Microfluidic fabrication of hollow protein microcapsules for rate-controlled release

Abstract

Droplet-based microfluidics is an emerging technique that is capable of producing sophisticated supramolecular microcapsules in one step. However, food materials, due to their physical and chemical complexity, have limited success with microfluidic processes. The objectives of this work were to produce food-grade protein microcapsules in a microfluidic system and to control their structural properties by adjusting the formulation and flow rates. In this study, a T-junction microfluidic chip was used to create an interface for zein to self-assemble, and therefore form microcapsules with tunable particle sizes, pore distributions, and permeabilities. Our SEM and CLSM results show that the particle size and number of pores increased with the flow rate of the dispersing phase, while the pore size decreased with the flow rate of the dispersing phase. In order to quantify the release profiles, the release half-life (t 50 ) was used as an indicator for the particle permeability. A wide range of t 50 , from 3 to 62 minutes, was achieved by changing the zein concentration and flow rate of the dispersing phase. Using Rhodamine B as an encapsulant, the release rate was positively correlated with the zein concentration and flow rate of the dispersing phase. Finally, response surface analysis of the formulation and flow rate was applied to aid the design of a carrier with a desirable release rate.

Numerical simulations of wall contact angle effects on droplet size during step emulsification

“…Such changes will have an effect on the study of single variables. Moreover, the addition of surfactants may be strictly limited sometimes, especially in certain medical 25 or biological 26,27 applications.…”

Ultrasonic modification of pectin for enhanced 2‐furfurylthiol encapsulation: process optimization and mechanisms

“…The thicker layer could potentially provide better protection of the core material in the oil phase. A similar strategy has been implemented in previous work to improve nutrient retention or to extend release duration by forming thick wall materials . It was also found that the surface tension of both UP1 and UP4 was lower than that of OP (supporting information, Table S1), indicating that an improvement in the surface activity of pectin was achieved through the ultrasonic treatment.…”

Fabrication of zein-modified starch nanoparticle complexes via microfluidic chip and encapsulation of nisin

“…The CD spectra were collected using JASCO J-715 spectropolarimeter (Jasco Inc., Easton, MD) and the method in a previous publication was used with some modifications ( Feng and Lee, 2017 ). The 100 times diluted samples were placed in an 1 cm path length quartz cell, and the wavelength ranged from 200 to 250 nm at 25 °C with the scanning speed of 50 nm/min.…”