A New Technique for Spray-Dried Encapsulation of Lycopene

A new technique for lycopene microencapsulation by spray drying using dehumidified air as the drying medium was developed and the optimum operating conditions for encapsulation efficiency were determined. A pilot-scale spray dryer was employed for the spray-drying process. The modification made to the original design consisted of connecting the dryer inlet air intake to an absorption air dryer. The dextrose equivalent (DE) of maltodextrin, ratio of core to wall material, feed temperature, inlet air temperature, drying air flow rate, and compressed air flow rate were the factors investigated with respect to encapsulation efficiency. The resulting microcapsules were evaluated in terms of moisture content, bulk density, rehydration ability, lycopene isomerization, and storage stability. The optimum operating conditions were found to be as follows: ratio of core to wall material, 1:3.3; feed temperature, 52°C; inlet air temperature, 147°C. Under these conditions, the maximum encapsulation efficiency was about 93%. The use of dehumidified air was proven to be an effective way of increasing lycopene encapsulation efficiency.     

Moisture Sorption Isotherms and Storage Stability of Spray-Dried Yogurt Powder

Moisture adsorption isotherms of spray-dried yogurt powder were determined at 10, 25, and 40°C using the standard, static-gravimetric method. Experimental data were fitted to five mathematical models (Guggenheim-Anderson-de Boer [GAB], Brunauer-Emmett-Teller [BET], Halsey, modified Oswin, and modified Henderson). A nonlinear regression analysis method was used to evaluate the constants of the sorption equations. The shelf-life of yogurt powder was predicted based on the relationship between permeability coefficient of the packaging material and moisture adsorbed by the powder determined by the GAB equation. Furthermore, the storage stability of spray-dried yogurt powder in terms of quality parameters including moisture content, water activity, color change, and thiobarbituric acid (TBA) value was studied in aluminum laminated polyethylene (ALPE) pouches under storage conditions of 25°C and 50% relative humidity (RH).     

Crystallization of Amorphous Components in Spray-Dried Powders

Spray-dried powders are typically produced as amorphous particles. Long storage of the particles tends to crystallize the powders, a reaction affected by moisture, time, and temperature. This work has examined partial crystallization from amorphous spray-dried powders by moisture sorption. Powders of citrus fiber with hibiscus extract, maltodextrin, coffee, tea, skim milk, and sucrose were produced with a laboratory-scale spray dryer. The powders were exposed to ambient temperature and various relative humidities, with weight measurements recorded over time. It has been found that, in different materials, the amorphous to crystalline state change is observed at varying rates depending on the relative humidities and molecular weights. This observation may be associated with all amorphous spray-dried materials.     

Crystallization of Amorphous Components in Spray-Dried Powders

Spray-dried powders are typically produced as amorphous particles. Long storage of the particles tends to crystallize the powders, a reaction affected by moisture, time, and temperature. This work has examined partial crystallization from amorphous spray-dried powders by moisture sorption. Powders of citrus fiber with hibiscus extract, maltodextrin, coffee, tea, skim milk, and sucrose were produced with a laboratory-scale spray dryer. The powders were exposed to ambient temperature and various relative humidities, with weight measurements recorded over time. It has been found that, in different materials, the amorphous to crystalline state change is observed at varying rates depending on the relative humidities and molecular weights. This observation may be associated with all amorphous spray-dried materials.     

Properties and Stability of Spray-Dried and Freeze-Dried Microcapsules Co-Encapsulated with Fish Oil,Phytosterol Esters,and Limonene

The objectives of this study were to investigate the properties and stability of microcapsules containing fish oil co-encapsulated with phytosterol ester and limonene, prepared by spray-drying and freeze-drying methods. Whey protein isolate and soluble corn fiber were used as wall materials in the encapsulation process. The properties of microcapsules, including structure, glass transition, volatile/non-volatiles retention, microencapsulation efficiency, oxidation stability, color measurement, and sensory profiles, were evaluated after drying and during a seven-day accelerated storage trial. The finding reveals that drying methods have an effect on the retention of volatile fraction and the physical structure of the wall matrix consisted of WPI and SCF, consequently influencing the storage stability of the powders. Significantly higher retention of volatile fraction (p < 0.05) and lower surface oil were found in the spray-dried samples, resulting in the higher microencapsulation efficiency. However, samples dehydrated by both methods have good redispersion properties, showing no statistical significance (p > 0.05). The oxidation of the encapsulated oils was comparable for both spray- and freeze-dried samples during the seven-day accelerated storage trial but the loss of limonene flavor was significantly higher in the freeze-dried samples (p < 0.05). Sensory evaluation indicated that the addition of limonene could mask the unpleasant fishy odor in the co-encapsulated microcapsules. Overall, freeze drying did not produce powders with superior properties and did not show better protection towards the core materials than spray drying.     

Effect of Additives on Quality of Spray-Dried Fructooligosaccharide Powder

Fructooligosaccharide (FOS) finds its applications as an alternative sweetener in powder form. The effect of different process parameters (feed concentration, feed flow rate, inlet air temperature), different additives (maltodextrin, gums, starch), and anticaking agents (in different combinations and concentrations) during spray drying were investigated. FOS solution with 2% magnesium oxide as an additive gave a maximum powder yield (43% w/w), and the spray-dried powder size was fine and the texture was like talcum powder. Flow properties and microbial analysis were found to be satisfactory. The addition of anticaking agents did not have a significant effect either on the color of the powder or on FOS content, indicating good quality of the powder with respect to flowability, microbial load, and texture.     

Physical and Functional Properties of Blackberry Freeze- and Spray-Dried Powders

The aim of the present work was to develop two products from blackberry juice by freeze and spray drying with potential use as food colorants or healthy ingredients. A characterization of the physical and functional properties of the powdered juices was done. Maltodextrin or a mixture of trehalose and maltodextrin were assessed as carrier matrices. Freeze-dried, maltodextrin-containing powders presented the best retention of bioactive compounds and antiradical activity; however, they showed a narrow relative humidity range for storage in the glassy state. Spray-dried powders showed better physical properties, bearing higher glass transition temperature and lower molecular mobility than freeze-dried formulations.     

Spray-Dried Chitosan Microspheres as a pDNA Carrier

Spray-dried chitosan microparticles with controlled size were prepared and crosslinked with the biocompatible reactant d,l-glyceraldehyde. Glutaraldehyde, the conventional cross-linking agent for proteins, was used as a control. The crosslinking degree was characterized through thermal analysis, X-ray diffraction, and infrared spectroscopy. In addition, the crosslinking effects were analyzed in terms of particle size, swelling capability, and surface charge. By properly choosing d,l-glyceraldehyde concentration and crosslink time, a high degree of control was achieved over the physical properties of particles. Yields around 78% as well as images obtained through fluorescence microscopy demonstrated the capability of the crosslinked chitosan microspheres to pDNA complexation.     

Drug Release Kinetics of Spray-Dried Chitosan Microspheres

The aim of this article was to investigate the drug release kinetics of spray-dried chitosan microspheres using various kinetic models. The mean particle size and encapsulation efficiency of cross-linked chitosan microspheres was between 3.8 and 4.2 μm and 96.3 and 98.7%, respectively. Spray-dried chitosan microspheres were spherical in shape with smooth surface. The surface morphology of spray-dried chitosan microspheres was affected by the crystallinity of the loaded drug and cross-linking agent. The release data of the spray-dried chitosan microspheres were treated with zero-order, first-order, Higuchi, Korsmeyer, and Kopcha kinetic models and best fit was observed with Higuchi model, indicating the release of drug from spray-dried chitosan microspheres followed Fick's law of diffusion.     

Drug Release Kinetics of Spray-Dried Chitosan Microspheres

The aim of this article was to investigate the drug release kinetics of spray-dried chitosan microspheres using various kinetic models. The mean particle size and encapsulation efficiency of cross-linked chitosan microspheres was between 3.8 and 4.2 μm and 96.3 and 98.7%, respectively. Spray-dried chitosan microspheres were spherical in shape with smooth surface. The surface morphology of spray-dried chitosan microspheres was affected by the crystallinity of the loaded drug and cross-linking agent. The release data of the spray-dried chitosan microspheres were treated with zero-order, first-order, Higuchi, Korsmeyer, and Kopcha kinetic models and best fit was observed with Higuchi model, indicating the release of drug from spray-dried chitosan microspheres followed Fick's law of diffusion.     

Influence of Feed Composition and Drying Parameters on the Surface Composition of a Spray-Dried Multicomponent Particle

Surface properties of multicomponent particles produced in spray drying can be controlled by selective accumulation of specific components, which are present in the liquid feed, on the particle surface. Such modification of the surface composition can take place only before a solid shell forms on the particle surface. In this contribution, the influence of the concentration of surface active component on modifications of the surface composition is discussed. Based on results of single-droplet drying simulations, changes in the concentration of the surface active component at the solution-air interface are related to the composition of spray-dried particles.     

Stabilization of Lipoxygenase-1 from Glycine max by Microencapsulation

Lipoxygenase from soybean was encapsulated and the effect of different carrier materials (whey protein, gum arabic, whey protein along with sodium alginate and maltodextrin) on enzyme stability during spray drying was studied and compared with freeze drying. The addition of polyethylene glycol (PEG-4000) during spray drying evidently enhanced enzyme stability. Total activity of lipoxygenase after spray drying was 1.14 × 10⁴(whey protein isolate), 1.2 × 10⁴(gum arabic), 1.09 × 10⁴ (whey protein isolate + sodium alginate), 1.44 × 10⁴(maltodextrin), and 1.55 × 10⁴(PEG + maltodextrin). Highest enzyme activity recovery of 72.02% was achieved with the combined addition of maltodextrin and PEG-4000. Moisture, scanning electron microscopy analysis, and storage studies were carried out for spray- and freeze-dried enzyme.     

An Improved Calculation Procedure on Surface Composition of Spray-Dried Protein-Sugar Two-Component Systems

In this short article, we present a new calculation procedure to estimate the surface concentration of any solute species for spray-dried multi-component particles based on the surface coverage data measured by the X-ray photoelectron spectroscopy (XPS) technique. In contrast to the continuum-theory-based estimation method, this new approach takes into account microscale molecular packing in the XPS detectable surface layer. Hence, it allows a more realistic interpretation of the XPS surface coverage data. Sample calculations on a lactose-casein two-component system demonstrate the effectiveness of the new method and prove indirectly the validity of a distributed parameter model for surface composition prediction. More importantly, the difference between XPS measurements and model predictions can be rationally explained when molecular level interpretation comes into play.     

Encapsulation of Proteins by Spray Drying and Crystal Transformation Method

Spray drying is commonly used as a dehydration technique in the pharmaceutical industry for making powdery products directly from liquid. It is also an attractive alternative for obtaining solid pharmaceutical molecules that are traditionally produced by freeze drying. Spray drying is often regarded as a harsh drying method, due to the high temperature of the drying gas. Therefore, some excipients were added to improve the stability in manufacturing process and storage. Emphasis was placed on the encapsulation of proteins by spray drying and crystal transformation method.     

Spray-Dried Solid Self-Emulsifying Delivery System of Ketoprofen: Development and Its Characterization

Ketoprofen is classified as BCS class II drug with low aqueous solubility, short half-life (2–2.5 h), and low oral bioavailability and also causes gastric irritation. The systems intended for oral administration were prepared by using soybean oil, Cremophor EL, and Maisine 35-1 and its adsorption on Aerosil 200. The spray-dried product demonstrated high process yield (52.2–68.3%) with good loading capacity (83.13–93.69%) and significant drug release compared to pure drug. The smooth spherical particles produced had no interaction with the excipients as demonstrated by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Differential scanning calorimetry (DSC) indicated the complete miscibility of the drug with excipients and X-ray diffraction (XRD) demonstrated the transformation from crystalline to amorphous form.     

Effect of Diffusion on Component Segregation During Drying of Aqueous Solutions Containing Protein and Sugar

Water content profiles within thin aqueous films of lactose and bovine serum albumin (BSA) were tracked during drying using inverse microscope Raman spectroscopy (IMRS). These film drying experiments provide useful insights into component diffusion within droplets during spray drying in the food industry. Virtually no segregation of lactose and BSA occurred in the films during drying at 30°C. Thus, in film drying simulations at this temperature, lactose and BSA can be assumed to be a single homogenous solute, and binary diffusion of water and this single solute can be modeled. A solute-fixed coordinate system drying model properly predicted the water content profiles and shrinkage of the films during the constant rate period. This represents a partial validation of the model. The drying model predicted significant gradients in water content in films dried at a higher temperature of 80°C, which have the potential to drive segregation of lactose and BSA. However, IMRS analysis of films dried at 80°C revealed no segregation of lactose and BSA. We propose that lactose and BSA are relatively immobile in the bulk of the film during drying, forming a homogenous gel that allows the significantly smaller water molecules to diffuse through. The observed accumulation of BSA as a monolayer at the surface of the dried films appears to be a local phenomenon most likely driven by the surface activity of BSA.     

Effect of cross-linking method on the activity of spray-dried chitosan microparticles with immobilized laccase

The effect of processing method on the properties of cross-linked chitosan microparticles and on the enzymatic activity of laccase immobilized in the particles has been investigated. Chitosan has been cross-linked by tri-polyphosphate (TPP) using two methods – the so called ex situ cross-linking whereby the solutions of chitosan, TPP and the enzyme have been pre-mixed and spray-dried by a standard two-fluid kinetic nozzle, and a novel in situ cross-linking method, whereby the solutions have been contacted at the tip of a three-fluid nozzle and cross-linking occurred within a drying droplet. The influence of the cross-linking method on the particle size and morphology, surface charge, and swelling ratio has been determined. The enzymatic activity of laccase toward the oxidation of a chromophore substrate (ABTS) has been systematically investigated and found to be superior in particles produced by the in situ cross-linking method.     

Volatile Retention and Antifungal Properties of Spray-Dried Microparticles of Lippia sidoides Essential Oil

Spray drying microencapsulation of Lippia sidoides essential oil was investigated. Maltodextrin DE10 and gum arabic at different proportions (4:1, 3:2, 2:3, 0:1 m/m) was used as a carrier. The content of essential oil related to the carrier was 20 and 25% in weight and the emulsions were atomized from 30% up to 60% (m/m) of total solid concentration. Spray dryer inlet temperatures varied from 140 to 160°C and the best thermal efficiency and powder recovery were found at 160°C. Product properties and process performance were assessed on the basis of microscopic features of the powder (shape and size of microparticles), moisture content, and powder recovery. Encapsulation efficiency was estimated through determination of the content of essential oil in the microcapsules. The best encapsulation efficiency was related to experimental parameters as follows: solid content of the encapsulating composition of 50% (m/m), maltodextrin:gum arabic ratio of 0:1 (m/m) and carrier:essential oil ratio of 4:1 (m/m). Antifungal activities of microparticles were evaluated, evidencing their potential as important antifungal agents. The positive findings in this study encourage further research and provide perspectives for the development of phytotherapeutic products from essential oil of Lippia sidoides.     

Spray-Dried Redispersible Emulsion to Improve Oral Bioavailability of Itraconazole

Dry emulsions are powdery, lipid-based formulations from which an o/w-emulsion can be easily reconstituted in vivo or when exposed to water. The objective of this work was to prepare and characterize dry emulsion of itraconazole (ITZ) to improve its solubility and bioavailability. Dry emulsions were prepared by spray-drying liquid o/w-emulsions containing carriers like maltodextrin, sucrose, and lactose. Propylene glycol monocaprylate was selected as oil phase, and surfactant blends of vitamin E tocopherol polyethylene glycol succinate and triblock PEO–PPO–PEO copolymer as emulsifying agents. Several oil:water and carrier:water ratios were tested. An optimum formulation was selected using 3² full factorial design. The droplet size, rheological behavior, and drug release from o/w-emulsion before and after reconstitution and the micromeritic properties of spray-dried product were investigated. Maltodextrin was used as a carrier for preparing dry emulsions. The optimized dry emulsion was characterized using DSC, SEM, PXRD, and in vivo study. The SEM analysis showed that dry emulsion consisted of well-separated particles with smooth surfaces. The DSC and XRD study showed that ITZ in the dry emulsion is in the molecular dispersion state. Globule size analysis showed that dry emulsion had good reconstitution properties. The emulsions were found to be thermodynamically stable when subjected to cyclical freeze–thaw cycles and centrifugation tests. The average globule size of emulsions ranged from 0.994 to 1.668 μm. A 71.35 % increase in C _max and 114.78 % increase in AUC was evident for ITZ dry emulsion as compared to plain ITZ.     

Influence of Oil Load and Maltodextrin Concentration on Properties of Tuna Oil Microcapsules Encapsulated in Two-Layer Membrane

The two layers of tuna oil-in-water emulsions containing different oil loads (5–10 wt%) and maltodextrin concentrations (10–20 wt%) were stabilized by a lecithin–chitosan membrane. The liquid emulsions were then spray dried at an inlet air temperature of 180 ± 2°C and an outlet air temperature of 85 ± 5°C. The characteristics of liquid emulsion (creaming and mean droplet size) and spray-dried microcapsules (moisture content, water activity, color, morphology, glass transition temperature, and encapsulation efficiency) were measured. The results suggest that two-layer oil-in-water emulsions are an effective system to produce high oil-loaded microcapsules, which may lead to its wide application for use in food products.