Microencapsulation of Dandelion (Taraxacum officinale L.) Leaf Extract by Spray Drying.

Research background: Due to numerous health-promoting properties, dandelion has been used in traditional medicine as a herbal remedy, but also as a food product. Dandelion health benefits are ascribed to the presence of different bioactive compounds in its tissues, among which polyphenols play a significant role. However, the low stability of polyphenols is a critical parameter for their successful implementation into products. Thus, their encapsulation using appropriate carrier vehicles is highlighted as an effective technique for their stabilization and protection. The aim of this study is to microencapsulate dandelion leaf extract using spray drying and different carrier materials for the first time. Experimental approach: In spray drying, low inlet temperature of 130 °C was employed to preserve sensitive dandelion polyphenols, while guar gum, gum arabic, inulin, maltodextrin, pectin and alginate were used as carriers. The influence of different carriers and their content on physicochemical, morphological and colour properties, polyphenolic content and encapsulation efficiency of polyphenols in dandelion powders was examined. Specific polyphenols were determined using HPLC-PAD analysis. Their release profiles and antioxidant capacity in simulated gastrointestinal conditions were also evaluated. Results and conclusions: Compared to plain dandelion powder, carrier-containing dandelion powders have favourably increased solubility, enhanced flow and cohesive properties, reduced particle size and prolonged release of polyphenols under simulated gastrointestinal conditions. Powders were characterized by low moisture content (~2-8%) and high solubility (~92-97%). Chicoric acid was the most abundant compound in dandelion powders. Pectin-dandelion powder showed to be the most effective for microencapsulation of polyphenols, especially for chicoric acid entrapment (74.4%). Alginate-dandelion powder enabled the slowest gradual release of polyphenols. Novelty and scientific contribution: Spray drying at 130 °C and the applied carriers proved to be effective for microencapsulation of dandelion extract, where polyphenolic-rich dandelion powders, due to good physicochemical and encapsulation properties, could serve for the enrichment/production of different functional food products. Also, due to the lack of data on dandelion encapsulation, the obtained results could be of great interest for researchers in the encapsulation field, but also for food industry, especially in the field of instant powders.

Effect of citric acid addition on functional properties of pasteurized liquid whole eggs.

The aim of this study was to examine the influence of different concentrations of citric acid (0, 300, 400 and 500 mg/L) on the physical and functional properties of pasteurized liquid whole eggs (LWE) over 4 weeks of storage. The properties tested include pH, conductivity, colour, particle size, rheological, and textural properties, as well as protein solubility, foaming and emulsification. The 4 weeks of storage had a statistically significant (P < 0.05) effect on every tested parameter, while the addition of citric acid had a statistically significant (P < 0.05) effect on pH, conductivity, L* and b* values, protein solubility, emulsion activity index, emulsion capacity, emulsion stability, and an increase in foaming and texture parameters, but not on rheological parameters. Citric acid addition and a storage period of 4 weeks resulted in a change of pH and an increase in protein solubility. It also led to a lower foaming capacity and a larger drainage of the system, which causes a lower power (work load) requirement to break formed gels. Apparent viscosity did not change significantly in the samples with citric acid.

Insight into High-Hydrostatic Pressure Extraction of Polyphenols from Tomato Peel Waste.

In this paper, high-hydrostatic pressure extraction (HHPE) as an emerging food processing and preservation technique constitutes an alternative to conventional thermal treatment that has been used for extraction of polyphenols from tomato peel waste generated by the canning industry. The impact of time (5 and 10 min), temperature (25, 35, 45 and 55 °C) and solvents (water, 1% HCl, 50 and 70% methanol with and without addition of HCl, and 50 and 70% ethanol), at a constant pressure of 600 MPa, has been evaluated in this paper with respect to polyphenols' yields. The results showed a significant (p < 0.05) variation in the contents of a great number of phenolic compounds in respect of the applied temperatures and solvents. On the other hand, the time invested in HHPE had no effect on polyphenols' yields. Among phenolic compounds, the p-coumaric acid (p-CA) and chlorogenic acid derivative (ChA der) are predominant, i.e., 0.57 to 67.41 mg/kg and 1.29 to 58.57 mg/kg, respectively, depending on the solvents and temperatures used. In particular, methanol (50 and 70%) at temperatures of 45 and 55 °C enhanced the recovery of polyphenols in comparison to other utilised solvents. In conclusion, this paper puts forth the theory that by applying HHPE with minimal expenditure of time, it is possible to achieve efficient production of polyphenols from low-cost tomato peel waste, generating income both for producers and agri-food industries.

Oral antiseptics and nickel-titanium alloys: mechanical and chemical effects of interaction.

The effect of oral antiseptics on the corrosion of nickel-titanium (NiTi) alloys with various coating was investigated. Uncoated, titanium nitride-coated and rhodium-coated NiTi archwires (0.020 × 0.020″) were tested in interaction with artificial saliva pH 4.8 and oral antiseptics based on hyaluronic acid (Gengigel), chlorhexidine (Curasept) and essential oils in alcohol base (Listerine). The dynamics of nickel and titanium ions release were recorded during 28 days. Springback ratio and modulus of resilience were assessed by three-point bending test. The results showed that corrosion of NiTi is related to type of antiseptic mouth rinse and coating formulations. Exposure to an artificial saliva and antiseptics tend to reduce flexibility and resilience of NiTi archwires. The influence of the media is more significant than the influence of the type of the alloys coating. The largest release of nickel ions is in the first 3 days. Antiseptics do not cause further deterioration of the elastic properties in uncoated NiTi compared to saliva. As a result of exposure of nitrified NiTi wires in Listerine, there is bigger release of nickel ions, decrease in elastic properties and lower force delivery in unload. Listerine tends to reduce elastic properties of rhodium-coated wires also. In conclusion, except for Listerine, changes of mechanical characteristics induced by antiseptics are small and would not have a clinically important impact. Generally, Curasept would be the most suitable option.

Assessment of Drying Characteristics and Texture in Relation with Micromorphological Traits of Carob (Ceratonia silliqua L.) Pods and Seeds.

Carob tree (Ceratonia siliqua L.) is a perennial leguminous evergreen tree native to the coastal regions of the Mediterranean basin and is considered to be an important component of vegetation for economic and environmental reasons. Two constituents of the pod, pulp and seeds, can be used as feed or in food production. In this study, drying characteristics, texture and microstructure of carob pods were studied. Three different carob samples were prepared: whole carob pod, carob pod parts and carob seed. The drying experiments and the modelling showed that carob seeds had the highest drying rate, followed by pod parts and the whole, intact carob fruit. Texture studies showed that the maximum compression force depended on the area of the carob fruit on which compression tests were performed. The seeds showed the highest compression force, followed by the stem zone, the tip and the centre of the fruit. Differences in drying behaviour and texture of carob pods can successfully be interpreted by the micromorphology of the carob pods and seeds. Determining the drying rate, maximum compressive force and micromorphological traits is of great importance for further carob processing (e.g. milling, sieving, carob bean gum production or usage in food or feed products).

Influence of Different Drying Processes on the Chemical and Texture Profile of Cucurbita maxima Pulp.

The effects of hot air (HAD), vacuum (VAD) and conductive (CD) drying on the chemical and textural profiles of Cucurbita maxima pulp were investigated to find suitable drying conditions to avoid postharvest losses of pumpkin. The results showed that the drying methods had a significant effect (p < 0.05) on the chemical and textural profiles of pumpkin pulp. The ash content was lower in VAD (up to 7.65%) than in HAD (up to 9.88%) and CD pulp (up to 9.21%). The samples of HAD, CD and VAD had a higher fat content, up to 3.07, 2.66 and 2.51%, respectively, than fresh pulp (1.55%). The total fibre content is lower for VAD (up to 8.78%) than for HAD (up to 15.43%) and CD pulp (13.94%). HAD pulp at 70 °C (~15.51%) and VAD and CD pulp processed between 50 and 60 °C (~22%) are good sources of protein. HAD and CD pulp at 70 °C and VAD at 50 °C resulted in a high sugar content (up to 83.23%). In addition to drying, the extraction time of 40 min used in ultrasound-assisted extraction is optimal, especially for protein and sugar recovery in dried samples. Drying also led to strong changes in the textural properties of the pulp, so that an excellent dried intermediate product is the one obtained using HAD at a temperature of 70 °C and an airflow of 0.5 m/s.

Effect of use of antiseptics and fluorides during orthodontic treatment on working properties of NiTi archwires in levelling dental arches : A randomized controlled trial.

PURPOSE: The goal was to investigate whether the application of antiseptics and fluorides during orthodontic treatment affects the biomechanics of the levelling of dental arches by changing the working properties of nickel-titanium (NiTi) archwires. METHODS: The sample consisted of 60 individuals aged 12-22 years (53% females). There were 20 individuals in each experimental group: (I) individuals conducted regular oral hygiene, (II) individuals used a high concentration of fluorides for intensive prophylaxis for the first month; and (III) individuals used chlorhexidine in the same manner. NiTi alloy archwires (dimensions 0.508â€¯× 0.508 mm) were analyzed 3 months after intraoral exposure and compared to as-received NiTi wires. Elastic modulus, yield strength, springback ratio, and modulus of resilience were calculated. Dimensions of the dental arches were analyzed when NiTi alloy (T1) was placed intraorally and after 3 months (T2). Change was quantified as the difference in dimensions (T2-T1). Anterior width-to-length ratio was used as a measure for dental arch shape. RESULTS: Intraoral exposure reduced elastic modulus, yield strength, springback ratio, modulus of resilience, loading, and unloading forces of NiTi wires (p ≤ 0.021). Chlorhexidine mouthwash and gel with high concentration of fluorides did not change these properties more than saliva with regular hygiene. The amount of change of dental arch shape in the maxilla and mandible did not differ significantly between the experimental groups. CONCLUSION: Using antiseptics or a high concentration of fluorides during orthodontic treatment does not significantly affect the mechanical properties of NiTi wires and would not have clinical implications in changing orthodontic biomechanics.

Long-term posterolateral spinal fusion in rabbits induced by rhBMP6 applied in autologous blood coagulum with synthetic ceramics.

Autologous bone graft substitute (ABGS) containing rhBMP6 in autologous blood coagulum (Osteogrow) is a novel therapeutic solution for bone regeneration. This study is aimed to investigate the long-term outcome of ABGS with synthetic ceramics (Osteogrow-C) in rabbit posterolateral spinal fusion (PLF) model. Osteogrow-C implants were implanted bilaterally between rabbit lumbar transverse processes. We compared the outcome following implantation of ABGS with ceramic particles of different chemical composition (TCP and biphasic ceramics containing both TCP and HA) and size (500-1700 µm and 74-420 µm). Outcome was analyzed after 14 and 27 weeks by microCT, histology, and biomechanical analyses. Successful bilateral spinal fusion was observed in all animals at the end of observation period. Chemical composition of ceramic particles has impact on the PLF outcome via resorption of TCP ceramics, while ceramics containing HA were only partially resorbed. Moreover, persistence of ceramic particles subsequently resulted with an increased bone volume in implants with small particles containing high proportion of HA. ABGS (rhBMP6/ABC) with various synthetic ceramic particles promoted spinal fusion in rabbits. This is the first presentation of BMP-mediated ectopic bone formation in rabbit PLF model with radiological, histological, and biomechanical features over a time course of up to 27 weeks.

Evaluation of synthetic ceramics as compression resistant matrix to promote osteogenesis of autologous blood coagulum containing recombinant human bone morphogenetic protein 6 in rabbit posterolateral lumbar fusion model.

Posterolateral lumbar fusion (PLF) is a commonly performed surgical procedure for the treatment of pathological conditions of the lumbosacral spine. In the present study, we evaluated an autologous bone graft substitute (ABGS) containing rhBMP6 in autologous blood coagulum (ABC) and synthetic ceramics used as compression resistant matrix (CRM) in the rabbit PLF model. In the pilot PLF rabbit experiment, we tested four different CRMs (BCP 500-1700 µm, BCP 1700-2500 µm and two different TCP in the form of slabs) which were selected based on achieving uniform ABC distribution. Next, ABGS implants composed of 2.5 mL ABC with 0.5 g ceramic particles (TCP or BCP (TCP/HA 80/20) of particle size 500-1700 µm) and 125 µg rhBMP6 (added to blood or lyophilized on ceramics) were placed bilaterally between transverse processes of the lumbar vertebrae (L5-L6) following exposition and decortication in 12 New Zealand White Rabbits observed for 7 weeks following surgery. Spinal fusion outcome was analysed by µCT, palpatory segmental mobility testing and selected specimens were either tested biomechanically (three-point bending test) and/or processed histologically. The total fusion success rate was 90.9% by both µCT analyses and by palpatory segmental mobility testing. The volume of newly formed bone between experimental groups with TCP or BCP ceramics and the different method of rhBMP6 application was comparable. The newly formed bone and ceramic particles integrated with the transverse processes on histological sections resulting in superior biomechanical properties. The results were retrospectively found superior to allograft devitalized mineralized bone as a CRM as reported previously in rabbit PLF. Overall, this novel ABGS containing rhBMP6, ABC and the specific 500-1700 µm synthetic ceramic particles supported new bone formation for the first time and successfully promoted posterolateral lumbar fusion in rabbits.

Non-Thermal Ultrasonic Extraction of Polyphenolic Compounds from Red Wine Lees.

This study presents the results of conventional aqueous (CE) and non-conventional ultrasound-assisted (UAE) extractions of polyphenolic compounds from lees extracts of red wine varieties (Merlot and Vranac). The effect of ultrasound extraction time (t, s), and amplitude (A,%) from a 400 W ultrasound processor with different ultrasonic probes diameters (Ds, mm) on the amount and profile of polyphenolic compounds in the obtained extracts was investigated and compared to CE. The optimal conditions resulting in maximum extraction of phenolic compounds were: Probe diameter of 22 mm, amplitude 90% and extraction time for Vranac wine lees 1500 s and for Merlot wine lees extraction time of 1361 s. UAE proved to be significantly more effective in enhancing the extraction capacity of trans-resveratrol glucoside (30.57% to 300%), trans-resveratrol (36.36% to 45.75%), quercetin (39.94% to 43.83%), kaempferol (65.13% to 72.73%), petunidin-3-glucoside (41.53% to 64.95%), malvidin-3-glucoside (47.63% to 89.17%), malvidin-3-(6-O-acetyl) glucoside (23.84% to 49.74%), and malvidin-3-(6-O-p-coumaroyl) glucoside (26.77% to 34.93%) as compared to CE. Ultrasound reduced the extraction time (2.5-fold) and showed an increase of antioxidant potential by 76.39% (DPPH) and 125.83% (FRAP) compared to CE.

Biomechanical Comparison of the Temporalis Muscle Fascia, the Fascia Lata, and the Dura Mater.

The purpose of our research is to prove that elastic biomechanical characteristics of the temporalis muscle fascia are comparable to those of the fascia lata, which makes the temporalis muscle fascia adequate material for dural reconstruction in the region of the anterior cranial fossa. Fifteen fresh human cadavers, with age range from 33 to 83 years (median age: 64 years; mean age: 64.28 years), were included in the biomechanical study. Biomechanical stretching test with the comparison of elasticity among the tissues of the temporalis muscle fascia, the fascia lata, and the dura was performed. The samples were stretched up to the value of 6% of the total sample length and subsequently were further stretched to the maximum value of force. The value of extension at its elastic limit for the each sample was extrapolated from the force-extension curve and was 6.3% of the total sample length for the fascia lata (stress value of 14.61 MPa), 7.4% for the dura (stress value of 6.91 MPa), and 8% for the temporalis muscle fascia (stress value of 2.09 MPa). The dura and temporalis muscle fascia shared the same biomechanical behavior pattern up to the value of their elastic limit, just opposite to that of the fascia lata, which proved to be the stiffest among the three investigated tissues. There was a statistically significant difference in the extension of the samples at the value of the elastic limit for the fascia lata in comparison to the temporalis muscle fascia and the dura ( p = 0.002; Kruskal-Wallis test). Beyond the value of elastic limit, the temporalis muscle fascia proved to be by far the most elastic tissue in comparison to the fascia lata and the dura. The value of extension at its maximum value of force for the each sample was extrapolated from the force-extension curve and was 9.9% of the sample's total length for the dura (stress value of 10.02 MPa), 11.2% for the fascia lata (stress value of 23.03 MPa), and 18.5% (stress value of 3.88 MPa) for the temporalis muscle fascia. There was a statistically significant difference in stress values at the maximum value of force between the dura and the temporalis muscle fascia ( p = 0.001; Mann-Whitney U test) and between the dura and the fascia lata ( p < 0.001; Mann-Whitney U test). Because of its elasticity and similarity in its mechanical behavior to the dura, the temporalis muscle fascia can be considered the most suitable tissue for dural reconstruction.

Recombinant Human Bone Morphogenetic Protein 6 Delivered Within Autologous Blood Coagulum Restores Critical Size Segmental Defects of Ulna in Rabbits.

BMP2 and BMP7, which use bovine Achilles tendon-derived absorbable collagen sponge and bovine bone collagen as scaffold, respectively, have been approved as bone graft substitutes for orthopedic and dental indications. Here, we describe an osteoinductive autologous bone graft substitute (ABGS) that contains recombinant human BMP6 (rhBMP6) dispersed within autologous blood coagulum (ABC) scaffold. The ABGS is created as an injectable or implantable coagulum gel with rhBMP6 binding tightly to plasma proteins within fibrin meshwork, as examined by dot-blot assays, and is released slowly as an intact protein over 6 to 8 days, as assessed by ELISA. The biological activity of ABGS was examined in vivo in rats (Rattus norvegicus) and rabbits (Oryctolagus cuniculus). In a rat subcutaneous implant assay, ABGS induced endochondral bone formation, as observed by histology and micro-CT analyses. In the rabbit ulna segmental defect model, a reproducible and robust bone formation with complete bridging and restoration of the defect was observed, which is dose dependent, as determined by radiographs, micro-CT, and histological analyses. In ABGS, ABC scaffold provides a permissive environment for bone induction and contributes to the use of lower doses of rhBMP6 compared with BMP7 in bovine bone collagen as scaffold. The newly formed bone undergoes remodeling and establishes cortices uniformly that is restricted to implant site by bridging with host bone. In summary, ABC carrier containing rhBMP6 may serve as an osteoinductive autologous bone graft substitute for several orthopedic applications that include delayed and nonunion fractures, anterior and posterior lumbar interbody fusion, trauma, and nonunions associated with neurofibromatosis type I.

Structuring new alginate network aimed for delivery of dandelion (Taraxacum officinale L.) polyphenols using ionic gelation and new filler materials.

Alginate hydrogels are often used for immobilization of plant-derived bioactive compounds by fast and simple ionic gelation technique. However, the structure of alginate gel network is very porous and mostly result with high-diffusion rates of encapsulated compound, what limits its application as delivery vehicle. In order to prevent losses of bioactives and prepare efficient encapsulation systems, the aim of this study was to evaluate a potential of new natural fillers, cocoa powder (CP) and carob (C) for structuring alginate network aimed for encapsulation of aqueous dandelion (Taraxacum officinale L.) leaf extract using ionic gelation. Whey protein isolates served as a standard filler. The influence of different concentrations of gelling medium (2% and 3% calcium chloride) on encapsulation properties of alginate systems was also evaluated. Calcium concentration affected morphological properties (more acceptable when using 3% CaCl2), while textural properties and encapsulation efficiency of polyphenols and retained antioxidant capacity were more influenced by selected delivery materials. Alginate-whey protein isolates beads were scored with the highest loading capacity of polyphenols (>93%), while newly formulated binary mixtures (alginate-cocoa powder and alginate-carob) also enabled highly efficient entrapment of polyphenols (>88%). The slowest release of polyphenols in simulated gastrointestinal fluids were obtained when alginate was combined with CP and C, where system alginate-cocoa powder prepared with lower concentration of calcium chloride (2% CaCl2) enabled the most extended release of total polyphenols and hydroxycinnamic acids. Obtained results strongly justified implementation of new plant-derived functional fillers (cocoa powder and carob) for encapsulation purposes and opened new directions for designing of binary carrier's.

Physical, bioactive and sensory quality parameters of reduced sugar chocolates formulated with natural sweeteners as sucrose alternatives.

In this study, sugar alcohols, dietary fibers, syrups and natural sweeteners were used as sucrose alternatives in the production of reduced sugar chocolates (50% of cocoa parts) with enhanced bioactive profile. Formulated chocolates were evaluated for their physical (particle size distribution, texture) and sensory properties, sugar composition, polyphenolic compounds content and antioxidant capacity. All produced reduced sugar chocolates ensured >20% lower calorific value than conventional chocolate (prepared with sucrose). Formulated chocolates containing stevia leaves and peppermint exhibited the best sensory properties (especially with regard to mouthfeel, sweetness and herbal aroma), as well as the highest polyphenolic content and antioxidant capacity. Particle size and hardness of chocolates increased in comparison to conventional chocolate, in particular when the combination of fructose and isomalt or lactitol was used. The bioactive profile of produced chocolates was enriched with phenolic acids, flavone (luteolin and apigenin) and flavonol (quercetin) derivatives, which were not identified in control chocolate.

Improving the controlled delivery formulations of caffeine in alginate hydrogel beads combined with pectin, carrageenan, chitosan and psyllium.

Alginate-based blends consisting of carrageenan, pectin, chitosan or psyllium husk powder were prepared for assessment of the best formulation aimed at encapsulation of caffeine. Alginate-pectin blend exhibited the lowest viscosity and provided the smallest beads. Alginate-psyllium husk blend was characterised with higher viscosity, yielding the largest bead size and the highest caffeine encapsulation efficiency (83.6%). The release kinetics of caffeine indicated that the porosity of alginate hydrogel was not reduced sufficiently to retard the diffusion of caffeine from the beads. Chitosan coated alginate beads provided the most retarded release of caffeine in water. Morphological characteristics of beads encapsulating caffeine were adversely affected by freeze drying. Bitterness intensity of caffeine-containing beads in water was the lowest for alginate-psyllium beads and chitosan coated alginate beads. Higher sodium alginate concentration (3%) for production of hydrogel beads in combination with psyllium or chitosan coating would present the most favourable carrier systems for immobilization of caffeine.