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Measurement of pH micro-heterogeneity in natural cheese matrices by flourescence lifetime imaging

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Show simple item record Burdikova, Suzana Svindrych, Zdenek Pala, Jan Hickey, Cian D. Wilkinson, Martin G. Panek, Jiri Auty, Mark A.E. Periasamy, Ammasi Sheehan, Jeremiah J. 2015-06-24T14:52:36Z 2015-06-24T14:52:36Z 2015
dc.description peer-reviewed en_US
dc.description.abstract Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM). In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening. en_US
dc.language.iso eng en_US
dc.publisher Frontiers en_US
dc.relation.ispartofseries Frontiers in Microbiology;6, article 183
dc.rights This document is protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission en_US
dc.subject cheese matrix en_US
dc.subject C-SNARF-4 en_US
dc.subject pH micro-heterogeneity en_US
dc.subject fluorescence lifetime en_US
dc.subject natural cheese en_US
dc.title Measurement of pH micro-heterogeneity in natural cheese matrices by flourescence lifetime imaging en_US
dc.type info:eu-repo/semantics/article en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.identifier.doi 10.3389/fmicb.2015.00183
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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