Spray-drying wall materials: relationship with bioactive compounds

Physical and Functional Properties of Powders Obtained during Spray Drying of Cyani flos Extracts

Edible flowers are a potential source of bioactive ingredients and are also an area of scientific research. Particularly noteworthy are Cyani flos, which have a wide range of uses in herbal medicine. The below study aimed to investigate the influence of selected soluble fiber fractions on the selected properties of physical and biochemical powders obtained during spray drying a water extract of Cyani flos. The drying efficiency for the obtained powders was over 60%. The obtained powders were characterized by low moisture content (≤4.99%) and water activity (≤0.22). The increase in the addition of pectin by the amount of 2-8% in the wall material resulted in a decrease in hygroscopicity, water solubility, and protection of flavonoids and anthocyanins both before and after digestion in the tested powders in comparison to the sample with only inulin as a carrier. Additionally, it was noted that all samples were characterized by high bioaccessibility when determining antioxidant properties and xanthine oxidase inhibition.

Influence of emulsifier on lipid oxidation in spray-dried microencapsulated O/W emulsions

Lipid oxidation limits the shelf-life of dried microencapsulated oils (DMOs), such as infant formula. However, it is poorly understood how lipid oxidation is affected by different types of emulsifiers. To improve our understanding, we prepared DMOs with different emulsifiers (whey protein isolate (WPI), pea protein isolate (PPI), and non-proteinaceous CITREM) and studied lipid oxidation in both the free and encapsulated fat. Only a small difference in oxidation rate was observed between these fat fractions for all formulations. We ascribed this to a non-discrete distribution of the fractions and the subsequent low fractionation selectivity as shown by Raman microscopy. The DMO with PPI showed hardly any oxidation during a 7-week incubation at 40 °C, whereas the DMOs with WPI and CITREM both reached significantly higher contents of oxidation products (lipid hydroperoxides, aldehydes, and epoxides). The enhanced stability of DMO-PPI could not be ascribed to the presence of phytic acid. In conclusion, we demonstrate the potential of using PPI to produce oxidatively stable DMOs.

Whey protein concentrate and skimmed milk powder as encapsulation agents for coffee silverskin extracts processed by spray drying

We tested the hypothesis that milk proteins, through microencapsulation, guarantee protection against bioactive substances in coffee silverskin extracts. Therefore, the aim of this study was to carry out technological, nutritional and physicochemical characterisation of a coffee silverskin extract microencapsulated using instant skim milk powder and whey protein concentrate as wall materials. The aqueous extract of coffee silverskin was spray-dried using 10% (w/v) skim milk powder and whey protein concentrate. The samples were characterised by determining the water content, water activity, particle size distribution, colour analysis and total phenolic compound content as well as antioxidant activity using 2,2-diphenyl-radical 1-picrylhydrazyl scavenging methods, nitric oxide radical inhibition and morphological analysis. The product showed water activity within a range that ensured greater stability, and the reduced degradation of the dried coffee silverskin extract with whey protein concentrate resulted in better rehydration ability. The luminosity parameter was higher and the browning index was lower for the encapsulated samples than for the pure coffee silverskin extract. The phenolic compound content (29.23 ± 8.39 and 34.00 ± 8.38 mg gallic acid equivalents/g for the coffee silverskin extract using skimmed milk powder and whey protein concentrate, respectively) and the antioxidant activity of the new product confirmed its potential as a natural source of antioxidant phenolic compounds. We conclude that the dairy matrices associated with spray drying preserved the bioactive and antioxidant activities of coffee silverskin extracts.

Atomization of Cocoa Honey Using Whey Protein Isolate to Produce a Dry Formulation with Improved Shelf Life for Industrial Application

Cocoa honey, a by-product obtained during the processing of cocoa, is a juice rich in pectin, organic acids, minerals and phenolic compounds with antioxidant properties. Fresh cocoa honey is quickly fermented due to its high content of reducing sugars, such as fructose and glucose, which limits its shelf life. Currently, cocoa honey is only commercialized in frozen form, as logistical challenges prevent the wide distribution or export of this by-product for applications in the market of sweets, jellies, beverages, confectionery, and nutraceutical foods among others. Spray-drying technology is a viable prospect for the large-scale stabilization of products such as cocoa honey, with less heat exposure compared to other conventional drying methods. This work aimed to evaluate the efficacy of drying adjuvants for a rapid removal of the water present in cocoa honey via atomization, since this process minimizes the effects of glass transition temperature (Tg) related to materials with high sugar contents. Physical parameters such as the moisture content, hygroscopicity, particle size, and yield of the products obtained were determined. Cocoa honey presented 85.3 ± 0.20 g/100 g of moisture. The formulations successfully decreased moisture content, which was lower than 11.72 ± 0.08 g/100 g in the formulations. Water activity ranged between 0.1464 ± 0.0043 and 0.1562 ± 0.029, with no significant difference between the formulations. The hygroscopicity of cocoa honey powders ranged from 29.29 to 29.87 g of water/100 g of cocoa honey. The combination of 20% maltodextrin and 1% whey protein isolate (WPI) led to the best yield, resulting in a free-flowing powder as the final product. On the other hand, the formulation composed of maltodextrin and whey protein isolate in the ratio of 29:1, respectively, led to the most stable product, with less loss of phenolic compounds during the drying process (6.04%). Regarding particle diameter, 90% of the accumulated distribution did not exceed 57 μm. The greatest dispersion of particles occurs in the Ma20W10 formulation with a span of 2.72, inferring greater variation in size between small (7.01 ± 0.06 μm), medium (18.25 ± 0.37 μm), and large (56.65 ± 1.17 μm) particles. The use of whey protein isolate as an adjuvant proved to be an efficient drying process in the production of cocoa honey powder, and was also advantageous for enriching the nutritional content of the final product due to its protein origin. Furthermore, the combination of spray-drying technology and the use of whey protein isolate as adjuvant led to a free-flowing cocoa honey powder with an adequate particle size and benefits in terms of shelf-life extension, providing new opportunities for the commercialization of cocoa honey as an ingredient for the food industry, with benefits for the circular economy.

Research progress of starch as microencapsulated wall material

Starch is non-toxic, low cost, and possesses good biocompatibility and biodegradability. As a natural polymer material, starch is an ideal choice for microcapsule wall materials. Starch-based microcapsules have a wide range of applications and application prospects in fields such as food, pharmaceuticals, cosmetics, and others. This paper firstly reviews the commonly used wall materials and preparation methods of starch-based microcapsules. Then the effect of starch wall materials on microcapsule properties is introduced in detail. It is expected to provide researchers with design inspiration and ideas for the development of starch-based microcapsules. Next the applications of starch-based microcapsules in various fields are presented. Finally, the future trends of starch-based microcapsules are discussed. Molecular simulation, green chemistry, and solutions to the main problems faced by resistant starch microcapsules may be the future research trends of starch-based microcapsules.

Native Potato Starch and Tara Gum as Polymeric Matrices to Obtain Iron-Loaded Microcapsules from Ovine and Bovine Erythrocytes

Iron deficiency leads to ferropenic anemia in humans. This study aimed to encapsulate iron-rich ovine and bovine erythrocytes using tara gum and native potato starch as matrices. Solutions containing 20% erythrocytes and different proportions of encapsulants (5, 10, and 20%) were used, followed by spray drying at 120 and 140 °C. Iron content in erythrocytes ranged between 2.24 and 2.52 mg of Fe/g; microcapsules ranged from 1.54 to 2.02 mg of Fe/g. Yields varied from 50.55 to 63.40%, and temperature and encapsulant proportion affected moisture and water activity. Various red hues, sizes, and shapes were observed in the microcapsules. SEM-EDS analysis revealed the surface presence of iron in microcapsules with openings on their exterior, along with a negative zeta potential. Thermal and infrared analyses confirmed core encapsulation within the matrices. Iron release varied between 92.30 and 93.13% at 120 min. Finally, the most effective treatments were those with higher encapsulant percentages and dried at elevated temperatures, which could enable their utilization in functional food fortification to combat anemia in developing countries.

Wall Materials for Encapsulating Bioactive Compounds via Spray-Drying: A Review

Spray-drying is a continuous encapsulation method that effectively preserves, stabilizes, and retards the degradation of bioactive compounds by encapsulating them within a wall material. The resulting capsules exhibit diverse characteristics influenced by factors such as operating conditions (e.g., air temperature and feed rate) and the interactions between the bioactive compounds and the wall material. This review aims to compile recent research (within the past 5 years) on spray-drying for bioactive compound encapsulation, emphasizing the significance of wall materials in spray-drying and their impact on encapsulation yield, efficiency, and capsule morphology.

Microencapsulation of Propolis and Honey Using Mixtures of Maltodextrin/Tara Gum and Modified Native Potato Starch/Tara Gum

Ethanolic extracts of propolis and bee honey contain substances beneficial to human health. Mixtures of wall materials were compared in spray-drying microencapsulation of ethanolic extracts of propolis and bee honey rich in bioactive compounds. Maltodextrin and tara gum were used to obtain microencapsulates A, and modified native potato starch and tara gum were used for microencapsulates B. High values of phenolic compounds, flavonoids, and antioxidant capacity were obtained in microcapsules A and B, and the results obtained in terms of encapsulation efficiency, yield, hygroscopicity, solubility, moisture, Aw, bulk density, and color were typical of the spray-drying process. On the other hand, spherical and elliptical microparticles of sizes between 7.83 and 53.7 µm with light and medium stability were observed. Thermogravimetric properties were similar in both microencapsulates; total organic carbon, SEM-EDS, and FTIR analyses corroborated the encapsulation. X-ray diffractogram exhibited amorphous structures, and the release kinetics of phenolic compounds presented high values from 8.13 to 12.58 mg GAE/g between 7 and 13 h. Finally, modified potato starch is a better encapsulant than maltodextrin because it has better core protection and controlled release of the encapsulated bioactive compounds.

Influence of spray drying parameters on the physicochemical characteristics of microencapsulated pomelo (Citrus grandis (L.) Osbeck) essential oil

This study aimed to evaluate the encapsulation of pomelo (Citrus grandis (L.) Osbeck) essential oils using the spray drying technique. The parameters of the process include concentration of maltodextrin (20-35% by wt%/wt%), concentration of essential oil (1-2.5% by wt%/wt%), inlet temperature of spray drying (120-180 °C), and feed flow rates (120-240 mL/h) were soundly examined. The utilization of suitable parameters as the concentration of maltodextrin at 30% (by wt%/wt%), the concentration of essential oil at 1.5% (by wt%/wt%), the inlet temperature of 140 °C, and feed flow rate of 120 mL/h showed the highest drying yields (90.05%), microencapsulation yield (75.59%), and microencapsulation efficiency (89.44%). TGA and DSC results verified higher stability of Citrus grandis essential oil after encapsulation. The encapsulation of pomelo essential oils maintained most of the major components in comparison with the non-encapsulated essential oils without any significant changing in powder-obtained quality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01161-5.

Engineered nasal dry powder for the encapsulation of bioactive compounds

In this review, we present the potential of nasal dry powders to deliver stable bioactive compounds and their manufacture using spray-drying (SD) techniques to achieve encapsulation. We also review currently approved and experimental excipients used for powder manufacturing for specific target drugs. Polymers, sugars, and amino acids are recommended for specific actions, such as mucoadhesive interactions, to increase residence time on the nasal mucosa; for example, high-molecular weight polymers, such as hydroxypropyl methylcellulose, or mannitol, which protect the bioactive compounds, increase their stability, and enhance drug absorption in the nasal mucosa; and leucine, which promotes particle formation and improves aerosol performance. Teaser: XXXX.

Recent development in fabrication and evaluation of phenolic-dietary fiber composites for potential treatment of colonic diseases

Phenolics have been shown by in vitro and animal studies to have multiple pharmacological effects against various colonic diseases. However, their efficacy against colonic diseases, such as inflammatory bowel diseases, Crohn's disease, and colorectal cancer, is significantly compromised due to their chemical instability and susceptibility to modification along the gastrointestinal tract (GIT) before reaching the colonic site. Dietary fibers are promising candidates that can form phenolic-dietary fiber composites (PDC) to carry phenolics to the colon, as they are natural polysaccharides that are non-digestible in the upper intestinal tract but can be partially or fully degradable by gut microbiota in the colon, triggering the release at this targeted site. In addition, soluble and fermentable dietary fibers confer additional health benefits as prebiotics when used in the PDC fabrication, and the possibility of synergistic relationship between phenolics and fibers in alleviating the disease conditions. The functionalities of PDC need to be characterized in terms of their particle characteristics, molecular interactions, release profiles in simulated digestion and colonic fermentation to fully understand the metabolic fate and health benefits. This review examines recent advancements regarding the approaches for fabrication, characterization, and evaluation of PDC in in vitro conditions.

Polysaccharides as wall materials in spray-dried microencapsulation of bioactive compounds: Physicochemical properties and characterization

Natural bioactive compounds (BCs) are types of chemicals found in plants and certain foods that promote good health, however they are sensitive to processing and environmental conditions. Microencapsulation by spray drying is a widely used and cost-effective approach to create a coating layer to surround and protect BCs and control their release, enabling the production of high functional products/ingredients with extended shelf life. In this process, wall materials determine protection efficiency, and physical properties, bioavailability, and storage stability of microencapsulated products. Therefore, an understanding of physicochemical properties of wall materials is essential for the successful and effective spray-dried microencapsulation process. Typically, polysaccharide-based wall materials are generated from more sustainable sources and have a wider range of physicochemical properties and applications compared to their protein-based counterparts. In this review, we highlight the essential physicochemical properties of polysaccharide-based wall materials for spray-dried microencapsulation of BCs including solubility, thermal stability, and emulsifying properties, rheological and film forming properties. We provide further insight into possibilities for the chemical structure modification of native wall materials and their controlled release behaviors. Finally, we summarize the most recent studies involving polysaccharide biopolymers as wall materials and/or emulsifiers in spray-dried microencapsulation of BCs.

Encapsulation of cinnamaldehyde: an insight on delivery systems and food applications

Cinnamaldehyde is an essential oil extracted from the leaves, bark, roots and flowers of cinnamon plants (genus Cinnamomum). Cinnamaldehyde has shown biological functions such as antioxidants, antimicrobials, anti-diabetic, anti-obesity and anti-cancer. However, poor solubility in water as well as molecular sensitivity to oxygen, light, and high temperature limit the direct application of cinnamaldehyde. Researchers are using different encapsulation techniques to maximize the potential biological functions of cinnamaldehyde. Different delivery systems such as liposomes, emulsions, biopolymer nanoparticles, complex coacervation, molecular inclusion, and spray drying have been developed for this purpose. The particle size and morphology, composition and physicochemical properties influence the performance of each delivery system. Consequently, the individual delivery system has its advantages and limitations for specific applications. Given the essential role of cinnamaldehyde in functional food and food preservation, appropriate approaches should be applied in the encapsulation and application of encapsulated cinnamaldehyde. This review systematically analyzes available encapsulation techniques for cinnamaldehyde in terms of their design, properties, advantages and limitations, and food application status. The information provided in this manuscript will assist in the development and widespread use of cinnamaldehyde-loaded particles in the food and beverage industries.

Spray drying encapsulation of bioactive compounds within protein-based carriers; different options and applications

Spray-drying is known as a common and economical technique for the encapsulation of various nutrients and bioactive compounds. However, shear and thermal tensions during atomization and dehydration, as well as physicochemical instability during storage, result in a loss of these compounds. As a solution, bioactives are stabilized into different carriers, among which proteins and peptides are of particular importance due to their functional properties, surface activity, and film/shell formability around particles. Given the importance of stabilization of bioactive compounds during spray drying, this paper focuses on the role of composition and type of carriers, as well as the characteristics and efficiency of various protein-based carriers in the encapsulation and maintaining of physicochemical, structural, and functional properties, along with biological activity of bioactive compounds (e.g., oleoresins, sterols, polyphenols, anthocyanins, carotenoids, probiotics, and peptides), and nutrients (e.g., vitamins, fatty acids and minerals) alone or in combination with other biopolymers.