Food-Grade Microencapsulation Systems to Improve Protection of the Epigallocatechin Gallate

Microencapsulation of Extracts of Strawberry (Fragaria vesca) By-Products by Spray-Drying Using Individual and Binary/Ternary Blends of Biopolymers

Valorization of agricultural and food by-products (agri-food waste) and maximum utilization of this raw material constitute a highly relevant topic worldwide. Agri-food waste contains different types of phytochemical compounds such as polyphenols, that display a set of biological properties, including anti-inflammatory, chemo-preventive, and immune-stimulating effects. In this work, the microencapsulation of strawberry (Fragaria vesca) plant extract was made by spray-drying using individual biopolymers, as well as binary and ternary blends of pectin, alginate, and carrageenan. The microparticle morphologies depended on the formulation used, and they had an average size between 0.01 μm and 16.3 μm considering a volume size distribution. The encapsulation efficiency ranged between 81 and 100%. The kinetic models of Korsmeyer-Peppas (R2: 0.35-0.94) and Baker-Lonsdale (R2: 0.73-1.0) were fitted to the experimental release profiles. In general, the releases followed a "Fickian Diffusion" mechanism, with total release times varying between 100 and 350 (ternary blends) seconds. The microparticles containing only quercetin (one of the main polyphenols in the plant) showed higher antioxidant power compared to the extract and empty particles. Finally, the addition of the different types of microparticles to the gelatine (2.7 mPa.s) and to the aloe vera gel (640 mPa.s) provoked small changes in the viscosity of the final gelatine (2.3 and 3.3 mPa.s) and of the aloe vera gel (621-653 mPa.s). At a visual level, it is possible to conclude that in the gelatine matrix, there was a slight variation in color, while in the aloe vera gel, no changes were registered. In conclusion, these microparticles present promising characteristics for food, nutraceutical, and cosmetic applications.

Statistical simplex centroid experimental design for evaluation of pectin, modified chitosan and modified starch as encapsulating agents on the development of vitamin E-loaded microparticles by spray-drying

Vitamin E encapsulation into biopolymer-based microparticles, obtained by spray-drying technology, was proposed to improve the encapsulation efficiency and the controlled release of fat-soluble vitamin. Binary and ternary blends of pectin, modified chitosan and modified starch, modified starch + modified chitosan, modified starch + pectin, modified chitosan + pectin and modified starch + modified chitosan + pectin ((0.33, 0.33, 0.33), (0.70, 0.15, 0.15), (0.15, 0.70, 0.15) and (0.15, 0.15, 0.70)) were proposed to produce and evaluate different carrier-based delivery systems. Vitamin E-loaded microparticles and empty microparticles were created with a product yield between 9 and 49 %. The mean diameter among all microparticles varied between 3.74 ± 0.02 and 421 ± 21 μm (differential volume distribution). Oval, spherical or irregular microparticles, with a variable morphology from a smooth to a high rough surface structure, with concavities, were produced. All vitamin E-loaded microparticles exhibited an encapsulation efficiency higher than 70 %. The slower vitamin E controlled release was observed from microparticles composed by modified chitosan (>36 h), while the faster release was achieved from microparticles individually composed by pectin (39 min). In general, the Fickian diffusion is the main release mechanism involved in the microparticles produced with modified chitosan, other formulations combine also other mechanisms such as swelling.

Recent Advances in Encapsulation for Food Applications

Food-related research is closely related to health [...].

A Brief Review on the Electrohydrodynamic Techniques Used to Build Antioxidant Delivery Systems from Natural Sources

Extracts from plants have been one of the main sources of antioxidants, namely polyphenols. The associated drawbacks, such as instability against environmental factors, low bioavailability, and loss of activity, must be considered during microencapsulation for a better application. Electrohydrodynamic processes have been investigated as promising tools to fabricate crucial vectors to minimize these limitations. The developed microstructures present high potential to encapsulate active compounds and for controlling their release. The fabricated electrospun/electrosprayed structures present different benefits when compared with structures developed by other techniques; they present a high surface-area-to-volume ratio as well as porosity, great materials handling, and scalable production-among other advantages-which make them able to be widely applied in different fields, namely in the food industry. This review presents a summary of the electrohydrodynamic processes, main studies, and their application.

Co-Encapsulation of Epigallocatechin-3-Gallate and Vitamin B12 in Zein Microstructures by Electrospinning/Electrospraying Technique

EGCG is a catechin known for its antioxidant and anti-inflammatory characteristics. Vitamin B12 is an essential vitamin found in animal-derived products, and its deficiency may cause serious health problems such as anemia. The effectiveness of both catechin and vitamin B12 depends on their stability and bioavailability, which can be lost during industrial processes due to degradation when exposed to external factors. A potential solution to this issue is the microencapsulation, which protects the compounds from external agents. The current study aims to microencapsulate EGCG and vitamin B12 in a polymer matrix of biological origin, zein. Microencapsulation was performed using an electrospinning technique, and different concentrations of zein (1–30% w/v) and active compound (0.5–5% w/w) were tested, resulting in the production of micro/nanoparticles, fibers, or the mixture of both. The microstructures were analyzed and characterized in terms of morphology, release profile and kinetics, and encapsulation efficiency. High encapsulation efficiencies were obtained, and the highest were found in the samples with 1% w/w of active substance and 30% w/v of zein. Controlled release studies were conducted in deionized water and in an ethanolic solution, and five kinetic models were applied to the release profiles. The results indicated that the Weibull model was the best fit for the majority of results.