Fabrication and characterization of gum arabic- and maltodextrin-based microcapsules containing polyunsaturated oils

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.

Algae-derived compounds: Bioactivity, allergenicity and technologies enhancing their values

As a rapidly growing source of human nutrients, algae biosynthesize diverse metabolites which have promising bioactivities. However, the potential allergenicity of algal components hinder their widespread adoption. This review provides a comprehensive review of various macro and micronutrients derived from algal biomass, with particular focus on bioactive compounds, including peptides, polyphenols, carotenoids, omega-3 fatty acids and phycocyanins. The approaches used to produce algal bioactive compounds and their health benefits (antioxidant, antidiabetic, cardioprotective, anti-inflammatory and immunomodulatory) are summarised. This review particularly focuses on the state-of-the-art of precision fermentation, encapsulation, cold plasma, high-pressure processing, pulsed electric field, and subcritical water to reduce the allergenicity of algal compounds while increasing their bioactivity and bioavailability. By providing insights into current challenges of algae-derived compounds and opportunities for advancement, this review contributes to the ongoing discourse on maximizing their application potential in the food nutraceuticals, and pharmaceuticals industries.

Improving the storage and oxidative stability of essential fatty acids by different encapsulation methods; a review

Linoleic acid and α-linolenic acid are the only essential fatty acids (EFAs) known to the human body. Other fatty acids (FAs) of the omega-6 and omega-3 families originate from linoleic acid and α-linolenic acid, respectively, by the biological processes of elongation and desaturation. In diets with low fish consumption or vegetarianism, these FAs play an exclusive role in providing two crucial FAs for maintaining our body's vital functions; docosahexaenoic acid and arachidonic acid. However, these polyunsaturated FAs are inherently sensitive to oxidation, thereby adversely affecting the storage stability of oils containing them. In this study, we reviewed encapsulation as one of the promising solutions to increase the stability of EFAs. Accordingly, five main encapsulation techniques could be classified: (i) spray drying, (ii) freeze drying, (iii) emulsification, (iv) liposomal entrapment, and (v) other methods, including electrospinning/spraying, complex coacervation, etc. Among these, spray drying was the frequently applied technique for encapsulation of EFAs, followed by freeze dryers. In addition, maltodextrin and gum Arabic were the main wall materials in carriers. Paying attention to industrial scalability and lower cost of the encapsulation process by the other methods are the important aspects that should be given more attention in the future.

Wood hemicelluloses as effective wall materials for spray-dried microcapsulation of polyunsaturated fatty acid-rich oils

The most commonly-used and effective wall materials (WMs) for spray-dried microencapsulation of bioactive compounds are either costly, or derived from unsustainable sources, which lead to an increasing demand for alternatives derived from sustainable and natural sources, with low calories and low cost. Wood hemicelluloses obtained from by-products of forest industries appear to be attractive alternatives as they have been reported to have good emulsifying properties, low viscosity at high concentrations, high heat stability and low heat transfer. Here, we investigated the applicability of spruce galactoglucomannans (GGM) and birch glucuronoxylans (GX), to encapsulate flaxseed oil (FO, polyunsaturated fatty acid-rich plant based oil) by spray drying; and the results were compared to those of the highly effective WM, gum Arabic (GA). It was found that depending on solid ratios of WM:FO (1:1, 3:1 and 5:1), encapsulation efficiency of GGM was 88-96%, and GX was 63-98%. At the same encapsulation ratio, both GGM and GX had higher encapsulation efficiency than GA (49-92%) due to their ability to produce feed emulsions with a smaller oil droplet size and higher physical stability. In addition, the presence of phenolic residues in GGM and GX powders enabled them to have a greater ability to protect oil from oxidation during spray drying than GA. Physiochemical properties of encapsulated powders including thermal properties, morphology, molecular structure, particle size and water adsorption intake are also investigated. The study has explored a new value-added proposition for wood hemicelluloses which can be used as effective WMs in the production of microcapsules of polyunsaturated fatty acid-rich oils for healthy and functional products in food, pharmaceutical and cosmetic industries.

Effect of Mixed Particulate Emulsifiers on Spray-Dried Avocado Oil-in-Water Pickering Emulsions

Avocado oil is a very valuable agro-industrial product which can be perishable in a short time if it is not stored in the right conditions. The encapsulation of the oils through the spray drying technique protects them from oxidation and facilitates their incorporation into different pharmaceutical products and food matrices; however, the selection of environmentally friendly emulsifiers is a great challenge. Four formulations of the following solid particles: Gum Arabic, HI-CAP^®100 starch, and phosphorylated waxy maize starch, were selected to prepare avocado oil Pickering emulsions. Two of the formulations have the same composition, but one of them was emulsified by rotor-stator homogenization. The rest of the emulsions were emulsified by combining rotor-stator plus ultrasound methods. The protective effect of mixed particle emulsifiers in avocado oil encapsulated by spray drying was based on the efficiency of encapsulation. The best results were achieved when avocado oil was emulsified with a mixture of phosphorylated starch/HI-CAP^®100, where it presented the highest encapsulation efficiency.

Effect of Gum Acacia on the Intestinal Bioavailability of n-3 Polyunsaturated Fatty Acids in Rats

Lipid emulsification is a technique that is being explored for improving the bioavailability of omega 3 (n-3) long chain (LC) fatty acid (FA). The nature of the emulsifiers can differently impact the lipid bioavailability via a modification of the lipolysis step. Among natural emulsifiers, gum acacia (GA), an indigestible polysaccharide, provides protective encapsulation of n-3 by forming a specifically crown-like shape around lipid drops, which could also impact the digestion step. Despite the interest in lipolysis rate, the impact of GA on lipid bioavailability has never been explored in a complete physiological context. Thus, we followed in a kinetics study the n-3 bioavailability in rat lymph, orally administered DHA-rich oil, formulated based on GA compared to the bulk phase form of the oil. The AUC values were significantly improved by +121% for total TG and by 321% for n-3 PUFA, specifically for EPA (+244%) and for DHA (+345%). Benefits of GA have also been related to the transport of FA in lymph, which was 2 h earlier (Tmax = 4 h), compared to the Tmax (6 h) obtained with the bulk phase oil. All the data showed that GA is one of the most favorable candidates of natural emulsifiers to improve n-3 bioavailability and their rate of absorption for health targets.