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Food powders were produced from olive pomace (Coratina, COP, and Arbequina, AOP) using freeze-drying with maltodextrin (MD) and native corn starch (NS) as wall materials in varying proportions. Optical microscopy revealed that OP was partially recovered by MD and NS. COP presented a total polyphenol content (TPC) of 53.8 g GAE/kg; meanwhile, AOP was 31.9 g GAE/kg. Accordingly, powders obtained from COP presented higher TPC than those from AOP. NS allowed obtaining powders with higher TPC and antioxidant activity. The greatest encapsulation efficiency was achieved by using 15% MD, achieving values of 94.9% for COP and 89.4% for AOP. Hydroxytyrosol was identified as the predominant polyphenol in the powders. It was demonstrated that powders could be added to food formulations and withstand cooking temperatures up to 220 °C without suffering a significant thermal degradation. Chemometric analysis of MIR and NIR spectra evidenced that they are analytical techniques capable of differentiating OP varieties and wall material types, besides variations in OP concentration. Results derived from this study demonstrated that it is feasible to give added value to olive pomace, obtaining powders rich in antioxidants to be used as ingredients of functional foods. [ABSTRACT FROM AUTHOR]

Background Results Conclusion The sorption characteristics and glass transition temperature are important attributes that determine the shelf life of foods, particularly in powder form, whereas color is a key factor influencing consumer acceptance. As the popularity of matcha green tea powder is increasing, this study investigated whether the country of origin of examples of matcha products available on the Polish market influenced the sorption properties, glass transition temperature, and color.All matcha powders exhibited sigmoidal water adsorption isotherms at 25 °C. The monolayer moisture content corresponding to the point of maximum stability ranged from 0.045 to 0.053 g water per g of sample. The glass transition temperature of anhydrous matcha powders varied between 106.3 and 139.0 °C. Based on the sorption and glass transition results, the matcha from Brazil should be the most stable during storage. The same sample showed the highest water solubility index values at temperatures above 80 °C and the lowest bulk density. The color parameters (L*, a*, b*, C*, and h) depended on the matcha powder variant.The results indicate that the optimal storage conditions for tea powders do not depend directly on the country of origin. Further research should therefore focus on analyzing the impact of climate or fertilization. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Many functional properties of spray-dried microparticles are affected by the presence and composition of the materials used in the matrix and on the surface. The characteristics of these materials are an essential factor because any damage or alteration on the microparticle surface can affect the protection and retention of the bioactive-loaded delivery system and influence its interaction with the environment. There is a real gap between scientific concerns from the field and accessible reviews on the subject. This review presents a detailed description of the surface modification of spray-dried powders for improving the powder quality, efficiency of the microencapsulation, and microencapsulation process design in food industries. Additionally, the theoretical foundation, mechanisms, and methods used to understand the surface modification of spray-dried food powders are highlighted. Therefore, for a better understanding of the mechanisms involved in the particle surface formation, the application of advanced microscopy techniques and x-ray photoelectron spectroscopy (XPS) used together have offered very precise and detailed results under different conditions at the molecular level. These findings will contribute to further research improvement about the surface composition of spray-dried microparticles and how they influence on their functional properties. [ABSTRACT FROM AUTHOR]

The extrusion processing of food powder relies heavily on its moisture content to aid in flow and proper cooking, shaping, and/or puffing. This study focused on the impact of the moisture content on the dynamic flow and shear properties of coarse food powders (corn meal, wheat farina, and granulated sugar). The dynamic flow properties explored were the specific basic flowability energy (SBFE), specific energy, stability index, and flow rate index. The shear properties were the angle of internal friction, unconfined yield strength, major principal stress, wall friction angle, flow factor (FF), and compressibility. Corn meal exhibited an increase in SBFE as the moisture content increased (6.70 mJ/g at 13.13% to 9.14 mJ/g at 19.61%) but no change in FF (4.94 to 5.11); wheat farina also showed an increase in energy requirement as the moisture increased (5.81 mJ/g at 13.73% to 9.47 mJ/g 19.57%) but a marked decrease in FF ratings (18.47 to 6.1); granulated sugar showed a decrease in energy requirements as the moisture increased (51.73 mJ/g at 0.06% moisture content to 13.58 mJ/g at 0.78% moisture content) and a decrease in FF ratings (8.53 to 3.47). Overall, upon the addition of moisture, corn meal became cohesive yet free-flowing; wheat farina became less compressible and more cohesive; and granulated sugar became more cohesive and compressible and less free-flowing. [ABSTRACT FROM AUTHOR]

The effect of short-term storage at 75% and 90% ambient humidity on the mechanical properties of selected materials was determined using a new device for measuring the strength of food powders. A series of tests were conducted on wheat flour and potato starch subjected to various consolidation loads. The high accuracy and repeatability of the measurements confirmed the suitability of the pull-based tester for assessing the degree of caking in food powders. The pull-based tester allows for the measurement of strength parameters of agglomerates under various consolidation loads while simultaneously wetting the powder, introducing a novel approach to assessing the mechanical properties of powders. The analysis of force oscillation during the withdrawal of the measuring rod from the powder facilitates the identification of the slip-stick effect in these materials and the determination of parameters characterizing that phenomenon. The outcomes of this study may be of interest to farmers, manufacturers, and companies processing raw materials. [ABSTRACT FROM AUTHOR]

Agglomeration is a technological process that is widely applied to obtain powdered products with the appropriate shape and particle size and different physical characteristics and stabilities. The purpose of this research was to study the influences of the composition and storage of powdered infant formulas on their thermal behaviours, as analysed by differential scanning calorimetry (DSC); fatty acid compositions, as determined by gas chromatography; and water activity and water content. This study investigated the influence of the storage time (six months) at temperatures of 20–22 °C and air humidities of 42–45% on powder mixtures and agglomerates. The isotherms of the agglomerates presented a shape and course similar to those of the isotherms of the mixtures from which they were obtained. The agglomeration process affected the stability of the fatty acids in the stored powdered infant formulas. The composition of the fatty acids changed during the storage process. The thermal properties of the powdered infant formulas were not significantly influenced by agglomeration. The compositions of the mixtures and agglomerates influenced the shape and course of the DSC diagrams. Using the DSC method, it was determined whether the fat was a natural component of the powder or it was added in the form of fatty acid preparations. Differences were observed between the shape and course of the DSC curves (heating and cooling) obtained for fresh and 6-month-stored mixtures and agglomerates. [ABSTRACT FROM AUTHOR]

Spray drying is a well-established approach to converting liquid food into powder. This review discusses four types of spray drying techniques currently being used for that purpose, namely: pulse combustion (PC) spray drying, electrostatic spray drying (ESD), nano spray drying (NSD), and extrusion porosification (EP). PC spray drying is still in the development phase in the food sector, having the disadvantage of lacking industrial technology for heat-sensitive foods like milk or whey protein concentrates. On the other hand, it is able to reduce or even eliminate the viscosity limitations of atomizers, in addition to being considered a potential energy-saving option compared to conventional spray drying. ESD and NSD show promise in drying bioactive or heat-sensitive compounds like enzymes, cells, and vitamins. A nano spray dryer contains a spray mesh technology and electrostatic collector, which results in variations in particle size and product yield compared to traditional spray drying. However, the current types of equipment are only available on a laboratory scale. Also, NSD could be unfavorable when considering the low concentrations of feed solutions (0.1–1 % w/v). Finally, EP is claimed to provide better physical powder characteristics and permit the drying of highly concentrated liquids. It is hoped that these additional features and technologies will be further investigated in food systems to enhance process performance and improve powder properties.

ABSTRACTSuperfine grinding is a cutting-edge food powder processing technology that produces particle sizes as small as the nano-level, resulting in products with exceptional characteristics. This review evaluates the potential benefits of superfine grinding in modifying functional properties, enhancing nutritional qualities, antioxidant activities, and sensory acceptability of food products. The technology has proven useful in producing functional foods, pharmaceuticals, nutraceuticals, and instant foods. By reducing particle size, superfine grinding increases surface area, resulting in powders that disperse easily, have excellent infusion properties, and release more efficient bioactive substances. Superfine grinding technology is vital for modifying functional properties and improving the bioavailability of nutrients and antioxidants, which conventional grinding methods cannot achieve. Moreover, superfine ground products have better sensory acceptability than their coarse counterparts. However, more research is needed to determine the effects of superfine grinding on anti-nutritional factors, heat-sensitive vitamins, and minerals in food products.

The aim of this work was to demonstrate the potential of the concept of clean-label-capable flow additives. These are spray-dried food ingredients whose particle size is small enough (

In multi-stage spray dryers, agglomeration is forced by recirculating fine material into the nozzle zone. Drying droplets collide with dry particles and form agglomerates. The aim of this study was to achieve a more comprehensive understanding and control of agglomerate formation. Agglomerates with different properties were produced using a pilot spray drying plant. An increased air mass flow of the fluidized bed as well as a reduced solids content of the feed solution resulted in an increased number of primary particles per agglomerate. A residence time-based approach was then applied to determine the agglomeration efficiency, defined as the number of successfully adhered primary particles per recirculation. It ranged from 0.33 to 0.71 and was correlated to collision and sticking probabilities in the nozzle zone. This value is of importance both for process optimization and for the validation of simulation approaches. [ABSTRACT FROM AUTHOR]

The Andean blueberry (Vaccinium meridionale Sw) is an underutilized wild fruit native to South America. It is known for its antioxidant properties and potential health benefits. In this study, Andean blueberry juice powders were produced via spray drying, using maltodextrin (MD), gum Arabic (GA) or a combination of both (MD:GA) as wall materials. The spray-dried juices were analyzed for the recovery percentage of total polyphenols and monomeric anthocyanins, as well as for their physicochemical and technological properties. Results showed that the type of carrier agent used caused statistically significant differences in the bioactive content and the antioxidant activity of the powders (p < 0.05). It was found that the MD samples has the highest monomeric anthocyanins content (0.88 ± 0.02 mg cyanidin 3-glucoside equivalents/g) and the highest anthocyanins recovery (96.3 ± 1.7%), while the MD:GA powders showed the highest values of total polyphenol content (5.70 ± 0.09 mg gallic acid equivalents/g), DPPH scavenging capacity (2.49 ± 0.02 mg gallic acid equivalents/g) and phenolics recovery (87.2 ± 1.1%). Furthermore, all the spray-dried powders exhibited low moisture content (<5.5%) and water activity (<0.40), as well as high solubility in water (>94%) and good flowability. Future prospects include evaluating the stability of the Andean blueberry juice powders during storage and exploring the formulation of new foods and beverages that incorporate these spray-dried powders. [ABSTRACT FROM AUTHOR]

Agglomeration is a technological process that is widely applied to obtain powdered products with the appropriate shape and particle size and different physical characteristics and stabilities. The purpose of this research was to study the influences of the composition and storage of powdered infant formulas on their thermal behaviours, as analysed by differential scanning calorimetry (DSC); fatty acid compositions, as determined by gas chromatography; and water activity and water content. This study investigated the influence of the storage time (six months) at temperatures of 20–22 °C and air humidities of 42–45% on powder mixtures and agglomerates. The isotherms of the agglomerates presented a shape and course similar to those of the isotherms of the mixtures from which they were obtained. The agglomeration process affected the stability of the fatty acids in the stored powdered infant formulas. The composition of the fatty acids changed during the storage process. The thermal properties of the powdered infant formulas were not significantly influenced by agglomeration. The compositions of the mixtures and agglomerates influenced the shape and course of the DSC diagrams. Using the DSC method, it was determined whether the fat was a natural component of the powder or it was added in the form of fatty acid preparations. Differences were observed between the shape and course of the DSC curves (heating and cooling) obtained for fresh and 6-month-stored mixtures and agglomerates.

Agglomeration in multi-stage spray dryers for food powder production is typically implemented by recycling fine material into the spray cone. The improved flow and reconstitution properties are offset by a process without direct control options. This study shows that the proportion of recycled fines allows for a more direct characterization of agglomerate formation during the process. With a measurement system based on isokinetic sampling, it was demonstrated that a total solids content of the feed solution of 30 to 50 %(w/w) resulted in a relative fines mass flow from 5.8 to 4.3 at constant process parameters. Increasing the main drying air mass flow had no effect on the relative mass flow of fines. As the fluidized bed air mass flow rate was increased, more particles were recycled, the relative mass flow rate of fines and the extent of agglomeration increased. Correlation to agglomerate size, porosity and shape confirmed that fines mass flow is a fundamental parameter for controlling and scaling agglomeration in the nozzle zone. [ABSTRACT FROM AUTHOR]

Superfine grinding is a cutting-edge food powder processing technology that produces particle sizes as small as the nano-level, resulting in products with exceptional characteristics. This review evaluates the potential benefits of superfine grinding in modifying functional properties, enhancing nutritional qualities, antioxidant activities, and sensory acceptability of food products. The technology has proven useful in producing functional foods, pharmaceuticals, nutraceuticals, and instant foods. By reducing particle size, superfine grinding increases surface area, resulting in powders that disperse easily, have excellent infusion properties, and release more efficient bioactive substances. Superfine grinding technology is vital for modifying functional properties and improving the bioavailability of nutrients and antioxidants, which conventional grinding methods cannot achieve. Moreover, superfine ground products have better sensory acceptability than their coarse counterparts. However, more research is needed to determine the effects of superfine grinding on anti-nutritional factors, heat-sensitive vitamins, and minerals in food products. [ABSTRACT FROM AUTHOR]

Maltodextrins are extensively used in the food industry to shape the physicochemical properties of food products. This multiscale study investigates three different Dextrose Equivalent (DE) maltodextrins as model matrices to elucidate the relationship between techno-functional behaviors and single particle surface properties. It was evidenced that environmental variations and glass transition influence single particle properties, significantly impacting the powder bulk behavior. Utilizing Confocal Laser Scanning Microscopy (CLSM) and environmental Atomic Force Microscopy (AFM) at the single particle level, correlations between the wetting and nanomechanical properties of all maltodextrins were provided. It was revealed that wetting properties are directly DE dependent, as higher DE maltodextrins had shorter wetting times. Moreover, glass transition plays a critical role in determining surface elasticity and capillary adhesion, as it alters both physicochemical properties and particle morphology. Indeed, a decrease of the Young modulus with Relative Humidity (RH) and glass transition correlated with the increase of capillary forces. This was corroborated by Scanning Electron Microscopy (SEM) and Specific Surface Area (SSA) measurements at different RH. These findings confirmed that glass transition drives particle morphology, with global surface smoothing and swelling occurring in the rubbery state. [Display omitted] • Environmental AFM was used to probe Young modulus and capillary adhesion evolution. • SEM was used to follow particle morphology evolution over RH and glass transition. • Reconstitution kinetics of single maltodextrins particle were studied by CLSM. • Specific surface area of maltodextrins was proved to be DE and Tg dependent. [ABSTRACT FROM AUTHOR]

The Andean blueberry (Vaccinium meridionale Sw) is an underutilized wild fruit native to South America. It is known for its antioxidant properties and potential health benefits. In this study, Andean blueberry juice powders were produced via spray drying, using maltodextrin (MD), gum Arabic (GA) or a combination of both (MD:GA) as wall materials. The spray-dried juices were analyzed for the recovery percentage of total polyphenols and monomeric anthocyanins, as well as for their physicochemical and technological properties. Results showed that the type of carrier agent used caused statistically significant differences in the bioactive content and the antioxidant activity of the powders (p < 0.05). It was found that the MD samples has the highest monomeric anthocyanins content (0.88 ± 0.02 mg cyanidin 3-glucoside equivalents/g) and the highest anthocyanins recovery (96.3 ± 1.7%), while the MD:GA powders showed the highest values of total polyphenol content (5.70 ± 0.09 mg gallic acid equivalents/g), DPPH scavenging capacity (2.49 ± 0.02 mg gallic acid equivalents/g) and phenolics recovery (87.2 ± 1.1%). Furthermore, all the spray-dried powders exhibited low moisture content (94%) and good flowability. Future prospects include evaluating the stability of the Andean blueberry juice powders during storage and exploring the formulation of new foods and beverages that incorporate these spray-dried powders.

Quantitative data on powder swelling kinetics is essential to understand phenomena occurring during rehydration, e.g. lump formation. In this study, swelling kinetics of food powders (gelatin powder, soy protein isolate, pea protein concentrate) were quantified by Nuclear Magnetic Resonance (NMR) relaxometry. Using gelatin plates as a model system, it was successfully demonstrated that NMR relaxometry is an efficient, non-destructive method to study swelling kinetics of non-dissolving systems with moderate swelling speeds. For plant-based proteins, high swelling speeds were observed. The obtained maximum water uptake due to swelling was 5.10 ± 0.80 g/g for soy protein isolate and 3.93 ± 0.16 g/g for pea protein isolate, which is in the expected range. Measurement speed was too low to resolve early swelling kinetics (below 84 s), evaluation was more elaborate and results less unambiguous. [Display omitted] • Successful investigation of NMR relaxometry as method to quantify powder swelling. • Water uptake of gelatin quantified with high accuracy using NMR. • Plant-based protein powders swell significantly faster than gelatin powder. • Quantification of water uptake possible for plant-based proteins but more complex. • Method recommended especially for slow and strongly swelling material. [ABSTRACT FROM AUTHOR]

Many consumer food products such as confectionary or culinary seasonings are particle-based systems containing varying amounts of lipids such as oils, fats, and greases. Lipid migration is the result of inherent metastability of multiphasic particulate food systems. Lipid instability is further aggravated by climatic conditions, interaction with packaging, porosity, material transitions, and even gravity. Resulting lipid mobility can lead to various quality defects such as fat bloom on chocolate or oil stains on fibrous paper-based wrappers. This review revisits the factors influencing lipid migration and the generally accepted transport mechanisms diffusion and capillary flow. The most common measurement methods and modelling approaches described in the literature are discussed and assessed. Modern mitigation strategies to control lipid mobility are reviewed, with discussion on applicability to different particle-based food types and structures. Current trends towards healthier diets, clean-label recipes and sustainable packaging challenge traditional methods to stabilise lipids in food. As such a fundamental understanding, and measurement, modelling and mitigation strategies of lipid migration are highly relevant for a wide range of lipid-containing particulate foods. [Display omitted] • Two thirds of consumer foods are sold in particle-based forms and contain lipids. • Oil, fat and grease are subject to migration within and out of the particle system. • Lipid leaking results in quality defects on the food surface and the packaging. • Modern migration measurement techniques, diffusion and capillary models are reviewed. • Innovative oil stabilisation strategies for particulate foods types are discussed. [ABSTRACT FROM AUTHOR]

The major limitation of the use of superheated steam spray drying (SHS-SD) for food products is the missing proof of its applicability for heat sensitive materials. A selection of food, in particular dairy products, were spray dried under superheated steam conditions in a lab scale spray dyer with an inlet steam temperature of 250 °C and outlet steam and product temperatures between 130 and 160 °C by pressure nozzle atomization. Powder attributes show that superheated steam spray drying of heat sensitive food products is technically feasible and does not necessarily result in major quality loss such as severe browning. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate oil and water absorption capacity of wheat, rice, and gram flour. The experiment was designed using Taguchi experimental model for observing best formulations of food powders. The experiment was design according to following formulations i.e. wheat flour (100, 80, 75, 70, 20 and 10 g), rice flour 100, 80, 75, 70,25,20,10 g) and gram flour (100, 80, 75, 70, 25,10g) were used to make food powder formulations. Each sample with formulations were analyzed for physiochemical and functional properties. The observations were determined (i.e., moisture, loose bulk density, tapped density, ash, dry matter, gluten, and functional properties swelling capacity, least gelation concentration (LGC), foam capacity (FC), foam stability (FS), emulsion capacity (EC), oil holding capacity (OHC) and water holding capacity (WHC)). The present study was resulted that the highest value of moisture, loose bulk density, tapped density, dry matter, gluten, swelling capacity, least gelation concentration, foam capacity, foam stability, emulsion capacity, water holding capacity and oil holding capacity were 55.54%, 0.97 g/mL, 0.98, 66.46%, 0.98%, 4.42%, 32.28%, 15.67, 26.77%, 20.24%, 22.49%, 20.22 g of water/g of flour and 22.53 g of oil/g of flour, respectively. The obtained results showed a remarkable wheat, rice and gram flours of water holding capacity and oil holding capacity, which indicates the enhanced hydrophobic character of proteins in the flours. The results were confirmed under industrial conditions, and can be considered as favorable for the preparation of viscous foods such as soups, gravies and bakery products. As well as wheat, rice and gram flour would improve the texture and quality of those foods products which are currently prepared from wheat, rice and gram flour. [ABSTRACT FROM AUTHOR]

This study aimed at evaluating the drying of mango-based pulps and the rehydration properties of the resulting powders produced by cast-tape drying (CTD), freeze drying (FD), and spray drying (SD). Mango powders were characterized for wetting time, contact angle, and solubility, as well as reconstituted with distilled water for the determination of color, particle size distribution, rheology, and microstructure. Mango powders produced by CTD and FD presented the smallest contact angles, shortest wetting times, and highest solubility. All the reconstituted pulps showed pseudoplastic behavior. Mango pulps reconstituted from powders produced by SD and FD have a color similar to the raw pulp, differently for those produced by CTD (with and without maltodextrin) result of oxidation reactions that change the powder color. The selection of the drying process determines the specific characteristics of the resulting powder and reconstituted suspension because the rheological behavior of reconstituted fruit pulps is an essential property to be considered for its use. Mango pulps reconstituted from powders produced by SD are suitable for juice preparation, due to their less viscous characteristics. CTD and FD mango powders could be used in numerous food formulations. [ABSTRACT FROM AUTHOR]

Spray-dried milk powders are characterized by an underrepresentation of hydrophilic compounds on the particle surface compared to the bulk, which renders reconstitution unfavourable. To overcome this issue, in the present study we instigated the coating of whole milk powder with two types of micronized lactose: crystalline and amorphous. We demonstrate that deposition of micronized lactose on the surface of whole milk powder leads to an increase in the reconstitution rate at 21 °C, correlated with a decrease in the apparent contact angle of the material. We also show that the physical solid state of micronized lactose is an important factor influencing the reconstitution performance of coated whole milk powder; If micronized lactose is amorphous, increasing the coating concentration beyond a certain point has little or no further effect on the reconstitution kinetics, which could be explained by viscosity build-up effects that hamper capillary penetration and sinking. [Display omitted] • Dry coating of whole milk powder with micronized lactose (crystalline/amorphous) • Enhancement of powder wettability and reconstitution at 21 °C • Powder sinking is influenced by the physical solid state of the coating material [ABSTRACT FROM AUTHOR]

During agglomeration in the nozzle zone of spray dryers, dry particles are forced to collide with drying droplets. These collisions ideally form agglomerates with improved flowability and reconstitution properties. However, the interactions of feed parameters on the collision outcomes are unclear. This study examines the influence of a varied total solid content of the feed solution on agglomerate formation in a pilot plant spray dryer. An increase in total solid content (TS) from 30 to 50% TS (w /w) resulted in an increase in porosity of the primary particles, whereby particle size development was reasoned by this effect. Agglomerate porosity increased but agglomerate size increased more due to a changed particle viscosity. By adding a marker powder, it was found that higher total solid contents resulted in less coalescence of the agglomerates. The counter-current air classification in the drying chamber affected the agglomerate properties such as size, density and shape. To investigate the fast micro processes during agglomeration in spray dryers, a marker powder stream was added into the spray zone. Total solid content of the feed solution and amount of marker powder influenced agglomerate properties. [Display omitted] • Increased total solid content caused increased primary particle porosity. • Effect on agglomerates' size caused by stickiness is more pronounced. • Marker powder enables variation of agglomerate properties. • Agglomerate properties result from air classification effect in the drying chamber. [ABSTRACT FROM AUTHOR]

An empirical equation was obtained to estimate the concentration distribution in a horizontal helical double-ribbon mixer for cohesive food powders for different load ratios, f, and rotational speeds, N. The mixing times were determined for f = 0.56, 0.61, 0.66 and N = 50, 75, 100 rpm. The highest mixing rate coefficient and lowest mixing time were obtained for an impeller speed of 100 rpm and a load ratio of 0.56. The product of mixing time, tM, and coefficient of mixing rate, ϕ, for different impeller speeds under the same load ratio was constant and characterized the impeller performance. [ABSTRACT FROM AUTHOR]

Summary: In this study, the oxygen barrier and physical properties of two maltodextrin/gum Arabic (MD/GA) (3:1 w/w) microcapsules with dextrose equivalence (DE) 26 and 6 were assessed with or without the incorporation of cellulose nanofibres (CNF). The oxygen diffusion coefficient (Deff) was between 10.6 × 10−15 m2 s−1 and 17.3 × 10−15 m2 s−1 for all microcapsules. The addition of CNF improved the oxygen barrier of MD/GA microcapsules. The incorporation of CNF did not significantly impact Tg due to the low quantity of CNF present in the microcapsules. Wettability was higher in CNF incorporated microcapsules, and dispersibility was lower only for microcapsules with maltodextrin of DE 26. Spray‐dried microcapsules exhibited poor flowability and high cohesiveness due to the moisture content (2.0–2.5%) of the powders. The results suggest that incorporation of CNF can increase the oxygen barrier of MD/GA microcapsules which may lead to better oxidative stability of micronutrients incorporated in the microcapsules. [ABSTRACT FROM AUTHOR]

In spray drying of sugar-rich foods, agglomeration is typically implemented by recycling the fine material into the spray cone where wet droplets and dry particles collide. The outcomes of the collisions affect particle structure and therefore product properties such as flowability and reconstitution properties. This study investigates these collision outcomes by introducing a dry marker powder stream (limestone) into the atomised feed solution (maltodextrin) in both single-stage and multi-stage setup of a pilot plant spray dryer. Results showed that for the multi-stage setup, limestone agglomerated with maltodextrin and agglomerates' size decreased with increased limestone addition rate. The limestone was distributed over the whole range of the agglomerates' size distribution, but <20% (w/w) of the total limestone in the powder were located on the agglomerates' surface. The conducted study therefore demonstrated that the nozzle zone agglomeration in spray dryers is predominantly characterised by a particle-drop coalescence. To investigate the fast micro processes during agglomeration in spray dryers, a marker powder stream was added into the spray zone. The location of the marker powder inside of agglomerates indicated that agglomeration is dominated by the incorporation of the marker material. Unlabelled Image • Marker powder enabled investigation of agglomeration in spray dryers. • Amounts of up to 50% (w/w) were agglomerated with the primary feed particles. • Marker powder was distributed equally over the particle size distribution. • Agglomeration in spray dryers coalescence dominated (> 80% (w/w) inside particles). [ABSTRACT FROM AUTHOR]

Dehydrated food powders with poor dissolution or dispersion can dramatically compromise food processing, with consequences for the final product quality and consumer experience. In this study, the reconstitution performance of maltodextrin powders with different moisture content and molecular weight, has been determined by varying the processing conditions, including agitation speed, liquid temperature, powder addition rate and mode of addition to the liquid surface. In particular, the inter-relationship between the glass transition temperature (T g) of the powder, its moisture content and the liquid temperature (T L) is highlighted. When T L ≥ T g , the individual maltodextrin granules tend to swell, restricting further dispersion and rehydration. It has been shown that higher liquid temperatures reduce the dispersion of food powders containing high molecular weight carbohydrates. Increasing the rate of powder addition to the liquid surface under low agitation conditions has been shown to result in faster reconstitution of low-molecular weight maltodextrins, whilst, on the other hand, the corresponding reconstitution rates of high-molecular weight maltodextrins are reduced. On the basis of this work and a previous study [X.Y. Ong, S.E. Taylor and M. Ramaioli, Pouring of Grains onto Liquid Surfaces: Dispersion or Lump Formation? Langmuir (2019) 1115011156] an improved, yet simple, approach to improve powder dispersion in a liquid is also demonstrated, by optimizing the distribution of the powder on the liquid surface. This approach avoids powder grains accumulating as heterogeneous lumps on the liquid surface and has been applied herein to a wide range of food powders. The table of contents of this journal contains Graphical Abstracts. Please provide a representative figure file (drawing, structure or reaction scheme) plus a text file of 50 words maximum that illustrates your work submitted: In order to avoid the powder grains accumulating as heterogeneous lumps on the liquid surface, a novel, yet simple, powder distributor has been developed as part of this study. This approach can significantly improve the reconstitution of powders by optimizing the distribution of the powder on the liquid surface. Unlabelled Image • The powder addition rate can affect the reconstitution kinetics. • High liquid temperature does not always improve the reconstitution of powders. • Novel powder distributor improves the reconstitution of powders. [ABSTRACT FROM AUTHOR]

Vegetable soups are complex mixtures containing vegetables in different percentages, thickeners, salt, fat, and emulsifying/wetting agents. When prepared as dehydrated powders in convenience foods, they need to be rehydrated before consumption and this can lead to formation of undesired lumps when carried out in hot water. Elimination of lumps and simplification of the preparation procedure were reached by granulating three different vegetable mixtures, each with a predominant vegetable (spinach, beetroot, and carrot), using an alternative liquid binder besides water. The use of an oil‐in‐water emulsion affected positively some technological properties of the dry products like granule strength and flowability, and the rehydrated soups in terms of complete dispersion in hot water. Also, the interplay between starches and soluble sugars, naturally present in vegetables, was found to impact the complete rehydration of the soups. [ABSTRACT FROM AUTHOR]

In recent years, there has been growing interest in the elimination of undesirable phenomena in the processing of bulk materials. In this study, the relationship between the mechanical properties of caking, as analysed with FTIR structural measurements, and the phenomena connected with fungal growth were investigated in wheat flour and potato starch. The materials were stored in high humidity conditions at room temperature (20 ± 2oC) in order to rapidly cause caking. The results showed changes in cake strength, for which the maximum force recorded by the sensor during storage was assumed. For the potato starch, the maximum strength occurred on the 8th day of storage and amounted to 29.4 N. From that day, the level of strength in this powder started to decrease, however, an increase in fungal contamination was also observed. Day 8 also marked the beginning of structural changes in the potato starch, which were observed in the FTIR spectra. The results obtained suggest that the strength of the agglomerates correlates with structural changes and fungal contamination. [ABSTRACT FROM AUTHOR]

Characterisation of the wettability of five poor wetting food powders was performed using static immersion and contact angle measurements. The effect of temperature (20, 50 and 70 °C) on wettability showed varying effects on the powders. Higher temperatures majorly improved the wettability of chocolate and high fat powders but worsened the wettability of sodium caseinate and milk protein isolate. Rate-limiting regime testing was performed by pouring a fixed mass of powder on to the surface of water in an agitated beaker and visually assessing what was rate-limiting rehydration after 1 minute. The rate limiting regime tended to be floating at lower agitation speeds and dispersed clumps of varying sizes at higher speeds. However, there were major differences observed between the powders. Some of the powders formed strong films at powder/water interfaces, that could act as a barrier to water penetration and wettability. Consequently, force displacement testing was performed on a layer of powder on the water surface to assess the strength of any powder film formed. Some of the powders formed strong films that may in-part explain their poor wetting behaviour and their propensity to form strong clumps that were difficult to disrupt.

The impact of the powder particle structure of spray dried and freeze dried carotenoid rich carrot concentrate powders on their oxidation stability and color was investigated. Depending on particle morphology (size distribution, porosity) and type of concentrate (crystalline or emulsified carotenoids), the encapsulation efficiency ranged from 43 to 88%, which led to marked differences in carotenoid stability during subsequent storage. For spray dried powders, the surface to volume ratio was recognized as crucial impact factor determining the encapsulation efficiency and carotenoid stability during storage. Spray dried powders with a low surface to volume ratio showed high carotenoid retention (76–77%) during storage (35 °C, 91 days), while the porous structure of freeze dried powders led to a rapid carotenoid degradation (69–93%) under the same storage conditions. • Carrot carotenoids were encapsulated using different drying technologies. • Drying technology and parameters influenced carrot concentrate powder structure. • Encapsulation efficiency was highest in spray dried powder with large particle size. • Correlations between powder particle size of SD powders and EE were established. • Particle size additionally influenced the color of the powder. [ABSTRACT FROM AUTHOR]

Rehydration of biopolymer powders is influenced by dissolution, viscosity development and swelling. Associated dynamic changes of powder characteristics correlate with their rehydration properties. Especially floating and particle aggregation negatively affect the rehydration process and powder quality. A deeper knowledge about these dynamics is crucial with regard to product development and quality improvement. The dynamics of swelling and viscosity development are of special importance. Controlling these parameters by a targeted modification will improve the rehydration process. Within this study the rehydration behavior of xanthan gum, guar gum and alginate was analyzed. Focus was on investigating their dynamic behavior and providing a detailed description of the rehydration process. Experiments were carried out using a model system, consisting of biopolymer coated glass beads. Rehydration was investigated experimentally and by simulation. The importance of dynamic effects and their mutual interaction was demonstrated. Results explain the mechanisms of the dynamic rehydration process of food powders. Rehydration of biopolymer powders was studied using a model system. A physical based simulation approach was established to simulate rehydration in terms of capillary liquid rise. By a parameter variation study the interrelation between dynamic changing powder characteristics was demonstrated and the mechanisms of the rehydration dynamics were explained. Unlabelled Image • Biopolymer rehydration was investigated based on a coated glass beads system. • Delay of capillary liquid rise is associated with surface-related dynamic processes. • A coating layer of 0.5 μm is enough to delay capillary liquid rise. • Viscosity development is restricted to the hydrated, swollen surface layer. • Simulation explains the relation between powder properties and rehydration. [ABSTRACT FROM AUTHOR]

• Review of surface tension forces to support dense particles at liquid surface. • Experiments show higher surface tension improves powder sinking. • Powders must be thought of as capillary networks and not individual particles. Quick powder reconstitution is generally necessary for consumer acceptance of dehydrated food materials; thus, an improved understanding of the mechanisms preventing complete reconstitution can help aid the discovery of solutions to improve product quality. Among the steps of reconstitution (wetting, sinking, dispersing, and dissolving), the "sinking" step is often described in the literature as being inhibited by a high surface tension, keeping particles afloat, insinuating that a reduced surface tension of the medium would improve sinking and thus overall reconstitution. In the current study, the sinking of food powders maltodextrin and whole milk powder were observed in an axially stirred vessel. Experiments were performed both in demineralized water (surface tension γ = 72 mN m−1) as well as in demineralized water with the surfactant polysorbate 20 added to its critical micelle concentration (CMC), with a surface tension γ = 32 mN m−1. Contrary to the scientific literature, the sinking behavior of the bulk powder was markedly worse when the liquid surface tension was lower. This can be explained due to the reduced capillary penetration into a porous powder bed when the surface tension is reduced. Thus in the scope of the sinking step of powder reconstitution, the powder must not be considered as individual particles, but rather as a porous capillary bed where capillary and resultant waterlogging drive the "sinking" step, particularly when developing physical models to predict the reconstitution behavior of powders. [ABSTRACT FROM AUTHOR]

Abstract Present work investigates the effect of thermal transitions and enthalpy relaxation phenomenon on the physico-chemical stability of paprika microencapsulated powders. Wall materials were combinations of soy protein isolates, maltodextrin and gum arabic. Powders stability was evaluated through the solid-water interactions, determined by sorption kinetics, calorimetry and color changes. The water sorption isotherms were well described by the GAB model. Below the critical condition, a w 0.6 and water content 11% (d. b.) the systems were in amorphous state at 25 °C, and enthalpy relaxations were detectable as endothermal events in the stored samples. The magnitude of the enthalpy relaxations increased with storage temperature below T g and with time of storage. In the amorphous microencapsulates, luminosity changes measured as (L o *-L*) values decreased as a function of time and a w , indicating pigment decoloration. The kinetics of the enthalpy relaxations changes, instead of the punctual values of the variables under study, were related to the dynamics of deteriorative changes. It can be concluded that enthalpy relaxation phenomenon can be established as a criterion for defining storage conditions or predict changes in microencapsulated and other systems that have to be stored in the glassy state. Highlights • Kinetics of encapsulated paprika discoloration were related to enthalpy relaxations. • Changes in glassy state can be related to enthalpy relaxation phenomenon. • Enthalpy relaxations can serve for predicting changes in glassy state. [ABSTRACT FROM AUTHOR]

In this study, the granulation behavior of food powders was simulated by taking into account the changes in the rheological properties and water content of the powders. Several food powders were studied and classified into self-agglomerating or non-agglomerating powders depending on the presence of a glass transition temperature. Cricket powder, which is incapable of self-agglomeration, was mixed with dextrin powder to enable the granulation process. Cricket + dextrin powder was used as a simulation model, and the glass transition temperature of dextrin and a newly derived evaporation model were adopted in our simulation studies. Similar tendencies were observed in both the experimental and simulation results. Our granulation model can describe all of the following: nucleation, granulation based on the powder properties and changes in particle water content due to evaporation; these behaviors have not been modeled in this way previously. [ABSTRACT FROM AUTHOR]

For the first time on food powders, environmental Atomic Force Microscopy (AFM) was used to probe single particle surface properties in real time by variating relative humidity (RH) and temperature. Low, intermediate, and high dextrose equivalent (DE) maltodextrins values were used as a model matrix. Humidity ramps from 20 to 80% at constant temperatures of 20 and 50 °C and temperature ramps from 20 to 50 °C at a constant RH of 20 and 80% were performed. Surface topography, roughness, and Young modulus distribution evolutions at the particle surface were studied under these conditions. It was observed that glass transition and RH are driving particle surface properties. Glass transition was always accompanied by a significant global surface smoothing, whatever the DE value. Surface smoothing phenomenon were also accompanied by a large decrease of the surface roughness with the increase of RH. Apart from the impact on surface topography, glass transition also impacted particle physics. Particles in the glassy state were relatively hard with a high and heterogenous Young modulus distribution. An increase in the RH made the particle progressively softer, whereas crossing the glass transition temperature leads to a really soft surface and to the homogenization of the Young modulus distribution. These results showed that glass transition significantly impacts particle surface properties and is promising to optimize food powder formulation and their shelf-life extension. [Display omitted] • Environmental AFM was used to probe single maltodextrins particles properties in real time. • AFM surface topographies revealed surface smoothing phenomenon with glass transition. • Young modulus decreases significantly and its distribution is homogenized with glass transition. [ABSTRACT FROM AUTHOR]

Fruit matrix modification caused by processing determines the reactivity of bioactives. In line with a new trend in foods development and nutrition, the study endeavored to recognize contribution of phenolics and amino acids from selected raw materials, i.e., Japanese quince, rosehip, haskap berry and blackcurrant in moderation of antioxidant, antidiabetic and antiglycation potential of freeze-dried powders. Qualitative and quantitative evaluation of phenolics and amino acids was performed for powdered fruit, pomace, juice and sugar-free juice products considered as different matrices. Phenolics' groups differently influenced antidiabetic activity depending on the composition of the matrix in which they were present. Flavonols affected the ability to inhibit advanced glycation end products (AGEs) derived from methylglyoxal and l -arginine. The involvement of individual amino acids in antioxidant capacity was identified, pointing to ornithine presence as the most influential one. Free radical scavenging activity of freeze-dried powders contributed to effectiveness as AGEs inhibitors. Results provided an insight for powdered fruit product development, stressing that composition of fruit-based matrix is a key point for creation of potential functional properties. • Flavonols affected antiglycation effect of freeze-dried fruit products. • Phenolics differently influenced antidiabetic ability depending on fruit matrix. • Amino acids were quantified in different fruit fractions for the first time. • Ornithine was strongly linked to the antioxidant capacity of fruit powders. [ABSTRACT FROM AUTHOR]

Galacto-oligosaccharides (GOS) can be produced with different purity levels that were hypothesized to alter water uptake and overall stability. Two purity GOS levels (55% and 90%) in commercially available mixtures were analyzed. Water was found to plasticize GOS (more effectively in the 55% compared to 90% GOS mixture), decreasing the glass transition temperature (Tg) causing the caking of powders and collapse of the amorphous structure. The critical a w for the 55% GOS mixture was between a w 0.23 and 0.33, corresponding to 3.7 and 5.9% moisture, and for the 90% GOS the critical a w was between a w 0.43 and 0.58, corresponding to 9.7 and 13.0% moisture. Differential thermogravimetric (DTG) curves demonstrated that water was more homogenous and difficult to remove as the Tg of GOS fell below storage temperature. DTG trends suggest that this analysis may be used to predict Tg of GOS mixtures, which is influenced by GOS purity level. [ABSTRACT FROM AUTHOR]

Both near infrared hyperspectral imaging (NIR-HSI) and Raman hyperspectral imaging (R-HSI) were investigated in combination with multivariate analysis to assess binary mixtures of food powders. NIR-HSI and R-HSI data of corn flour (CF), icing sugar (IS) and binary mixtures of both in concentrations of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90% CF ( w /w) were used to develop CF and IS concentration prediction models. The best model for IS concentration prediction in CF using NIR-HSI was developed using PLS-R based on 7 selected bands (RMSE CV 0.58%, RPD CV 55.4, RMSE P 1.00%, RPD P 48.6, R 2 1.000, 2LV), while the best model for IS concentration prediction in CF using R-HSI was developed using PLS-R on 11 selected bands (RMSE CV 1.75%, RPD CV 18.4, RMSE P 1.26%, RPD P 24.9, R 2 0.997, 4LV). Mixing quality of samples was assessed using the standard deviation of NIR-HSI prediction maps of CF and IS mixtures (50:50 ( w /w)) mixed for 0, 1, 3, 7, 10, 15, and 30 s. The standard deviation reduced from 23.4% prior to mixing to 3.2% after 30 s of mixing. The prediction maps developed provide spatial information which can be used to evaluate mixture quality during both the convective and diffusion phases of mixing. Both hyperspectral imaging techniques investigated were demonstrated to have high potential for assessment of binary mixtures of food powders in process analytical technology applications. [ABSTRACT FROM AUTHOR]

The rehydration behavior of biopolymer powders was investigated. Problems that arise during powder rehydration, e.g., floating and formation of particle aggregates, are mainly attributed to the dynamics of capillary water uptake. Common methods for analysis are too slow to assess the fast changes and do not allow conclusions about causal relationships. For a more detailed understanding, relevant powder properties were investigated. Results show that viscosity development in the rehydration liquid as well as swelling, and in particular their dynamics, are crucial for powder rehydration. The dynamic capillary rise was modeled based on the Washburn equation and results were linked to the physical powder characteristics. The approach allows the evaluation, whether viscosity or swelling effects lead to a critical rehydration behavior. [ABSTRACT FROM AUTHOR]

The interrelations between moisture content and mechanical properties of dry and wet native starches of wheat, maize, and potato were investigated. Strength parameters of powders were tested using direct shear and ring shear tester. Carr indices and associated parameters were determined using a Hosokawa Powder Tester. Particle size distribution of powder was analysed using an Infrared Particle Sizer. Uniaxial compression test was conducted to determine the reaction of powder in a cylindrical probe to vertical load. Mechanical behaviour of the material was found to be changing with increasing moisture content. Mechanical behaviour of potato starch was found to be different from that of cereal starches, which may require different utilisation in some processes.

Characterisation of the wettability of five poor wetting food powders was performed using static immersion and contact angle measurements. The effect of temperature (20, 50 and 70 °C) on wettability showed varying effects on the powders. Higher temperatures majorly improved the wettability of chocolate and high fat powders but worsened the wettability of sodium caseinate and milk protein isolate. Rate-limiting regime testing was performed by pouring a fixed mass of powder on to the surface of water in an agitated beaker and visually assessing what was rate-limiting rehydration after 1 minute. The rate limiting regime tended to be floating at lower agitation speeds and dispersed clumps of varying sizes at higher speeds. However, there were major differences observed between the powders. Some of the powders formed strong films at powder/water interfaces, that could act as a barrier to water penetration and wettability. Consequently, force displacement testing was performed on a layer of powder on the water surface to assess the strength of any powder film formed. Some of the powders formed strong films that may in-part explain their poor wetting behaviour and their propensity to form strong clumps that were difficult to disrupt. [ABSTRACT FROM AUTHOR]