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This work is aimed to study the effects of component size and solubility on the surface composition of spray dried (SD) uniform two-component particles fabricated by micro-fluidic spray dryer. Various precursor liquid consisting of small molecular of methionine (Met, 33 g/L) or lysine (Lys, 739 g/L) and large-sized silica (12 nm) were prepared by adjusting the mass ratio of components. X-ray energy dispersive results showed that the respective enrichment degree (De) of Met and Lys on the surface of SD-M1S9 and -L1S9 prepared at 150 °C were 182 ± 9% and 125 ± 14%. The De of hydrophobic Met for SD-M1S1 and -M9S1 were 46 ± 9% and 4 ± 2%, respectively, whereas relative hydrophilic Lys mainly distributed internal of the particle meanwhile the De of silica on the surface for SD-L1S1 and -L9S1 were 17 ± 4% and 12 ± 1%, respectively. Drying temperature (120 and 180 °C) showed more apparent effect on the De of amino acid for the particles of less amino acid. The possible formation mechanism of surface composition and the surface composition impact on the wettability of particles were explored. These results provide new guidance for manufacturing functional SD powders with various components.

A spray-drying assisted solid-state method to prepare spherical layer-structured H2TiO3 ion sieve (LSTIS) particles is reported herein. The effects of synthesis parameters (calcination temperature, calcination time, and the lithium-titanium molar ratio) on adsorption–desorption performance (the delithiation ratio, titanium dissolution loss, and the adsorption capacity) were investigated. The as-prepared LSTIS exhibited an equilibrium adsorption capacity of 30.08 mg·g–1 (average of 25.85 mg·g–1 over 5 cycles) and ultra-low titanium dissolution loss of less than 0.12% (average of 0.086% over 5 cycles). The LSTIS showed excellent selectivity toward Li+ in Na+, K+, Mg2+, and Ca2+ coexisting saline solutions where its adsorption capacity reached 27.45 mg·g–1 and the separation factors of Li+ over the coexisting cations exceeded 100. The data suggests that the LSTIS is promising to competitively enrich Li+ from saline solutions.

In this work, a hierarchical reduced graphene oxide (RGO) supportive matrix consisting of both larger two-dimensional RGO sheets and smaller three-dimensional RGO spheres was engineered with ZnO and SnO2 nanoparticles immobilized. The ZnO and SnO2 nanocrystals with controlled size were in sequence engineered on the surface of the RGO sheets during the deoxygenation of graphene oxide sample (GO), where the zinc-containing ZIF-8 sample and metal tin foil were used as precursors for ZnO and SnO2, respectively. After a spray drying treatment and calcination, the final ZnO@SnO2/RGO-H sample was obtained, which delivered an outstanding specific capacity of 982 mAh·g-1 under a high current density of 1000 mA·g-1 after 450 cycles. Benefitting from the unique hierarchical structure, the mechanical strength, ionic and electric conductivities of the ZnO@SnO2/RGO-H sample have been simultaneously promoted. The joint contributions from pseudocapacitive and battery behaviors in lithium-ion storage processes bring in both large specific capacity and good rate capability. The industrially mature spray drying method for synthesizing RGO based hierarchical products can be further developed for wider applications.

Zirconium carbide hollow microspheres (ZrC HMs) were fabricated via spray drying process and polymer-derived ceramics technique. The stable and homogeneous ZrC precursor solution can be prepared by mixing polyzirconoxane (PZO), phenolic resin (PR), curing agent p-toluenesulfonic acid (TsOH) and solvent n-propanol. The precursor solution was spray-dried to form hollow precursor microspheres. During the spray drying process, morphology of the hollow precursor microspheres can be regulated by adjusting temperature of inlet hot N2, concentration of precursor solution and the amount of curing agent TsOH. The prepared hollow precursor microspheres were carbonized at 700 °C and then converted into ZrC HMs by carbothermal reduction reaction above 1500 °C. During the pyrolysis process, nanosized ZrO2 grains produced by PZO decomposition are evenly dispersed, so is the carbon produced by PR pyrolysis, as prevents overgrowth of ZrO2 grains in the following process, even when it is changed to ZrC. ZrC HMs maintained excellent spherical morphology at temperatures of 1500–1900 °C, with particle size Dv(50)=16.4–18.7 μm, which enable their promising applications in ultra-high temperature insulation material. This preparation method is simple and can be prepared on a large scale.

Phenolic compounds constitute important parts of natural bioactive ingredients due to their various biological activities. However, phenolic compounds are to some extent restricted by low solubility, poor stability, unpleasant taste and low bioavailability. Spray-drying microencapsulation is an effective strategy to ameliorate or even tackle such problems and it is crucial to choose optimal wall materials which may affect functional properties of the encapsulated components. In this review, we first described and discussed the physicochemical characteristics of commonly used wall materials for spray drying. Then we summarized the work done in past 16 years about the microencapsulation of phenolic compounds including anthocyanidin, curcumin, catechins, gallic acid, and resveratrol using spray drying is reviewed with a focus on the role of wall materials. Furthermore, we propose some targeted encapsulation strategies for different bioactive ingredients to explore their applications. Finally, we intend to encourage more research in rational selection of the wall materials.

Spray-dried products, such as synthetic peptides and hormones, have already been approved by the U.S. Food and Drug Agency and the European Medicines Agency, while spray-dried antibodies or interleukins, are not yet available on the market. Concerning the latter group, knowledge on whether and how spray-drying (SD) can be performed without adversely affecting their biological activity is lacking. Accordingly, this study aimed at establishing a SD process (Buchi B-90 spray dryer) using three Interleukin-8 based proteins (7–74 kDa) that were dispersed in phosphate buffered saline to maintain their stability. A Box-Behnken Design of Experiments was conducted to identify the appropriate process parameters taking into account the thermal stability of interleukin-8. In parallel, a FD process was developed. Both powders were stored for up to 12 weeks. Powder characterization included residual moisture evaluation and the mean particle size of the SD powder was investigated with Laser Diffraction Analysis. The hydrodynamic volume was measured via size exclusion chromatography and sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The secondary structure of the model proteins in the solid state was assessed with Fourier-transformation infrared spectroscopy for detecting the protein folding patterns and reconstituted with Circular Dichroism Spectroscopy. Finally, the binding affinity was studied with Surface Plasmon Resonance and Isothermal Fluorescence Titration, the protein stability with Chaotropic Unfolding, and the activity studies were carried out with the chemotaxis assay. The results showed that SD and FD powders with a residual moisture of less than 5 wt% were obtained. The interleukins showed no unfolding upon processing, neither in solid state nor reconstituted. Oligomerization was observed for FD, but not for SD interleukins. However, the unfolding, binding affinity and activity of all interleukins examined did not decrease in neither SD nor FD powders, even after 12 weeks of storage. Thus, it can be concluded that SD of interleukin formulations at outlet temperatures close to ambient temperature is a promising process for transferring them into a stable powder.

Spray and freeze drying practices for production of the probiotic Bacillus amyloliquefaciens H57 as a power for feed applications were investigated. The importance of inlet temperature, feed rate, solid content, and limestone, a heating protectant, concentration was demonstrated. Spray drying outlet temperature appeared to be crucial for survivability of B. amyloliquefaciens H57. Studying inactivation kinetics at 80, 90, and 100 °C revealed the highest D-value at 260.7 ± 47.3 min at 80 °C before gradually declining with increasing temperature. By considering the D-value, a high survival rate of 100%, which was far superior to freeze drying at 60 ± 4%, was obtained when the spray drying outlet temperature was maintained at 80 °C with 175 ± 2 °C inlet temperature, 20.9 ± 0.4 mL min−1 feed rate, 20% solid content, and 1:0.3 ratio of dry mass of the probiotic material to limestone. After 50-days of storage, significant differences in the viability of B. amyloliquefaciens H57 were observed between the powders obtained by the two drying methods. Storage temperature had a substantial impact on the probiotic stability. Best viability retention was spray dried powder stored at 4 °C. This work demonstrates that spray drying can be an effective method for producing a functional probiotic and highlights its potential for applications in feed supplement manufacturing.

Crystalline lactose microparticles with uniform size and spherical shape are greatly desirable for various applications, but still challenging. Herein, uniform lactose microspheres with high crystallinity were fabricated via spray drying lactose/polyethylene glycol (200 Da) (PEG 200) combined with ethanol/water post-treatment process. The effects of feed solution composition and ethanol/water volume ratio on particle size, morphology, density, crystal property and hygroscopicity were investigated. The obtained spherical lactose/PEG 200 microparticles were partially crystallized (30-50%), exhibiting dominant crystal forms of anhydrous Lα and Lβ. After removing PEG 200 by ethanol/water, the resulting microparticles remained uniform and spherical with enhanced crystallinity (92.90 ± 1.40%), high Lα·H2O content (68.57%) and ultra-low hygroscopicity (0.29%). Possible mechanism of “micro-zone competitive dissolution-reprecipitation” was proposed to reveal the influence of PEG 200 and ethanol/water volume ratio on promoting crystallinity and maintaining spherical morphology of lactose microparticles. This work provides a promising and up-scalable way to manufacture spherical crystalline microparticles.

In this study metronidazole drug was encapsulated by hydroxypropyl methylcellulose and polyvinylpyrrolidone polymers from solutions using nano spray drying technology. The influence of the process parameters and formulation variables were investigated on product morhology and structure, production yield and entrapment efficiency. The use of surface active admixtures (polyvinyl alcohol, Tween-80 and Pluronic F68) increased the product yield substantially. The entrapped metronidazole was partially in crystalline and amorphous state in both amorphous polymers as confirmed by DSC and powder X-ray diffraction measurements. In the composites with hydroxypropyl methylcellulose the degree of crystallinity was between 50.2 and 81.0%, and with polyvinylpyrrolidone between 35.0 and 50.0% (with respect to the drug content). Melting point decrease phenomena was observed by differential scanning calorimetry between bulk metronidazole and spray dried products. Peak broadening was indicated by powder X-ray diffraction measurements, which could be the result of formation of small drug crystallites. The TEM images showed beside the larger crystals (200–400 nm) a fraction of smaller crystals (20–50 nm in diameter), which are in good correlation with the calculated coherent scattering domain sizes of 19–87 nm based on X-ray data. The drug-polymer composites produced by nano spray drying process were identified as crystalline-amorphous nanostructured micronized solid dispersions.

Face centered central composite design was used to investigate the effect of spray drying process parameters (inlet temperature, atomization pressure and feed flow rate) on selected quality parameters of whole camel milk. During storage by freezing, the integrity of camel milk fat globules is maintained with observed aggregation. Whole camel milk contains 12.18% total solids, 3.5% protein and 3.99% [w/w] lactose whereas for the powders, the total solids content was in the range of 94–97%, protein 22–29% and lactose 27–31% [w/w]. By combining response surface methodology with desirability function, the spray drying process of whole camel milk was optimized with objectives of maximizing the yield and minimizing undesired quality degradation parameters. Consequently, it was possible to recover 62% of total solids without affecting the desired aspects of the final physico-chemical properties of powders (minimum insolubility index of 0.1 mL and surface fat content of 4.2% [w/w]) with targeted final moisture content of 4.5% [w/w]. These properties would make the powders safe during extended period of storage.

Despite the advantages of targeting the pulmonary route through Dry Powder Inhalers (DPIs), the efficient delivery of biologics to the lungs still presents a considerable challenge: the generation of a powder with adequate aerodynamic properties while preserving the integrity of the biologic. Hence, the particle engineering technology employed to meet this balance plays a pivotal role. The present work describes a proof-of-concept study to investigate the effect of spray drying (SD) outlet temperature (Tout), atomization flow rate (Rotatom) and feed flow rate (Ffeed) on powder properties such as particle morphology and aerodynamic performance but also on the enzyme activity and protein conformational stability of a trehalose:leucine spray-dried powder featuring Cu,Zn-superoxide dismutase (Cu,Zn-SOD). This enzyme, often implicated in a broad spectrum of oxidative stress related diseases, from cystic fibrosis to rheumatoid arthritis, was used as a model Active Pharmaceutical Ingredient (API). Morphology and aerodynamic performance of the SD powders were determined by scanning electron microscopy (SEM), focused ion beam – SEM, laser diffraction and Andersen Cascade Impaction. For each SD run, enzyme activity retention (EAR) was measured by spectrophotometry and the protein melting temperature by differential scanning fluorimetry. To further understand the interaction between input and output variables, a statistical analysis was performed using SIMCA v13.0.3.0 software. Cu,Zn-SOD:trehalose:leucine spray dried powders were successfully generated upon different processing conditions, displaying fine particle fractions of ≈60% and EAR ranging from 50–80% with no loss of protein conformational stability. This technology thus proved to be suitable to prepare Cu,Zn-SOD based DPI powders within the considered working ranges.

Objective Fluoride (F)-releasing restoratives typically are either weak mechanically or release only low levels of F ions. The objectives of this study were to: (1) develop a novel photo-cured nanocomposite with strong mechanical properties and high levels of sustained F ion release via a two-step “co-precipitation + spray-drying” technique to synthesize CaF2 nanoparticles (nCaF2); and (2) investigate the effect of spray-drying treatment after co-precipitation of nCaF2 on mechanical properties and F ion release of composite. Methods Two types of CaF2 particles were synthesized: A co-precipitation method yielded CaF2cp; “co-precipitation + spray-drying” yielded nCaF2cpsd. Composites were fabricated with fillers of: (1) 0% CaF2 + 70% glass; (2) 10% CaF2cp + 60% glass; (3) 15% CaF2cp + 55% glass; (4) 20% CaF2cp + 50% glass; (5) 10% nCaF2cpsd + 60% glass; (6) 15% nCaF2cpsd + 55% glass; and (7) 20% nCaF2cpsd + 50% glass. A commercial F-releasing nanocomposite served as control. Results The nCaF2cpsd had much smaller particle size (median = 32 nm) and narrower distribution (22–57 nm) than CaF2cp (median = 5.25 μm, 162 nm–67 μm). The composite containing nCaF2cpsd had greater flowability, flexural strength, elastic modulus and hardness than CaF2cp composite and commercial control composite. At 84-day immersion in water, the nanocomposites containing 20% nCaF2cpsd had 65 times higher cumulative F release, and 77 times greater long-term F-release rate, than commercial control. Conclusions A novel two-step “co-precipitation + spray-drying” technique of synthesizing nCaF2 was developed. The photo-cured nanocomposite containing 20% nCaF2cpsd possessed strong mechanical properties and excellent long-term F-release ability, and hence is promising for dental restoration applications to inhibit secondary caries.

The aim of this work was to encapsulate of citrulline extract from watermelon rind (by-product) by spray drying. Two different pectins were probed as wall materials in addition to maltodextrin. A Box-Behnken design was applied and three different parameters were evaluated as factors: commercial pectin (CP) concentration, orange produced pectin (OPP) concentration, and inlet air temperature. Different powder properties were evaluated as response variables including drying yield and encapsulation efficiency. The spray drying process was optimized by the desirability function. Higher drying yields, moisture contents and encapsulation efficiencies were reached at higher commercial pectin concentration. The optimal spray drying conditions were also determined. The obtained powder at the optimal conditions was characterized using Modulated differential scanning calorimetry and thermogravimetric analysis. In conclusion, citrulline extract spray-dried powders showed that could be stable during storage, so it might be used as an additive in foods to obtain functional products for human consumption.

Mesoporous graphene and other carbon derivative nanospheres have attracted intensive research attention owing to their many unique characteristics and fascinating properties. However, facile synthesis of these mesoporous nanospheres with a small particle size and controllable morphology is still a grand challenge. Herein, we report a Kirigami-inspired approach to prepare mesoporous spherical graphene oxide (MSGO) particles through spray drying of holey GO sheets. By increasing pore size and porosity of the holey GO sheets, the spray-dried particles underwent the transition from rough crumpled structure to smooth spherical shape. The prepared MSGO particles have tunable diameters smaller than 200 nm and a high specific surface area of 503 m2/g, which enable consistent high-efficiency physical adsorption removal of organic dyes such as Rhodamine B from polluted water with a high adsorption rate of 335.6 mg/(g min). Moreover, the reported synthetic route provides the freedom to easily incorporate other functional nanoparticles such as TiO2, CuO or post-dope MSGO with nitrogen elements for construction of multifunctional composite particles with tailorable structures, which may enable a broad range of promising applications.

The graphene oxide powder (GOP) obtained from the spray drying process often exhibits poor re-dispersibility which is considered due to the partial reduction of GO sheets. The reduction of drying temperature can effectively increase the re-dispersibility of GOP, but result in a decreased drying efficiency. Herein, we found that the re-dispersibility of GOP is strongly affected by its microstructure, which is determined by the feed concentration. With the increase of feed concentration, the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly, making the morphology of the GOP transform from ball-like (the most crumpled one) to flake-like (the least crumpled one), and the 0.8 mg·ml−1 is the threshold concentration for the morphology, structure, and re-dispersibility change. Once the feed concentration reaches 0.8 mg·ml−1, the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree, which greatly improves the polar parts surface tension of the solid GOP, making the GOP easier to form hydrogen bonding with water during the redispersion process, thus stabilizing dispersion. This work provides useful information for understanding the relationships between the morphology, microstructure, and final re-dispersibility of GOPs.

Insecticides based on Azadirachta indica have been demonstrated as useful in pest control and bioinsecticides that are microencapsulated can reduce the amount of product utilized, and minimize impacts on the environment and human health. The objective of this study was to optimize drying, and evaluate the release and degradation kinetics of microencapsulated extracts from A. indica seeds. The Box-Behnken model (33) and surface response methodologies were used to find the best spray drying conditions for the chosen variables. They were: in-let temperature of 160 °C, feed flow of 3.3 mL/min, and nozzle diameter of 0.7 mm. The drying efficiency and EE under these conditions were respectively 71.15% ± 2.18 and 56.88% ± 0.28. In the release kinetics study, the release time for Azadirachtin (100%) was 20h. The 50% photo-degradation time for Azadirachtin was 21.07 days. Our results support industrial scale-up studies, and can help application measures in the field.

Zinc sulphate heptahydrate was microencapsulated by spray-drying using maltodextrin, HI-CAP® 100 and whey protein isolate as wall materials. Spray-drying conditions were optimised using Taguchi orthogonal array design with encapsulation efficiency and bulk density as responses. The influences of wall material, wall material to zinc ratio and inlet air temperature were evaluated. Microcapsules prepared with HI-CAP® 100 in 20:1 loading ratio at 185 °C had maximum encapsulation efficiency (92.65%), whereas 10:1 ratio yielded maximum bulk density (541.2 kg/m3). SEM micrographs revealed the spherical structure of microcapsules, while EDX confirmed the presence of zinc in the microcapsules. SEM micrographs, FTIR and XRD analyses showed that zinc was successfully encapsulated as microcapsules. The tapped, bulk and particle densities of zinc microcapsules were in the range of 586.15–698.15, 437.40–541.20 and 1263.25–1436.50 kg/m3, respectively, while flowability was ‘fair' to ‘passable’. The adsorption isotherm of microcapsules was sigmoidal, and was described by GAB model. Fortification of milk with zinc microcapsules did not affect its inherent organoleptic qualities.

This study aimed to evaluate the potential of maltodextrin (MD) combination with gum arabic (GA), and whey protein isolate (WPI) on the microencapsulation of gurum seeds oil by a spray-drying method. Three formulations of protein-based (PB) (WPI: MD, 2:1), carbohydrate-based (CHOB) (GA: MD, 2:1), and mixed (MIX) (WPI: GA: MD, 1:1:1) wall materials were designed. The moisture content and water activity were in the range of 1.65–3.67% and 0.17–0.31, respectively, which is suitable for long-term storage. The best results were achieved when gurum seed oil was microencapsulated with carbohydrate-based, where it had the highest microencapsulation yield (92.80%) and microencapsulation efficiency (97.38%). Carbohydrate-based showed the highest relative crystallinity (32.25%) and the temperature of the glass transition (58.20 °C). FT-IR revealed that the oil was well encapsulated in the microcapsules. SEM of microcapsules showed spherical shapes without any apparent cracking on the surfaces. During the oxidative stability study, carbohydrate-based microencapsulation was the wall material that best protected the active materials against lipid oxidation.

To increase their stability, therapeutic (or monoclonal) antibodies (mAbs) are often formulated as solids by using a variety of drying techniques, e.g. freeze-drying, spray-drying, or spray freeze-drying. The addition of excipients is required to preserve stability of the protein during the drying process and subsequent storage of the resulting solid form. The addition of low molecular weight excipients, such as amino acids, to sugar based spray- and freeze-dried formulations has been suggested to improve the storage stability of proteins in the dried state. In this study sugars (sucrose, trehalose), amino acids (Gly, Ala, Pro, Ser, Val, Leu, Ile, Gln, His, Lys, Arg, Phe, Trp) and combinations thereof were investigated for their stabilizing effect during spray-drying and subsequent storage and for their reconstitution time reducing effect. Two IgG4 mAbs were used as model antibodies. From an initial screening study, basic and small neutral amino acids, in combination with a sugar, such as sucrose or trehalose, showed reconstitution time reducing and stabilizing properties. Arg in particular displayed excellent reconstitution and stability enhancing properties. Moreover, Arg was the only amino acid providing stabilizing properties comparable to sucrose or trehalose. Previous work by the authors described a statistically substantiated comparison between the three basic amino acids in a sugar containing formulation, albeit limited to a single concentration level [5]. Therefore, a follow-up design of experiments (DoE) study was performed to determine the optimum trehalose/amino acid content required for an optimal protein stability and reconstitution time and to compare the effects of two basic amino acids, Lys and Arg, to those of two neutral amino acids, Gly and Pro. The conducted DoE covered a wide range of trehalose (30-120 mM) and amino acid (50-150 mM) concentrations. The concentration of trehalose was found to be the main contributor to a reduction in reconstitution time and an increase in stability. Here we show that the addition of amino acids such as Gly, Pro, and Lys does not improve stability nor does it reduce the reconstitution time. Of the tested amino acids, only Arg showed a marked reduction in reconstitution time and improvement in stability compared to a trehalose. Moreover, the properties displayed by Arg could justify its application as the main stabilizer in spray-dried mAb formulations, eliminating the need for a sugar matrix altogether. But the weight ratio of stabilizer to protein was found the factor exerting the strongest overall influence on the formulation's reconstitution time and stability. More specifically, sufficient physical stability and an acceptable reconstitution time could be obtained with a protein to stabilizer weight ratio of at least 1:1. ispartof: EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS vol:156 pages:131-142 ispartof: location:Netherlands status: published

Phospholipids constitute biocompatible and safe excipients for pulmonary drug delivery. They can retard the drug release and, when PEGylated, also prolong the residence time in the lung. The aim of this work was to assess the structure and coherence of phospholipid coatings formed by spray drying on hydrophilic surfaces (silica microparticles) on the nanoscale and, in particular, the effect of addition of PEGylated lipids thereon. Scanning electron microscopy showed the presence of nanoparticles of varying sizes on the microparticles with different PEGylated lipid concentrations. Atomic force microscopy confirmed the presence of a lipid coating on the spray-dried microparticles. It also revealed that the lipid-coated microparticles without PEGylated lipids had a rather homogenous coating whereas those with PEGylated lipids had a very heterogeneous coating with defects, which was corroborated by confocal laser scanning microscopy. All coated microparticles had good dispersibility without agglomerate formation, as indicated by particle size measurements. This study has demonstrated that coherent coatings of phospholipids on hydrophilic surfaces can be obtained by spray drying. However, the incorporation of PEGylated lipids in a one-step spray-drying process to prepare lipid coated microparticles with both controlled-release and stealth properties is very challenging. (C) 2020 The Authors. Published by Elsevier Inc.

Microparticles containing the photosensitive spinosad (SP) were obtained using a combination of chitosan (CH) and sodium lignosulfonate (SL) as encapsulating materials to develop a photoprotective system for intake administration. The microparticles were obtained by a spray drying technique and were characterized in terms of morphology (scanning electron microscopy - SEM) and particle size. In vitro release studies showed an initial burst effect that fits very well with the zero order kinetic model and then a slow release of the bioinsecticide, which fits best with the first order model. The results of this work demonstrate that the bioinsecticide carrier system developed with natural polymeric materials presents high stability to photodegradation and adequate insecticide release for use as a strategy to reduce negative impacts on the environment in agronomic practices.

The gelation properties of soy protein isolate (SPI) were influenced by the addition of salt ions (SI) before spray drying combined with dynamic high-pressure microfluidization (DHPM). Compared with SPI, SPI treated using SIDHPM (SIDHPM-SPI) markedly increased in gel hardness, springiness, cohesivenessand chewiness upon heating (p

Maltodextrin, modified starch, inulin, alginate, gum arabic, and combinations thereof were used as carrier agents for spray drying of carotenoid-rich goldenberry (Physalis peruviana L.) juice and compared to cellobiose as an alternative carrier. Powders were analyzed with respect to particle size and morphology, yield, moisture content, cold water solubility, suspension stability, hygroscopicity, carotenoid encapsulation efficiency, and carotenoid retention during storage. A high initial carotenoid concentration after spray drying, a high encapsulation efficiency of 77.2%, and a slow carotenoid degradation kinetics favored the high carotenoid content of the cellobiose powder at the end of the storage. Cellobiose might protect the carotenoids from degradation processes by light exposure, high temperature, and oxygen due to a tighter particle crust and larger particle sizes. Therefore, cellobiose may be considered a potential carrier agent for the encapsulation of carotenoid-rich fruit juices., Graphical abstract Image 1, Highlights • Goldenberry juice was spray dried with different carrier agents. • Cellobiose was used as carrier agent in the present study for the first time. • The cellobiose powder provided the best retention of carotenoids. • Spray drying promoted isomerization reactions of all-trans-β-carotene. • Cellobiose proved to be effective for spray drying of carotenoid-rich juices.

In this study, spinel lithium titanate (Li4Ti5O12, LTO) anode materials were synthesized from two titanium sources (P25 TiO2, 100% anatase TiO2) using a spray-drying method and subsequent calcination at various temperatures. The electrochemical performance of both a Li/LTO half cell and a LiNi0.5Mn1.5O4/LTO (LNMO/LTO) full cell were investigated. The electrochemical performance of the LTO material prepared from P25 TiO2 was superior to that of the LTO prepared from 100% anatase TiO2. After modification of LTO material with AlPO4, the LTO coated with 2 wt% of AlPO4 (denoted “2%AlPO4-LTO”) provided the best performances. The specific (delithiation) capacities of the 2%AlPO4-LTO anode material was 189.7 mA h g−1 at 0.1C/0.1C, 184.5 mA h g−1 at 1C/1C, 178.8 mA h g−1 at 5C/5C, and 173.1 mA h g−1 at 10C/10C. From long-term cycling stability tests, the specific capacity at the first cycle and the capacity retention after cycling were 185.5 mA h g−1 and 98.06%, respectively, after 200 cycles at 1C/1C and 182.1 mA h g−1 and 99.18%, respectively, after 100 cycles at 1C/10C. For the LNMO/2%AlPO4-LTO full cell, the average specific capacity (delithiation) and coulombic efficiency after the first five cycles were 164.8 mA h g−1 and 93.30%, respectively, at 0.1C/0.1C. The specific capacities at higher C-rates were 156.1 mA h g−1 at 0.2C/0.2C, 135.7 mA h g−1 at 1C/1C, 97.5 mA h g−1 at 3C/3C, and 46.5 mA h g−1 at 5C/5C. After twenty-five cycles, the C-rate returned to 1C/1C and the specific capacity, coulombic efficiency, and capacity retention were maintained at 134.1 mA h g−1, 99.17%, and 98.82%, respectively.

International audience; The effects of two pretreatments (microwaves or oven-drying) on the dogfish (Squalus acanthias) skin as well as two drying processes (freeze-drying or spray-drying) on the extracted gelatins were studied. Thus six types of gelatins were obtained, three of which were freeze-dried (FG) and the others were spray-dried (SG), from the untreated skin (US), microwaves-pretreated skin (MS) and oven-pretreated skin (OS). The highest yield (8.67%) was obtained for the OSFG, while the lowest one (3.06%) was measured for the OSSG. Interestingly, all gelatins exhibited relatively high protein (84.02-89.53%), and low lipid (0.50-1.71%) and ash (3.05-7.17%) contents. In addition, gelatins were analyzed by the Fourier transform infrared and the spectra displayed important differences in some specific peaks, particularly in the amide I, amide II and amide III. The gelatins extracted from the untreated skin, regardless the drying method, presented the highest foaming capacity. The textural profile analysis showed that USSG was the hardest (213.6 g) and the chewier (23.8 N × mm) gelatin. Moreover, analysis of thermal properties showed that USSG also has the highest glass-transition temperature. The interesting properties of gelatin extracted from dogfish skin encourage their future use as a functional ingredient in industrial food formulations.

This work studied pineapple-mint juice drying by spray drying. The effect of 0, 3, and 15% of maltodextrin addition in the solution fed in the spray dryer was evaluated. The results showed that it is possible to dry pineapple-mint juice without a carrier agent. A two-level full factorial design of experiments was applied to quantify the effect of spray drying conditions (including the addition of 3% maltodextrin on pineapple-mint juice) on powder physicochemical properties. The estimated effects demonstrated that all variables have affected responses (except powder solubility). Interested in investigating pineapple-mint drying without maltodextrin, the two-level factorial design was further expanded to a central composite design, and additional experiments were realized, resulting in preservation of the natural green color of pineapple-mint juice, and a yield of 35%. The results suggest that mint may help in pineapple-mint juice drying.

Spray-drying is an encapsulation method that can be used to protect iron from oxidation. Hydrolysed glucomannan has shown potential as an encapsulant due to its ability to form a fine, dense network upon drying. The aim of this study was to evaluate the potential of hydrolysed glucomannan as a matrix for iron at inlet air temperatures of spray-drying of 110 °C, 120 °C, 130 °C and 140 °C. The physicochemical properties and performance of the iron encapsulation powder were determined. The results indicated that the inlet air temperature influences the properties and performance of the powder. An increase in the inlet air temperature from 110 °C to 140 °C led to a greater loading capacity and particle size distribution but had an insignificant impact on the moisture content, solubility and swelling. Higher drying air temperatures tended to produce a darker powder. The morphological analysis revealed that higher inlet drying air temperatures produced powders with rounder shapes, whereas lower temperatures produced irregular shapes that tended to form deep concavities on the powder surface. The samples from all inlet temperatures showed similar functional groups but in different intensities. The release of iron at pH 6.8 was higher for the lower inlet temperatures. Samples with the highest inlet temperature showed the highest performance in protecting iron from oxidation. Considering the performance, 130 °C is recommended as the inlet air temperature for iron spray-drying encapsulation using hydrolysed glucomannan.

Background The essential fatty acids (EFAs) are recognized as functional oils for humans as they possess nutritional and pharmaceutical benefits and can promote whole-body health in different ways. Scope and approach This review describes and classifies different types of EFAs, gives an overview of the spray drying process alongside its probable challenges for encapsulation of functional oils. Also, various used wall materials, and the effects of the process conditions on the encapsulation efficiency of functional oils have been discussed. Moreover, it focuses on the spray drying encapsulation of functional oils derived from marine and plant-based sources in recent years (2016-2019), and the fortification of different foods with encapsulated functional oils. Key findings and conclusions Protecting EFAs through efficient methods such as spray drying encapsulation and enriching the various foods with encapsulated functional oils is an emerging field, which has drawn lots of attention these days. The wall materials (carriers) and spray drying conditions are two major influential factors that can easily affect the properties of final produced powders.

Active pharmaceutical ingredient (API) nanosuspensions from naproxen (Nap) and itraconazole (Itra) stabilized with Kollidon®VA64 (KVA) and sodium dodecyl sulfate (SDS) were produced in two different size classes each by wet media milling. These API nanosuspensions were spray dried with lactose, trehalose and sucrose as matrix formers in different proportions and at different drying temperatures (Toutlet). Toutlet as well as the API content significantly influenced the redispersibility of the API nanoparticles. It could be shown that these two parameters are related to each other, with an increasing API content leading to a decreasing maximum applicable Toutlet (Tcritical). Drying above Tcritical always led to an alteration of the size characteristics of the API nanoparticles and thus to a non-redispersible product with respect to the defined quality criteria. For each proportion of API to matrix former, a Tcritical could be found. Tcritical showed a linear relation to the API content. The linear regression of this relation was defined as process boundary. The y-intercept of the process boundary correlated well with the glass transition temperature (Tg) of the pure matrix former used for spray drying. The two APIs under investigation led to virtually identical behaviour if other parameters were kept constant. The particle size of the initial nanosuspension had an important influence. Nanosuspensions with comparatively small particle sizes led to a significantly stronger decrease of the process boundaries compared to the use of larger particle sizes. The maximum API content that leads to a redispersible product is thus decisively determined by Toulet of the spray dryer, Tg as well as the proportion of the matrix former and by the particle size of the API nanoparticles used.

Particle size and morphology are of high industrial importance due to the fact that product properties and performance can be affected by this factors. For instance, bulk properties, processability and appearance of the final product are given by particle size and shape. In this regard, the optimization of process parameters for particle development is required when targeting formulation of specific product and/or particular properties. Response surface methodology (RSM) was used to optimize the spray drying process for the development of aquasolv lignin particles with desired particle size and morphology. The inlet drying temperature X1: 180–200 °C, atomization pressure X2: 1.3–1.7 bar and feeding rate X3: 65–75 mL min−1 were kept as independent variables while the optimizing responses were: Yield fine of particles with desired particle size and particle size (D50). The quadratic part of the equation and statistical analysis showed substantial effect of the atomizing pressure and feeding rate on the responses and the optimized conditions validated the model. Optimum processing conditions for spray drying of aquasolv lignin were inlet temperature of 173 °C, 1.8 bar atomization pressure and 62 mL/min feeding rate. With this, desired responses of powder were 66% of yield and particle size of D50

The aim of this study was to investigate the characteristics of the Fingered citron extract (FCE) microcapsules powders with different formulations of the encapsulation carrier agents [gum arabic (GA), maltodextrin (MD), modified starch (MS), and whey protein (WP)], which are obtained through spray drying. Encapsulation yield, encapsulation efficiency, moisture content, hygroscopicity, water activity, density properties, Carr's index, cohesiveness, flowability, porosity, wettability, solubility, color, particle size, thermal behavior, relative crystallinity, and micrographs were analyzed. Moreover, chemical structure of the microcapsule powder was identified using Fourier transform infrared spectroscopy (FT-IR). Best results were achieved when Fingered citron extract was encapsulated using gum arabic/maltodextrin/modified starch (GMS) formulation as carrier agents, where it had the highest encapsulation yield (89.39%) and encapsulation efficiency (87.20%). Furthermore, it achieved the best result in density properties, flowability, porosity, wettability, and relative crystallinity. These results have shown that using gum arabic/maltodextrin/modified starch formulation was superior for production of the Fingered citron extract microcapsules powders.

A spray drying technique was developed to prepare injectable and biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres encapsulating a model luteinizing hormone-releasing hormone agonist (LHRHa)-based peptide, leuprolide. Various spray drying parameters were evaluated to prepare 1-month controlled release formulations with a similar composition to the commercial Lupron Depot® (LD). A single water-in-oil emulsion of aqueous leuprolide/gelatin solution in PLGA 75/25 acid capped (13 kDa Mw) dissolved in methylene chloride (DCM) was spray-dried before washing the microspheres in cold ddH2O and freeze-drying. The spray-drying microencapsulation was characterized by: particle size/distribution (span), morphology, drug/gelatin loading, encapsulation efficiency, and residual DCM and water content. Long-term release was tested over 9 weeks in PBS + 0.02% Tween 80 + 0.02% sodium azide pH 7.4 (PBST) at 37 °C. Several physical-chemical parameters were monitored simultaneously for selected formulations, including: water uptake, mass loss, dry and hydrated glass transition temperature, to help understand the related long-term release profiles and explore the underlying controlled-release mechanisms. Compared with the commercial LD microspheres, some of the in-house spray-dried microspheres presented highly similar or even improved long-term release profiles, providing viable long-acting release (LAR) alternatives to the LD. The in vitro release mechanism of the peptide was shown to be controlled either by kinetics of polymer mass loss or by a second process, hypothesized to involve peptide desorption from the polymer. These data indicate spray drying can be optimized to prepare commercially relevant PLGA microsphere formulations for delivery of peptides, including the LHRHa, leuprolide.

While nanoparticulate drugs for deep lung delivery hold promise for particular disease treatments, their size-related physical instability and tendency of being exhaled during breathing remain major challenges to their inhaled formulation development. Here we report a viable method for converting drug nanosuspensions into inhalable, stable and redispersible nano-agglomerates through combined in-situ thermal gelation and spray drying. Itraconazole (ITZ) nanosuspensions were prepared by flash nanoprecipitation, and co-spray dried with two different grades of the gel-forming polymer, methylcellulose (MC M20 and MC M450) as protectants. MC M20 was found superior in protecting ITZ nanoparticles against thermal stress (through nanoparticle entrapment within its gel network structure) during spray drying. In terms of redispersibility, an Sf/Si ratio (i.e., ratio of nanoparticle sizes after and before spray drying) of unity (1.02 ± 0.03), reflecting full particle size preservation, was achieved by optimizing the suspending medium content and spray drying parameters. Formulation components, nanosuspension concentration and spray drying parameters all showed a significant impact on the aerosol performance of the resulting agglomerates, but an absence of defined trends or correlations. Overall, the MC-protected nano-agglomerates displayed excellent in-vitro aerosol performance with fine particle fractions higher than 50% and mass median aerodynamic diameters within the 2-3 µm range, which are ideal for deep lung delivery.

Development of spray drying of biomolecules has proved challenging primarily due to protein instability caused by high drying temperatures and atomization process. This study suggests a two-step approach towards a better understanding of spray drying process of large biomolecules. Using lysozyme as a model biomolecule a full factorial Design of Experiments (DoE) was employed to define the most critical process and formulation parameters. With respect to parameters such as feed rate, outlet temperature (Tout) and feed solid concentration, Tout was determined to be the most significant factor affecting the enzymatic activity. Forced deactivation studies were performed to identify critical points of potential enzymatic degradation during the drying process. Results show that lysozyme in solid form significantly inactivated when heated up to temperatures similar to Tout (70–90 °C). The approaches presented herein provide an improved understanding of the critical process and formulation parameters required for the successful spray drying of biomolecules.

Curcumin has been incorporated for the development of new products with applicability in food, pharmaceutical and cosmetic fields. However, the poor solubility in aqueous systems and very high sensitivity are the main concerns that need to be overcome during storage and processing. Microencapsulation technology may provide the required protection and stabilization of curcumin, preventing or reducing its degradation. The present work focuses on a new approach for the microencapsulation of curcumin from turmeric oleoresin (in alcoholic solutions) by a spray drying process using different biopolymers such as gum arabic, sodium alginate and a water-soluble modified chitosan as wall materials. Thus, a series of curcumin microcapsules were prepared and their physicochemical properties were analysed by laser granulometry and by scanning electron microscopy (SEM). Spherical microparticles with a mean diameter between 9 and 30 μm, considering a volume distribution, have been observed for all the biopolymers tested. The microparticles formed with gum arabic and alginate presented a very rough surface; on the other hand, the particles formed with the modified chitosan presented a smooth surface. The product yield obtained for the microparticles ranged from 46.1% to 57.3%. Curcumin release studies were performed and validated by a UV/VIS spectrophotometer using absorbance analysis. The results showed that all release profiles were similar, however with different total release times: 35 min, 2 h and 4 h for modified chitosan, alginate and gum arabic respectively, and the encapsulation efficiencies (EE) are between 93.8% and 97.6%. Moreover, all curves fit well to the Weibull model and to the Korsmeyer-Peppas model. This work shows that it is possible to encapsulate curcumin (in alcoholic solutions) using different biopolymers, through a spray-drying process.

In this study, oil palm milk was spray dried to produce palm milk powder in order to prolong the shelf life and easy storage. The objective of this research was to determine the effect of spray drying parameters on palm milk powder properties, which were inlet temperatures (120 °C, 140 °C, and 160 °C), feed flow rates (5 mL/min, 7 mL/min, and 14 mL/min), and ratio of additive (maltodextrin) to oil palm milk. Based on the powder yield, the optimum conditions for oil palm milk powder production was determined. Moisture content, fat content, solubility in water, flowability of powder, and hygroscopicity were analysed for the powder samples. Powders produced at the highest inlet temperature show the lowest moisture and fat contents. Inversely, the moisture and fat contents were the highest at the highest feed flow rate. However, the moisture content was the lowest and fat content was the highest at the highest ratio of maltodextrin to oil palm milk. The powder were easily soluble in water as shown by the time taken to dissolve varies between 8 and 24 s. Based on Hausner ratio, the palm milk powder was categorised as low cohesiveness which match to good flowability as indicated by Carr’s Index. The powder achieved non-hygroscopic state when it was produced with the highest ratio of maltodextrin to oil palm milk. The optimum spray drying conditions was at 160 °C for inlet temperature and 7 mL/min for flow rate and 9% (w/v) of maltodextrin for percentage ratio of maltodextrin with the highest powder yield obtained was 45%.

Owing to its high theoretical capacity, P2-type Na2/3Fe1/2Mn1/2O2 has been considered as a kind of promising cathode material. However, the practical application is limited due to excessively high calcining temperature during traditional preparation processes. Here, we report the synthesis of P2-Na2/3Fe1/2Mn1/2O2 by using a facile spray-drying method followed by calcining at low temperature. Under the optimal conditions, the well-crystallized P2-Na2/3Fe1/2Mn1/2O2 material with excellent rate capability and cycle ability is obtained. And the sample exhibits the initial discharge capacities of 217.9, 171.3 and 117.4 mAh g−1 at 0.1 C, 0.5 C and 2 C rate, respectively. The developed Na2/3Fe1/2Mn1/2O2 material, synthesized by a new spray drying-calcining procedure, may potentially be used as a suitable cathode in sodium ion batteries.

Spray drying is commonly used to manufacture food and dairy powders at industrial scale. Bioactive peptides, as hydrolysis products from various food proteins, are gaining interest due to their biological functionality including immunomodulation, antimicrobial, and antioxidant properties. This article reviews several bioactive peptides/hydrolysates from different food sources, focusing on their processing and final powder characteristics. Additionally, we propose a strategy for encapsulation of food peptide/hydrolysate via spray drying. The identification of suitable drying parameters and/or formulation could help overcome the limitations associated with the current processing of food peptides.

Current production of probiotic preparations must meet several criteria to be competitive on the market, like inexpensive growth medium based on sustainable resources, reduction of the number of unit operations, and exploitation of cost-effective preservation method. Implementation of the new solutions should not negatively affect the quality of the product, such as the number of living cells or the product safety. In the present study, we used a highly concentrated, raw corn flour-based (CF) medium for cultivation of probiotic L. plantarum LOCK 0860 strain and as a matrix in the following spray-drying process. Prior to drying, the post-culturing liquid was supplemented with a newly developed, optimized blend of protective agents, shown to increase the cell’s viability over 4-fold. Experimentally obtained data were used for the process model simulation at industrial scale, where the optimized probiotic component was supplemented with inulin as the prebiotic and standardization agent. Techno-economic analysis of this process model indicated a high net present value (NPV) at a selling price of $5.00 per kg of the preparation, which represent highly promising economic benefits. Sensitivity of unit production cost and the number of batches per year was estimated in the simulation, and the critical factors were identified, as well.

The objectives of the current work were (a) to investigate the suitability of soluplus®, a hydrophilic polymer, as a carrier for the entrapment of curcumin (CUR) SEDDS by the spray-drying process, and (b) to compare soluplus® with neusilin® US2, a hydrophobic high-capacity adsorbent for solid SEDDS. Both carriers produced free flowing powders with high CUR entrapment efficiency. When filled into capsules, approximately 95% of CUR was dissolved from the soluplus® powder within 120 min and only 41% from the neusilin® US2 base powder. When the powders were compressed into tablets, a slow CUR release was observed over 24 h, which varied as a function of compression force and the percentage of disintegrant used. In conclusion, current study demonstrated the feasibility of using soluplus® as a carrier for the preparation of solid SEDDS with more favorable release profiles when compared to the conventional hydrophobic adsorbents.

Application behavior of spray dried powders such as reconstitution behavior and flowability is indirectly influenced by powder particle morphology. We here investigated the influence of the drying conditions and composition for whey protein (WP), maltodextrin (MD) and their mixtures on particle morphology during pilot-scale spray drying. Even though all powders showed a variety of morphologies, MD powders contained more wrinkled particles and had high bulk density, whereas pure WP powders contained more hollow particles. Mixture powders (75:25 WP:MD) show more hollow particles with increasing inlet temperature, with a lower bulk density. The observed morphologies for different formulations corresponded roughly to previous observations during sessile single droplet drying, but the results indicate that the morphology is also influenced by the faster pilot-scale drying, which was not evident in the slower single droplet drying.

This paper reports the synthesis of LiNi0.8Co0.15Al0.05O2 (NCA) cathode powders using a simple flame assisted spray pyrolysis (FSP) and a spray drying (SD) processes, in which metal salt precursors dissolved in glycerol were used for spraying. X-ray diffraction confirms that the NCA powders have a layered structure, with a low order of cationic mixing. Electron microscopy shows that the particles produced by FSP have a relatively smaller size and a smoother surface than that produced by SD. The NCA powder from the FSP process has an initial discharge capacity of 200.2 mAh/g in voltage range of 3.0–4.3 V at 0.1C. It shows very good capacity retention of 91.5% at 1C and 89.4% at 5C after 200 cycles. These results demonstrate that glycerol can replace water and be used as a solvent in spray processes to make cathode powders, promising a new environmentally-friendly synthesis route for battery powder materials production.

This study investigated the microencapsulation of fermented noni juice (FNJ) via a novel pilot scale micro-fluidic-jet-spray-dryer (MFJSD). Different concentrations of maltodextrin (M1, 10–13 DE; M3, 17–20 DE) and gum acacia (GA) were used as wall materials. The physicochemical properties, microstructure, droplet-to-particle formation process and bioactives stability of the powders produced by the MFJSD were examined. Results showed that the M1 powders with 28% solid content (M1, 28%) exhibited better bulk density, particle size, glass transition temperature and hygroscopicity than the other three powders produced (namely the M1 (21%), M3 (28%) and GA (21%) powders). The FNJ powders underwent five different stages during the drying process, from isotropical drying, crust formation, solidification and buckling to final particle formation. The external surface morphology of the powders was obviously influenced by the wall materials selected. However, the drying and wall material type have limited effect on the stability of bioactives in the FNJ powders after microencapsulation and during storage. This study provided insight into the micro-fluidic-jet spray drying of FNJ, and evaluated the properties and stabilities of the powders produced.

Anchovy oil was successfully encapsulated into multi-core microcapsule powder using a two-step microencapsulation method. The inner and outer shells of the microcapsules were created separately using gelatin-SHMP complex coacervates as shell materials. Fucoidan extract was used to crosslink these complex coacervates shells of microcapsules before spray drying. The spray dried microcapsules produced using the two-step method exhibited high encapsulation efficiency (99.83%), low surface oil content (0.10%), high oil payload (55.68%) and significantly improved oxidative stability. The formation of the outer shell during the second cooling step of two-step microencapsulation method significantly improved the oxidative stability of the anchovy oil by smoothing the surface of the microcapsules.

The formulation of bioactive powders is crucial to their property, functionality and bioaccessibility. This study investigated the incorporation of Ca2+ as a protectant aid for producing active dry probiotics via spray drying, and explored the mechanism underlying the positive effect of Ca2+ on cell viability. At inlet temperature of 98 °C and outlet temperature of 65 °C, supplementing 1 mM CaCl2 to either 10 wt% lactose or 10 wt% trehalose solution increased the survival ratio of Lactobacillus rhamnosus GG (LGG) from 5% to 30%. The growth capability of dried LGG was also enhanced in the presence of calcium. Powder properties including particle morphology, amorphous state and infrared spectrum were minimally influenced at such a low Ca2+ loading. By contrast, adding 1 or 100 mM Ca2+ in reconstitution solution or MRS agar plates notably improved the survival of LGG cells during single droplet drying with pure lactose protectant. The findings suggested that the protective mechanism of Ca2+ is based on enhancing the intrinsic tolerance of LGG cells, rather than modifying the powder properties. Given the protective effect of Ca2+ on probiotic cells under stressful conditions, calcium-containing dry probiotic products that confer duel benefits to consumers may be developed as new types of functional foods.

A series of morphology-selected copper ferrite (CuFe2O4) anode materials for sodium ion batteries were firstly prepared via a highly efficient spray drying method using glycine as the complex and accelerator. It was found that the glycine/nitrate (G/N) molar ratio has an important influence on the crystallinity, morphology and electrochemical properties of sodium storage. Compared with the other prepared materials, the G/N-0.3 (glycine-nitrate molar ratio of 0.3) exhibits the most excellent electrochemical performance. The excellent electrochemical properties can be attributed to the optimized molar ratio of glycine-nitrate, which induce a good crystallinity with a proper porous structure, thereby improving the cycle life of the battery.

The encapsulation of phase change materials (PCM) is the essential step to make PCM easily utilizable. Aiming for a feasible process on a large scale, the combination of PCM/sol-gel emulsion and the spray-dry process was employed for the production of PCM encapsulated in silica shell matrices. Two PCMs, methyl palmitate and n-octadecane, with operating temperature appropriated for thermal comfort in trocical countries were selected. The composition of emulsion, i.e. tetraethyl orthosilicate (TEOS), cetyl trimethyl ammonium bromide (CTAB), and n-octadecane or methyl palmitate, was varied to find the optimal conditions for encapsulation. The influence of composition and process time on PCM's emulsion stability, size and structure of microcapsules, and encapsulation efficiency were investigated. The results showed that the optimal PCM to silica ratio was determined by the maximum quantity that could maintain the rigidity of the microcapsule structure. The low surfactant concentration that could still sustain emulsion stability contributed to improved encapsulation efficiency.

In this research, date powder was produced by drying aids including Tween 80, pectin, and whey protein concentrate (WPC) at different pH values (5.0, 6.5, 8.0, and 9.5) and using a spray drier at different temperatures (160, 170, 180, and 190 °C); then moisture content, solubility, hygroscopicity, bulk density, and total phenolic compounds (TPC) were determined and their correlation with structural characteristics of date powder was analyzed by Taguchi method. Interactions of pectin-surfactant, and pectin-WPC were more effective on moisture and bulk density of date powder, respectively. Although hygroscopicity of different treatments was in narrow range of 25–29%, temperature had the highest impact on TPC; beyond 170 °C, TPC of date powder decreased. Treatment No. 7, with the highest WPC level and pH values of 5, maintained the highest TPC content (701 mg 100 g−1) in date powder. SEM images revealed that pH = 9.5 and lower temperatures led to smaller particles.

Condensed skim milk (CSM) was high pressure jet (HPJ) processed at 100–500 MPa and then spray dried to obtain skim milk powders (SMP-100 to SMP-500). Physical and instant properties of SMP-100 to SMP-400 were similar to those of the control. However, SMP-500 showed a higher apparent particle density (1.25 g cm−3) and a lower solubility (93.2%) compared to the control. A marked increase in foam expansion index (FEI) and foam volume stability index (FVSI) was observed for the reconstituted SMP-400 and SMP-500, with the latter showing a FEI > 110% and a FVSI > 85%, 8 h after foaming. Moreover, emulsions prepared with reconstituted SMP-500 showed a higher emulsion stability index (ESI) compared to other SMPs. The observed differences in interfacial properties of reconstituted SMP-400 and SMP-500 are consistent with HPJ-processed skim milk, which showed extensive pressure- and shear-induced casein micelle modifications.