Spray drying powder properties

Typically, grape skin extract has a specific gravity of 1.13 g/mL at 20°C, a solids content of 28—32° Brix (=t3°), a pH of 3.0, and a color strength as anthocyanin of about 1.25% (as measured at 520 nm ia pH 3.0 citrate buffet). Grape skin extract is also available as spray-dried powders with color values three to four times those of the liquid. The properties and uses of grape skin extract ate similar to those of grape color extract. 

Emulsions made with a fine oil droplet particle size, usually less than one micron, are more stable with the oil droplets less likely to coalesce and separate. The encapsulation of a good quality emulsion is generally more efficient with less surface oil on the spray-dried powder. We wanted to build surfactant properties into the starch backbone to improve encapsulation efficiencies. Studies of the mechanism by which surfactants stabilize emulsions were made in order to accomplish this. 

The bark of the tree is incised and the exudate allowed to dry on the bark. The dried exudate is then collected, processed to remove bark, sand, and other particulate matter, and graded. Various acacia grades differing in particle size and other physical properties are thus obtained. A spray-dried powder is also commercially available. 

Guterres SS, Weiss V, de Lucca Freitas L, Pohlmann AR. Influence of benzyl benzoate as oil core on the physicochemical properties of spray-dried powders from polymeric nanocapsules containing indomethacin. Drug Deliv 2000 7(4) 195—199. 

Copovidone is a product of pharmaceutical purity. It is a white or yellowish-white spray-dried powder that has a relatively fine particle size and good flow properties. It has a typical slight odour and a faint taste in aqueous solutions. 

Properties Tan, free-flowing, spray-dried powder, containing 70-80% total lignin sulfonates, balance wood sugars. Combustible. 

Much of the work in this area has been done in emulsions having a droplet size of more than 1 pm, and the application of submicron (nano) emulsions in encapsulation of oils and flavors is relatively new in the literature. Some works have been carried out to determine the influence of submicron emulsions produced by different emulsification methods on encapsulation efficiency and to investigate the encapsulated powder properties after SD for different emulsion droplet sizes and surfactants. The process has been referred to as nanoparticle encapsulation since a core material in nanosize range is encapsulated into a matrix of micron-sized powder particles (Jafari et al., 2008). This area of research is developing. Some patents were filed in the past describing microemulsion formulations applied to flavor protection (Chung et al., 1994 Chmiel et al., 1997) and applications in flavored carbonated beverages (Wolf and Havekotte, 1989). However, there is no clear evidence on how submicron or nanoemulsions can improve the encapsulation efficiency and stability of food flavors and oils into spray-dried powders. 

The spray-dried powders have a small particle size (10-100 pm) with poor handling properties. Very often in the food industry, at the outlet of the spray-drying chamber, the spray-dried particles are modified by additional treatment such as agglomeration, allowing the modification/increase of powder size/porosity and improvement of solubility/dispersibility properties (i.e., instant powder, decrease of fine particles proportion) (Buffo et al., 2002). 

The key implication of denaturation of protein is the disruption and possible destruction of both the secondary and tertiary structures of proteins. If a protein is denatured during powder formation while spray drying, the resultant spray-dried powders may not dissolve and lose their therapeutic effectiveness as well as other functionalities such as gelling and emulsification. The denaturation of protein negatively impacts the properties of consumer products when they are used as ingredients. 

To effectively prevent denaturation of protein in spray-dried powders, one needs to be able to pinpoint at what stage of drying the protein was denatured. A model that can predict the timing and degree of denaturation as a function of process parameters as well as material properties (e.g., presence of protectant solids) will greatly help design process and material parameters that allow production of minimally denatured protein powders. 

Hydrous sodium silicate granules can be prepared from the spray-dried powders by compaction operations to enlarge bulk density to about 500-900 g/L (see Table 22.1). This property is essential for many applications, for example, automatic dishwash detergents [65,66]. 

Weuts 1, Van Dycke F, Vootspoels J, De Cort S, Stokbroekx S, Leemans R et til (2011) Physicochemical properties of the amorphous drug, cast films, and spray dried powders to predict formulation probability of success for sohd dispersions etravirine. J Pharm Sci 100 260-274... 

Physical and Mechanical Properties Depending on the manufacturing technology used for the manufacture of the amorphous solid dispersion, the material will have different physical properties clearly impacting flow and compression behavior of the material. Comparing spray-dried powders, for instance, with milled extrudates will reveal the difference of both materials. The smaller spray-dried particles have a higher tendency towards cohesion and thus impacting powder flow. On the other... 

In the following sections, encapsulation of flavor by means of spray drying will be discussed. We will focus on flavor retention during spray drying, stability of the encapsulated flavor on the basis of emulsion properties, and on the release and oxidation rates in the spray-dried powder. 

Note, however, that the described classification of release mechanisms is valid for a given single microcapsule. A mixture of microcapsules usually includes a distribution of capsules varying in size and wall thickness. Since any spray-dried powder produced from an emulsion is essentially such a mixture of microcapsules with variations in their properties, the parameter n in Eq. 6.6 varies depending on the properties of the powder. Equation 6.6 is essentially analogous to the equation of Kohlraush-Williams-Watts (KWW). This relationship can be expressed as (Williams and Watts, 1970)... 

Jansson A, Jamstrom L, Ratto P, Thuvander F. 2006. Physical and Swelling Properties of Spray-Dried Powders made from Starch and Poly(vinyl alcohol). Stttfch/Starke 58(12) 632-641. 

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