Microchannel emulsification: A promising technique towards encapsulation of functional compounds

Abstract

This review provides an overview of microchannel emulsification (MCE) for production of functional monodispersed emulsion droplets. The main emphasis has been put on functional bioactives encapsulation using grooved-type and straight-through microchannel array plates. MCE successfully encapsulates the bioactives like β-carotene, oleuropein, γ-oryzanol, β-sitosterol, L-ascorbic acid and ascorbic acid derivatives, vitamin D and quercetin. These bioactives were encapsulated in a variety of delivery systems like simple and multiple emulsions, polymeric particles, microgels, solid lipid particles and functional vesicles. The droplet generation process in MCE is based upon spontaneous transformation of interfaces rather than high energy shear stress systems. The scale-up of MCE can increase the productivity of monodispersed droplets >100 L h and makes it a promising tool at industrial level.

Recent progress in food‐grade double emulsions: Fabrication, stability, applications, and future trends

“…MCE is a promising technology that is driven by interfacial tension and is able to produce monodisperse emulsion droplets (Figure 2b). The formation of droplets in MCE requires minimal energy input with no external shear force, as the dispersed phase through the channel spontaneously transforms into emulsion droplets under the action of interfacial tension (Khalid et al., 2018). The advantage of MCE is that the process parameters can be fine‐tuned to produce droplets with adjustable sizes in a larger range, generate uniform droplets, and accurately control the size and shape of droplets.…”

“…MC arrays for MCE are divided into grooved MC and straight through MC (including circular, rectangular, and asymmetric) (Vladisavljevic, 2016). Due to these advantages mentioned before, this technology has ideal application prospects, which can produce monodispersed emulsions, giant vesicles, uniform size oil droplets containing functional lipids, and so on (Khalid et al., 2018).…”

“…At present, the two‐step method is the most common method for preparing double emulsions. It has been confirmed that membrane emulsification (ME), phase inversion, and microchannel emulsification (MCE) are better than conventional emulsification to produce stable double emulsions (Khalid et al., 2018). In a recent study, a surface modification method was proposed to fabricate polydimethylsiloxane microfluidic devices with partial hydrophilic and hydrophobic surfaces to generate double emulsion droplets (Kamnerdsook et al., 2021).…”

Recent progress in oil-in-water-in-oil (O/W/O) double emulsions

“…A new advanced approach for formulating the O/W/O emulsion was developed, i.e., microfluidic homogenization, which is a modified microchannel emulsification method (Khalid et al 2018). Figure 2d aqueous droplets also can be tailored by altering the breakup rates at the junctions.…”

Recent Advances in Lipases and Their Applications in the Food and Nutraceutical Industry

“…These derivatives are formed by the addition of a donor acyl to the primary alcohol to produce the corresponding 6-O-ascorbyl ester without interfering with its antioxidant capacity, catalyzed by lipases, and generating compounds such as ascorbyl palmitate and ascorbyl oleate (Figure 3). Another method to improve the stability and physicochemical properties of vitamin C involve using emulsions and microchannel emulsification, which promote less interaction of the compound with the oxygen present in the medium and provide greater solubility in fats [115,116]. However, ascorbyl esters of unsaturated fatty acids possess equally good properties, such as miscibility in hydrophobic media [117].…”