Traffano-Schiffo Maria Victoria, Laghi Luca, Castro-Giraldez Marta, Tylewicz Urszula, Rocculi Pietro, Ragni Luigi, Dalla Rosa Marco, Fito Pedro J
Instituto Universitario de Ingeniería de Alimentos para el Desarrollo, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain.
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.
Food Chem. 2017 Dec 1;236:87-93. doi: 10.1016/j.foodchem.2017.02.046. Epub 2017 Feb 12.
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.
渗透脱水（OD）是一种广泛应用的保鲜技术，它通过将生物组织浸泡在高渗溶液中来降低食品的水分活度。本研究的目的是利用核磁共振（NMR）分析脉冲电场（PEF）作为OD预处理对传质的影响。从这个意义上说，PEF预处理使用了三种不同的电压（100、250和400V/cm）和60个脉冲数。猕猴桃的OD在25°C的61.5%蔗糖溶液中进行，接触时间为0至120分钟。通过NMR弛豫测量研究了水分在细胞组织中的分布。总之，NMR是一种出色的技术，可根据水分子在果实组织中的相互作用对其进行量化，获得吸附水，并为应用BET模型拟合整个水分活度范围内的吸附等温线提供了可能性。
