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In the current study, a walnut oil (WO) emulsion was prepared with WO as the core material and sodium caseinate and maltodextrin as the wall materials. The effects of spray drying (SD) and freeze drying (FD) on the structure and quality of WO microcapsules were compared, and the role of WO microcapsules as a substitute for commercial creamer in coffee was investigated. The results demonstrated that the WO microcapsules prepared by the SD method had dense microstructure, spherical particles, no oil drop aggregation, small particle size, good fluidity, an embedding rate of up to 93.60%, an unsaturated fatty acid content of 87.00%, and no significant difference in thermal stability or stability of the restored emulsion compared with FD. The freeze-dried WO microcapsules have irregular structure, porous surface structure, high oil content on the surface, 76.84% embedding rate, some accumulation of droplets, large grain size, and poor fluidity. The electronic nose and electronic tongue results reveal that the microcapsules prepared by the two methods have similar flavor when applied to coffee. The spray-dried WO microcapsules are prepared with a flavor closer to that of commercial creams. In summary, microcapsules prepared by SD are superior to FD and are promising for industrial production; further, the nondairy creamer based on WO has great potential for coffee application. • Spray-dried microcapsules have better mobility, stability and encapsulation rate than freeze-dried microcapsules. • Use of walnut oil as a fat substitute in non-dairy creamers. • Spray-dried walnut oil non-dairy creamer applied to coffee has a good flavor. [ABSTRACT FROM AUTHOR]

Spray drying, as an important way of protein drying, greatly promotes the industrial production of emulsion, but it will cause protein aggregation and functional reduction. In this work, we aimed to study the efficacy of protein particles produced by co-spray drying with a sugar (trehalose), a polysaccharide (maltodextrin) and a surfactant (polyglycerol fatty acid ester, PGE). Soybean protein isolate (SPI) and pea protein isolate (PPI) were used as model proteins. SPI, PPI and powders containing 10 % above additives in each protein were produced through spray drying. Pickering emulsions with 75 % oil phase were produced using the particles of protein (control) and particles of protein containing the above additives. Compared to that of pure protein, the particle size and surface hydrophobicity of rehydrate powders of protein containing additives were significantly lower. For the SPI group, SPI-maltodextrin, SPI-trehalose, and SPI-PGE had better emulsifying properties than that of SPI. For the PPI group, the PPI-maltodextrin and PPI-trehalose were better, while PPI-PGE had weaker emulsifying properties than that of PPI. The Pickering emulsion prepared by PPI-PGE stabilized emulsion was water-in-oil type while others were oil-in-water type. The emulsions stabilized by SPI-trehalose and PPI-trehalose particles had the smallest particle size (59.2 μm and 149.1 μm, respectively), the highest viscosity, produced the most stable emulsions. These findings show that sugar and polysaccharide based co-spray drying agents can improve the physicochemical and emulsifying properties of protein particles, of which trehalose appears to be highly effective. The outcomes of the work are expected to facilitate the properties of protein particles and the production application of Pickering emulsions in food industry. • The protein particles were produced with three different co-spray drying agents. • The physicochemical and emulsifying properties of prepared particles were improved. • The prepared particles were popularly used to stabilize Pickering emulsions. • This study facilitates the application of Pickering emulsions in food industry. [ABSTRACT FROM AUTHOR]

Resveratrol emulsions do not have long shelf life hence drying to obtain powder can result in the resveratrol protection, shelf life extension and can unlock versatile applications in food, pharmaceuticals, and cosmetics. In this work resveratrol was emulsified using drop-by-drop ("batch" and "continuous" membrane) and classic (ultrasound) emulsification methods followed by the emulsion spray drying to obtain resveratrol loaded microparticles. Influence of the emulsification techniques on the microparticles properties, resveratrol encapsulation efficiency and retention were evaluated and the energy density required by each emulsification process was estimated. 10 and 15 μm pore membranes produced droplets between 154 and 42 μm, while with the ultrasound droplets of 0.16 μm were produced. The microparticles obtained by spray-drying of the emulsions produced by ultrasound and "batch membrane system" had the highest encapsulation (∼97%) efficiency and similar resveratrol retention (∼89%). This confirms that membrane systems (even producing larger droplet size compared to ultrasound emulsions) could achieve high encapsulation efficiency and resveratrol retention. Since no cooling is needed during membrane emulsification due to the low energy input, membrane systems with their ability to be scaled up, should be considered in food and pharma as an alternative to classical emulsification systems especially when shear and heat sensitive compounds are emulsified and encapsulated. • Batch and Continuous membrane systems were used to produce emulsions. • Process conditions of the membrane systems were set using dyed emulsions. • Sonicated emulsions had droplet size much smaller than membrane emulsions. • Batch membrane and sonicated provided particles of resveratrol retention ≥90%. • The Batch membrane required 14 times less energy density than the ultrasound. [ABSTRACT FROM AUTHOR]

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. • CSM was HPJ-processed at 100–500 MPa and spray dried into SMPs. • SMP-500 showed a higher apparent particle density and a lower solubility. • SMP-400 and SMP-500 showed markedly enhanced foaming properties. • SMP-500 showed a modest increase in emulsion stability. • HPJ-processing of CSM enhances functionality of SMPs. [ABSTRACT FROM AUTHOR]

This paper presents a computational fluid dynamics (CFD) method combined with deep reinforcement learning to simulate and optimize the spray drying process of Lonicerae Japonicae Flos (LJF) extract. The computational model firstly incorporates the drying kinetics information, which was experimentally determined by drying of individual droplets. Secondly, the difference between this study and previous work is that a distributed optical fiber temperature measurement system (DTS) was used to measure the temperature field of a pilot-scale drying tower for model verification. The mean percentage errors between the experimentally measured temperature and the simulated values at 3 heights (0.18 m, 0.48 m, and 0.78 m) were 8.8%, 7.1%, and 3.1%, respectively. The measured temperature in the drying tower is consistent with the simulation, which can well explain the change of droplets during the drying process. Based on experimental and simulation data, a powder yield prediction model was established. Deep reinforcement learning model was then applied to continuously interact and iterate with the prediction model, realizing the automatic optimization of the spray drying process. The results show that the process can be optimized to increase the powder yield by around 5%. The model can thus be used as a basis for equipment improvement and to provide optimal operating conditions for spray drying process to replace traditional empirical adjustment method. • A CFD model of the spray drying process of LJF extract was established. • A deep reinforcement learning model is established for process optimization. • Temperature distribution field in the drying tower was measured experimentally. • This computational model incorporates the CDC model of the actual feed. [ABSTRACT FROM AUTHOR]

This review is primarily focused on the comparison of three emerging techniques: electrospraying, nano spray drying, and electrostatic spray drying techniques. There are persistent advances to develop efficient drying technique for sensitive bioactives and to overcome their hurdles. These processes involve electrostatic forces as a promising factor for better encapsulation and stability of dried particles. Their potential differences in experimental setup, influencing factors and recent applications are listed. Introduction of electrostatic interaction between the components during atomization allows electrospraying and electrostatic spray drying as an advanced drying technique for heat-sensitive and labile products. Electrospraying and nano-spray drying demonstrated an effective drying with different solvent systems (organic or non-organic solvents) and also, achieved to encapsulate complex food ingredients (vitamins, minerals, phenolic compounds, probiotics etc.). These electric-assisted technologies showed higher encapsulation efficiency, uniform particle morphology and longer stability of dried powders than classical technologies. Nano-spray dryer with spray mesh technology and electrostatic collector brings out difference in dried powders in terms of particle size and product yield when compared to conventional spray drying. Electrospraying and nano-spray drying have been beneficial for highly valued research products (such as cells, enzymes, genes, etc.) but the scaling up of these processes is still currently in process. • Three emerging spray drying technologies using electric fields have been reviewed. • Electrospraying, nano-spray & electrostatic spray drying works at lower temperature. • These processes involve electrostatic forces allowing droplets & particle repulsion. • Overall technical considerations, advantages and limitations are discussed. • Industrial set up of electrostatic spray drying is commercially available. [ABSTRACT FROM AUTHOR]

Abstract Red onion microcapsules were produced by spray freezing into liquid cryogenic (SFLC) and spray drying (SD) and their anthocyanin contents were evaluated kinetically at different water activities (a w) at 35 °C. The spreading pressure-area isotherms were determined at 35 °C. These isotherms provide important information about the different phases of adsorbed water present in SD and SFLC capsules, which can be related to minimal integral entropy and to chemical stability during storage. The porosity of the microcapsules was examined using low-temperature adsorption of nitrogen. The maximum anthocyanin stability occurred at a w from 0.108 to 0.318, and 0.108 to 0.515, for SD and SFLC, respectively. SD products were nonporous whereas SFLC were mesoporous. The tendency to contraction of the adsorbed water film was compared with the minimum integral entropy and was proposed as a new stability criterion to predict suitable storage conditions of dehydrated foods. Highlights • Red onion extract was microencapsulated by SD and SFLC processes. • The SD and SFLC microcapsules were analyzed using SEM, nitrogen and water adsorption. • The spreading pressure parameter was proposed to determine the better storage conditions. • SEM, porosity and the integral entropy study confirm the microcapsules storage stability. [ABSTRACT FROM AUTHOR]

Abstract Rapeseed and honeydew honey were spray dried by dehumidified air, with NUTRIOSE® as a drying carrier, to create a product with prebiotic properties, in line with current "clean label" trend. Because of the low inlet air humidity, drying temperature was decreased (inlet/outlet: 75/50 °C). Such an approach gave the possibility to reduce the amount of added carrier. Thus, honey powders containing 80% of honey solids were produced and characterized. Drying was performed with very high powder recovery (84.4–93.9%), especially in the variants containing 80% of honey solids. Although there were some differences in the physical properties between powders produced by the application of dehumidified air and by the traditional spray drying (but containing the same ratio of honey to carrier), the overall properties were comparable: low water content (below 2.5%) and low water activity (below 0.2), medium or high cohesiveness, high hygroscopicity (above 20%), bed porosity between 50 and 70%. [ABSTRACT FROM AUTHOR]

The effects of cheese age and addition of dairy ingredients on cheese powder properties have not been previously investigated. Hence, the effect of addition 2% sodium caseinate plus 2% buttermilk powder (B2S2) or 4% buttermilk powder (BMP) were evaluated. The addition of these ingredients led to a decrease of the Power Law consistency index in cheese feeds made from 16 to 30 weeks old Danbo cheeses. Powders containing B2S2 presented homogeneous particle size distributions, lower amount of free fat and better flowability, due to improved fat emulsification, confirmed by confocal laser microscopy. Powders with BMP presented higher browning index, cohesiveness and spontaneous primary agglomeration. These powders were also more sensitive to an increased temperature difference (ΔT) between inlet and outlet spray drying temperatures, causing more browning. Cheese powder properties could thus be significantly improved by addition of 2% SC plus 2% BMP, whereas no improvements were observed using only BMP. [ABSTRACT FROM AUTHOR]

Spray drying is an effective method to encapsulate volatile compounds in a carrier matrix. The exact mechanism of volatile retention during spray drying is not well understood but could facilitate optimization of the drying process and contribute to better formulation of the encapsulation matrix. Therefore, a thin film dryer equipped with a photo-ionisation detector was constructed to measure online the volatile release and drying kinetics of maltodextrin solutions with acetone. Thin films of maltodextrin-acetone mixture were exposed to drying air for 1 h at 105 °C. The acetone release occurred mostly during the first 10 min of drying which aligned with the constant drying period. This period decreased for films containing higher initial solids as the falling rate period started earlier. Maltodextrin DE12 films retained more acetone than DE21, thanks to its higher viscosity lowered acetone diffusivity. A mechanistic drying model was developed that confirmed the observed correlations between acetone release and drying kinetics. [Display omitted] • A photo-ionisation detector was used to monitor acetone release in-line during drying. • Reducing the constant rate period in drying is most effective to improve acetone retention. • High initial solids and low maltodextrin DE reduce release during the constant rate period. • Acetone release was described by diffusion in multicomponent mixtures. [ABSTRACT FROM AUTHOR]

A well-known probiotic strain, L. rhamnosus GG, was encapsulated by spray-drying in milk water-insoluble matrices upon reconstitution in hot water by exploiting and controlling the clotting reaction of milk proteins during the process. The feed solution, composed of probiotic bacteria and milk proteins, was or not subjected to the action of chymosin, a proteolytic enzyme. To optimize microencapsulation efficiency, different outlet air temperatures were tested (55, 70 and 85 °C). After spray-drying, small microparticles were recovered for further characterization. All drying conditions led to excellent bacterial survival rates (<0.5 log reduction) whereas only the highest outlet air temperature allowed the production of microparticles with acceptable moisture contents (<7%) to ensure storage stability. Finally, enzymatic cleavage of milk proteins by chymosin before atomization led to matrices presenting innovative functionalities when microparticles are reconstituted with water: rehydration or dispersion in cold (8 °C) or warm (40 °C) water, respectively. [ABSTRACT FROM AUTHOR]

Crucial for achieving premium agglomerated powder products through spray drying is that the primary particle morphology and the degree of agglomeration can be controlled. However, the costs of trial runs and the wide range of products properties complicate achieving this control of particle structure during spray drying. Single droplet drying approaches are employed to study the development of the primary particle morphology and the collision behavior of droplets under well-defined conditions. These studies shed light on the underlying mechanisms but have been related less often to realistic drying and especially agglomeration. This review focuses on the potential and limitations of single droplet drying approaches to unravel the evolution of primary particle morphology and nozzle-zone agglomeration phenomena during spray drying. We discuss advances in single droplet drying approaches and how to combine these with pilot-scale spray drying to obtain the desired particle structures. • A wide range of SDD techniques exist, each providing their own benefit. • Collision behavior of droplets can be studied by modified SDD approaches. • Particle morphology development can only be studied for individual particles. • Pilot scale equipment is required to study full nozzle zone agglomeration. [ABSTRACT FROM AUTHOR]

Changes of secondary structure and protein interactions of whey protein (WPs) present in native, sweet, acid and salty-WPCs were analyzed following storage at 4, 25 or 45 °C and 22 or 33% relative humidity for a period of 90-days. WPs aggregated predominantly through covalent crosslinking, achieving maximum at 45 °C and 33% RH. Greater participation of β-lactoglobulin in covalent crosslinking was evident in all WPCs, while that of α-lactalbumin was significantly ( p < 0.05) high in acid-WPC only. Reaction order of β-LG denaturation in acid and salty-WPCs was approximately 2 while approximately 1 in native and sweet-WPCs. Activation energy was significantly ( p < 0.05) higher in native and sweet-WPCs, with averages recorded as 97 and 49.8 kJ mol −1 , respectively, than that in acid and salty-WPCs with averages of 27.5 and 33.8 kJ mol −1 , respectively, mainly attributed to inherently high concentrations of lactic acid and salts in these WPCs. [ABSTRACT FROM AUTHOR]

This study evaluated the environmental performance by life cycle assessment (LCA) of five popular drying processes (freeze drying, spray drying, spouted bed drying, convective hot air oven drying, and foam mat drying) to obtain polyphenol-rich acerola powders from acerola juice and pomace. To the best of our knowledge, this is the first report in the literature showing the total polyphenol content (TPC) as the target quality index to evaluate the LCA of fruit-based dried ingredients, taking the potential functionality into consideration. Acerola powders had low moisture content (1.43%–5.20%) and water activity (0.301–0.433), and remarkably high TPC (79–287 mg GAE/g). LCA results showed that the re-purposing of readily available and burden-free pomace is a smart and eco-friendly solution to secure polyphenol-rich fruit powders with lower environmental impact (<10%) and resource availability (<50%). On the contrary, juice-derived powders have higher potential ecological impact associated to agricultural cultivation. Oven drying exceeded in 75–80% the impact to the ecosystems of other drying processes, which jeopardizes process viability. Drying attributes that dictate environmental performance were identified, such as powder productivity and carrier selection, with maltodextrin having >60% lower impact than albumin in 9 out of 10 mid-point categories evaluated. High powder productivity (35.8 g/h and 34.7 g/h for juice- and pomace-derived powders, respectively) and robustness endorse spray drying as an eco-minded drying strategy for the efficient processing of naturally polyphenol-rich materials. This research provides comprehensive data to support the upcycling of fruit pomaces as smart feedstocks to produce phytochemical-rich food ingredients. [Display omitted] • Acerola juice and pomace were evaluated as valuable upcycling polyphenol sources. • Total polyphenol content was used as target quality index for environmental analysis. • Powder productivity and type of drying carrier influenced environmental impact. • Pomace re-purposing is an eco-friendly way of sourcing natural polyphenols. • Spray drying high productivity dictated its positive environmental performance. [ABSTRACT FROM AUTHOR]

Vacuum spray drying is a new technique used to produce concentrated orange juice powder using maltodextrin as a drying agent. The dryer was developed for the low-temperature (40–50 °C) drying powderization of liquefied food using superheated steam (200 °C) as a heating medium. The physicochemical properties of orange juice powder with four different combinations of juice solids: maltodextrin solids at 60:40, 50:50, 40:60, and 30:70 were determined. The moisture content, hygroscopicity, water activity, particle size, particle morphology, color characteristics, rehydration and ascorbic acid retention were significantly affected by the maltodextrin concentration and drying conditions. Water sorption and the glass transition temperature of orange juice powder conditioned at various water activities were also evaluated. The obtained data were well fitted to both BET and GAB models. A strong plasticizing effect of water on Tg was able to predicted by the Gordon–Taylor model, where Tg was greatly reduced by the increasing moisture content of the powder. [ABSTRACT FROM AUTHOR]

The article presents a literature review on modifications and the latest achievements in the field of spray drying (SD). Although the history of this method of drying dates back to more than a hundred years ago, and in the case of many products, the process is widely recognized and does not create problems, many others are still looking for new design and technological solutions to reduce energy expenditure, improve the process flow and improve properties of received products. Since early development SD system has evolved in its construction, and currently there are numerous system modifications already available in the market, apart from other being on early implementation or laboratory stage. This paper begins with a brief background of SD and existing technologies. The main part of the paper is devoted for the description of less developed approaches. As was presented, the particular drawbacks of conventional SD system can be overcome by innovative approaches. It is hoped that these added-value features/technologies will find their place in industrial systems to boost the process performance and/or powders properties. • Spray drying (SD) system has evolved since early development. • Drawbacks of conventional SD systems can be overcome by innovative approaches. • To reduce thermal degradation, vacuum, dehumidified air, or ultrasound SD can be applied. • Reduction of stickiness can be achieved by dehumidified air-assisted SD. • Particle size/morphology can be modified by foam, flame, ultrasound and nano SD. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of the processing and storage conditions on the physical and functional properties of egg yolk (EY) powders. The spray-drying temperature (160 °C vs . 180 °C), storage temperature (15 °C vs. 30 °C) and time (1, 2, 4 and 8 months) and n−3 enrichment through hen diet were investigated. The spray drying temperature and storage conditions modified the water content, water activity and the particle size distribution of EY powders. Flowability of the powders and the emulsifying properties were not significantly affected from an industrial point of view. On the opposite, the viscosity increased with the spray-drying temperature as well as the temperature and time of storage in rehydrated powders. Powders prepared with n−3 enriched egg yolks exhibited lower melting peaks temperatures, a marked yellow colour and higher fluidity of the solutions, but the overall properties remained unchanged. This study clearly attests the possibility of an industrial production of n−3 enriched EY powders. [ABSTRACT FROM AUTHOR]

Highlights: [•] Microwave-assisted extraction and spray drying were used to produce orange peel extract powder. [•] A peak yield trend and high recoveries of phenolic compounds were found during spray drying. [•] The combined process is economically feasible. [•] The powder selling price, the labor cost and the orange peel cost are the three most important costs. [Copyright &y& Elsevier]

Objectives of the present study were to spray dry high total solids content single layer (SL) and layer-by-layer (LBL) emulsions, and to compare the ability of the SL and LBL powders in preventing the loss of carotenoids upon storage in the vicinity of the glass transition temperature (T g ). Carotenoids stability in humidified spray dried (HSD), non-humidified freeze-dried (NHFD), and humidified freeze-dried (HFD) systems were determined as well. The loss of carotenoids followed first order loss kinetics. An initial rapid followed by a second slower first order loss kinetics was observed in the non-humidified spray dried (NHSD) systems. Storage of systems above the T g delayed carotenoids losses based on the rate constants. The loss of carotenoids in LBL systems was more heat sensitive as the activation energies were generally higher. Activation energy decreased above T g indicating that the loss of carotenoids became less temperature dependent. The application of LBL interface structure reduced the rate of carotenoids losses and can be applied to prevent loss of oil soluble bioactives in formulated materials. [ABSTRACT FROM AUTHOR]

Abstract Atomisation is an integral element of the spray-drying process, whereby a bulk liquid feed is converted to discrete droplets, greatly increasing the surface area of the feed liquid and thereby increasing considerably the achievable rates of evaporation of water. These droplets, through evaporation of water in the main dryer chamber, become individual powder particles during the spray-drying process. This review provides a comprehensive examination of the most recent developments in atomisation technology for spray-drying, with a particular focus upon dairy applications (e.g. , skim and whole milk powders, casein- and whey-based powders, and fat-filled milk powders). As well as a review of principles of different technologies for atomisation, such as rotary atomisers, pressure nozzle atomisers, pneumatic atomisers, ultrasonic atomisers and electrospray atomisers, the industrial applicability and challenges in use of each approach to atomisation are presented. Approaches for monitoring the atomisation process and other factors that influence atomisation, such as feed composition and key process parameters, are considered to provide a holistic analysis of the atomisation process. Highlights • The principles of atomisation within spray-drying applications are outlined. • Conventional and novel atomisers are critically discussed. • Developments in approaches for monitoring atomisation are described. • Effects of feed composition and process variables on atomisation are reviewed. [ABSTRACT FROM AUTHOR]

Abstract Date powder is a promising choice for replacement of white sugar in food formulation, especially due to its natural nutritious substances. In this research, for the first time, the impact of biopolymer complexes on microstructural properties of date powder was studied. So, effects of different concentrations of whey protein concentrate (WPC), pectin, and Tween 80 as well as pH values and temperatures on properties of date powder obtained by spray drying were surveyed through Taguchi approach. Drying yield and color of date powders were measured and microstructural characteristics of date powder were assessed by Fourier transform infrared, differential scanning calorimetry, and scanning electronic microscopy to detect critical changes, e.g. new emerging bonds, ascribed to different drying variables. High drying yield of 70% was achieved when WPC maximized and pH value kept at 5.0. Fourier transform infrared analysis revealed that the temperature of 170 °C and WPC level of 10% played crucial role in obtaining distinctive structure and hydrogen bonds between pectin and WPC of date powder. While glass transition temperatures of date powders were varied between 32.5 and 55.8 °C, higher glass transition temperatures seemed to be due to thermal shields caused by either film formation of WPC (in some treatments) or more protein-polysaccharide complex formation (in other treatments). Considering all parameters, 1% surfactant, 5% pectin, 10% WPC at drying temperature of 170 °C and pH value of 8.5 were determined as optimum values. Highlights • Effect of WPC-pectin complex on drying quality was surveyed for the first time. • Effect of WPC level on microstructure of date powder seems to be critical. • Pectin had the highest effect among all variables on production yield of date powder. • WPC shows distinctive thermal protection for date powders at its isoelectric point. [ABSTRACT FROM AUTHOR]

Abstract: The present study aimed to conduct a simultaneous optimization of different carrier agents and temperatures for the production of jaboticaba extracts by spray-drying microencapsulation. The 30% maltodextrin (control), 25% arabic gum + 5% maltodextrin and 25% Capsul™ + 5% maltodextrin carriers were used at air-drying inlet temperatures of 140, 160 and 180°C. The following responses were evaluated: anthocyanin retention (AR), moisture content (MC), total solids (TS), hygroscopicity (H), overall color difference and antioxidant activity. Scanning electron microscopy (SEM) analysis was also performed. The AR, MC, H and overall color difference parameters were selected for simultaneous optimization by the desirability approach. The results showed that the highest desirability (0.7–0.8) was achieved when 30% maltodextrin was used at 180°C. According to the SEM analysis, the use of maltodextrin and gum arabic allowed for the formation of more homogeneous particles, which is recommended in spray-drying microencapsulation. [Copyright &y& Elsevier]

Abstract: A steady state mathematical model for cocurrent spray drying was used to find the optimal spray drying process for sugar-rich foods. Maltodextrin-sucrose solution was used as a sugar-rich food model. The optimization of the spray drying process was carried out by finding a set of inlet variables to minimize the between the outlet air temperature and the glass transition temperature of the final products. The minimization was simplified by approaching the outlet drying air and average powder moisture content with the polynomial equations of the inlet variables in a range of interest. The drying condition at the lowest between outlet air temperature and product glass transition temperature provided the highest powder recovery at the cyclone obtained from experiment. This result shows that the stickiness of a particular sugar-rich food in spray drying can be minimized by choosing proper inlet variables using the glass transition temperature concept. [Copyright &y& Elsevier]

The purpose of this study is to evaluate the properties of encapsulated lysozyme (at 0.714 g/L concentration) by spray-drying as well as the effect of complexation with increased pectin concentrations (0–4 g/L) on the preservation of lysozyme structure and activity. Maximum turbidity of spray-dried complexes was lower than unprocessed ones at a threshold pectin concentration above which turbidity was reduced. This result could be attributed to the formation of more individual complexes with decreased aggregation upon application of spray-drying due to configurational changes of the complexes. At higher pectin concentrations (above 0.5 g/L), spray-dried complexes exhibited lower antimicrobial activity compared with unprocessed complexes probably because of high limitation in diffusion and accessibility of substrate to active sites of the encapsulated enzyme within the polysaccharide network. Conformational changes of lysozyme and formation of complexes with pectin upon spray-drying were determined by using fluorescence and UV–Vis absorption measurements. The results revealed that spray-drying had a significant effect on lysozyme structure, activity, and mobility particularly at higher pectin concentrations (above 0.5 g/L). [ABSTRACT FROM AUTHOR]

Highlights: [•] A micro-fluidic-jet spray dryer was used to fabricate SFD and SD uniform skim milk microparticles. [•] Higher feed solid content led to spherical and hollow SD microparticles with less shrinkage. [•] The majority of fat enrichment on the surface was during atomization regardless of the feed solid content. [•] Larger proportion of protein migration to surface happened during drying, and was retarded by higher feed solid content. [•] Higher feed solid content led to SD microparticles of better wettability, but lower solubility. [ABSTRACT FROM AUTHOR]

Advances in existing drying techniques are essential for upgrading large scale industries. Enzymes are often degraded by drying processes. Spray drying (SD) has detrimental effects on bioactive molecules at high temperatures. Freeze-drying (FD) is a reference technique capable of drying sensible molecules at low temperature. In this paper, electrostatic spray drying (ESD) was utilized for the first time to encapsulate β-gal (β-galactosidase) and compared with conventional SD and FD techniques. Matrices such as maltodextrin, trehalose, shellac, skim milk and arabic gum were used to encapsulate β-gal. The residual enzyme activity was analyzed based on lactose hydrolysis and quantified using HPLC. Morphologies, particle sizes, shapes and reconstitution times were also compared. SD at inlet air temperature of 170 °C, degraded enzyme functionality and reconstitution ability. ESD at intermediate temperatures (inlet/outlet – 90 °C/44 °C) produced microparticles with better characteristics than SD. In addition, ESD microparticles showed maximum preservation of β-gal in maltodextrin, trehalose, and shellac with a 1–3 kV voltage supply, and the residual enzyme activity was similar to that of FD. Thus, ESD is an alternative technique to FD, which is often considered efficient, but time consuming and expensive. [Display omitted] • β-galactosidase was efficiently microencapsulated in different stabilizing matrices. • Enzyme activity was highly recovered after ESD & FD microparticles rehydration. • SD with 170 °C inlet air temperature degraded the enzyme functionality. • ESD was capable to encapsulate β-gal with better microparticle characteristics. [ABSTRACT FROM AUTHOR]

Abstract: A predictive tool (SD2P®) based on a drying by desorption method was recently developed in order to determine the key process parameters values prior to spray drying. However, the SD2P® software cannot currently take into account the risk of stickiness during the process. In the study reported here, new standardized desorption method was tested and with this new method an equation was proposed to evaluate the dry glass transition temperature (T g) of a concentrate according to its total solid content, its viscosity and its average evaporation rate. The concentrate’s behaviour during spray drying could then be predicted on the basis of the T g. Four validation experiments were performed using different infant formula samples; the concentrates prepared from the four infant formula powders were then spray dried using a one-stage pilot dryer. The drying parameters were predicted using the SD2P® software. The results showed that the T g predicted using this method were 18–30°C higher than T g measured by DSC (Differential Scanning Calorimetry). The drying temperatures predicted by SD2P® corresponded well to the values measured and this new method can correctly predict the behaviour of a concentrate with regard to spray drying. The advantage of the method presented here is that it can easily and quickly evaluate a concentrate’s T g range and spray drying behaviour by direct analysis of the fresh concentrate sample. [Copyright &y& Elsevier]

Abstract: The stability of microencapsulated fish oil prepared using various drying methods is investigated. The fish oil with ratio of 33/22, eicosapentaenoic acid (EPA):docosahexaenoic acid (DHA), is emulsified with four combinations of matrices, and emulsions are dried by spray granulation (SG), spray drying (SD), and freeze drying (FD) to produce 25% oil powders. The objective is to identify the most critical factors to determine powder stability and to further examine the superiority of the SG process compared to other drying processes. The stability is examined by measurement of peroxide values (PV) and GC-headspace propanal after 8-week’s storage at room temperature (±21°C) The best matrices are a combination of 10% soybean soluble polysaccharide (SSPS) and 65% octenyl succinic anhydride (OSA-starch). Microencapsulation of 620mg/g omega−3 fish oil with these matrices then dried by SG is able to produce powder having a very low propanal content and with a shelf life of 5weeks at ±21°C. The results indicate that microcapsules produced by SG are actually formed firstly by agglomeration of seed particles. These agglomerated particles are then covered by successive layers. The particle enlargement is determined by mechanism of the layer growth. Therefore, the SG process produces “multiple encapsulations” granules which provide maximum protection to the oil droplets. Comparison of the SG, SD, and FD processes confirms that combination of matrices, drying temperature, microcapsule morphology, and processing time are among the most critical factors governing stability. Exposure to heat is proved to be a limiting factor for drying unstable emulsion. [Copyright &y& Elsevier]

Abstract: A new and modified spray drying setup was arranged to produce spray-dried crystalline lactose particles. According to Williams–Landel–Ferry kinetics (WLF), it was suggested that a higher particle temperature and lower glass-transition temperature would increase the crystallization rate of the particles during the spray-drying process while still giving dry powders. The new experimental setup allowed the particle temperature to reach higher values by using an insulated drying chamber and also allowed the particle glass-transition temperature to reach lower values by maintaining a higher gas humidity with the aid of a condenser unit attached to the dryer. Modulated differential scanning calorimetry (MDSC) and moisture-induced sorption analysis were used to verify the crystallinity of the spray-dried lactose powders. These analyses showed a higher degree of crystallinity for the particles than have previously been reported in the literature. X-ray diffraction and Raman spectroscopic analyses were further used to identify different lactose anomers. The results suggest that only α-lactose anomer exists in the products as obtained from the modified spray-drying system. The micrographs from scanning electron microscopic analysis also indicated a very crystalline nature for the particles. [Copyright &y& Elsevier]

Abstract: The most frequently used technique for dehydration of dairy products is spray drying. This is an effective method for preserving biological products as it does not involve severe heat treatment and it allows storage of powders at an ambient temperature. Due to the variety and complexity of the concentrates to be dried, a more rigorous understanding of spray drying based on physico-chemical and thermodynamic properties has now become necessary. However, the current state of the art and knowledge do not allow determination of the parameters of spray drying of dairy products. The only way to determine these parameters is to perform several complex and expensive experiments with spray dryer pilots. In this study, a new method was developed to evaluate the ratio of bound to unbound water by using drying by desorption. The results, combined with thermodynamic and physico-chemical parameters (such as, absolute and relative humidity of air, total solids and temperature of concentrate, and air flow rate), provide more precise determination of certain spray drying parameters such as inlet air temperature and mass flow rate. More than 50 experiments were performed to correlate calculated and measured parameters in a pilot plant (Bionov) using water, skim milk, infant formula milk, caseinate maltodextrin and other food concentrates. The results showed that the difference between the calculated and measured inlet air temperature was less than 5%, the determination coefficient being close to 0.96. The economic value of this system is obvious, because it is easy to anticipate the spray drying parameters by using a controller integrating the water availability of the concentrate and certain thermodynamic parameters. Software based on this step was developed (SD2P®, spray drying parameter simulation and determination) and registered at the APP (Association pour la Protection des Programmes). [Copyright &y& Elsevier]

Abstract: A steady state mathematical model for co-current spray drying was developed for sugar-rich foods with the application of the glass transition temperature concept. Maltodextrin–sucrose solution was used as a sugar-rich food model. The model included mass, heat and momentum balances for a single droplet drying as well as temperature and humidity profile of the drying medium. A log–normal volume distribution of the droplets was generated at the exit of the rotary atomizer. This generation created a certain number of bins to form a system of non-linear first-order differential equations as a function of the axial distance of the drying chamber. The model was used to calculate the changes of droplet diameter, density, temperature, moisture content and velocity in association with the change of air properties along the axial distance. The difference between the outlet air temperature and the glass transition temperature of the final products (ΔT) was considered as an indicator of stickiness of the particles in spray drying process. The calculated and experimental ΔT values were close, indicating successful validation of the model. [Copyright &y& Elsevier]

A description of morphological changes of particles along spray drying was carried out by means of scanning electron and light microscopy. Samples of atomized material (40% maltodextrin solution) were withdrawn during drying from a laboratory spray drier at various vertical distances from the atomizing nozzle, photographs of these materials were taken and images analyzed for detecting processes such as crust formation, inflation and shrinking. Final product was analyzed by SEM, mean size of particles determined and fractal dimension of projected perimeter was evaluated by means of the box counting method. This parameter of particles allowed for distinguishing between irregular and smooth contours of final powders. It was possible to explore qualitative relations of morphology and moisture content of particles with air drying temperatures along the actual drying operation, especially those related to breakage and inflation (intermediate and high drying temperatures) and with collapse (low-temperature drying). [Copyright &y& Elsevier]

Tomato powders were produced by spray drying tomato pulp using a modified spray drying system. Modifications to the original dryer design consisted of connecting the spray dryer inlet air intake to an air dehumidifier. Samples of tomato pulp with a 14% constant total solids concentration were used. Sixty-four different experiments were conducted keeping constant the feed rate, the feed temperature and the atomizer pressure, and varying the compressed air flow rate, the flow rate of drying rate, and the air inlet temperature. In all experiments, the atomizer pressure, the feed rate and the feed temperature were kept at 5 ± 0.1 bar, 1.75 ± 0.05 g/min, and 32.0 ± 0.5 °C respectively. The variable operating conditions were within the following ranges: inlet air temperatures 110–140 (±1) °C; drying air flow rate 17.50–22.75 (±0.18) m3/h, and compressed air flow rate 500–800 (±20) l/h. The tomato powders were analyzed for moisture content, bulk density and solubility.Analysis of experimental data yielded correlations between the powder properties and the variable operating conditions. Regression analysis was used to fit mathematical models to the data of each of the powder properties evaluated. Comparisons between the moisture content, the bulk density, and the solubility of powders produced by the two drying systems proved that the use of dehumidified air, promoting rapid particulate skin formation, decreased powder moisture content and increased powder bulk density and solubility. The modified spray drying system proved advantageous over the standard laboratory spray dryer. Preliminary air dehumidification improved not only product recovery, but, also product properties. [Copyright &y& Elsevier]

This work investigates the performance of a modified spray dryer for tomato powder preparation by spray drying of tomato pulp. A pilot scale spray dryer (Buchi, B-191) with cocurrent operation and a two-fluid nozzle atomizer was employed for the spray drying process. The modification made to the original design consisted in connecting the spray dryer inlet air intake to an absorption air dryer. Samples of tomato pulp with a 14% constant total solids concentration were used. Sixty-four different experiments were conducted keeping constant the feed rate, the feed temperature and the atomizer pressure, and varying the compressed air flow rate, the flow rate of drying rate and the air inlet temperature.Data for the residue remaining on the walls and for the product collected in the receiving vessel were gathered. Analysis of experimental data yielded correlations between product recovery and the variable operating conditions. The modified spray drying system was proved advantageous over the standard laboratory spray dryer. Preliminary air dehumidification reduced residue accumulation, allowing the product to be dried at lower air outlet temperatures. [Copyright &y& Elsevier]

Abstract: Bifidobacterium Bb-12 was microencapsulated by spray drying with whey. This present work investigated the survival of these microcapsules under simulated gastrointestinal conditions, as well as their tolerance to NaCl and their viability during storage. The results showed a small decrease in the viability of microencapsulated Bifidobacterium at low pH. In relation to the exposure of Bifidobacterium to bile, microencapsulation with whey did not protect the probiotic cells; however, the viability of the microcapsules remained >6log cfu/g, even after 24h of incubation at the highest bile concentration analyzed. No growth was noted with either the free cells or the microencapsulated cells on MRS-LP with NaCl. The viability of the microcapsules stored at 4°C remained high and constant for 12weeks. When the microcapsules were added to a dairy dessert, the probiotic count remained above 7log cfu/g for 6weeks. Therefore, whey is a promising encapsulating agent for Bifidobacterium Bb-12. [Copyright &y& Elsevier]

Breakthrough energy savings were recently projected by a spray-dryer free dairy powder manufacturing process based on superconcentration and granulation. The extent of superconcentration and the recirculation rate of powder for granulation, determines process performance. In this study, the evolution of physical properties during superconcentration and granulation was investigated for a model system (skim milk microfiltrate) using rheological and shear-cell based techniques. Results demonstrated that superconcentration leads to the development of a cohesive non-flowing state. The transition from concentrate to cohesive wet powder regime, manifested as a sharp increase in cohesiveness, occurring at around 82% w/w dry matter (DM). Powder addition for successful granulation was related to DM at the end of the cohesive phase (∼89% w/w DM). Interestingly, laboratory-based rheological and shear cell measurements were well correlated with the amperage of the mixer used; similar measurements could be applied in-process providing a better understanding and control of the product behavior within the system. • Flow behavior of dairy superconcentrates was successfully modelled. • Onset of a highly cohesive phase restricts superconcentration processes. • Shear-cell based tests provide critical information about cohesive phase. • Agitator power consumption reliably reflects evolution in product flow behavior. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to study the influence of spray drying conditions on the physicochemical properties of açai powder. The process was carried out on a mini spray dryer and maltodextrin 10DE was used as carrier agent. Seventeen tests were made, according to a central composite design. Independent variables were: inlet air temperature (138–202°C), feed flow rate (5–25g/min) and maltodextrin concentration (10–30%). Moisture content, hygroscopicity, process yield and anthocyanin retention were analysed as responses. Powder moisture content and process yield were positively affected by inlet air temperature and negatively affected by feed flow rate, which are directly related to heat and mass transfer. Process yield was also negatively influenced by maltodextrin concentration, due to the increase on mixture viscosity. Powders hygroscopicity decreased with increasing maltodextrin concentration, decreasing temperature and increasing feed flow rate. Powders with lower moisture content were more hygroscopic, which is related to the greater water concentration gradient between the product and the surrounding air. Anthocyanin retention was only affected by temperature, due to its high sensitivity. In respect to morphology, the particles produced at higher temperature were larger and a great number of them showed smooth surface. [Copyright &y& Elsevier]

This study evaluated the effect of high-pressure nitrogen (N 2) gas injection prior to spray drying on the subsequent rehydration properties of regular and agglomerated milk protein concentrate (MPC) powders. Conductivity measurements demonstrated a slower release of ions for powders produced using N 2 injection (NI) as they took longer to wet and sink due to their lower density. However, analysis of particle size distribution on reconstitution at both 23 and 50 °C showed an improvement in powder dispersion with NI. Powder solubility, when measured at 23 °C, was higher for the NI powders, while agglomeration negatively impacted solubility. Confocal laser scanning microscopy analysis showed a faster diffusion of dye into MPC powder particles produced using NI. The improvement in powder dissolution with NI was attributed to higher porosity and the presence of air voids which facilitated increased water transfer and accelerated the breakdown of primary powder particles. • Diffusion was higher for powders produced using nitrogen (N 2) gas injection. • Agglomerated powders absorbed more water than non-agglomerated samples. • N 2 injection enhanced the dissolution of regular and agglomerated powders. • Agglomeration alone reduced powder solubility. [ABSTRACT FROM AUTHOR]

Abstract: The introduction of natural fruit fibres as an encapsulating agent has demonstrated encouraging results as a replacement carrier for spray drying sticky materials. The combination of these fruit fibres and bioactives (Hibiscus sabdariffa L.) has created a novel nutraceutical product suitable for a variety of applications in functional food manufacturing. Through characterisation of the product, it appears that the material is appropriate in terms of its moisture content and encapsulation of the bioactive material. It also maintains a free-flowing form under appropriately controlled humidity conditions suitable for manufacturing purposes. The presence of the bioactive material in the fibres does not appear to affect the product size or shape significantly. An unusual moisture change phenomenon was observed during exposure of the spray-dried powder to ambient air. A rapid moisture sorption and gradual slow desorption pattern was seen and is believed to be associated with crystallisation behaviour. [Copyright &y& Elsevier]

Abstract In the present work, five polysaccharides were selected as co-encapsulant of skim milk based matrix and used for the microencapsulation of Lactobacillus paracasei Lpc-37 by spray drying. The morphological characterization, physical properties, encapsulation efficiency, gastrointestinal simulation, and storage stability of microencapsules were examined to evaluate the protective capacity against the adverse conditions of the different wall matrices. Addition of polysaccharides was associated with the enhancement of physical performance of microencapsulated powders, such as the flowability and water activity. Encapsulation matrices containing gum Arabic showed the greatest encapsulation efficiency of 97.1% (maximum survival 7.78 log CFU/g). L. paracasei Lpc-37 encapsulated with the matrices incorporating sodium alginate or sodium carboxymethylcellulose exhibited higher survival (>6.5 log CFU/g) after exposed to simulated gastrointestinal condition and lower viability loss (<0.3 log CFU/g) after 8 weeks of refrigerated storage. The application of polysaccharides, however, showed the tendency of higher hygroscopicity and lower stability of the powders in high temperature and humid environment. Highlights • The applied polysaccharides improved the flowability of microencapsulated powder. • Gum Arabic maintained L. paracasei viable during spray-drying process. • Sodium alginate and sodium carboxymethylcellulose enhanced L. paracasei viability during simulated digestion. [ABSTRACT FROM AUTHOR]

Abstract The objective of this research was to study the co-encapsulation of Coenzyme Q 10 (CoQ 10) and vitamin E (VE) using single droplet drying (SDD) and micro-fluidic-jet spray drying (MFJSD), to study the particle formation-structure-function relationships of the microcapsules. Single droplets of selected CoQ 10 and VE-containing emulsions were studied for their particle formation under convective drying (at 70 and 90 °C for 10 min) and rehydration processes using the SDD device. The emulsions were also spray-dried (at 160 and 190 °C) by MFJSD to form monodisperse microcapsules, followed by analyses of powder properties and functionalities. Results from SDD showed emulsion droplets with 30% w/w solids content were associated with earlier crust formation (30 s faster) and less particle shrinkage during drying compared to those with 10% w/w solid content. Comparing the spray-dried microcapsules produced from the emulsions containing 30% and 10% w/w solids content, the former gave larger particle size (172–175 μ m vs. 116 μ m), higher microencapsulation efficiency (ME) (98–99% vs. 96%), lower tapped density (0.532–0.599 g/cm3 vs. 0.406–0.502 g/cm3) and better flow properties (Carr's index of 22.06–29.19% vs. 22.70–40.64%). Overall, the CoQ 10 and VE retention, antioxidant capacities and colour of the microcapsules were relatively stable when spray-dried at 190 °C than at 160 °C. Highlights • Coenzyme Q 10 and vitamin E were co-encapsulated in powder microcapsules. • Formation-structure-function relationships of microcapsules were investigated. • Emulsions with higher solids content formed skin earlier during drying. • Emulsions with higher solids content produced better quality microcapsules. • Higher spray drying temperature produced more stable microcapsules. [ABSTRACT FROM AUTHOR]

In the present study, peony seed oil was encapsulated using a combination of whey protein isolate, corn syrup and soy lecithin (0.75%) as wall materials by spray drying. This formulation exhibited highest encapsulation efficiency and oxidative stability and least loss of bioactive compounds. The microstructure showed the peony seed oil microcapsules formed a complete core-shell structure with smooth surface and no apparent cracks or fissures. In-vitro digestion behavior showed more than 80% of the encapsulated oil was released from microcapsules after simulated gastrointestinal digestion. [ABSTRACT FROM AUTHOR]

Production of powders of heat sensitive bioactive compounds in a bench scale spray drier was studied under cocurrent and mixed flow pattern conditions using two inlet air temperatures of 200 and 120 °C. Two natural colorants (riboflavin-5-phosphate and red beet) and an enzyme (alpha-amylase), were selected for experimentation. Thermographic studies showed interesting asymmetric profiles of temperatures outside and inside of the drying chamber, because turbulent air flow conditions and thermal trajectories of atomized drops during its drying process were dependent on flow patterns. Powders of natural colorants maintained its color strength, and alpha-amylase powders retain more than 82.9% of its enzyme activity even at the highest air temperature of 200 °C and using mixed flow. This work concludes that spray drying under cocurrent and mixed-flow patterns of heat labile bioactive compounds is feasible, influencing drying yields and the properties of powders obtained. • A commercial spray drier was modified to operate under cocurrent and mixed flow. • Thermographic studies showed asymmetric temperature profiles during spray drying. • Natural colorants were stable even when spray dried under mixed flow at 200 °C. • Alpha-amylase retain more than 82.9% of activity under mixed flow at 200 °C. • Thermographic studies help to select optimal spray drying operation conditions. [ABSTRACT FROM AUTHOR]

Abstract State-space thermodynamic modeling of vanilla ethanolic extracts spray drying with heat pump and N 2 was developed. Thermodynamic modeling considers activity coefficients for Raoult law deviations of ethanol vapor pressure, water vapor pressure, ethanol evaporation latent heat and water evaporation latent heat in a N 2 -ethanol-water-vanilla solids system. State space considers 12 ordinary differential equations (ODEs) for ethanol and water concentrations in solid, N 2 and condensed liquid; temperatures and condensed liquid rate. The model was validated with 32 treatments of vanilla ethanolic extract experimentally spray dried with heat pump and N 2. The mathematical model reproduced the experimental gas outlet temperature with 4% of averaged error. An additional two parameters fit reached 11.4% of averaged error with respect to product outlet moisture and gas outlet temperature simultaneously. Proposed model demonstrated that heat pump spray drying can reach a 58% of thermal efficiency and a conventional spray drying can reach only 30%. Highlights • Ethanolic vanilla extracts were spray dried with heat pump and N2. • State-space thermodynamic model was developed for the process. • Model resulted in 12 ODEs for state variables including the heat pump systema. • Model predicted output temperature with 4% of averaged error. • Thermal analysis and energy saving strategies were developed. [ABSTRACT FROM AUTHOR]

Cocoa hull waste phenolic extract (CHWPE) 1 were encapsulated by fine-disperse anionic liposomes at optimum concentration of 0.2% (w/v) with encapsulation efficiency of 73.6%. Primary anionic liposomes were coated with cationic chitosan (0.4%, w/v) by layer-by-layer deposition method and obtained secondary liposomes were spray dried using maltodextrin as a carrier agent. Bioaccessibility of CHWPE was increased at least 6 fold when encapsulated in secondary liposomes and it did not change during spray drying process after in-vitro digestion. Changes in major phenolic compounds, namely, catechin, epicatechin, quercetin, ferulic acid, gallic acid, p -coumaric acid, syringic acid, transcinnamic acid, vanilic acid and vanillin were investigated before and after in-vitro digestion. p -coumaric acid was the main phenolic compound detected in secondary liposome dispersion with CHWPE, CHWPE powder, and liposomal powder with CHWPE. [ABSTRACT FROM AUTHOR]

Abstract: Different materials appear to crystallize to varying extents inside spray dryers. By comparing the characteristic time scales for both nucleation and crystal growth with sodium chloride and lactose, it is possible to get some insight into why these differences occur. Differences in growth rates during the crystallization step and to glass-transition temperatures during the amorphous to crystalline transition may be the key effects here. The advantages and disadvantages of crystallizing different materials inside spray dryers are also considered, and reasons for not finding crystallization in many spray-dried dairy powders are discussed, with the presence of proteins and other components in milk slowing down the crystallization step. [Copyright &y& Elsevier]

Spray-drying and freeze-drying strategies were used to obtain novel protein powders from an aqueous combination of sodium caseinate and blackcurrant concentrate. The powders differed in physical and functional properties. The effects of incorporating these different novel protein powders into a cookie recipe at a replacement level of 0%, 5%, 10%, and 15% were evaluated in relation to the physicochemical and nutritional properties of cookies. Colour, and texture properties of the cookies, important factors for customer acceptance, changed (p < 0.05) with the addition of these protein ingredients. Protein content increased (p < 0.05) with increasing addition levels, as too did the antioxidant values of the cookies. The addition of these novel protein ingredients reduced (p < 0.05) starch digestion, indicating the potential to be used to develop some functional foods with hypoglycemic effects. • Blackcurrant concentrate, encapsulated in sodium caseinate, has beenincorporated in cookies. • Physical characteristics of fortified cookies were influenced by the encapsulates. • Encapsulates has increased phenolic content and antioxidant activity of fortified cookies. • Encapsulates decreased the in vitro glycaemic response, namely thehypoglycaemic properties. [ABSTRACT FROM AUTHOR]

This study investigated the influence of injecting nitrogen (N 2) gas under high pressure into milk protein concentrate (80%, w/w, protein; MPC) prior to spray drying and examining the physical and bulk handling properties of regular (non-agglomerated) and agglomerated powders. MPC powders produced using the N 2 injection (NI) process had significantly lower bulk density and flowability, higher wall friction angles and increased levels of interstitial and occluded air. Agglomerated MPC powders had higher flow index values, lower wall friction angles, but were more friable, compared to regular powders. Surface composition analysis of MPC powders showed that NI caused fat to preferentially migrate to the surface in comparison to powders spray dried without NI. The results obtained in this study demonstrate that the injection of N 2 into liquid MPC directly prior to spray drying, as well as agglomeration by fines return, can produce ingredients with unique particle and bulk powder properties. • N 2 injection decreased the density of milk protein concentrate powders. • Flow index values of powders decreased with N 2 injection. • Agglomeration by fines return improved powder flowability. • N 2 injection promoted the migration of fat to the surface of powder particles. [ABSTRACT FROM AUTHOR]

This study investigated the influence of injecting nitrogen (N 2) gas under high pressure into milk protein concentrate (80%, w/w, protein; MPC) prior to spray drying and examining the physical and bulk handling properties of regular (non-agglomerated) and agglomerated powders. MPC powders produced using the N 2 injection (NI) process had significantly lower bulk density and flowability, higher wall friction angles and increased levels of interstitial and occluded air. Agglomerated MPC powders had higher flow index values, lower wall friction angles, but were more friable, compared to regular powders. Surface composition analysis of MPC powders showed that NI caused fat to preferentially migrate to the surface in comparison to powders spray dried without NI. The results obtained in this study demonstrate that the injection of N 2 into liquid MPC directly prior to spray drying, as well as agglomeration by fines return, can produce ingredients with unique particle and bulk powder properties. • N 2 injection decreased the density of milk protein concentrate powders. • Flow index values of powders decreased with N 2 injection. • Agglomeration by fines return improved powder flowability. • N 2 injection promoted the migration of fat to the surface of powder particles. [ABSTRACT FROM AUTHOR]

The spray drying process is considered a conventional method to convert liquids to powders with some but at an acceptable level of degradation and oxidation of volatile compounds. Spray drying is based on the preparation, homogenization, atomization, dispersion and subsequently dehydration of the solution. Wall deposition is a key processing problem in the spray dryer particles that indirectly affects the quality and quantity of the product. The degree of wall deposition is affected by several factors including operating parameters, type and size of spray dryer and the spray dryer wall properties. The development of wall depositions in the spray dryer deteriorates the yield of the products and hence increases the costs of manufacturing and maintenance. And constructive models are very resourceful in understanding the mechanism of wall deposition which will result in direct economic benefits to the food industry. The aim of this review is to give a physical and chemical description of the wall deposition mechanism and introduce the classified models to simulate and visualize this behavior in spray dryers. [ABSTRACT FROM AUTHOR]