20 research outputs found

    Molecular Dynamics Test of the Stress-Thermal Rule in Polyethylene and Polystyrene Entangled Melts

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    Anisotropic thermal transport induced by deformation and the linear relation between the thermal conductivity and stress tensors, also known as the stress-thermal rule (STR), are tested via molecular dynamics simulations in well-entangled linear polyethylene (PE) and polystyrene (PS) melts subjected to extensional flow. We propose a method to determine the stress in deformed molecular melts, a key component missing in prior simulation studies on thermal transport in polymers that prevented verification of the STR. We compare our results with available data from previous experimental and simulation studies. Thermal conductivity (TC) is found to increase (decrease) in the direction parallel (perpendicular) to the imposed stretch. We find that the STR is valid for both PE and PS over a wide range of deformation rates and stress levels. In direct agreement with experimental evidence and the STR, we observe that for a given strain, the anisotropy in TC increases with the strain rate. Surprisingly, our results for PE question the universal behavior with respect to polymer chemistry suggested by experiments by showing a significantly higher proportionality constant (the stress-thermal coefficient) between stress and anisotropy in TC. We argue that this discrepancy can be explained by the high degree of entanglement interactions in PE affecting the transport of energy at the molecular level. Our conjecture is tested by studying an entangled linear PS melt, a polymer with a much lower entanglement plateau, for which thermal transport experimental results are available. For PS, the normalized stress-thermal coefficient is found to be commensurate with the experimental value. Finally, we test the fundamental molecular hypothesis of preferential energy transport along the backbone of polymer chains used to formulate the STR, which was prompted by early experimental evidence showing an increase in TC with chain length. We are able to establish that the increase in TC with chain length in PE melts fades as the system becomes entangled (i.e., TC remains constant beyond the critical entanglement chain length that marks the transition to entanglement-dominated rheological behavior). Our findings are of key importance in developing robust molecular-to-continuum methodologies for the study of nonisothermal macroscopic flows that are extremely relevant to polymer manufacturing processes.European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie IF MTCIATTP 750985

    Experimental and theoretical study of the structure of the atmospheric boundary layer in Spata plain

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    The objective of this thesis is the experimental and theoretical study of the structure of the Atmospheric Boundary Layer (ABL) in Messogia Plain of Attica, focusing in the study of the Mixing Height (MH) and the Low Level Jet (LLJ) characteristics. This work introduces a newly developed algorithm for the estimation of Mixing Height with the use of data from a SODAR-RASS system. The MH characteristics during a 2-year period are studied with respect to the synoptic conditions of the lower troposphere and the mesoscale phenomena observed over Messogia Plain. The large scale LLJs clearly exhibited the highest MH values, especially during the night, due to the strong wind regime and the strong wind shear. The categories with the lowest MH values are the pure sea breeze and the easterlies, due to the close distance from the shoreline and the capping inversion that accompanies these meso-scale flows, while the calm wind conditions observed during the night, also produce very shallow mixed layers favoring the development of thermal inversions. The High-Low and the closed anticyclone synoptic types give the highest MH values during the day since these types are associated with the large scale LLJs. Τhe interaction of the different scale physical processes that control the development and evolution of the LLJs was investigated with the use of the Hilbert-Huang Transform (HHT) and the application the numerical model MM5. Two types of large scale LLJs (warm/cold period) were identified and studied as well as a typical case of a nocturnal LLJ. The synoptic forcing and the local circulation that leads to the alteration of the LLJ characteristics were found to be the generating mechanisms for the two representative cases analyzed in this work. Strong and significant amplitudes of inertial motions with elliptical nature were associated with the frontal events, while strong diurnal cycle variations associated with the local baroclinic field were detected for the case of the warm period LLJ. Finally, the analysis of the nocturnal LLJ showed that the major generation mechanism was the inertial oscillation due to the frictional decoupling in the layer of the jet. This work highlights the capability of the radio-acoustic systems to estimate significant parameters like the MH and provides useful information regarding the role of the different scale physical processes at the structure of the ABL over a coastal area of Eastern Mediterranean.Η διατριβή αυτή έχει ως αντικείμενο την πειραματική και θεωρητική μελέτη της δομής του Ατμοσφαιρικού Οριακού Στρώματος (ΑΟΣ) στην πεδιάδα των Σπάτων, εστιάζοντας στη μελέτη των χαρακτηριστικών του Ύψους Ανάμειξης (ΥΑ) και των Αεροχειμάρρων Χαμηλού Ύψους (ΑΧΥ). Για την αντικειμενική εκτίμηση του ΥΑ αναπτύχθηκε αλγόριθμος με τη χρήση δεδομένων συστήματος SODAR-RASS. Τα αποτελέσματα της εφαρμογής του αλγόριθμου σε δεδομένα δύο ετών συσχετίστηκαν με τους συνοπτικούς τύπους και τα φαινόμενα μέσης κλίμακας που παρατηρούνται στην περιοχή. Κατά την ανάπτυξη ΑΧΥ, το ΥΑ εμφάνισε τις υψηλότερες τιμές, ιδιαίτερα κατά τη διάρκεια της νύκτας, λόγω των ισχυρών ανέμων και της έντονης διάτμησης του ανέμου. Οι κατηγορίες με τις χαμηλότερες τιμές ΥΑ είναι αυτές της θαλάσσιας αύρας και των ανατολικών ανέμων λόγω της μικρής απόστασης από την ακτή και την θερμοκρασιακή αναστροφή που επικάθεται της ροής, ενώ οι συνθήκες άπνοιας κατά τη διάρκεια της νύκτας ευνοούν την ανάπτυξη ισχυρών θερμοκρασιακών αναστροφών οδηγώντας σε πολύ ρηχά στρώματα ανάμειξης. Οι συνοπτικοί τύποι Υψηλού-Χαμηλού και κλειστού αντικυκλώνα έδωσαν τις μεγαλύτερες τιμές ΥΑ οι οποίες συνδέονται με την εμφάνιση ΑΧΥ. Πραγματοποιήθηκε επίσης μελέτη της αλληλεπίδρασης των φυσικών μηχανισμών που ελέγχουν τη δημιουργία και εξέλιξη των ΑΧΥ με τη χρήση του μετασχηματισμού Hilbert-Huang (HHT) και την εφαρμογή του αριθμητικού μοντέλου ΜΜ5. Αναγνωρίσθηκαν και μελετήθηκαν δύο τύποι ΑΧΥ μεγάλης κλίμακας (θερμής/ψυχρής περιόδου) όπως και μια περίπτωση ενός τυπικού νυκτερινού ΑΧΥ. Η μελέτη ανέδειξε ως κύριους μηχανισμούς για την ανάπτυξη των ΑΧΥ μεγάλης κλίμακας τη συνοπτική κυκλοφορία και τις τοπικές ροές που οδηγούν στη διαφοροποίηση των χαρακτηριστικών των αεροχειμάρρων. Αναγνωρίστηκαν αδρανειακές κινήσεις ελλειπτικής φύσης με ισχυρά πλάτη κατά της διάρκεια της διέλευσης μετώπων, ενώ σημαντικές μεταβολές ημερήσιου κύκλου που σχετίζονται με το τοπικό βαροκλινικό πεδίο εντοπίστηκαν για την περίπτωση του ΑΧΥ της θερμής περιόδου. Τέλος, η μελέτη του νυκτερινού ΑΧΥ ανέδειξε ότι ο κύριος μηχανισμός ανάπτυξης του αεροχειμάρρου είναι η αδρανειακή ταλάντωση μετά από την αποδέσμευση του στρώματος ευστάθειας από την τριβή. Η εργασία αναδεικνύει τις δυνατότητες των ραδιο-ακουστικών συστημάτων μέτρησης στον υπολογισμό σημαντικών παραμέτρων όπως το ΥΑ και παρέχει χρήσιμες πληροφορίες σχετικά με τον ρόλο των φυσικών μηχανισμών διαφορετικής κλίμακας στη δομή του ΑΟΣ σε μια παράκτια περιοχή της Ανατολικής Μεσογείου

    Νεοφιλελεύθερος λόγος και θεωρίες της δημοκρατίας

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    Η παρούσα διατριβή εξετάζει κριτικά τη σχέση μεταξύ του νεοφιλελεύθερου λόγου και της δημοκρατίας. Αρχικά, παρέχει έναν σαφή ορισμό του νεοφιλελεύθερου λόγου και τονίζει τη σημασία της μελέτης αυτού του θέματος. Εξετάζεται η έννοια της δημοκρατίας, συμπεριλαμβανομένης της ιστορικής της εξέλιξης, των βασικών αρχών της και της σημασίας της στη σύγχρονη κοινωνία. Εμβαθύνει στο ιστορικό υπόβαθρο του νεοφιλελευθερισμού, ανιχνεύοντας τις απαρχές και την εξέλιξή του, θέτοντας τις βάσεις για την κατανόηση των επιπτώσεών του στην κοινωνία. Διερευνά τον τρόπο με τον οποίο ο νεοφιλελεύθερος λόγος διαμορφώνει την κοινωνία, εστιάζοντας στην έμφαση στον ατομικισμό και την αποτελεσματικότητα της αγοράς αναλύοντας την επιρροή τους στις νεοφιλελεύθερες πολιτικές, αποκαλύπτοντας την ευθυγράμμισή τους με τη νεοφιλελεύθερη ατζέντα και τις επιπτώσεις τους στην κοινωνική συνοχή, την ανισότητα και τη δημόσια σφαίρα. Η δημιουργία νέων μορφών υποκειμενικότητας διερευνάται, υπογραμμίζοντας την επίδραση της κοινωνικής κατασκευής, της τεχνολογικής διαμεσολάβησης, του καταναλωτισμού, της παγκοσμιοποίησης, του φύλου, της σεξουαλικότητας, της αντίστασης και των ηθικών προβληματισμών. Αξιολογεί κριτικά την προβληματική σχέση μεταξύ νεοφιλελευθερισμού και δημοκρατίας. Εξετάζει τη στενή αντίληψη του νεοφιλελευθερισμού για την ιδιότητα του πολίτη, τον αντίκτυπο του ορθολογισμού της αγοράς στην ιδιότητα του πολίτη, την αποδέσμευση από την πολιτική, την ανισότητα, τον αποκλεισμό και τη διάβρωση της δημόσιας σφαίρας μέσω της ιδιωτικοποίησης. Αναλύονται επίσης, η αποδυνάμωση των δημόσιων θεσμών, η διάβρωση της αυτονομίας τους, η επιρροή της λογικής της αγοράς, η πολιτική παρέμβαση και οι επιπτώσεις τους στη δημοκρατία και τη λογοδοσία. Διερευνά τον τρόπο με τον οποίο ο νεοφιλελευθερισμός συμβάλλει στις κοινωνικοοικονομικές ανισότητες, όπως η συγκέντρωση του πλούτου, η επισφαλής εργασία, η άνιση πρόσβαση στις υπηρεσίες, η οικονομική αστάθεια και η άνιση ανάπτυξη. Επιπλέον, διερευνά το ρόλο του νεοφιλελεύθερου λόγου στη διαμόρφωση της κοινωνίας και των ανθρώπινων υποκειμένων. Ενσωματώνει τη θεωρία της Chantal Mouffe για την κατανόηση των πολιτικών διαστάσεων του νεοφιλελευθερισμού. Εξετάζονται οι κριτικές του νεοφιλελεύθερου λόγου από μελετητές όπως ο David Harvey, η Nancy Fraser και η Wendy Brown, αναδεικνύοντας τις προοπτικές τους σχετικά με τον αντίκτυπο του νεοφιλελευθερισμού στην κοινωνία και τη δημοκρατία. Στη διατριβή τονίζεται η ανάγκη επανεξέτασης της σχέσης μεταξύ νεοφιλελευθερισμού και δημοκρατίας. Αντιμετωπίζονται οι επικρίσεις για τις επιπτώσεις του νεοφιλελευθερισμού στη δημοκρατία και προτείνεται ο επαναπροσδιορισμός της δημοκρατίας στη νεοφιλελεύθερη εποχή. Παρουσιάζονται πιθανές λύσεις για τις προκλήσεις που θέτει ο νεοφιλελευθερισμός, όπως η ενίσχυση της κοινωνικής πρόνοιας, των εργασιακών δικαιωμάτων, της περιβαλλοντικής βιωσιμότητας, η προώθηση της δημοκρατικής συμμετοχής, η αναθεώρηση των οικονομικών προτύπων και η μεταρρύθμιση των διεθνών θεσμών. Συμπερασματικά, καλεί σε κριτικό προβληματισμό σχετικά με τη σχέση μεταξύ του νεοφιλελεύθερου λόγου και της δημοκρατίας. Επισημαίνει την ανάγκη αντιμετώπισης των προκλήσεων που θέτει ο νεοφιλελευθερισμός μέσω εναλλακτικών προσεγγίσεων που δίνουν προτεραιότητα στην κοινωνική ευημερία, τη δημοκρατική συμμετοχή, τη βιωσιμότητα και την οικονομική δικαιοσύνη. Επαναπροσδιορίζοντας και διεκδικώντας τη δημοκρατία απέναντι στον νεοφιλελευθερισμό, οι κοινωνίες μπορούν να αγωνιστούν για ένα πιο περιεκτικό, δίκαιο και δημοκρατικό μέλλον.The present thesis critically examines the relationship between neoliberal discourse (or views) and democracy. It begins by providing a clear definition of neoliberal discourse and emphasizes the importance of studying this topic. The concept of democracy is examined, including its historical evolution, its basic principles, and its significance in modern society. The thesis delves into the historical background of neoliberalism, tracing its origins and development, setting the foundations for comprehending its implications on society. It investigates the way neoliberal discourse shapes society, focusing on the emphasis, on individualism and on market efficiency. Furthermore, it analyzes the influence of individualism as well as the market’s efficiency on neoliberal policies, revealing their alignment with the neoliberal agenda and their implications on social cohesion, inequality, and the public sphere. In addition, the creation of new forms of subjectivity is explored, highlighting the impact of social construction, technological mediation, consumerism, globalization, gender, sexuality, resistance, and moral speculations. The thesis critically evaluates the problematic relationship between neoliberalism and democracy. It examines neoliberalism's narrow conception in reference to the citizenship, the impact of market rationality on citizenship, the disengagement from politics, inequality, exclusion, and the pervasion of the public sphere through privatization. The weakening of public institutions, including the pervasion of their autonomy, the influence of market logic, the political intervention, and the consequences for democracy and accountability are also analyzed. The thesis investigates how neoliberalism contributes to socio-economic inequalities, such as wealth concentration, risky labor, unequal access to services, economic instability, and unequal development. Furthermore, the thesis looks into the role of neoliberal discourse in shaping society and human subjects. It incorporates Chantal Mouffe's theory regarding the understanding of the political dimensions of neoliberalism. The reviews of neoliberal discourses of the scholars David Harvey, Nancy Fraser, and Wendy Brown are examined, pinpointing their perspectives on neoliberalism's impact on society and democracy. The necessity to reevaluate the relationship between neoliberalism and democracy, is emphasized in the thesis. It addresses criticisms of neoliberalism's impact on democracy and proposes redefining democracy in the neoliberal era. Possible solutions to the challenges posed by neoliberalism are presented, including strengthening of social welfare, labor rights, environmental sustainability, promotion of democratic participation, revision of economic paradigms, and reformation of international institutions. In conclusion, the thesis calls for critical reflection on the relationship between neoliberal discourse and democracy. It underlines the need to address the challenges posed by neoliberalism through alternative approaches that prioritize social welfare, democratic participation, sustainability and economic justice. By redefining and claiming democracy against neoliberalism, societies can strive for a more inclusive, equitable, and democratic future

    Cable and pipeline corridors under the legal framework of UNCLOS and the Energy Treaty. Geopolitical considerations at the Eastern Mediterranean Sea

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    This article is divided in three sections; the first is presenting the plethora of fiber optic and power cable geographical distribution, providing to the reader an insight to underwater infrastructure. Readers can bind together the importance of survey, lay, repair and maintenance of underwater cables and pipelines, based on the legal framework provided by the Energy Treaty and UNCLOS. The second section provides a brief report on notions mentioned in the International Energy Treaty. We also mention the Energy Treaty and the Energy Treaty Charter as a case study for pipeline and power cable installations; At the third section, we focus especially at the genesis of UNCLOS with regards to the EEZ maritime zone regime; At this section, we will present the difference between the terms marine research and cable route study, based on the applicable UNCLOS conventional terminology. The last section of this article will be an effort to carefully examine whether these two Treaties are sufficient to regulate transnational cable surveying and laying operations under the current geopolitical frame in the Eastern Mediterranean Sea; as new oil and gas fields are being developed in the region two factors affect the geopolitical equilibrium: 1) The disputed EEZ's in the Eastern Mediterranean, 2) The role of Turkey based on its destabilizing and revisionist stand as this is highlighted by extreme geopolitical behaviors causing the present instability in the geopolitical environment of the Eastern Mediterranean, mainly with regards to the supply of energy from discovered gas reservoirs in the Eastern Mediterranean

    Molecular Characterization and Enological Potential of A High Lactic Acid-Producing Lachancea thermotolerans Vineyard Strain

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    Lactic acid production is an important feature of the yeast Lachancea thermotolerans that has gained increasing interest in winemaking. In particular, in light of climate change, the biological acidification and ethanol reduction by the use of selected yeast strains may counteract the effect of global warming in wines. Here, the enological potential of a high lactate-producing L. thermotolerans strain (P-HO1) in mixed fermentations with S. cerevisiae was examined. Among the different inoculation schemes evaluated, the most successful implantation of L. thermotolerans was accomplished by sequential inoculation of S. cerevisiae, i.e., at 1% vol. ethanol. P-HO1produced the highest levels of lactic acid ever recorded in mixed fermentations (10.4 g/L), increasing thereby the acidity and reducing ethanol by 1.6% vol. L. thermotolerans was also associated with increases in ethyl isobutyrate (strawberry aroma), free SO2, organoleptically perceived citric nuances and aftertaste. To start uncovering the molecular mechanisms of lactate biosynthesis in L. thermotolerans, the relative expressions of the three lactate dehydrogenase (LDH) paralogous genes, which encode the key enzyme for lactate biosynthesis, along with the alcohol dehydrogenase paralogs (ADHs) were determined. Present results point to the possible implication of LDH2, but not of other LDH or ADH genes, in the high production of lactic acid in certain strains at the expense of ethanol. Taken together, the important enological features of P-HO1 highlighted here, and potentially of other L. thermotolerans strains, indicate its great importance in modern winemaking, particularly in the light of the upcoming climate change and its consequences in the grape/wine system

    Biodiversity and Enological Potential of Non-Saccharomyces Yeasts from Nemean Vineyards

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    Vineyards in Nemea, the most important viticultural zone in Greece, were surveyed for indigenous non-Saccharomyces (NS) yeasts of enological potential. NS populations were isolated from the final stage of alcoholic fermentation and identified by a range of molecular methods. The enological profiles of Hanseniaspora guilliermondii, H. osmophila, Lachancea thermotolerans, Starmerella bacillaris and Torulaspora delbrueckii strains were evaluated. Significant interspecies variation was observed in fermentation kinetics. H. osmophila and T. delbrueckii showed the highest capacity for prompt initiation of fermentation, while S. bacillaris achieved a higher fermentation rate in the second half of the process. Significant differences were also observed in the chemical parameters of NS strains. S. bacillaris SbS42 and T. delbrueckii TdS45 were further evaluated in mixed-culture fermentations with Saccharomyces cerevisiae. NS strains achieved lower population densities than S. cerevisiae. SbS42 exhibited a higher death rate than TdS45. The chemical profiles of different ferments were separated by principal component analysis (PCA). Both NS strains were associated with lower levels of ethanol, when compared to single S. cerevisiae inoculation. TdS45 increased the ethyl acetate levels, while SbS42 caused a different production pattern of higher alcohols. This is the first report to explore the enological potential of NS wine yeast populations from Nemea. Based on prominent enological traits identified, the selected S. bacillaris and T. delbrueckii strains may be further exploited as co-culture starters for improving the quality and enhancing the regional character of local wines

    <i>Torulaspora delbrueckii</i> May Help Manage Total and Volatile Acidity of Santorini-Assyrtiko Wine in View of Global Warming

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    Non-Saccharomyces (NS) yeasts are gaining popularity in modern winemaking for improving wine quality. Climate change is one of the biggest challenges winegrowing now faces in warm regions. Here, Lachancea thermotolerans LtS1 and Torulaspora delbrueckii TdS6 combined with Saccharomyces cerevisiae ScS13 isolated from Assyrtiko grapes from Santorini island were evaluated in grape must fermentation with the aim to mitigate major consequences of temperature rise. Different inoculation protocols were evaluated, including simultaneous and sequential mixed-strain inoculations, displaying significant variation in the chemical and kinetic characteristics. Both LtS1 and TdS6 could raise the titratable acidity (TA). TdS6 also reduced the volatile acidity (VA) and was thus chosen for further evaluation in microvinifications and pilot-scale fermentations. Consistent with lab-scale trials, sequential inoculation exhibited the longest persistence of TdS6 resulting in minimum VA levels. Diethyl succinate, ethyl propanoate, and ethyl isobutyrate were significantly increased in sequential inoculations, although a decline in the net total ester content was observed. On the other hand, significantly higher levels of TA, succinic acid, and 2-methylpropanoic were associated with sequential inoculation. The overall performance of TdS6 coupled with a high compatibility with S. cerevisiae suggests its use in the fermentation of Santorini-Assyrtiko or other high sugar musts for the production of structured dry or sweet wines

    Citrus medica and Cinnamomum zeylanicum Essential Oils as Potential Biopreservatives against Spoilage in Low Alcohol Wine Products

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    Low alcohol wine is a new entry in the global wine market, due to the increase in consumers’ concern for health, economic and modern lifestyle issues. As low alcohol products are prone to spoilage, the adoption of natural-derived products with antimicrobial activity as biopreservatives seems to be an intriguing alternative. Thus, the aim of the present study was to investigate the possible antimicrobial properties of Citrus medica and Cinnamomum zeylanicum essential oils (EOs) and assess their commercial prospective in the wine industry. The main constituents identified by GC/MS analysis were limonene (38.46%) and linalool (35.44%) in C. medica EO, whereas trans-cinnamic-aldehyde (63.58%) was the dominant compound in C. zeylanicum EO. The minimum inhibitory (MIC), non-inhibitory (NIC) and minimum lethal concentration (MLC) values against common wine spoilage microbes were initially determined. Subsequently, their efficiency was further validated in low alcohol (~6% vol) wines, either separately or in combination at 0.010% (v/v), as well as in wines deliberately inoculated with Gluconobacter cerinus, Oenococcus oeni, Pediococcus pentosaceus, Dekkera bruxellensis, Candida zemplinina, Hanseniaspora uvarum, Pichia guilliermondii or Zygosaccharomyces bailii. EO addition led to considerable spoilage and microbial growth delay during storage at room or refrigerated temperature, suggesting their potential use as wine biopreservatives

    Slip spring-based mesoscopic simulations of polymer networks:methodology and the corresponding computational code

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    \u3cp\u3eIn previous work by the authors, a new methodology was developed for Brownian dynamics/kinetic Monte Carlo (BD/kMC) simulations of polymer melts. In this study, this methodology is extended for dynamical simulations of crosslinked polymer networks in a coarse-grained representation, wherein chains are modeled as sequences of beads, each bead encompassing a few Kuhn segments. In addition, the C++ code embodying these simulations, entitled Engine for Mesoscopic Simulations for Polymer Networks (EMSIPON) is described in detail. A crosslinked network of cis-1,4-polyisoprene is chosen as a test system. From the thermodynamic point of view, the system is fully described by a Helmholtz energy consisting of three explicit contributions: entropic springs, slip springs and non-bonded interactions. Entanglements between subchains in the network are represented by slip springs. The ends of the slip springs undergo thermally activated hops between adjacent beads along the chain backbones, which are tracked by kinetic Monte Carlo simulation. In addition, creation/destruction processes are included for the slip springs at dangling subchain ends. The Helmholtz energy of non-bonded interactions is derived from the Sanchez-Lacombe equation of state. The isothermal compressibility of the polymer network is predicted from equilibrium density fluctuations in very good agreement with the underlying equation of state and with experiment. Moreover, the methodology and the corresponding C++ code are applied to simulate elongational deformations of polymer rubbers. The shear stress relaxation modulus is predicted from equilibrium simulations of several microseconds of physical time in the undeformed state, as well as from stress-strain curves of the crosslinked polymer networks under deformation.\u3c/p\u3

    Preliminary Evaluation of the Use of Thermally-Dried Immobilized Kefir Cells in Low Alcohol Winemaking

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    Low alcohol wines (&le;10.5% vol) are novel products that have gradually been gaining the consumers&rsquo; and market&rsquo;s interest over the last decade. Taking into account the technological properties of immobilized cell systems alongside with the commercial need for dry cultures, the aim of the present study was to assess the suitability of thermally-dried immobilized kefir cells on DCM, apples pieces, and grape skins in low alcohol wine production. Storage of thermally-dried kefir culture in various temperatures (&minus;18, 5, and 20 &deg;C) resulted in high viability rates for immobilized cells (up to 93% for yeasts/molds immobilized on grape skins and stored at &minus;18 &deg;C for 6 months). Fermentation activity was maintained after storage in all cases, while high operational stability was confirmed in repeated batch fermentations for a period of 6 months. Principal Component Analysis (PCA) revealed that the fermentation temperature rather than the state of kefir culture affected significantly volatiles detected by Head Space Solid-Phase Microextraction Gas Chromatography&ndash;Mass Spectrometry analysis. Notably, all new products were of high quality and approved by the sensory panel
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