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Compte tenu de l'importance des pigments naturels dans les aliments et leur sensibilité aux traitements thermiques, les cinétiques de dégradation des anthocyanes ont été étudiées à très hautes températures (100 à 180 ºC). Pour obtenir une base de données expérimentale fiable dissociant les transferts d'énergie et de matière, un mini-réacteur étanche a été utilisé pour le traitement d'une matrice modèle (jus de mûre et sable) en faisant varier la température et l'activité de l'eau (0,20<aw<0,99). L'hypothèse d'une réaction d'ordre 1 pour la dégradation des anthocyanes a permis de modéliser et de déterminer les paramètres cinétiques suivant une méthode non-isotherme prenant en compte à la fois le profil de température et indépendamment l'homogénéité ou l'hétérogénéité du champs de température au sein de la matrice. Il a été démontré que les constantes de réaction sont très influencées par la diminution de l'activité de l'eau, facteur qui fait augmenter la réactivité. Ces résultats originaux ont été validés sur une matrice alimentaire (papaye verte-jus de mûre) soumise au couplage d'un procédé de formulation par déshydratation par immersion-imprégnation, suivi d'une opération de friture, à l'aide d'un modèle qui intègre les transferts de vapeur et d'énergie et la cinétique réactionnelle. Le modèle permet une meilleure compréhension des phénomènes et il peut être intégré dans une démarche d'optimisation séquentielle associant différentes opérations unitaires avec des traitements thermiques à très hautes températures. / Given the importance of natural pigments in foods and their sensitivity to heat treatment, degradation kinetics of anthocyanins have been studied at very high temperatures (100 to 180 ºC). For a reliable experimental database that dissociates heat and mass transfer, a hermetic mini-reactor was used for the treatment of a model matrix (blackberry juice and sand) by varying the temperature and activity water (0.20<aw<0.99). The assumption of a first order reaction for the anthocyanins degradation was used to model and determine the kinetic parameters using a non-isothermal method taking into account both the temperature profile and independently the homogeneity or heterogeneity of the matrix temperature field. It has been shown that the rate constants are strongly influenced by the water activity reduction, a factor that increases the anthocyanins reactivity. These original results were validated on a food matrix (green papaya-blackberry juice) submitted to the coupling of a formulation process by osmotic dehydration, followed by a deep-fat frying operation, using a model which includes the vapor and heat transfer and the reaction kinetics. The model allows a better understanding of the phenomena and can be integrated into a sequential optimization approach combining different unit operations with heat treatments at high temperatures.

<p>U okviru ove disertacije ispitan je hemijski, mineralni i<br />polifenolni sastav, kao i biolo&scaron;ki potencijal četiri sorte<br />kupina sa dva različita lokaliteta sjeverozapadnog dijela<br />Bosne i Hercegovine, sa lokaliteta Verići (divlja i<br />kultivisana sorta Čačanska bestrna) i sa lokaliteta<br />Javorani (divlja sorta i kultivisana sorta Chester<br />Thornles). Određen je sadržaj suve materije, pepela,<br />sirove celuloze, ukupnih &scaron;ećera, ukupna kiselost i sadržaj<br />askorbinske kiseline. Sadržaj mineralnih materija<br />detektovan je metodom optičke emisione spektrometrije<br />(ICP-OES). Za izdvajanje ekstrakata je kori&scaron;tena klasična<br />ekstrakciona tehnika prema Soxhlet-u uz upotrebu 80 %<br />etanola (v/v). Spektrofotometrijskim metodama određen<br />je sadržaj ukupnih polifenola, flavonida, flavonola,<br />ukupnih i monomernih antocijana. Kvalitativnom i<br />kvantitativnom HPLC metodom je utvrđen sadržaj<br />pojedinačnih polifenolih jedinjenja. Biolo&scaron;ki potencijal<br />uzoraka je utvrđen u sistemima in vitro, gdje je određena:<br />antioksidativna aktivnost, antihiperglikemijska aktivnost,<br />antiproliferativni efekat i antimikrobna aktivnost.<br />Antioksidativna aktivnost uzoraka je ispitana sa četiri<br />metode: DPPH test, ABTS test, sposobnost neutralizacije<br />hidroksil radikala i metodom inhibicije Briggs Rauscherovih oscilatornih reakcija. Antihiperglikemijska aktivnost<br />ispitivanih uzoraka kupine je dokazan na osnovu<br />sposobnosti inhibicije enzima &alpha;-glukozidaze.<br />Antiproliferativni efekat ispitivanih uzoraka je određen<br />prema inhibiciji rasta četiri humane ćelijske linije: HeLa<br />(epitelnog karcinoma cerviksa), HT-29 (adenokarcinoma<br />debelog crijeva), MRC-5 (zdravim ćelijama fibroblasti<br />pluća) i prema ćelijskoj liniji MCF7 (adenokarcinoma<br />dojke). Antimikrobna aktivnost je utvrđena prema gram<br />pozitivnom soju (G⁺) bakterija S. Aureus i gram<br />negativnom (G^-) soju E. coli, rastu micelija Aspergillusa<br />niger i Candida albicans. Regresionom analizom prema<br />Pirson-u su određeni odnosi između sadržaja polifenolnih<br />jedinjenja i biolo&scaron;kog potencijala, sa statističkim<br />značajem (p &le; 0,01).</p> / <p>The chemical, mineral, polyphenolics composition and<br />biological potentials of four blackberries varieties from two<br />different locations in the northwestern part of Bosnia and<br />Herzegovina (Verići - wild and cultivated variety Čačanska<br />bestrna and Javorani - wild and cultivated variety Chester<br />Thornless) were determined. The contents of dry matter, ash,<br />crude cellulose, total sugars, total acidity and ascorbic acid were<br />obtained. The contents of mineral matter were detected by<br />optical emission spectrometry (ICP-OES) method. A classic<br />Soxhlet extraction technique with 80% ethanol (v/v) was<br />applied to obtain extracts. The spectrophotometric methods<br />were used to determine the content of total polyphenolics,<br />flavonoids, flavonols, and total and monomer anthocyanins. The<br />content of individual polyphenolic compounds was determined<br />by HPLC method. The biological potentials (antioxidant<br />activity, antihyperglycemic activity, antiproliferative effect and<br />antimicrobial activity) of the samples were determined in vitro<br />systems. The antioxidant activity was tested with four methods:<br />DPPH test, ABTS test, ability to neutralize OH radicals and the<br />method of inhibiting Briggs Rauscher oscillatory reactions. The<br />antihyperglycaemic activity of the tested blackberry samples<br />was based on the ability to inhibit &alpha;-glucosidase enzyme. The<br />antiproliferative effect of the tested samples was determined by<br />inhibiting the growth of four human cell lines: epithelial<br />carcinoma of the cervix (HeLa), colon adenocarcinoma (HT-<br />29), healthy lung fibroblast cells (MRC-5) and the cell line of<br />breast adenocarcinoma (MCF7). The extracts showed the<br />highest inhibitory effect on the cell line of breast<br />adenocarcinoma (MCF-7). The antimicrobial activity was<br />determined according to gram-positive bacteria (G ⁺) of<br />Staphylococcus aureus, Gram-negative bacteria (G ^-)<br />Escherichia coli, growth of mycelium Aspergillus niger and<br />fungi Candida albicans. The Pearson correlations were<br />statistically determined the relationship between the content of<br />polyphenolic compounds and biological potential, with<br />statistical significance (p &le; 0.01).</p>