Physicochemical Properties,Antioxidant Capacity,Prebiotic Activity and Anticancer Potential in Human Cells of Jackfruit (Artocarpus heterophyllus) Seed Flour

The general aim of this study was to evaluate physicochemical properties, prebiotic activity and anticancer potential of jackfruit (Artocarpus heterophyllus) seed flour. The drying processes of jackfruit seeds were performed at 50, 60 and 70 °C in order to choose the optimal temperature for obtaining the flour based on drying time, polyphenol content and antioxidant capacity. The experimental values of the moisture ratio during jackfruit seed drying at different temperatures were obtained using Page’s equation to establish the drying time for the required moisture between 5 and 7% in the flour. The temperature of 60 °C was considered adequate for obtaining good flour and for performing its characterization. The chemical composition, total dietary fiber, functional properties and antioxidant capacity were then examined in the flour. The seed flour contains carbohydrates (73.87 g/100 g), dietary fiber (31 g/100 g), protein (14 g/100 g) and lipids (1 g/100 g). The lipid profile showed that the flour contained monounsaturated (4 g/100 g) and polyunsaturated (46 g/100 g) fatty acids. Sucrose, glucose, and fructose were found to be the predominant soluble sugars, and non-digestible oligosaccharides like 1-kestose were also found. The total polyphenol content was 2.42 mg of gallic acid/g of the sample; furthermore, the antioxidant capacity obtained by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 901.45 µmol Trolox/100 g and 1607.87 µmol Trolox/100 g, respectively. The obtained flour exhibited good functional properties, such as water and oil absorption capacity, swelling power and emulsifier capacity. Additionally, this flour had a protective and preventive effect which is associated with the potential prebiotic activity in Lactobacillus casei and Bifidobacterium longum. These results demonstrate that jackfruit seed flour has good nutritional value and antioxidant and prebiotic activity, as well as potential protective effects and functional properties, making it an attractive food or ingredient in developing innovative functional products.     

Freeze vs. Spray Drying for Dry Wild Thyme (Thymus serpyllum L.) Extract Formulations: The Impact of Gelatin as a Coating Material

Freeze drying was compared with spray drying regarding feasibility to process wild thyme drugs in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration and heat-, ultrasound-, and microwave-assisted extractions. Higher total powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% w/w) provided better TPC recovery by 70% in case of lyophilization and higher total powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53–75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation was distinguished from the others by a higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process mainly affected the position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray-dried formulations compared to freeze-dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and a higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151–223 µm) compared to small microspheres (~8 µm) in spray-dried powder.     

Physicochemical Properties and Storage Stability of Microencapsulated DHA-Rich Oil with Different Wall Materials

This study aimed to evaluate the physicochemical properties and storage stability of microencapsulated DHA-rich oil spray dried with different wall materials: model 1 (modified starch, gum arabic, and maltodextrin), model 2 (soy protein isolate, gum arabic, and maltodextrin), and model 3 (casein, glucose, and lactose). The results indicated that model 3 exhibited the highest microencapsulation efficiency (98.66 %) and emulsion stability (>99 %), with a moisture content and mean particle size of 1.663 % and 14.173 μm, respectively. Differential scanning calorimetry analysis indicated that the Tm of DHA-rich oil microcapsules was high, suggesting that the entire structure of the microcapsules remained stable during thermal processing. A thermogravimetric analysis curve showed that the product lost 5 % of its weight at 172 °C and the wall material started to degrade at 236 °C. The peroxide value of microencapsulated DHA-rich oil remained at one ninth after accelerated oxidation at 45 °C for 8 weeks to that of the unencapsulated DHA-rich oil, thus revealing the promising oxidation stability of DHA-rich oil in microcapsules.     

Effects of different carriers on the production of isoflavone powder from soybean cake

The objectives of this study were to use soybean cake as the raw material for the production of isoflavone powder and compare the effects of different carriers as well as drying methods on the powder quality. Results showed that with spray drying, a level of 40% maltodextrin as carrier produced the highest yield (mass) of isoflavone powder, followed by 10% gelatin and 1% sodium alginate. However, a reversed trend was observed for the isoflavone content. With 1% sodium alginate, freeze drying generated the greatest yield of isoflavone powder, followed by vacuum drying and spray drying. The isoflavone content also exhibited the same tendency. With poly-gamma-glutamic acid (gamma-PGA) as carrier, all six levels studied (0.57, 0.28, 0.14, 0.028, 0.014 and 0.003%) were capable of forming powder containing high amounts of total isoflavone, which was comparable to that using 1% sodium alginate by freeze drying. Both high- and low-molecular-weight gamma-PGA showed similar effects in terms of powder yield and isoflavone content.     

Preparation and characterization of scandia-doped tungsten powders prepared by a spray-drying method

Scandium oxide-doped tungsten powders were prepared by a new method of spray drying combined with two-step hydrogen reduction. The particle size of doped tungsten, powder morphology, and distribution of doped scandium oxide were characterized by scanning electron microscopy, X-ray diffraction, and laser diffraction particle size analysis. Experimental results indicated that the predecessor powders prepared by spray drying were spherical in shape. Two compounds, WO₃ and Sc₂W₃O₁₂, in the raw powder calcined at 600???C were transformed into metallic tungsten and scandia after reduction at 850???C by hydrogen for 1?h. The scandia-doped tungsten powders obtained had an average size of 950?nm and scandium oxide was distributed evenly throughout the tungsten powder. The mechanism of reduction of the doped tungsten oxide is discussed in this paper.     

Changes in Physicochemical Properties and Volatile Compounds of Roselle (Hibiscus sabdariffa L.) Calyx during Different Drying Methods

Fresh roselle are high in moisture and deteriorate easily, which makes drying important for extending shelf-life and increasing availability. This study investigated the influence of different drying methods (oven-drying, freeze-drying, vacuum-drying, and sun-drying) on the quality of roselle calyx expressed as physicochemical properties (moisture content, water activity, soluble solids, color), volatile compounds, and microstructure. Oven-drying and freeze-drying reduced moisture content most while vacuum-drying and sun-drying were not as efficient. All drying methods except sun-drying resulted in water activities low enough to ensure safety and quality. Vacuum-drying had no impact on color of the dry calyx and only small impact on color of water extract of calyx. Drying reduced terpenes, aldehydes, and esters but increased furans. This is expected to reduce fruity, floral, spicy, and green odors and increase caramel-like aroma. Sun-drying produced more ketones, alcohols, and esters. Scanning electron microscopy revealed that freeze-drying preserved the cell structure better, and freeze-dried samples resembled fresh samples most compared to other drying techniques. The study concludes that freeze-drying should be considered as a suitable drying method, especially with respect to preservation of structure.     

Preparation and characterization of chitosan/gelatin microcapsules containing triclosan

Chitosan/gelatin (C/G) microcapsules containing triclosan were prepared by a spray drying method. The core material, triclosan (TS) dissolved in octyl salicylate (OS), were emulsified in an aqueous solution containing variable ratios of chitosan/gelatin. The microcapsules were obtained by spray-drying the emulsions. On the scanning electron micrographs, the microcapsules were spherical and exhibited a core and shell morphology. The thermograms of the microcapsules showed no evidence for the melting of TS, suggesting that TS remained dissolved in the cores of the microcapsules and did not exist as a solid crystalline even after dry microcapsules were formed. According to the results of microelectrophoresis study, the point of zero charge of the microcapsules occurred around pH 9.0 and a higher content of chitosan in the microcapsule wall resulted in a higher positive charge of zeta potential. The degree of release of TS and OS from the C/G microcapsules in an aqueous solution of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was investigated. When chitosan is included in the wall of microcapsules, the degree of release was suppressed. This indicates that chitosan forms a more compact wall than gelatin. On the other hand, TS was released much more than OS. The preferred release of TS is probably due to the higher solubility of TS in the HP-beta-CD solution.     

Solid state studies on molecular inclusions of <Emphasis Type="Italic">Lippia sidoides</Emphasis> essential oil obtained by spray drying

Inclusion complexes of Lippia sidoides essential oil and β-cyclodextrin were obtained by slurry method and its solid powdered form was prepared using spray drying. The influence of the spray drying, as well as the different essential oil:β-cyclodextrin ratio on the characteristics of the final product was investigated. With regard to the total oil retention 1:10 mass/mass ratio as optimal was found between the essential oil and β-cyclodextrin. Thermoanalytical techniques (TG, EGD, TG-MS) were used to support the formation of inclusion complex and to examine their physicochemical properties after accelerated storage conditions. It may be assumed that the thermal properties of the complexes were influenced not only by the different essential oil/ β-cyclodextrin ratio but also by the storage conditions. In the aspect of their thermal stabilities, complex prepared with 1:10 m/m ratio (essential oil:β-cyclodextrin) was the most stable one.     

Kilogram‐Scale Production of SnO2 Yolk–Shell Powders by a Spray‐Drying Process Using Dextrin as Carbon Source and Drying Additive

A simple and general method for the large‐scale production of yolk–shell powders with various compositions by a spray‐drying process is reported. Metal salt/dextrin composite powders with a spherical and dense structure were obtained by spray drying and transformed into yolk–shell powders by simple combustion in air. Dextrin plays a key role in the preparation of precursor powders for fabricating yolk–shell powders by spray drying. Droplets containing metal salts and dextrin show good drying characteristics even in a severe environment of high humidity. Sucrose, glucose, and polyvinylpyrrolidone are widely used as carbon sources in the preparation of metal oxide/carbon composite powders; however, they are not appropriate for large‐scale spray‐drying processes because of their caramelization properties and adherence to the surface of the spray dryer. SnO₂ yolk–shell powders were studied as the first target material in the spray‐drying process. Combustion of tin oxalate/dextrin composite powders at 600 °C in air produced single‐shelled SnO₂ yolk–shell powders with the configuration SnO₂@void@SnO₂. The SnO₂ yolk–shell powders prepared by the simple spray‐drying process showed superior electrochemical properties, even at high current densities. The discharge capacities of the SnO₂ yolk–shell powders at a current density of 2000 mA g^?1 were 645 and 570 mA h g^?1 for the second and 100th cycles, respectively; the corresponding capacity retention measured for the second cycle was 88 %.     

Particle design using a 4-fluid-nozzle spray-drying technique for sustained release of acetaminophen

We prepared matrix particles of acetaminophen (Act) with chitosan (Cht) as a carrier using a newly developed 4-fluid-nozzle spray dryer. Cht dissolves in acid solutions and forms a gel, but it does not dissolve in alkaline solutions. Therefore, we tested the preparation of controlled release matrix particles using the characteristics of this carrier. Act and Cht mixtures in prescribed ratios were dissolved in an acid solution. We evaluated the matrix particles by preparing a solid dispersion using a 4-fluid-nozzle spray dryer. Observation of the particle morphology by scanning electron microscopy (SEM) revealed that the particles from the spray drying process had atomized to several microns, and that they had become spherical. We investigated the physicochemical properties of the matrix particles by powder X-ray diffraction, differential scanning calorimetry, and dissolution rate analyses with a view to clarifying the effects of crystallinity on the dissolution rate. The powder X-ray diffraction peaks and the heat of the Act fusion in the spray-dried samples decreased with the increase of the carrier content, indicating that the drug was amorphous. These results indicate that the system formed a solid dispersion. Furthermore, we investigated the interaction between the drug and carrier using FT-IR analysis. The FT-IR spectroscopy for the Act solid dispersions suggested that the Act carboxyl group and the Cht amino group formed a hydrogen bond. In addition, the measurement results of the 13C CP/MAS solid-state NMR, indicated that a hydrogen bond had been formed between the Act carbonyl group and the Cht amino group. In the Act-Cht system, the 4-fluid-nozzle spray-dried preparation with a mixing ratio of 1 : 5 obtained a sustained release preparation in all pH test solutions.     

Reference materials for food analysis laboratories in India

An attempt has been made to prepare a Secondary Reference Material for heavy metals in milk powder. From fresh milk obtained locally, two batches of milk powder have been prepared by pasteurising, homogenising, evaporating and spray drying. One of the batches, treated as an experimental batch, was spiked before the preparation with lead, cadmium and arsenic solutions (imported BDH standards) at a level about 1 mg/kg. After spray drying, both batches were packed under nitrogen using a polyester-aluminium/polyethylene foil as inner pouch and an outer cover of metallised polyester/polyethylene as a supporting film. Preliminary data have been obtained for the concentrations of Pb, Cd and As in both batches using acid digestion and flame AAS and UV/Vis spectrophotometry. Correspondence to: M. N. Krishnamurthy     

Effect of Spray Dryer Scale Size on the Properties of Dried Beetroot Juice

Experiments detailing the spray drying of fruit and vegetable juices are necessary at the experimental scale in order to determine the optimum drying conditions and to select the most appropriate carriers and solution formulations for drying on the industrial scale. In this study, the spray-drying process of beetroot juice concentrate on a maltodextrin carrier was analyzed at different dryer scales: mini-laboratory (ML), semi-technical (ST), small industrial (SI), and large industrial (LI). Selected physicochemical properties of the beetroot powders that were obtained (size and microstructure of the powder particles, loose and tapped bulk density, powder flowability, moisture, water activity, violet betalain, and polyphenol content) and their drying efficiencies were determined. Spray drying with the same process parameters but at a larger scale makes it possible to obtain beetroot powders with a larger particle size, better flowability, a color that is more shifted towards red and blue, and a higher retention of violet betalain pigments and polyphenols. As the size of the spray dryer increases, the efficiency of the process expressed in powder yield also increases. To obtain a drying efficiency >90% on an industrial scale, process conditions should be selected to obtain an efficiency of a min. of 50% at the laboratory scale or 80% at the semi-technical scale. Designing the industrial process for spray dryers with a centrifugal atomization system is definitely more effective at the semi-technical scale with the same atomization system than it is at laboratory scale with a two-fluid nozzle.     

Diverse effects of β-carotene on secretion and expression of VEGF in human hepatocarcinoma and prostate tumor cells

Oral administration of β-carotene (BC) was found to exert opposite effects on plasma levels of vascular endothelial growth factor (VEGF) in two animal models. One study in nude mice injected via tail vein with hepatocarcinoma SK-Hep-1 cells showed that BC decreases the plasma VEGF level, whereas the other study in nude mice injected subcutaneously with prostate tumor PC-3 cells showed that BC increases the plasma VEGF level. Herein we investigated whether BC (0.5-20 μM) possesses diverse effects on VEGF secretion in SK-Hep-1, PC-3 and melanoma B16F10 cells. We found that incubation of SK-Hep-1 cells with BC (1-20 μM) for 6 h significantly decreased VEGF secretion, whereas BC (1-10 μM) significantly increased the VEGF secretion in PC-3 cells. However, these effects disappeared at 12 h of incubation. Similar effects occurred in VEGF mRNA and protein expression after treatment of SK-Hep-1 and PC-3 cells with BC for 6 h. In contrast, BC (0.5-20 μM) did not affect mRNA and protein expression and secretion of VEGF in B16F10 cells. We also found that the proliferation of SK-Hep-1 and B16F10 cells was significantly inhibited by 20 μM BC at 6 and 12 h of incubation, whereas the proliferation of PC-3 cells was significantly inhibited by 20 μM BC at 12 h of incubation. In summary, the present study demonstrated the tumor-specific effect of BC on VEGF secretion in different cancer cell lines.     

Influence of spray-dried hydroxyapatite-5-fluorouracil granules on cell lines derived from tissues of mesenchymal origin

In our previous work we described the preparation and characterization of spray dried hydroxyapatite micro granules loaded with 5-fluorouracil (5-FU). These loaded particles are used as a model drug delivery system (DDS). In this study we examined the in vitro response of two cell lines derived from different tissues to 5-FU loaded granules (LG). Both cell lines, either L929 cells of a mouse fibroblast lineage or cells originating from a rat osteosarcoma (ROS 17/2.8) showed a dose dependent decrease in cell proliferation in response to 5-FU-, either dissolved in the culture medium or loaded onto particles. The response of the two cell lines to loaded and nonloaded particles was different. The effect of LG and of a corresponding concentration of free 5-FU was practically the same for the ROS 17/2.8 cells indicating that ROS 17/2.8 cells were not affected by the carrier material. In contrast, L929 cells showed a slight decrease in cell proliferation also in the presence of granules not loaded with 5-FU. This is thought to be attributed to the inhibition of mitogenesis by phosphocitrates, already demonstrated in fibroblasts. In summary, we found that the loaded 5-FU kept its effectivity after the spray drying process and that the response towards the granules varied with cell type. This is the first step towards a tissue specific DDS.     

Influence of different divalent metal ions on the properties of alginate microcapsules and microencapsulated cells

Different divalent metal ions (Ba²⁺, Sr²⁺, Ca²⁺, Zn²⁺) were selected as crosslinkers. The mechanical properties, cytocompatibility, histocompatibility, cell proliferation and long-term cultivation were investigated. The resulting microcapsules had good sphericity, smooth surface and particle size distribution of 300–400 μm. Sr²⁺ microcapsules exhibited a better mechanical strength. The molecular weights cut-off of all membranes were between 24 and 67 kDa. All microcapsules had no cytotoxicity. After intraperitoneal transplantation, the recovered microcapsules still maintained good mechanical strength and morphology with no fibrosis or macrophage aggregation phenomena. The microencapsulated PC12 cells showed no significant variation after recultivation following microcapsule breaking. The cell activity sequence of different microcapsules after 72 h was as follows: bare control cell >Sr²⁺ > Ca²⁺ > Ba²⁺ > Zn²⁺. After 9 weeks’ in vitro culture, the cell survival rate was higher than 80 %. This paper will be of scientific interests for the basic research and clinical application of alginate/chitosan microcapsules embedded with drugs or cells.     

Surface composition of spray-dried milk protein-stabilised emulsions in relation to pre-heat treatment of proteins

Several important technical properties of spray-dried food powders depend on particle-liquid interactions (e.g. wettability, dispersability) and particle-particle interactions (e.g. flowability). It can be assumed that the chemical composition of the surface layer of the particles to a large extent determine these properties. The present study has been aimed to investigate the relation between the surface composition of spray-dried milk protein-stabilised emulsions and pre-heat treatment of the proteins. Solutions of WPC were heat-treated at low (60-90 degrees C) and high (140 degrees C) temperature and the degree of denaturation was determined, prior to the preparation of emulsions with rapeseed oil. The surface composition of the dry powders were established by using ESCA (electron spectroscopy of chemical analysis). The emulsions were characterised by droplet size distribution before spray drying and after dissolution of the powders. Also free fat extractions and estimations of wettability (dissolution rates) were performed. The powder surface coverage of protein decreased with increasing degree of protein denaturation before the emulsification, whereas the emulsion droplet size increased both before spray drying and after reconstitution of powders. The free fat extraction as well as the dissolution rate, whereof the latter decreased with increasing surface fat coverage, correlated well with the fat coverage of the powder surface.     

Buckling and crumpling of drying droplets of colloid-polymer suspensions

Spray drying of complex liquids to form solid powders is important in many industrial applications. One of the challenges associated with spray drying is controlling the morphologies of the powders produced; this requires an understanding of how drying mechanics depend on the ingredients and conditions. We demonstrate that the morphology of powders produced by spray drying colloidal polystyrene (PS) suspensions can be significantly altered by changing the molecular weight of dissolved poly(ethylene oxide) (PEO). Samples containing high-molecular-weight PEO produce powders with more crumpled morphologies than those containing low-molecular-weight PEO. Observations of drying droplets suspended by a thin film of vapor suggest that this occurs because the samples with high-molecular-weight PEO buckle earlier in the drying process when the droplets are larger. Earlier buckling times are likely caused by the decreased stability, demonstrated by bulk rheology experiments, of PS particles in the presence of high-molecular-weight PEO at elevated temperatures. We present a consistent picture in which decreased particle stability hastens droplet buckling and leads to more crumpled powder morphologies; this underscores the importance of interparticle forces in determining the buckling of particle-laden droplets.     

海藻酸钠和壳聚糖聚电解质微胶囊及其生物医学应用

本文综述了天然多糖聚电解质海藻酸钠和壳聚糖的结构与化学性能（包括凝胶性能、生物相容性、生物可降解性及温和反应性）;微胶囊制备技术及其强度性能和膜渗透性评价方法;微胶囊作为细胞载体在体内分泌治疗性物质（如：胰岛素、多巴胺）或分解代谢毒性物质（如：尿素）,作为三维药物筛选系统、干细胞增殖分化研究工具,以及药物释放载体等生物医学领域的研究进展;最后讨论了天然多糖微胶囊研究与应用中需要解决的问题。     

The Unexplored Wound Healing Activity of Urtica dioica L. Extract: An In Vitro and In Vivo Study

Wound healing is a great challenge in many health conditions, especially in non-healing conditions. The search for new wound healing agents continues unabated, as the use of growth factors is accompanied by several limitations. Medicinal plants have been used for a long time in would healing, despite the lack of scientific evidence veryfying their efficacy. Up to now, the number of reports about medicinal plants with wound healing properties is limited. Urtica dioica L. is a well-known plant, widely used in many applications. Reports regarding its wound healing potential are scant and sparse. In this study, the effect of an Urtica dioica L. extract (containing fewer antioxidant compounds compared to methanolic or hydroalcoholic extracts) on cell proliferation, the cell cycle, and migration were examined. Additionally, antioxidant and anti-inflammatory properties were examined. Finally, in vivo experiments were carried out on full-thickness wounds on Wistar rats. It was found that the extract increases the proliferation rate of HEK-293 and HaCaT cells up to 39% and 30% after 24 h, respectively, compared to control cells. The extract was found to increase the population of cells in the G₂/M phase by almost 10%. Additionally, the extract caused a two-fold increase in the cell migration rate of both cell lines compared to control cells. Moreover, the extract was found to have anti-inflammatory properties and moderate antioxidant properties that augment its overall wound healing potential. Results from the in vivo experiments showed that wounds treated with an ointment of the extract healed in 9 days, while wounds not treated with the extract healed in 13 days. Histopathological examination of the wound tissue revealed, among other findings, that inflammation was significantly reduced compared to the control. Urtica dioica L. extract application results in faster wound healing, making the extract ideal for wound healing applications and a novel drug candidate for wound healing.