Physicochemical Properties Of Powders Research Articles

Formulation of synbiotic buttermilk powder with higher viability of probiotic cells

The present study focused on the use of trehalose (TRE), whey protein concentrate (WPC), pullulan (PUL), and calcium lactate gluconate (CAL) as a protectant in the formulation of synbiotic buttermilk powder by application of spray drying. The spray drying of the solution mixture was carried out at an inlet temperature of 150 °C, a feed flow rate of 15mL/min, and compressed air at 3 kg/cm2 while keeping the outlet temperature constant at 70 ± 5 °C. TRE4 + CAL0.5 showed good results with the viability of Bifidobacterium bifidum as 6.04 ± 0.13 after 16 weeks followed by TRE2 + CAL0.5, TRE4, CAL0.5, WPC6, PUL4, and Control. The addition of protectants and Fructooligosaccharide (FOS) as a prebiotic did not affect the powder properties. The moisture content, water activity, bulk density, hygroscopicity, solubility, particle size, and scanning electron microscopy (SEM) of SBMP were better than the control sample for 17 weeks. SEM results showed spherical shapes without any cracks for SBMP containing TRE4 + CAL0.5. The present work demonstrated that the formulation containing TRE4 + CAL0.5 showed excellent results in terms of the viability of probiotic cells and also physicochemical properties of powder during storage for 16 weeks at 4 ± 1 °C.

Fish oil encapsulation by genipin-crosslinked complex coacervation between gelatin and different anionic polysaccharides

Herein, a combination approach of bovine bone gelatin (BBG)/anionic polysaccharide (AP) complex coacervation with genipin crosslinking was developed to successfully fabricate fish oil-loaded genipin-crosslinked BBG/AP (fish oil@BBG-genipin-AP) powders. The genipin crosslinking process promoted the formation of larger fish oil@BBG-genipin-AP particles from the BBG/AP particles and fish oil@BBG/AP particles. AP types (gum Arabic, GA; sodium alginate, SA; sodium carboxymethyl cellulose, CMC) and concentrations significantly affected the critical pH to form complex coacervated particles, the powder physicochemical properties, the powder oxidative stability, and the powder in vitro digestion. The fish oil@BBG-genipin-CMC powder at the CMC preparation concentration of 17.5 mg/mL showed the highest loading capacity value (44.3% ± 0.8%), almost the highest encapsulation efficiency value (90.9% ± 0.7%), and the highest encapsulation yield (91.3% ± 2.0%). Due to the environmental pH change, the powders changed to emulsion droplets in the gastric phase and then released free fatty acids in the small intestinal phase. The highest FFA release percentages after the gastrointestinal phase (2 h in the gastric phase and 2 h in the small intestinal phase) were dependent on both AP types and their concentrations (GA: 64.8 ± 2.9%, 62.5 mg/mL; SA: 55.0 ± 3.1%, 15 mg/mL; and CMC: 48.9 ± 1.5%, 12.5 mg/mL). GA at a concentration of 62.5 mg/mL might be the best system to prepare fish oil@gelatin-genipin-anionic polysaccharide powders for fish oil digestion. This work provided useful information to develop oil-encapsulation powders for functional foods and understand the influences of wall materials on the fabrication and properties of powder foods.

Impact of Processing and Physicochemical Parameter on Hibiscus sabdariffa Calyxes Biomolecules and Antioxidant Activity: From Powder Production to Reconstitution.

Hibiscus sabdariffa is a tropical plant with red calyxes whose anthocyanins, phenols, and antioxidant activity make it attractive to consumers both from a nutritional and medicinal standpoint. Its seasonality, perishability, and anthocyanin instability, led to the setup of stabilization methods comprising drying and powdering. However, its properties can often be altered during these stabilization processes. Treatments such as dehumidified-air-drying, infrared drying, and oven-drying, and their combination showed better quality preservation. Moreover, powder production enables superior biomolecule extractability which can be linked to a higher bioaccessibility. However, the required temperatures for powder production increase the bioactive molecules degradation leading to their antioxidant activity loss. To overcome this issue, ambient or cryogenic grinding could be an excellent method to improve the biomolecule bioavailability and accessibility if the processing steps are well mastered. To be sure to benefit from the final nutritional quality of the powder, such as the antioxidant activity of biomolecules, powders have to offer excellent reconstitutability which is linked to powder physicochemical properties and the reconstitution media. Typically, the finest powder granulometry and using an agitated low-temperature reconstitution media allow for improving anthocyanin extractability and stability. In this review, the relevant physicochemical and processing parameters influencing plant powder features from processing transformation to reconstitution will be presented with a focus on bioactive molecules and antioxidant activity preservation.

Calcium-Reduced Micellar Casein Concentrate-Physicochemical Properties of Powders and Functional Properties of the Dispersions.

This study aimed to examine the physicochemical properties of 30% calcium (Ca)-reduced micellar casein 80% protein powders (RC-MCC) and the functional properties of the resultant dispersions. The calcium reduction in the micellar casein (MCC) powder was achieved by subjecting the liquid micellular casein obtained from the microfiltration of pasteurized skim milk to carbon dioxide (CO2) treatment before and during ultrafiltration. The CO2 injection was controlled to obtain a 0 and 30% reduction in calcium in the C-MCC (control) and RC-MCC powders, respectively. The MCC powders were tested for physicochemical properties such as chemical composition, particle size distribution, and bulk density. The MCC powders were reconstituted in deionized water to test the functional properties of the dispersions, i.e., solubility, viscosity, heat stability, emulsifying capacity, emulsion stability, foam capacity, and foam stability. The CO2 injection did not result in any significant differences in the composition except mineral contents, particularly calcium. The particle size and bulk density of RC-MCC powders were significantly (p < 0.05) lower than control powders. The RC-MCC powder dispersions showed increased heat stability compared to control, whereas no significant changes in viscosity and emulsification capacity were observed between the two dispersions. However, the emulsion stability and foam stability of RC-MCC dispersions were significantly lower than C-MCC dispersions. This study showed that by utilizing a novel microfiltration–CO2 injection–ultrafiltration process, 30% calcium-reduced MCC powder was commercially feasible. This research also provides a detailed understanding of the effect of calcium reduction on the functional properties of resultant MCC dispersions. It showed that calcium reduction could improve the solubility of the powders and heat stability and foam capacity of the dispersions.

Encapsulation of coffee silverskin extracts by foam mat drying and comparison with powders obtained by spray drying and freeze-drying.

Coffee silverskin is a coproduct that has a rich composition in bioactive compounds. However, most of these compounds are susceptible to the conditions used during food processing and storage. Encapsulation is a process of great interest to increase the stability of these bioactive compounds, and different methods can influence the final characteristics of the product. Therefore, this study aimed to evaluate the encapsulation methods by foam mat drying, spray drying and freeze-drying for producing powder from coffee silverskin extracts. Density, porosity, overrun, and stability foam were evaluated and the physicochemical properties of powders, such as water activity, moisture, wettability, hygroscopicity, solubility, color, antioxidant activity, and total phenolic were determined. The optimal condition required for the feed mixture for foam formation was 7.6% gum arabic, 2% maltodextrin, and 10.4% egg albumin. All methods presented powders with desirable values of water activity, moisture content, and hygroscopicity, being considered stable for storage, and high content of bioactive compounds. Higher temperatures for foam mat drying produced powders with higher encapsulation efficiency (>77%) and longer wettability than lower temperatures (50 and 60°C). Therefore, this study verified that foam mat drying can be considered an efficient and promising method for encapsulating bioactive compounds from coffee silverskin extract. PRACTICAL APPLICATION: Foam mat drying can be considered an alternative method to conventional encapsulation by spray drying and freeze-drying. This method is simple, inexpensive, and generates high-quality products. Optimization of foam properties is necessary to ensure successful drying.

Relationship between drying and grinding parameters and physicochemical properties of Hibiscus sabdariffa calyx powders

To set up a stabilization process preserving the beneficial properties of Hibiscus sabdariffa calyxes, known as coupled drying and grinding, an option for powdering is proposed. The impacts of these unitary operations on powder physicochemical properties and flowability were studied. Calyxes were sun-dried and/or oven-dried for 1 or 2 h then ground at 10,000, 12,000, or 14,000 rpm. Upon increase in drying duration and/or grinding frequency, more heterogeneous and irregularly shaped particles of smaller-sized, low fiber powder was obtained which in turn affected the flow properties. Powders are less cohesive, therefore, they are less sensitive to compression and shear. This results in a good flowability. The red color intensity of powder solutions related to the anthocyanin content was raised when decreasing the drying duration and increasing the grinding frequency. However, to improve the solubility of these powder solutions, high drying duration and grinding frequency was required. High drying duration and grinding frequency may be ideal to achieve an easy-flowing powder, a long shelf life, and an appealing red-colored product for consumers.

Optimization of microencapsulation of yellow mombin juice by spray drying using a central composite rotatable design and powder physicochemical properties

Yellow mombin juice was microencapsulated by spray drying. Optimum operating conditions were selected from the outcomes of tests carried out according to a central composite rotatable design, using air inlet temperature (90 to 190 °C), feed flow rate (0.20 to 1.00 L/h) and 15 DE maltodextrin concentration (10 to 30%) as the independent variables, while powder moisture content, water activity, hygroscopicity, total carotenoids retention, and process yield as the responses. As expected, water activity, moisture content and yield of samples were significantly reduced by spray drying. The powder prepared under optimum conditions, whose reconstituted nectar was the most appreciated by panelists in sensory analysis, was partially characterized in terms of physicochemical properties. It exhibited an apparent density of 0.59 g/mL and a solubility of 81.49%. Particles generally occurred in clusters and exhibited spherical shape and smooth surface. The antioxidant activity was shown to be weak to intermediate.

The production of white mulberry molasses powders with prebiotic carrier by dehumidified air‐assisted spray drying

AbstractWhite mulberry molasses was powdered with the addition of prebiotic carrier by conventional spray drying (inlet/outlet air temperature: 180/80°C) and by dehumidified air‐assisted spray drying at low temperature (inlet/outlet: 80/45°C). As a consequence of decreasing the drying temperature, it was possible to obtain powder containing 90% of molasses (solids, wt/wt), which was not presented for this kind of material before. Moreover, highly satisfactory powder recovery (64.0–96.5%) was observed for the variants spray dried at low temperature. Physicochemical properties of powders were investigated. All of obtained powders characterized with water activity (Aw) below 0.25, which classify them as physiochemically and microbiologically stable. Powder spray dried traditionally was characterized with irregular particles of bigger dimension than powders obtained at low drying temperature. Furthermore, total phenolics content and antioxidant capacity of molasses before and after drying were studied. The expression of retention coefficient was proposed to describe the effect of drying on total phenolics content of dried material. In this calculation the presence of carrier is excluded because it is not the source of phenolics in powder. Spray drying at low drying temperature enabled better preservation of the polyphenolics (TPC varying from 1,491 ± 38 to 2,852 ± 48 mg GAE/100 g solids) and antioxidant capacity (EC50 ABTS ranging from 0.15 ± 0.01 to 0.10 ± 0.01 mg solids/mL) of white mulberry molasses than conventional spray drying (TPC 1,412 ± 13 mg GAE/100 g solids and EC50 ABTS 0.23 ± 0.04 mg solids/mL).Practical ApplicationsWhite mulberry molasses powders may be a more practical alternative to concentrated molasses because of the high viscosity of molasses leading to problems with dosing, storage, and transportation. Molasses powdered at low temperature contains only 10% of a carrier, and as a result of high antioxidant capacity may be implemented in functional foods.

Scale-up and optimization of the spray drying conditions for the development of functional microparticles based on chia oil

A factorial design was performed for the microencapsulation of chia oil by spray drying at pilot-scale, to validate the results obtained previously at laboratory scale in a Büchi-B290. The effects of drying-air inlet (Tinlet) and outlet (Toutlet) temperatures in a Niro Production Minor on the solid yield, thermal efficiency, theoretical droplet evaporation times, and physico-chemical properties of powders were analyzed. The theoretical droplet evaporation times (0.31−0.54 s) were calculated considering the constant and falling rate periods and a negligible relative velocity between spray and air. Critical diameters between 31.77–41.57 μm were estimated for microcapsules, depending on the process conditions. After scale-up of the spray drying operation, higher solid yields (74.24–79.79%), thermal efficiencies (27.56–73.19%), encapsulation efficiencies (96.97–98.57%), and enhanced flowability of products, compared with experiments at laboratory scale, were observed. Moreover, the scale-up did not affect the chemical composition of microencapsulated oils, their fatty acid composition before and after in-vitro digestion processes. A global optimization was performed at pilot-scale and the process conditions that simultaneously optimized all the responses was 160 °C × 90 °C (Tinlet × Toutlet).

How Do the Different Types of Carrier and Drying Techniques Affect the Changes in Physico-Chemical Properties of Powders from Chokeberry Pomace Extracts?

Chokeberry fruit, one of the richest plant sources of bioactives, is processed into different foodstuffs, mainly juice, which generates a considerable amount of by-products. To follow the latest trends in the food industry considering waste management, the study aimed to produce chokeberry pomace extract powders and conduct experimental and chemometric assessment of the effect of different carriers and drying techniques on the physico-chemical properties of such products. The PCA analysis showed that the examined powders were classified into two groups: freeze-dried (variation in case of moisture content, water activity, colour, and browning index) and vacuum-dried (bulk density). No clear pattern was observed for the physical properties of carrier added products. The sum of polyphenolics (phenolic acids, anthocyanins and flavonols) ranged from 3.3–22.7 g/100 g dry matter. Drying techniques had a stronger effect on the polyphenols profile than the type of carrier. Hydroxymethyl-L-furfural formation was enhanced by inulin addition during high-temperature treatment. Overall, the addition of maltodextrin and trehalose mixture for freeze drying and vacuum drying at 90 °C caused the highest retention of polyphenolics and the lowest formation of hydroxymethyl-L-furfural; however, an individual and comprehensive approach is required when the obtainment of high-quality chokeberry powders is expected.

Residence time distribution in fluidized beds: diffusion, dispersion, and adsorption

The residence time distribution (RTD) characterizes the flow patterns of tracer particles in continuous systems to identify phenomena like channelling, dispersion, dead volume, and back-mixing. Understanding the hydrodynamics in experimental reactors is imperative to derive reaction kinetics. Here, we applied the RTD methodology to examine the relationship between the physico-chemical properties of powders and gas flow patterns in an 8 mm diameter quartz micro-fluidized bed. H2 and He tracers egressed the reactor sooner than Kr, O2, CO, CH4, CO2 demonstrating that gas diffusivity is a factor to consider when choosing a tracer gas. Intraparticle porosity is a second factor that delays the RTD curve: the residence time was 7% greater for virgin vanadium pyrophosphate catalyst (VPP) with a lower particle density than an equilibrated VPP. These results suggest that RTD experiments are sensitive enough to detect phenomena like catalyst sintering and pore blocking due to coke in situ. The RTD curve of CO and CH4 tracers with a bed of fluid catalytic cracking catalyst (FCC) had a noticeable trailing edge (tail). For the CO2 tracer, the leading edge of the RTD curve was delayed, the peak height was 50% shorter, and the tail was extended demonstrating adsorption phenomena like a chromatographic effect. The residence time of Kr, with a similar gas diffusivity as CO2 was also longer compared to CO or CH4, but the tail was shorter than for CO2, which confirms the adsorptive nature of the FCC surface with CO2. A bolus-pulse input function detected these hydrodynamic anomalies with a greater certainty than a Heaviside-step input.

Encapsulation of Russian Olive Water Kefir as an Innovative Functional Drink with High Antioxidant Activity.

Processing of Russian olive water kefir (RWK), as a fermented functional drink made with Russian olive juice and water kefir grains with high antioxidant activity, into powder is crucial for improving its stability for the commercialization of this product. For the first time, this study aimed to encapsulate water kefir microorganisms and bioactive compounds in RWK using carrier materials to develop a synbiotic functional powder using spray drying as an encapsulation method. The goal was maximizing antioxidant activity, product yield, and survival rate of water kefir microorganisms in the producedRussian olive water kefir powder. The optimal spray drying conditions were observed to be at an inlet air temperature of 120ºC, 35 % feed flow rate, and 7 % concentration of drying aid. The effects of spray drying conditions on the quality of microcapsules were assessed and modeled, and the validity of the model was verified. Also, the spray-dried powder's physicochemical properties were assessed and showed promising microbial and physicochemical characteristics compared with the freeze-dried powder.

The Effect of Maltodextrin and Acacia Gum on Encapsulation of Fig Powder Physicochemical Properties

In this study, the effect of coating material composition on the encapsulation of physical and chemical properties of fig powder was investigated. As coating material maltodextrin and acacia gum at different ratios were chosen (100% and 75%:25%). The core to coating ratio was 1:1. The microcapsules were prepared with high-speed homogenizer at 10000 rpm for 10 min. The vacuum dried microcapsules were analyzed in terms of moisture, total soluble solid, bulk and tapped density, Carr’s index, Hausher ratio, total flavonoid content, and antioxidant activity. The antioxidant activity was mostly higher when coating ratio was 100% acacia gum in the core and coating ratio of 1:1 as compared to others. There was positive correlation between total flavonoid content and antioxidant activity. Combination of coating agent in ratio 75%: 25% vice versa significantly improve the physical properties of fig powder. The ratio of maltodextrin and gum arabic had significant effect on all physical and chemical properties analyzed.

Spray drying of pure kiwiberry pulp in dehumidified air

Food producers are interested in products with “clean” composition and natural origin. Thus, the elimination of the carriers additions perfectly fits this trend. The aim of the work was to spray dry pure kiwiberry pulp at low drying air temperature (100 °C and 120 °C), possible by the application of dehumidified air. An additional goal was to compare the effect of the kiwiberry variety (Weiki, Geneva and Bingo) and temperature on powder recovery and physicochemical properties of powders. The powder recovery was up to 93%. Kiwiberry powders were characterized by low hygroscopicity and water activity and high total polyphenolics content. Based on hierarchical cluster analysis method, it was found that the kiwiberry variety had a greater impact on the properties of powders than drying temperature: Weiki powders were characterized by the lowest polyphenolics content and the lowest antioxidant activity, while Weiki and Bingo powders had the highest content of aromatic compounds. Powders obtained at lower temperature were characterized by higher water content and activity, lower hygroscopicity, higher apparent density, smaller particle size and wider particle size distribution. The results are of high practical potential, because powders did not contain any carrier material and were characterized by low hygroscopicity. The most recommended is to use Bingo variety and drying temperature 120 °C.

Fabrication of Spray-Dried Microcapsules Containing Noni Juice Using Blends of Maltodextrin and Gum Acacia: Physicochemical Properties of Powders and Bioaccessibility of Bioactives during In Vitro Digestion.

Microencapsulation of fermented noni juice (FNJ) into powder format could protect bioactive compounds, reduce the unpleasant odour and improve the acceptability for consumers. Blends of maltodextrin (MD) and gum acacia (GA) were used to achieve spray-drying microencapsulation of noni juice at different blending ratios. The physicochemical properties including microstructure, moisture content, water activity, particle size, bulk/tapped density, dissolution rate, ATR-FTIR and the bioaccessibility of bioactive compounds in powders during in vitro digestion were examined. Results showed that blends produced with more GA produced microcapsules with lower moisture content, water activity and bulk/tapped density, but slower powder dissolution. The ATR-FTIR results suggested that there were no significant chemical interactions between the core material and carrier or between the MD and GA in the blend powders. The spray-dried noni juice powder produced using the blends with higher ratio of GA to MD showed a better protection on the bioactive compounds, resulting in a higher bioaccessibility of powders during in vitro digestion. This study provides insights into microencapsulation of noni juice using blends of MD and GA and examines the physicochemical properties and bioaccessibilities of spray-dried powders as affected by the selected carriers.

Production and characterization of pineapple-mint juice by spray drying

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

Reformulation of spray-dried apple concentrate and honey for the enhancement of drying process performance and the physicochemical properties of powders.

Apple concentrate and honey were spray-dried with traditional carriers (maltodextrin, Nutriose®, Kleptose®) and with skimmed milk powder as a carrier substitute offering added value for the final product. Skimmed milk powder, although having the lowest glass transition temperature, was the best carrier in terms of the highest powder recovery (higher than 80% was achieved) and with powder physical properties comparable to those obtained with other carriers. Thus, skimmed milk powder was used to produce honey powder of reduced carrier content (to 25% solids). The physical properties of the powders obtained and lower powder recovery indicated more problematic drying of AC. Powders produced with skimmed milk were characterized by enhanced nutritional value compared with variants with traditional carriers. Thus, skimmed milk is proposed as a natural carrier for spray-drying, offering high processing yield, the possibility to reduce carrier content in honey powder, and to create products of nutritional added value. © 2020 Society of Chemical Industry.

Storage stability of freeze-dried arazá (Eugenia stipitata Mc Vaugh) powders. Implications of carrier type and glass transition

Arazá, a flavorsome fruit rich in antioxidants (phenolics/carotenoids/flavonoids/ascorbic acid) may be appropriate for preparing powdered-functional foods and beverages. Variations in water-activity (aw) and matrix physical state (glassy/rubbery) can induce undesirable changes in dehydrated products color antioxidant composition/activity reducing shelf-life. Solving this problem requires a thorough analysis of the aw/physical state effects on the arazá powder physicochemical properties. Objectives were to: (a) analyse aw, glass-transition temperature (Tg) and carrier-type (maltodextrin-DE10/Arabic-gum) effects on freeze-dried arazá color, antioxidant composition/activity; (b) Determine storage-time influence on antioxidant content/activity/polyphenol composition considering the best performing aw values previously determined. Critical aw values calculated from Tg/aw interrelationship overestimated the aw limit corresponding to samples color/antioxidant composition/activity maximum stability, therefore, Tg was not a reliable indicator of the properties stabilities. Antioxidant content/activity storage behavior (20 °C/aw = 0.11 (best performing aw optimized across all properties)) were satisfactorily predicted by the Weibull equation. Shelf-lives, calculated considering 90% properties retention as the acceptability limit, were 34 (arazá/maltodextrin) and 50 (arazá/Arabic-gum) days. Polyphenolic profile included 6 phenolic acids, one coumaric acid derivative, 4 flavonoids and one ellagitannin. Using a mix of maltodextrin-DE10/Arabic-gum might improve antioxidant content/activity stability obtained with the single carriers and extend their shelf-life.

Application of gum Arabic and maltodextrin for encapsulation of eggplant peel extract as a natural antioxidant and color source

Our aim was to produce an encapsulated powder loaded with eggplant peel extract as a natural source of color and antioxidants through gum Arabic and maltodextrin. The effect of spray drying inlet temperature (140–170°C) and various carriers (maltodextrin, gum Arabic, and their combination) on powder production yield, physical properties, flowability, color, total phenolic content (TPC), antioxidant activity, infrared spectroscopy (FTIR), microstructure and particle size were investigated. Our results revealed that physicochemical properties of powders were influenced by the carrier type and inlet temperature. Obtained powders by maltodextrin at 170°C showed the highest TPC (5.2mg/g), DPPH (73.4%), ABTS (90.5%), TEAC (2. 5mM), hydroxyl radicals scavenging activity (79.1%) and reducing power (1.2 Abs700) among all samples. FTIR spectroscopy indicated that the extract was encapsulated by the carriers. Microstructure evaluation of powders showed some hollow particles with matrix-type structures. Sensory evaluation indicated that addition of encapsulated eggplant extract into the formulation of gummy candy improved its color and overall acceptability.

Freeze-drying of maple syrup: Efficient protocol formulation and evaluation of powder physicochemical properties

An efficient two-step protocol for freeze-drying of dark grade maple syrup was developed from glass transition temperature determinations, online-thermal history, and drying kinetics. Maple sugar powders (MSP), produced under two drying times (25 and 30 h), were analyzed for their physicochemical properties. Moisture content and water activity (aw) of MSP were determined to be in the range of 3–4% dry basis and 0.19–0.21 aw, respectively. The powders exhibited fair to poor flow characteristic owing to its cohesiveness. However, they have instant-like properties with dissolution times shorter than 14 s. MSP were highly hygroscopic, requiring to be stored below 0.36 aw at ambient temperature.