Effects of Temperature on the Physicochemical Properties of Bioinspired, Synthetic, and Biogenic Hydroxyapatites Calcinated under the Same Thermal Conditions.

The paper studies the changes in physicochemical properties of three types of hydroxyapatite (HAp): HAp-HB (from bovine sources), HAp-SC (chemically synthesized), and bioinspired HAp-SE (synthesized using eggshells) calcined under identical thermally controlled conditions from room temperature to 400, 500, 600, 650, 680, 700, 720, 750, 800, and 900 °C in furnace air. The thermogravimetric analysis (TGA) indicated distinct thermal transitions and coalescence phenomena at different temperatures for these samples due to their sources and mineral composition differences. Inductively coupled plasma (ICP) showed that HAp-H (human), HAp-HB (bovine), and HAp-SE (bioinspired) have similar Ca, P, and Mg contents. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the coalescence phenomena increased in the crystallite size as the temperature increased. X-Ray diffraction (XRD) patterns revealed partial phase changes in the bioinspired sample (HAp-SE) and crystallite growth in all samples, resulting in full width at the half maximum (FWHM) and peak position alterations. Fourier-transform infrared spectroscopy (FTIR) showed that HAp-SE exhibited a partial phase change due to dehydroxylation and the presence of functional groups (PO43-, OH, and CO32-) with varying vibrational modes influenced by the obtained method and calcination temperature. Raman spectra of the HAp-SE samples exhibited fluorescence at 400 °C and revealed vibrational modes of surface P-O. It observed the bands of the internal phosphates of the crystal lattice and shifts in the band positions at higher temperatures indicated phosphorus interacting with carbon and oxygen, triggering dehydroxylation.

The effect of the electromagnetic field on the physicochemical properties of isolated corn starch obtained of plants from irradiate seeds.

Maize grains are composed of the pericarp, endosperm, and germ. Consequently, any treatment, such as electromagnetic fields (EMF) must alter these components, which in turn alters the physicochemical properties of the grain. Since starch is a major component of corn grain, and given the great industrial importance of starch, this study investigates how EMF affects the physicochemical properties of starch. Mother seed were exposed to three different intensities 23, 70, and 118 µT for 15 days. Except for a slight porosity on the surface of the starch of the grains of plants exposed to higher EMF, the starch showed no morphological differences between the different treatments and the control (according to scanning electron microscopy). The X-ray patterns showed that the orthorhombic structure was kept constant, unaffected by the intensity of EMF. However, the pasting profile of starch was affected, and a decrease in the peak viscosity was obtained when the intensity of EMF increased. In contrast to the control plants, FTIR shows characteristic bands which can be attributed to the stretching of the CO bonds at wave number 1.711 cm-1. EMF can be considered a physical modification of starch.

Influence of physicochemical changes of the avocado starch throughout its pasting profile: Combined extraction.

This work focused on studying the effect of lamellae presence on the pasting profile of isolated avocado starch (C-type) obtained by a combined mechanical and ultrasonic process. Inductively Couple Plasma indicates that this starch is rich in P, K, Na, and Ca. This starch exhibits the most crystalline structure reported so far. The correlation between the morphological and structural properties throughout its pasting profile explains its apparent viscosity behavior. Granules exhibit a non-conventional irregular morphology with sizes ranging from 35 to 40 µm in their long side. DSC reveals endothermal transitions at 68 °C and 119 °C associated with the nanocrystals solvation and amylose-lipid complex, respectively. After gelatinization, the presence of lamellae originated from the partial fragmentation of the crystals. The pasting end exhibited a combined behavior between custard and hydrogel. This correlation could be considered a new methodology to understand the pasting behaviors in any starch.

Study of morphological, structural, thermal, and pasting properties of flour and isolated starch from unripe plantain (Musa paradisiaca).

This work focused on studying the mineral composition, morphology, thermal, structural, and pasting properties of isolated plantain starch. Plantain starch is rich in K, and other ions as Mg, Ca, P, and Si were found. This starch exhibits lenticular, elliptical, and semispherical morphologies. Two endothermal events present in the thermogram were identified as the hexagonal and orthorhombic solvation. C-type starch formed by hexagonal and orthorhombic nanocrystal was completely indexed. The ash content showed the presence of calcium phosphate (KCaP2O7), Calcium Magnesium Phosphate (Ca2.71Mg0.29(PO4)2), and silicon oxide (SiO2). The pasting profile of this starch behaves between a custard and a hydrogel. Scanning electron microscopy of the lyophilized samples along pasting profile confirms that the shear and van der Walls forces and slurry morphology govern the pasting profile changes.

Modification on the polyphenols and dietary fiber content of grape pomace by instant controlled pressure drop.

Instant controlled pressure drop (DIC) has been used as a pre-treatment to increase extractable polyphenols (EPP), mainly attributed to matrix structure expansion. This work aimed to evaluate the effect of DIC on non-extractable polyphenols (NEPP), EPP, and dietary fiber on grape pomace. At 0.2 MPa-60 s was observe an increase of total EPP and total anthocyanins. Despite the increment of EPP, was observe the lowest anthocyanins and non-extractable proanthocyanidins content at 0.4 MPa-120 s. This increase was due to a partial transformation of anthocyanins into phenolic acids and the depolymerization of proanthocyanidins. Also was observe partial solubilization of insoluble dietary fiber. Morphologically, the size of the pores generated by DIC was more significant at higher pressures. Thus, DIC modified the morphology and profile of the polyphenols of grape pomace, producing phenolic compounds of simpler structure and improving their antioxidant capacities.

Physicochemical characterization of Amaranth starch insulated by mechanical separations.

This work focused on the physicochemical properties of isolated Amaranth starch. Inductively coupled plasma (ICP) showed that amaranth is low-lipid calcium and magnesium source for the human diet. Scanning Electron Microscopy showed that isolated granules are in the range of sub and micro size. DSC starch thermogram showed a gelatinization temperature of 67.9 °C and an enthalpy of 10. 6 J/g suggesting the presence of an ordered crystalline structures. High-resolution X-ray diffraction showed the isolated starch contents nanocrystals with an orthorhombic crystalline structure whose pattern was indexed. The pasting profile showed that this kind of starch has an end cold viscosity as a custard, making it useful for infantile formulations. It does not present dynamic viscosity and would not be a problem when swallowed. A very important finding in this work was that the orthorhombic nanocrystals, after solvation during gelatinization, do not contribute to the apparent viscosity development.

Determination of basal bone mineral density in the femur bones of male and female Wistar rats.

Changes in bone mineral content of calcium (Ca), phosphorous (P), magnesium and potassium for male and female Wistar rats during their development from 3 weeks old to adulthood (27 weeks old) were measured. Bone mineral content was related to areal bone mineral density (BMD) which was measured in vivo at the femoral neck using a calibrated X-ray transmission system to obtain basal curves as a function of the age of the specimen. Diagnostic curves were built to determine low BMD (osteopaenia) and osteoporosis in female rats fed a Ca-depleted diet (50%) based on the obtained data and the criteria established by the World Health Organization. Bone mineral content is directly related to sex and age, but P did not change throughout the experimental period. P content did not exhibit significant changes with growing, while Ca was greatest in male rats, producing significant differences in the Ca:P ratio. Male rats reach the Ca:P ratio peak before female rats. However, areal BMD does not follow the same trend. On the other hand, osteoporosis produced a 45% decrease in this parameter for young and mature adults. These results make Z-score values available to diagnose bone-mass losses and hence the possibility of improving the conditions of non-contact measurement of BMD in vivo. This technique can be used for future experiments with Wistar rats.

Amylose-lipid complex formation from extruded maize starch mixed with fatty acids.

Functional modifications of starch, such as paste properties, retrogradation, water absorption indexes, solubility, and swelling capacity, are induced by the amylose-lipid complex. This research comprehends the study of functional properties of extruded maize starch mixed with fatty acids (stearic acid, oleic acid, and maize oil) and the formation of amylose-lipid complexes. Maize starch with lipids (5 or 10 %), moisture (35 %) was extruded (single screw). Starch granule was modified by extrusion, to a lesser extent at 10 % of lipids, especially stearic acid, which covers starch granule surface. Viscosity decreased meaningfully with stearic acid addition. DSC showed both starch gelatinization enthalpy and amylose-lipid complex enthalpy for stearic or oleic acid, but it was just the first enthalpy for maize oil. X-ray diffraction showed orthorhombic crystals with or without the presence of lipids. Our results indicated that stearic acid yielded the highest amount of amylose-lipid complexes.

Starch from two unripe plantains and esterified with octenyl succinic anhydride (OSA): Partial characterization.

Chemical modification with octenyl succinic anhydride (OSA) helps to control the physicochemical and thermal properties of isolated starches. The main objective, herein, was to partially characterize modified starches from Dominico-Harton plantain and FHIA 21 planted in Colombia. The highest degree of substitution was found in FHIA 21 (0.020) starch with 3% OSA and 4-h reaction at room temperature. The grain morphology was not affected, but small changes on the surface were evident. Both modified starches reported absorption bands in the IR at 1566 and 1738 cm-1, proper for these types of starch derivatives. The hexagonal and monoclinic structures of starch were altered through chemical modification. In the bending curves, a drastic decrease in the viscosity of the modified starches was observed with respect to the native one. The gelatinization temperatures of the modified starches were similar to those of the isolated starches.

Calcium Deficiency in Diet Decreases the Magnesium Content in Bone and Affects Femur Physicochemical Properties in Growing Rats.

This study evaluates the effect of three calcium levels in the diet (normal, moderate, and severe calcium depletion) on bone metabolism of male Wistar rats during their growth period. Bone mineral density (BMD) and femur length were determined in vivo during the growth stage using a single X-ray transmission system. The apparent calcium absorption was calculated in the rat adolescent and adulthood stages. At the end of the experiment, calcium concentrations in serum and urine were analyzed. The bones were evaluated postmortem to corroborate in vivo analyses. Microstructural properties of cortical and trabecular tissues of femurs bones were assessed using scanning electron microscopy. Bone mineral contents (Mg, Ca, P, and K) were quantified by inductively coupled plasma. Severe calcium depletion in the diets in the development stage affects the bone quality parameters such as bone mineral density and mineral content. Moreover, it was found thinner cortical and trabecular bone areas. Additionally, it was found that severe calcium depletion increased the apparent absorption of calcium as a defense mechanism, but with the decrease of the BMD peak, and the thickness of cortical bone as well as trabecular bone porosity. The severe calcium depletion increased the efficiency of apparent absorption calcium as a defense mechanism, but, even so, decreases the BMD peak as well as the thickness of cortical bone and trabecular bone porosity.

Effect of Nopal (Opuntia ficus indica) Consumption at Different Maturity Stages as an Only Calcium Source on Bone Mineral Metabolism in Growing Rats.

This work determines the effect nopal consumption at different maturity stages (60, 200, 400, and 600 g) as the only calcium source in bone metabolism. The apparent mineral absorption, the biomarkers of bone metabolism, the bone mineral density at different femoral regions, and crystal properties of the bone were evaluated during the growth stage. The Ca absorption was increased with the rat age in most of the experimental groups, while Mg supplementation decreased intestinal absorption probably due to a saturation process. Intestinal Ca and Mg absorption showed an opposite trend; this result suggests that both ions can compete for vitamin D absorption sites. The percentage of absorption of K was lower in the groups fed with Nopal; nevertheless, due to supplementation, the net absorption was higher than the control group. In all groups, osteocalcin levels decreased with the rat age. Nopal consumption increased osteocalcin levels during the adolescence stage in comparison to the control group. Amino N-terminal propeptide of type I procollagen levels increased in puberty and adolescence in all groups compared to the control group. Bone mineral density in different femoral regions was lower in the groups fed with nopal at early maturity stages (N-60 and N-200) than the groups fed with nopal at late maturity stages (N-400 and N-600). The crystal size of hydroxyapatite exhibited changes for all the groups, indicating the inclusion of mono and divalent ions in calcium replacement. On this basis, the nopal at late maturity stage contributed to bone formation.

In situ study of hydroxyapatite from cattle during a controlled calcination process using HT-XRD.

In situ High-Temperature X-ray diffraction (HT-XRD) from 400 to 900 °C was carried out to obtain patterns of bio hydroxyapatite every 20 °C during calcination processes at heating rates of 3, 6, and 9 °C/min to determine changes in its structural parameters as well as in its thermal expansion coefficient (TEC) for a and c lattice parameters. Additionally, High-Resolution Transmission Electron microscopy (HR-TEM) demonstrates that this HAp has an ordered nano like plate crystalline structure. The raw sample exhibits broad X-ray peaks originated by its nano size, and after calcination at about 700 °C, these become narrowed due to crystal growth. The calculation of the TEC as a function of the temperature for this hydroxyapatite shows a nonlinear increment for the a and c lattice parameters. Lattice thermal expansion occurs as water and organic matter are lost as the coalescence of HAp crystals take place; furthermore, as the heating rate increases, so does the lattice volume. Thermal analyses confirm that crystal growth is a process that starts after the bone sample has lost all its organic material and then bio-hydroxyapatite size changes from nano to micro-scale. A simulation using the PDF-4 software confirmed the nanometric size of the hydroxyapatite.

Physicochemical characterization of quinoa (Chenopodium quinoa) flour and isolated starch.

This work studies the physicochemical properties of quinoa flour and isolated starch. Starch in the seed forms clusters rich in amylopectin that are immersed in a matrix with spherical and polygonal shapes in the submicron scale. The isolated quinoa starch is rich in Sulphur and Magnesium. The quinoa flour has a higher content of protein, carbohydrates and lipids than isolated starch. Water absorption and water solubilized indexes of starch exhibited high values that could had originated by the extraction method. The broad peaks found for the X-ray patterns of isolated quinoa starch indicate that amylose and amylopectin are composed by nanocrystals, according to the PDF-4+2019 software. The viscosity of isolated starch had a higher value than flour; therefore, the quinoa starch could be used as a thickener in different formulations with the advantage of keeping a significant presence of minerals which are important to the human health.

Effect of the Nano Crystal Size on the X-ray Diffraction Patterns of Biogenic Hydroxyapatite from Human, Bovine, and Porcine Bones.

This paper focuses on the study of the effect of the change of the crystal size on the shape and width of the X-ray diffraction patterns for defatted and deproteinized bones as well as incinerated biogenic hydroxyapatite obtained from bovine, porcine, and human bones. Inductively Couple Plasma showed the presence of some ions such as Mg, K, Al, Fe, Zn, and Na for all samples. The nanometric size of the crystals was determined through High Resolution Transmission Electron Microscopy in which ordered crystals were found. The calcination of raw clean bones at 720 °C produced a transition of crystal size from nano to micro due to a coalescence phenomenon, this was accompanied by a decrease of the peak width of the X-ray diffraction patterns due to the decrease of the inelastic scattering contribution from the microcrystals. A simulation of the effect of the crystallite size on the shape and width of the X-ray patterns was done using PDF-4 software which confirmed that raw ordered bone crystals produce broad peaks which so far have been erroneously assigned to polycrystalline hydroxyapatite with low crystalline quality.

Structural, morphological, chemical, vibrational, pasting, rheological, and thermal characterization of isolated jicama (Pachyrhizus spp.) starch and jicama starch added with Ca(OH)2.

This work focused in the study of the changes on the physicochemical properties of isolated jícama starch (IJS), and IJS added with 0.15, 0.20, 0.30% Ca(OH)2 w/w. including: the structural, morphological, chemical, vibrational, pasting, rheological, and thermal characteristics. K, Ca, Na, and P were found in IJS. X-ray patterns, which showed that nanocrystals form the IJS according to the PDF-4 simulation. The functional properties were affected by the Ca inclusion, which originated electrostatic interactions. The gelatinization temperatures shifted to high values and exhibited an unfolding. The calculation of the IR absorption coefficient (ß) of the gelatinized samples as a function of the Ca2+ for the C-OH showed that the Van der Waals interaction causes the changes in the rheological-mechanical properties. The SEM images demonstrated that starch without alkali exhibited a porous network structure, while the starch with lime exhibited flakes and porous network. The gels of Jicama starch with Ca(OH)2 showed a viscoelastic behavior (G' > G″) with a reduction of their elastic module.

Morphological, structural, thermal, compositional, vibrational, and pasting characterization of white, yellow, and purple Arracacha Lego-like starches and flours (Arracacia xanthorrhiza).

This work is focused on the chemical, structural, morphological, thermal, IR vibrational, and pasting characterization of isolated white, yellow, and purple Arracacha starches from Colombia. Inductive couple plasma showed that these starches are rich in potassium. Scanning Electron Microscopy (SEM) images show that the starch granules are formed by ovoid fully filled Lego-like starch microparticles, the circular cross-section has a diameter between 9 and 15µm and mayor axis between 20 and 30µm. Each one of these ovoids is formed by irregular wedge-shaped 6 to 10 isolated starch granules with an average size between 4 and 12µm. The amylose content ranged between 31 and 36%. Arracacha starches exhibited high viscosity values (between 20.000 and 28.000cP), which could be influenced by the high content of potassium ions, due to the C-H~K Van Der Waals interaction that was identified by using IR spectroscopy. According to the X-ray diffraction analysis, the starch patterns exhibited broad diffracted peaks which could be associated with the existence of nano-crystals and lamellae; the Differential Scanning calorimetry (DSC) result showed starches with a low gelatinization temperature of about 60°C.

Improvement of physico-chemical properties and phenolic compounds bioavailability by concentrating dietary fiber of peach (Prunus persica) juice by-product.

BACKGROUND: This study aimed to concentrate dietary fiber (DF) from peach (Prunus persica) juice by-product (PJBP), to improve its functional properties, and its polyphenols bioavailability. The dietary fiber concentrates (DFCs) were obtained from PJBP using water/ethanol treatments (100:0, 20:80, 50:50, 80:20, and 0:100, v/v) at 1:5 ratio (wet weight/solvent, w/v) for 5 and 20 min at 21 °C. RESULTS: All treatments concentrated condensed tannins, total and insoluble DF, with the highest content found with 100% H2 O treatment. The major polyphenols of DFC were 4-O-caffeoylquinic, chlorogenic, and 1,5-di-O-caffeoylquinic acids. Water and oil retention capacity and maximum glucose diffusion rate were improved mainly with 100% H2 O treatment. Healthy rats were fed with a standard diet supplemented with 8% of PJBP, DFC obtained with 100% H2 O for 5 min, or DFC obtained with 20% EtOH for 5 min. Gastrointestinal digesta weight and viscosity were increased in animals supplemented with 100% H2 O DFC. Moreover, the urinary excretion of polyphenol metabolites, mainly glucuronide and sulfate conjugates, was increased with this treatment, indicating a greater bioavailability of PJBP polyphenols, which was associated with an increased dietary fiber porosity. CONCLUSION: Water treatment could be used to potentiate PJBP functional properties and polyphenols bioavailability. © 2017 Society of Chemical Industry.

Physicochemical properties of nixtamalized corn flours with and without germ.

This research studied the influence of the germ components on the physicochemical properties of cooked corn and nixtamalized corn flours as a function of the calcium hydroxide content (from 0 to 2.1 w/w) and steeping time (between 0 and 9h). A linear relationship was found between calcium content in germ and steeping time used during nixtamalization process. X-ray diffraction analysis showed that calcium carbonate is formed into the germ structure to 2.1 w/w of calcium hydroxide and 9h steeping time. The presence of the germ improves the development of peak viscosity in flours, and it is related to the increases in calcium concentration in germ and the formation of amylose-lipid complexes. No significant changes were observed in palmitic, stearic, oleic and linoleic acids of corn oil. The levels of further corn oil deterioration were 2.1 w/w of calcium hydroxide concentration and 9h of steeping time.

Analysis of the pasting profile in corn starch: Structural, morphological, and thermal transformations, Part I.

This work is focused on the understanding of the apparent viscosity profile of corn starch, in terms of the physicochemical and morphological changes that take place during the thermal profile of starch-water suspension to its respective gel formation. A mathematical model was used to obtain the experimental operating conditions that satisfy the Froude number. Freeze drying samples are studied in different stages along the pasting profile. Changes in the structural properties of the samples are studied using X-ray diffraction, and the morphological changes are followed using scanning electron microscopy, differential scanning calorimetry was used to analyze the thermal changes in starch. The changes in the pasting profile are associated with structural, thermal,and morphological changes of the system and the analysis of the physicochemical transformation that occur during the pasting profile are explained. The finding in this work does not show evidence of gel retrogradation at the end of the cooling process.

Analysis of thermal pasting profile in corn starch rich in amylose and amylopectin: Physicochemical transformations, part II.

This work focused on the study of the behaviors of the apparent viscosity profiles of isolated corn starches rich in amylose and amylopectin, through the physicochemical and morphological changes that take place during the thermal profile and the gel formation. Frozen dry samples were studied at different stages along the pasting profile. Changes in the structural properties of the samples were studied using X-ray diffraction, and the morphological changes were followed using scanning electron microscopy, differential scanning calorimetry was used to analyze the thermal changes. The changes in the pasting profile (curve of apparent viscosity) were associated with structural, thermal, and morphological changes of the starch-water suspension. From the results obtained, a new interpretation of the parameters measured with the pasting profile is introduced. In this work does not show evidence of retrogradation at the end of the cooling process for starch rich in amylopectin and that starch rich in amylose does not develop viscosity.