasts are often exposed to variations in Osmotic pressure in their natural environments or in their substrates when used in fermentation industries. Such changes may lead to cell death or activity loss. Although the involvement of the plasma membrane is strongly suspected, the mechanism remains unclear. Here, the integrity and functionality of the yeast plasma membrane at different levels of dehydration and rehydration during an Osmotic Treatment were assessed using various fluorescent dyes. Flow cytometry and confocal microscopy of cells stained with oxonol, propidium iodide, and lucifer yellow were used to study changes in membrane polarization, permeabilization, and endocytosis, respectively. Cell volume contraction, reversible depolarization, permeabilization, and endovesicle formation were successively observed with increasing levels of Osmotic pressure during dehydration. The maximum survival rate was also detected at a specific rehydration level, of 20 MPa, above which cells were strongly permeabilized. Thus, we show that the two steps of an Osmotic Treatment, dehydration and rehydration, are both involved in the induction of cell death. Permeabilization of the plasma membranes is the critical event related to cell death. It may result from lipidic phase transitions in the membrane and from variations in the area-to-volume ratio during the Osmotic Treatment.
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viability of escherichia coli after combined Osmotic and thermal Treatment a plasma membrane implication
Biochimica et Biophysica Acta, 2002Co-Authors: Yannick Mille, Laurent Beney, Patrick GervaisAbstract:This study investigates the influence of temperature (T) and Osmotic pressure (Pi) on the viability of Escherichia coli K12 during an Osmotic Treatment. Osmotic shock (dehydration and rehydration within 1 s) in liquid media at different temperatures (4, 10, 30 and 37 degrees C) and different levels of Osmotic pressure (26, 30, 35, 40, 82 and 133 MPa) were realized. Results show that a sudden dehydration, below 40 MPa, destroyed up to 80% of the bacterial population for each tested temperature, whereas viability was greater than 90% for an Osmotic pressure less than 26 MPa. The influence of T and Pi on the membrane's physical structure is finally considered to explain the results in light of FTIR and electron microscopy study of the influence of temperature and Osmotic pressure on E. coli membrane phospholipids conformation.
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Viability of Escherichia coli after combined Osmotic and thermal Treatment: a plasma membrane implication
Biochimica et Biophysica Acta:Biomembranes, 2002Co-Authors: Yannick Mille, Laurent Beney, Patrick GervaisAbstract:This study investigates the influence of temperature (T) and Osmotic pressure (Π) on the viability of Escherichia coli K12 during an Osmotic Treatment. Osmotic shock (dehydration and rehydration within 1 s) in liquid media at different temperatures (4, 10, 30 and 37 °C) and different levels of Osmotic pressure (26, 30, 35, 40, 82 and 133 MPa) were realized. Results show that a sudden dehydration, below 40 MPa, destroyed up to 80% of the bacterial population for each tested temperature, whereas viability was greater than 90% for an Osmotic pressure less than 26 MPa. The influence of T and Π on the membrane's physical structure is finally considered to explain the results in light of FTIR and electron microscopy study of the influence of temperature and Osmotic pressure on E. coli membrane phospholipids conformation.
W E L Spiess - One of the best experts on this subject based on the ideXlab platform.
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Mass Transfer in Strawberry Tissue During Osmotic Treatment II: Structure-function Relationships
Journal of Food Science, 2003Co-Authors: M Ferrando, W E L SpiessAbstract:The surface response method demonstrated macroscopic changes in strawberry tissue during Osmotic Treatment (OT). Changes in the structural elements of strawberry were determined by evaluating bulk phenomena such us water loss, solid gain, and shrinkage. The changes were related to microstructural changes (determined in Part I) that took place in the same range of process conditions. The extension of impregnation, with respect to dewatering, increased as cellular shrinkage and cell destruction increased. The macroscopic effective diffusivity of water ranged from 5.1 ± 1.0 × 10(−10) to 0.7 ± 0.2 × 10(−10) m(2)/s, which was 2 orders of magnitude higher than the microscopic effective diffusivity of water (in the order of magnitude of 10(−12) m(2)/s), calculated from cellular shrinkage.
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Mass Transfer in Strawberry Tissue During Osmotic Treatment I: Microstructural Changes
Journal of Food Science, 2003Co-Authors: M Ferrando, W E L SpiessAbstract:Microstructural changes in strawberry tissue were quantified during Osmotic Treatment (OT) with sucrose solutions in concentrations of is to 65 (% w/w). The response-surface method was used to determine how the process variables (processing time and concentration) influence cellular shrinkage and cell destructions. With regard to the concentration of the Osmotic sulution, the kinetics of cell destruction followed a 1st-order model. The diffusional approach for modelling water transport in a layer of cells inside the strawberry tissue showed that water diffusivity is related to the concentration of the sucrose solution. Water diffusivity ranged from 16 ± 2 10 -12 to 6.2 ± 0.6 10 -0.3 m 2 /s with sucrose solutions in concentrations between 15 and 65 (% w/w).
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Transmembrane Mass Transfer in Carrot Protoplasts during Osmotic Treatment
Journal of Food Science, 2002Co-Authors: M Ferrando, W E L SpiessAbstract:Minimized experiments with Confocal Scanning Laser Microscopy were used to describe mass transfer of isolated carrot protoplasts from at the usual conditions of the Osmotic Treatments (OT). Carrot protoplasts during OT with 30, 40 and 50% sucrose solutions were monitored. The ratio of cellular volume before and after OT with 30, 40 and 50% sucrose solutions was 0.88 0.12, 0.41 ± 0.04 and 0.17 ± 0.02, respectively. Trans-membrane water flux was determined from cellular shrinkage, and the coefficient for water membrane permeability was (5.2 ± 0.9) 10 -8 mol 2 /Jm 2 s, To describe water transport in protoplasts at transient conditions, the diffusional approach was used. The effective water diffusivity during OT with 50% sucrose solutions was in the (0,8-1.8) 10 -12 m 2 /s range.
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cellular response of plant tissue during the Osmotic Treatment with sucrose maltose and trehalose solutions
Journal of Food Engineering, 2001Co-Authors: M Ferrando, W E L SpiessAbstract:Abstract The impact of three disaccharides – sucrose, maltose, and trehalose – on cellular shrinkage and cell viability undergone by onion epidermis and strawberry cortex tissue during the Osmotic Treatment (OT) and further rehydration, in case of onion epidermis, was investigated. Differences in cellular response were observed between both plant tissues. The nature of the sugar employed significantly affected the shrinking behaviour of onion epidermis without having any impact on the cellular shrinkage of strawberry tissue. Cell viability did not suffer any significant change regarding to the nature of the sugar whereas cell viability of strawberry tissue was strongly affected by sugar concentration. The rehydration of onion epidermis showed the ability of plasmolysed cells to respond to environmental changes, keeping their compartmental properties. During OT a redistribution of the cell membrane took place, causing a reduction of the surface membrane available for swelling. A protective effect of maltose and trehalose on plasma membrane was only appreciated in onion epidermis.
Malgorzata Nowacka - One of the best experts on this subject based on the ideXlab platform.
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ultrasound assisted Osmotic dehydration of organic cranberries vaccinium oxycoccus study on quality parameters evolution during storage
Food Control, 2018Co-Authors: Malgorzata Nowacka, Urszula Tylewicz, Silvia Tappi, Lorenzo Siroli, Rosalba Lanciotti, Santina Romani, Dorota WitrowarajchertAbstract:Abstract Cranberries are appreciated for their high amount of antioxidants such as flavonoids, anthocyanins, phenolic acids, carotenoids and vitamins. However, due to their sour and tart taste they request to be processed into sweeter dried fruits in order to be acceptable for the consumers. The aim of this work was to analyse the effect of ultrasound assisted Osmotic dehydration on mass transfer parameters and on quality characteristics during storage of cranberries. Ultrasound Treatment was performed at the frequency of 21 kHz for 30 min in three Osmotic solutions - 61.5% sucrose, 30% sucrose with an addition of 0.1% of steviol glycosides and 40% trehalose on cut in half cranberries. Afterwards, the cranberry samples were subjected to Osmotic dehydration process at 40 °C for 72 h. The osmodehydrated samples both with or without ultrasound pre-Treatment were collected and stored at 10 °C in climatic chamber in microperforated plastic bags (PLA) for 8 weeks. The weight reduction, dry matter, water activity, colour, and microbiological analysis were performed after 1, 2, 4 and 8 weeks of storage. The obtained results indicated that ultrasound application significantly affected the mass transfer parameters during Osmotic Treatment, as well as it did the type of Osmotic solution used. Thermal analysis showed variations in sugar melting temperature and enthalpy as a result of Osmotic Treatment and storage. During the storage, lower weight loss and higher lightness were observed in US pre-treated samples. The sample that preserved the best chemico-physical and microbiological characteristics during storage was the one treated with 61.5% sucrose solution, due to its lowest water activity.
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influence of power ultrasound on the main quality properties and cell viability of Osmotic dehydrated cranberries
Ultrasonics, 2018Co-Authors: Malgorzata Nowacka, Aleksandra Fijalkowska, Magdalena Dadan, Artur Wiktor, Urszula Tylewicz, Marco Dalla Rosa, Dorota WitrowarajchertAbstract:The aim of the study was to investigate the effect of ultrasound Treatment in two Osmotic solutions, carried out at different time, on some physical properties, antioxidant activity and cell survival of cranberries. Ultrasound Treatment was conducted at 21kHz for 30 and 60min in liquid medium: 61.5% sucrose solution and 30% sucrose solution with 0.1% steviol glycosides addition. Some samples before the ultrasound Treatment were subjected to cutting or blanching. The results showed that dry matter content and concentration of the dissolved substances increased during ultrasound Treatment in Osmotic solution, however higher value was observed for Treatment in 61.5% sucrose solution and for longer time. Water activity and volume of cranberries did not change after the ultrasonic Treatment. Combined Treatment led to colour and antioxidant activity alterations as well. A cell viability of whole and cut samples decreased after 60min of Osmotic Treatment and completely lost in the blanched samples.
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NMR and DSC Water Study During Osmotic Dehydration of Actinidia deliciosa and Actinidia chinensis Kiwifruit
Food Biophysics, 2011Co-Authors: Urszula Tylewicz, Malgorzata Nowacka, Valentina Panarese, Luca Laghi, Pietro Rocculi, Giuseppe Placucci, Marco Dalla RosaAbstract:This study investigated mass transfer and water state changes promoted by Osmotic dehydration on two kiwifruit species, Actinidia deliciosa and Actinidia chinensis. Osmotic Treatment was performed in a 61.5% w/v sucrose solution at three different temperatures (25, 35 and 45 °C), with Treatment time from 0 to 300 min. Treatment time positively influenced kiwifruit water loss and solid gain while temperature significantly affected only water loss. Peleg’s model highlighted that the main response differences between the two species occurred during the initial phase of the Osmotic Treatment. Thermal properties and relaxation time measurements offered a complementary view concerning the effects of Osmotic dehydration on kiwifruit. DSC parameters appeared to be sensitive to water and solid exchange between fruit and Osmotic solution. LF-NMR proton T2 revealed the consequences of the water–solid exchange on the cell compartments, namely vacuole, cytoplasm plus extracellular space and cell wall. During the Osmotic Treatment, the initial freezing temperature and the freezable water content decrease was dependent on time and Treatment temperature, showing a similar tendency for both the kiwifruit species. They evidenced the same Treatment response also concerning the reduction of vacuole and the increase of cytoplasm plus extracellular space T2 values.
Elham Azarpazhooh - One of the best experts on this subject based on the ideXlab platform.
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optimization of ultrasound assisted Osmotic Treatment of aleo vera gel impregnated with grape pomace phenolic compounds using response surface methodology
Agricultural Engineering International: The CIGR Journal, 2020Co-Authors: Elham Azarpazhooh, Parvin Sharayei, Hosahalli S. RamaswamyAbstract:This study was focused on investigating the use of pulsed ultrasound-assisted Osmotic dehydration (UAOD) for enhancing the infusion of phenolic compounds extracted from grape pomace (GPx) to Aloe vera ( Aloe barbadensis Miller,) gel (AVG) using response surface methodology (RSM) and produce a dehydrated product with high antioxidant content. Fresh AVG were initially immersed in a sucrose solution of 50° B with three levels of GPx (10, 20, and 30 v/v) and subjected to pulsed ultrasound (US) Treatment with a probe of 2 cm diameter, two levels of ultrasound amplitude (UA) (50 and 100%), and three ultrasound Treatment times (UT) (30, 135 and 210 min). The pulsed on and off times were set at 15 and 1 min, respectively. A multiple regression analysis was carried out to develop second-order polynomial models with high coefficients of determination value ( R 2 > 0.81). The optimal conditions were obtained using the Design Expert software. The best condition obtained for the UAOD optimization was UA = 59%, 20% grape pomace extract in 50% sucrose, UT = 173 min to result in a moisture loss of 51.3 % (predicted 49.9%), solid gain of 4.3 % (5.0%), total phenolic contents of 30.5 mg/g (31.8%), and DPPH radical scavenging activity of 15.3% (15.0%). UAOD therefore appears to be a promising process for antioxidant incorporation and preparing added value product.
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ultrasound assisted Osmotic Treatment of model food impregnated with pomegranate peel phenolic compounds mass transfer texture and phenolic evaluations
Food and Bioprocess Technology, 2018Co-Authors: Fatemeh Hamedi, Mohebbat Mohebbi, Fakhri Shahidi, Elham AzarpazhoohAbstract:Food impregnation with nutraceutical components due to the health beneficial property is of great importance for food processing industry. In this study, Osmotic dehydration was used to impregnate model food with phenolics extracted from pomegranate peel. Intermittent acoustic Treatment was applied to enhance mass transfer. This process was carried out at three sucrose concentrations of 40, 50, and 60% and two levels of power ultrasound, 50 and 100% in an experimental setup, which was equipped with a pump circulating Osmotic solution frequently. Results showed that increase in sucrose concentration resulted in an increase in the amounts of water loss and solutes gain. Additionally, application of higher power ultrasound led to higher values of water loss and solid gain. Mass transfer modeling using Azuara model predicts water loss and solid gain values at equilibrium. Results revealed the good correlation of experimental values with the model (due to the R2 values greater than 0.94). The microstructure of samples was investigated using scanning electron microscopy (SEM). Images revealed pores and cavities made by ultrasound waves as the result of spongy effects. Texture profile analysis (TPA) was applied for the determination of hardness, springiness, and gumminess of the samples. Results also showed significant effects of the sucrose concentration and ultrasound power on textural properties. Measurements of total phenolic content and antiradical activity, which were carried out by a colorimetric method and antiradical scavenging assay, EC50, respectively indicated that Osmotic dehydration is a possible way for uptaking phenolic compounds of pomegranate peel presented in Osmotic solution into food matrices.
