Milk powder agglomerate growth and properties in fluidized bed agglomeration

Abstract

Carcel Carrión, JA.; Dumoulin, E. (2013). Milk powder agglomerate growth and properties in fluidized bed agglomeration. Dairy Science and Technology. 93(4-5):523-535. doi:10.1007/s13594-013-0132-7.Milk powder agglomerate growth and properties in fluidized bed agglomerationAbstract Fluidized bed agglomeration is used to produce large and porous dry agglomerates with improved instant properties. Water (or binder solution) is sprayed in the fluidized bed of particles to render their surface sticky. The agglomerate growth results from the repetition of different steps (wetting of the particle surface, particles collision and bridging, and drying) and depends on the processing conditions and product properties. In this work, skim and whole milk powders were fluidized in hot air and agglomerated by spraying water in a bench-scale batch fluidized bed. The aim was to study the impact of the sprayed water flow rate (0-5.5 g.min − 1 ), particle load (300-400 g), initial particle size (200-350 μm), and composition (skim-whole milk) on the growth mechanisms and on the properties of the agglomerates obtained. Powder samples were regularly taken in the fluidized bed during agglomeration and characterized for the size, size distribution, and water content. Whatever the conditions tested, the size increase and the evolution of the particle size distribution during agglomeration were found to mainly depend on the relative amount of water sprayed in the particle bed. Agglomeration occurred in two stages, with first the rapid association of initial particles into intermediate structures, and second, the progressive growth of porous agglomerates. In any case, agglomeration allowed improving instant properties of the milk powder.

Influence of top spray fluidized bed agglomeration conditions on the reconstitution property and structure modification of skim yoghurt powder

“…That can be attributed to forming of large particle size and large pores between agglomerates. Similar results were obtained for skim milk powder that wettability time decrease from more than 1 hr to 3–4 s (Barkouti et al, ). Solubility of agglomerated yoghurt powders slightly increased compared to nonagglomerated yoghurt powder (Table ).…”

“…Final drying without spraying is a necessary step that decrease the moisture content of powders. At the similar researches, some authors dried powders for 15 min (Jinapong et al, ; Szulc & Lenart, ) some did not in order to avoid breakage due to the attrition of particles (Barkouti et al, ). In our study after all trials powders was dried for 5 min till the temperature of bed reaches to 32–34 °C.…”

“…Agglomeration process is defined as the transformation of small native particles into larger size agglomerates. In the literature, different wet agglomeration techniques such as top sprayed fluidized bed agglomeration (Barkouti, Turchiuli, Carcel, & Dumoulin, ; Chen et al, ; Ji et al, ; Jinapong et al, ), bottom sprayed fluidized bed agglomeration (Szulc & Lenart, ), high shear mixer granulation (Ji, Fitzpatrick, Cronin, Fenelon, & Miao, ) and reverse wet agglomeration (Rondet, Cuq, Cassan, & Ruiz, ) were studied. These techniques are popular processes that commonly use in pharmaceutical, food, and chemical industries.…”

“…Spraying binder render particles sticky. Sticky particles collide with each other and form liquid bridges and allow adhesion (Avil es-Avil es, Dumoulin, & Turchiuli, 2015; Barkouti et al, 2013;Turchiuli et al, 2013). Drying by the hot fluidization results consolidation of wet particles.…”

Effect of composition on physical properties of food powders

“…It is also applied for improvement of transport properties of the material (flowability), or improvement in product attractiveness in terms of both its visual features and sensorial properties, and a decrease in its density, as well as prevention of caking during the storage. Such physical properties of agglomerated products as particle size, porosity, solubility, wettability, shape, and bulk density depend on the type of agglomeration and process parameters applied (Barkouti et al, 2013). Agglomeration in the fluidized bed is suitable for obtaining products in a form of agglomerate with high porosity and good mechanical strength significant in further processes connected with their turnover (Dacanal and Menegalli, 2010;Jianpong et al, 2008;Szulc and Lenart, 2010;Vissotto et al, 2010).…”