Fluorescence Recovery after Photobleaching as a Probe of Diffusion in Starch Systems

Abstract

The diffusion coefficients of dextran probes of various molecular weights in starch solutions over a wide concentration range were carried out using fluorescent recovery after photobleaching (FRAP), combined with a confocal microscope and tracer probe diffusion. The technique is simple to implement and can be carried out using increasingly common microscopy apparatus, giving access to a wide variety of new structural and kinetic information. The data can be rationalized in terms of the effects of probe molecular weight and on matrix starch concentration and structure. This provides a new tool to investigate the behavior of systems where starch is an ingredient that contributes to the processing and textural properties of food.

Characterization of the Concentration-Dependence of Solute Diffusivity and Partitioning in a Model Dextran–Agarose Transport System

“…In the mixture framework extended in our recent studies 5, 35, it was assumed to a lowest-order approximation that solute diffusivity and partitioning are constant material properties in the model. However, it is known from experiments that these properties may vary significantly with solute concentration 28, 40, 44 and with gel porosity 12, 22, 28, 32, 46, 47. Indeed, osmotic loading of cells with membrane-permeant osmolytes may involve a wide range of concentrations in certain applications, ranging for example from 0 to 1.4 M 56.…”

From macroscopic to molecular scale investigations of mass transfer of small molecules through edible packaging applied at interfaces of multiphase food products

“…It has been extended to other fields, mostly for systems in a liquid state or in a high hydration state, and in which diffusion follows the Stokes-Einstein law (Häglund, Elison, & Sundelöf, 1988;Kovaleski & Wirth, 1997;Perry, Fitzgerald, & Gilbert, 2006). It covers a wide range of diffusion coefficients, from 10 − 20 to 10 − 9 m 2 •s − 1 .…”

Evaluation of amylopectin clusters and their interaction with nonionic surfactants

“…A very interesting application of starch is the biodegradability enhancement of resins or the plastic matrix when it is added as blend [5][6][7]. In addition, the gelatinized starch paste, which is encountered in low-fat products or bread, is a consequence of the disruption of its granules [3,4,8]. The stability of starch products (the staling of bread, and the freeze-thaw stability) is dependent on a recrystallization process, the retrogradation [4,8,9].…”

“…In addition, the gelatinized starch paste, which is encountered in low-fat products or bread, is a consequence of the disruption of its granules [3,4,8]. The stability of starch products (the staling of bread, and the freeze-thaw stability) is dependent on a recrystallization process, the retrogradation [4,8,9]. ' For this reason, in the last few years, many investigations about the interaction between starch or its biopolymers with several additives have been performed [10][11][12].…”

“…Sodium dodecyl sulfate and hexadecyltrimethylammonium bromide have been used as model compounds for obtaining a better understanding of the retrogradation of starch in the presence of lipids. The diffusion of molecules in the starch matrix has also been studied through laser light scattering experiments [16] and fluorescence recovery after photobleaching measurements [8].…”