Microencapsulation of Yerba mate extract: The efficacy of polysaccharide/protein hydrocolloids on physical, microstructural, functional, and antioxidant properties

Comparative Analysis of Different Natural Polymers as Coating Agents for Freeze-Dried Microencapsulation of Cosmos caudatus Kunth Compounds

The flavonoid compounds in C. caudatus K., known for their various benefits, are prone to quick degradation, leading to reduced biological activity. This research aimed to evaluate the types of coatings: gum Arabic (GA), maltodextrin (MD), and a combination of both (MDGA) in C. caudatus K. extract microcapsules. The extract of C. caudatus K. was encapsulated by different coating materials, GA, MD, and MDGA, and then dried using a freeze-drying technique. The evaluation was carried out by comparing the encapsulation efficiency values, biological activity, and release tests of each type of microcapsule coating. The research results indicate that coating agents have impacts significantly at p < 0.05 on efficiency encapsulation. Flavonoids were retained up to 79.67% by the MDGA coating, compared with 72.8% and 47.66%a retained by single GA and MD coatings, respectively. The results of the encapsulation efficiency are supported by the results of characterization using a scanning electron microscope (SEM), where MDGA has rounder shapes with smoother surfaces compared with a single coating alone, like GA or MD. In addition, by particle size analysis using a particle size analyzer (PSA), the average sizes of MDGA, GA, and MD microcapsules were shown at 154.13 µm, 152 µm, and 166.81 µm, respectively. The three microcapsules showed an order of activities as MDGA > GA > MD coatings in alpha-amylase inhibition assay. Similar results were also shown in the antioxidant assay, which demonstrated that the three microcapsules had moderate antioxidant activities, again in the order of MDGA > GA > MD. The three different coating types showed greater release at pH 7.4 compared to those at pH 2.2 in the controlled release test, which ran from 30 to 120 min. In summary, freeze-drying microencapsulation using biodegradable polymers was identified as a viable method for harnessing the health benefits of C. caudatus K. extracts. This process produced a convenient powder form that could be used in drug delivery systems. The use of MDGA mixed coating resulted in better impact based on %EE value and biological activity, as well as improved characteristics of microcapsules compared with single coating.

Sweet tea extract encapsulated by different wall material combinations with improved physicochemical properties and bioactivity stability

Aim: To prepare sweet tea extract microcapsules (STEMs) via a spray-drying by applying different wall material formulations with maltodextrin (MD), inulin (IN), and gum arabic (GA). Methods: The microcapsules were characterised by yield, encapsulation efficiency (EE), particle size, sensory evaluation, morphology, attenuated total reflectance-Fourier transform infra-red spectroscopy and in vitro digestion studies. Results: The encapsulation improved the physicochemical properties and bioactivity stability of sweet tea extract (STE). MD5IN5 had the highest yield (56.33 ± 0.06% w/w) and the best EE (e.g. 88.84 ± 0.36% w/w of total flavonoids). MD9GA1 obtained the smallest particle size (642.13 ± 4.12 nm). MD9GA1 exhibited the highest retention of bioactive components, inhibition of α-glucosidase (96.85 ± 0.55%), α-amylase (57.58 ± 0.99%), angiotensin-converting enzyme (56.88 ± 2.20%), and the best antioxidant activity during in vitro gastrointestinal digestion. Conclusion: The encapsulation of STE can be an appropriate way for the valorisation of STE with improved properties.

Advances in protein-based microcapsules and their applications: A review

Due to their excellent emulsification, biocompatibility, and biological activity, proteins are widely used as microcapsule wall materials for encapsulating drugs, natural bioactive substances, essential oils, probiotics, etc. In this review, we summarize the protein-based microcapsules, discussing the types of proteins utilized in microcapsule wall materials, the preparation process, and the main factors that influence their properties. Additionally, we conclude with examples of the vital role of protein-based microcapsules in advancing the food industry from primary processing to deep processing and their potential applications in the biomedical, chemical, and textile industries. However, the low stability and controllability of protein wall materials lead to degraded performance and quality of microcapsules. Protein complexes with polysaccharides or modifications to proteins are often used to improve the thermal instability, pH sensitivity, encapsulation efficiency and antioxidant capacity of microcapsules. In addition, factors such as wall material composition, wall material ratio, the ratio of core to wall material, pH, and preparation method all play critical roles in the preparation and performance of microcapsules. The application area and scope of protein-based microcapsules can be further expanded by optimizing the preparation process and studying the microcapsule release mechanism and control strategy.

Stability of yerba mate extract, evaluation of its microencapsulation by ionic gelation and fluidized bed drying

Studies show that yerba mate (Ilex paraguariensis) has high antioxidant capacity occasioned by its high contents of total phenolic compounds. Microencapsulation, specifically ionic gelation, since it does not use heating during process, is considered as an alternative for preserving and applying the extract. The purpose of this study was to evaluate general characteristics and stability of hydroalcoholic extract of yerba mate, conduct the extract microencapsulation by ionic gelation followed by microparticle fluidized bed drying. The extract was evaluated for color stability, total phenolic compounds, and antioxidant activity for nine weeks and at three temperatures (5, 15, and 25 °C). From the extract, a double emulsion (W/O/W), generation of microparticles (ionic gelation by dripping), and fluidized bed drying were conducted. The extract had 32912.55 mg GAE/100 g of phenolic compounds and 2379.49 μmol TE/g of antioxidant activity. The main compound observed was chlorogenic acid (5-CQA) with 0.35 ± 0.01 g/100 mL. In the stability study, the temperature was observed to influence in phenolic compounds reduction, as well as in total color difference of the extract. Double emulsion has shown to be stable and appropriate for use. The values of microparticles total phenolic compounds and antioxidant activity were 423.18 ± 8.60 mg GAE/100 g and 21.17 ± 0.24 μmol TE/g, respectively. After drying, the moisture of microparticles was reduced from 79.2% to 19%. The extract had high total phenolic compound content and high antioxidant activity. Storage at the lowest temperature (5 °C) assured better preservation of extract total phenolic compounds. The dried microparticles showed content of total phenolic compounds and antioxidant activity with potential for commercialization and future application in food matrices.