Control of the morphology and the size of complex coacervate microcapsules during scale‐up

Abstract

Scale‐up of complex coacervation, a fat encapsulation technology, is not trivial since the microcapsules morphology and size are highly affected by the processing conditions. So far it has been achieved empirically (trial and error approach). The goal of this study was to produce at various scale capsules with a single‐oil droplet as the core material and small enough to be below sensory threshold. The turbulence level was identified as the main scale‐up criterium and a master‐curve could be drafted showing the capsule mean diameter as function of the Reynolds number, independent of the level of production scale. From a parent emulsion with specific oil droplets size (12–15 μm), the Reynolds number had to be maintained above a critical value (15,000) to avoid capsules agglomeration with multiple oil cores and large particle sizes. To avoid aggregation, this turbulence level had to be kept until the temperature dropped below a critical value (14°C for a cooling rate of 35°C/2 h). Applying these learning led to a successful scale‐up from bench (2 L) to a pilot plant scale of 50 L. © 2009 American Institute of Chemical Engineers AIChE J, 2009

Particle size characteristics of buriti oil microcapsules produced by gelatin-sodium alginate complex coacervation: Effect of stirring speed

“…All the coacervation assays were carried out at Reynolds number higher than 10000, which is the limit between laminar and turbulent flow in agitated vessels. [24] Lemetter et al [14] observed that increasing Reynolds number led to lower particle size in complex coacervation using gelatin and gum Arabic and stated that this dimensionless number was the correct parameter to consider for scalability of the coacervation process. Our data suggest that above a certain value of Reynolds number (≈ 70000), there is a trend of stabilization in the mean particle size.…”

“…There are a great number of publications concerning the performance of different pairs of biopolymers in the complex coacervation of several lipophilic core materials, but only a limited number of works has been published reporting the effect of processing conditions on the microcapsule characteristics. Jegát and Taverdet [13] and Lemetter et al [14] focused on the effect of stirring speed during coacervation on the size, morphology, and release profile of lipophilic materials encapsulated by complex coacervation in gelatin-gum Arabic, without varying the wall material concentration. To contribute to knowledge of the influence of hydrodynamic conditions during complex coacervation on properties of the resulting microcapsules, the present work was carried out aiming to evaluating the effect of stirring speed and wall polymer concentration on the size and morphology of buriti oil microcapsules produced by complex coacervation of gelatin and sodium alginate.…”

A review of the preparation and application of flavour and essential oils microcapsules based on complex coacervation technology

“…One of them, called ‘polymer‐rich’, contains the precipitate coacervate, and another, called ‘solvent‐rich’, which contains the solvent of the solution . The production of microcapsules by complex coacervation comprises five basic steps (Fig. ): Dissolution .…”

Hydrocolloid Gums – Their Role and Interactions in Foods

“…Such associations tend to be induced when the two hydrocolloids carry opposite charge. Examples include mixtures of gelatin and carrageenan (Michon et al, 1995(Michon et al, , 2000Haug et al, 2003), gelatin and gum Arabic (Lemetter et al, 2009) and β-lactoglobulin and gum Arabic (Schmitt et al, 1998). The properties of such complexes change as a function of pH and salt, imparting structural change triggers, which may be of use in their applications.…”