Structural analysis of spray‐dried powders by confocal laser scanning microscopy

Abstract

The internal and external morphology of spray‐dried powders were investigated as a function of the operating conditions of the spray dryer by using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The blend of gum arabic (GA) and maltodextrin (MD) solution, which is normally used in the encapsulated food industry, was prepared at 30% solid content of the mass ratio of GA and MD of 1 to 3. In order to make the powder particles visible by CLSM, fluorescein sodium was used to label the solid materials. The solutions were fed through an Ohkawara L‐8 type spray dryer at different inlet air temperatures and atomizing speeds. An increase in the vacuole as well as the particle size was observed when the inlet air temperature was increased. Smaller vacuoles and lower yields of vacuoles were observed when using low atomization speeds. The density of powders decreased with an increase of the inlet air temperature as well as with an increase of the atomizing speed. Furthermore, the surface morphology presented smooth and shriveled particles for all powders, but deeper surface grooving for low inlet air temperatures. More grooves were observed by using a low atomizing speed. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.

Testing Tools and Physical, Chemical, and Microbiological Characterization of Microencapsulated Systems

“…0.02À700 Adamiec et al, 2012;Baranauskiené et al, 2006;Bhandari et al, 1992;Choi et al, 2009;Fieber et al, 2011;Finney et al, 2002;Kaasgaard and Keller, 2010;Kim and Morr, 1996;Ko et al, 2012;Li et al, 2013;Ma et al, 2013;McNamee et al, 1998;Paramita et al, 2012;Patel et al, 2013;Rodríguez et al, 2013;Shah et al, 2012;Soottitantawat et al, 2004Soottitantawat et al, , 2005Soottitantawat et al, , 2007Yang et al, 2012a,b;Zandi et al, 2014. Optical microscopy Accessibility, low cost, simple operation, color distinguishability ability.…”

“…This microscopic technique is based on point-by-point laser beam scanning of a fluorescent-labeled specimen (Lamprecht et al, 2000a,b) and enables a 3D image of specimen to be constructed using electronic-computer software. The CLSM technique was proven feasible for characterization of the cross-sectional structures of spray-dried powders of maltodextrin (DE 5 2 and 20) when florescent markers were used to label the wall material (Soottitantawat et al, 2007). Yang et al (2012a,b) used CLSM to study the internal structure of vanilla oil encapsulates, including oil distribution.…”

“…0.02À1000 Baranauskiené et al, 2006Baranauskiené et al, , 2007Bhandari et al, 1992;BringasLantigua et al, 2011;Chen et al, 2013;Choi et al, 2009;Finney et al, 2002;Jimenez et al, 2010;Fabra et al, 2012;Kaasgaard and Keller, 2010;Kim and Morr, 1996;Ko et al, 2012;Li et al, 2013;McNamee et al, 1998McNamee et al, , 2001Paramita et al, 2012;Penbunditkul et al, 2012;Shah et al, 2012;Sillick and Gregson, 2012;Soottitantawat et al, 2005Soottitantawat et al, , 2007Sosa et al, 2013;Syamaladevi et al, 2012;Yang et al, 2012a,b;Yeo et al, 2005;Zandi et al, 2014.…”

“…(Source:Soottitantawat et al, 2007; Reproduced with permission from John Wiley and Sons, Hoboken, NJ. )…”

Variation of Product Properties of Granules Spray‐Dried from Nanoscale SiO2

“…Erste Ansätze zur Quantifizierung innerer Granulatstrukturen lieferten Walker et al [5] und Soottitantawat et al [6]. Sie versuchten die Größe der Hohlräume in Granulaten [5] wie auch den Anteil an Hohlgranulaten innerhalb einer Probe [6] abzuschätzen.…”