Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR

Maria Victoria Traffano-Schiffo; Luca Laghi; Marta Castro-Giraldez; Urszula Tylewicz; Pietro Rocculi; Luigi Ragni; Marco Dalla Rosa; Pedro J Fito

doi:10.1016/j.foodchem.2017.02.046

Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR

Food Chem. 2017 Dec 1:236:87-93. doi: 10.1016/j.foodchem.2017.02.046. Epub 2017 Feb 12.

Authors

Maria Victoria Traffano-Schiffo¹, Luca Laghi², Marta Castro-Giraldez³, Urszula Tylewicz⁴, Pietro Rocculi², Luigi Ragni², Marco Dalla Rosa², Pedro J Fito¹

Affiliations

¹ Instituto Universitario de Ingeniería de Alimentos para el Desarrollo, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain.
² Department of Agricultural and Food Sciences, University of Bologna, P.zza Goidanich 60, 47521 Cesena, Italy; Interdepartmental Centre for Agri-Food Industrial Research, University of Bologna, Via Quinto Bucci 336, 47521 Cesena, Italy.
³ Instituto Universitario de Ingeniería de Alimentos para el Desarrollo, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain. Electronic address: marcasgi@upv.es.
⁴ Department of Agricultural and Food Sciences, University of Bologna, P.zza Goidanich 60, 47521 Cesena, Italy.

PMID: 28624093
DOI: 10.1016/j.foodchem.2017.02.046

Abstract

Osmotic dehydration (OD) is a widely used preservation technique that consists in the reduction in food water activity by the immersion of the biological tissue in hypertonic solutions. The aim of this work was to analyze the effect of pulsed electric fields (PEF) in mass transfer as a pre-treatment of the OD using NMR. In this sense, PEF pre-treatments were done using three different voltages (100, 250 and 400V/cm) and 60 number of pulse. The OD of kiwifruit was carried out in 61.5% of sucrose solution at 25°C, for a contact period from 0 to 120min. The water distribution into the cellular tissue was studied by NMR relaxometry. In conclusion, NMR is an excellent technique for quantifying water molecules according to their interactions in the fruit tissue, obtaining the adsorbed water and opening the possibility to apply the BET model to fit the adsorbed isotherm over the whole range of water activity.

Keywords: Kiwifruit; Osmotic dehydration; Pulsed electric fields; TD-NMR; Water distribution.

MeSH terms

Actinidia / chemistry*
Dehydration
Food Preservation / methods*
Fruit / chemistry
Osmosis