Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes

Oana Viorela NISTOR; Aida VASILE; Doina G. ANDRONOIU; Gabriel D. MOCANU; Elisabeta BOTEZ; Nicoleta STĂNCIUC

doi:10.15835/nsb729547

Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes

Authors

Oana Viorela NISTOR “Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați (RO)
Aida VASILE “Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați (RO)
Doina G. ANDRONOIU “Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați (RO)
Gabriel D. MOCANU “Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați (RO)
Elisabeta BOTEZ “Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați (RO)
Nicoleta STĂNCIUC “Dunărea de Jos” University of Galați, Faculty of Food Science and Engineering, Domnească Street 111, 800201, Galați (RO)

DOI:

https://doi.org/10.15835/nsb729547

Keywords:

minimal processing; pear purée; pectin methylesterase; rheological behavior

Abstract

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.

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Published

2015-06-21

How to Cite

NISTOR, O. V., VASILE, A., ANDRONOIU, D. G., MOCANU, G. D., BOTEZ, E., & STĂNCIUC, N. (2015). Ohmic Treatment of Pear Purées (cv. ‘Conference’) in Terms of Some Quality Related Attributes. Notulae Scientia Biologicae, 7(2), 232–238. https://doi.org/10.15835/nsb729547

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Issue

Vol. 7 No. 2 (2015)

Section

Research articles

CITATION

DOI: 10.15835/nsb729547

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Papers published in Notulae Scientia Biologicae are Open-Access, distributed under the terms and conditions of the Creative Commons Attribution License.

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