Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes
The effect of ohmic treatment on some quality related characteristics of pear purée (cv. ‘Conference’) such as color, reducing sugars, total phenols, rheological behavior and microbial counts, was analyzed. The inactivation kinetics of pectin methyl esterase (PME) in pear crude extract and purée wer...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Society of Land Measurements and Cadastre from Transylvania (SMTCT)
2015-06-01
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| Series: | Notulae Scientia Biologicae |
| Online Access: | http://www.notulaebiologicae.ro/index.php/nsb/article/view/9547 |
| _version_ | 1818176283065974784 |
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| author | Oana Viorela NISTOR Aida VASILE Doina G. ANDRONOIU Gabriel D. MOCANU Elisabeta BOTEZ Nicoleta STĂNCIUC |
| author_facet | Oana Viorela NISTOR Aida VASILE Doina G. ANDRONOIU Gabriel D. MOCANU Elisabeta BOTEZ Nicoleta STĂNCIUC |
| author_sort | Oana Viorela NISTOR |
| collection | DOAJ |
| description | The effect of ohmic treatment on some quality related characteristics of pear purée (cv. ‘Conference’) such as color, reducing sugars, total phenols, rheological behavior and microbial counts, was analyzed. The inactivation kinetics of pectin methyl esterase (PME) in pear crude extract and purée were studied by conventional thermal and ohmic treatments. Thermal inactivation of PME in crude extract was described by a first-order kinetic model. The activation energy values suggested the presence of two isoenzymes with different thermostability. The ohmic heating reduced PME activity by 96% at 25 V·cm-1. Minimal changes induced by ohmic heating on above quality related aspects were observed. Supporting this statement, there were no significant changes in the nutritional and sensorial attributes. It was reported an increase of 3% of reducing sugar content for the ohmic heated samples. The phenolic content of the treated samples registered a reduction of 59% in comparison with fresh pear purée. The pear purée presented a non-Newtonian pseudoplastic behaviour. The Ostwald de Waele model was fitted to rheograms and the consistency coefficient (m) and flow behavior index (n) were determined. Results obtained for the microbial charge were higher in the control samples. Thus, microbial counts showed complete inactivation of yeast and mold at voltage gradient higher than 17.5 V·cm-1. |
| first_indexed | 2024-12-11T20:13:43Z |
| format | Article |
| id | doaj.art-4b12f98429b8491ba73a140acd41ea88 |
| institution | Directory Open Access Journal |
| issn | 2067-3205 2067-3264 |
| language | English |
| last_indexed | 2024-12-11T20:13:43Z |
| publishDate | 2015-06-01 |
| publisher | Society of Land Measurements and Cadastre from Transylvania (SMTCT) |
| record_format | Article |
| series | Notulae Scientia Biologicae |
| spelling | doaj.art-4b12f98429b8491ba73a140acd41ea882022-12-22T00:52:14ZengSociety of Land Measurements and Cadastre from Transylvania (SMTCT)Notulae Scientia Biologicae2067-32052067-32642015-06-017223223810.15835/nsb7295478144Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related AttributesOana Viorela NISTOR0Aida VASILE1Doina G. ANDRONOIU2Gabriel D. MOCANU3Elisabeta BOTEZ4Nicoleta STĂNCIUC5“Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați“Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați“Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați“Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați“Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați“Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, GalațiThe effect of ohmic treatment on some quality related characteristics of pear purée (cv. ‘Conference’) such as color, reducing sugars, total phenols, rheological behavior and microbial counts, was analyzed. The inactivation kinetics of pectin methyl esterase (PME) in pear crude extract and purée were studied by conventional thermal and ohmic treatments. Thermal inactivation of PME in crude extract was described by a first-order kinetic model. The activation energy values suggested the presence of two isoenzymes with different thermostability. The ohmic heating reduced PME activity by 96% at 25 V·cm-1. Minimal changes induced by ohmic heating on above quality related aspects were observed. Supporting this statement, there were no significant changes in the nutritional and sensorial attributes. It was reported an increase of 3% of reducing sugar content for the ohmic heated samples. The phenolic content of the treated samples registered a reduction of 59% in comparison with fresh pear purée. The pear purée presented a non-Newtonian pseudoplastic behaviour. The Ostwald de Waele model was fitted to rheograms and the consistency coefficient (m) and flow behavior index (n) were determined. Results obtained for the microbial charge were higher in the control samples. Thus, microbial counts showed complete inactivation of yeast and mold at voltage gradient higher than 17.5 V·cm-1.http://www.notulaebiologicae.ro/index.php/nsb/article/view/9547 |
| spellingShingle | Oana Viorela NISTOR Aida VASILE Doina G. ANDRONOIU Gabriel D. MOCANU Elisabeta BOTEZ Nicoleta STĂNCIUC Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes Notulae Scientia Biologicae |
| title | Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes |
| title_full | Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes |
| title_fullStr | Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes |
| title_full_unstemmed | Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes |
| title_short | Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes |
| title_sort | ohmic treatment of pear purees cv conference in terms of some quality related attributes |
| url | http://www.notulaebiologicae.ro/index.php/nsb/article/view/9547 |
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