Physicochemical properties of pectin-Fe(III) gained by HG-type hawthorn with different esterification degree.

In this study, the complexation ability of HG-type hawthorn pectin with trivalent iron ions after de-esterification was investigated. The moderate esterification reaction could significantly increase the iron content in HG-type hawthorn pectin. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) experiments proved that -OH and -COOH in the pectin acted as a bridge connecting Fe3+ leading to the formation of ß-FeOOH structure, and the trivalent iron ions were successfully complexed into the HG-type hawthorn pectin. In addition, infrared and ultraviolet spectroscopic scans, particle size, and potentiometric measurements were carried out to demonstrate the complexation coordination mechanism of hawthorn pectin with Fe3+, and there were differences in the complexation effect of HG-type hawthorn pectin with different degrees of esterification. The gelling properties of HG-type hawthorn pectin were subsequently verified by in vitro gastrointestinal tract simulation experiments to aid the smooth passage of ferric ions through the gastric juices and reduce irritation. The success of the experiments demonstrated that HG-type hawthorn pectin is an excellent raw material for metal complexation, and the degree of esterification is one of the important factors affecting its complexation effect, which proves its potential application value as an iron supplement.

Construction of a pectin/sodium alginate composite hydrogel delivery system for improving the bioaccessibility of phycocyanin.

In this study, different concentrations of sodium alginate were compounded with pectin and phycocyanin to co-prepare composite hydrogel spheres (HP-PC-SA 0.2 %, 0.6 %, 1.0 %, 1.4 %) to evaluate the potential of the composite hydrogel spheres for the application as phycocyanin delivery carriers. The hydrogel spheres' physicochemical properties and bioaccessibility were assessed through scanning electron microscopy, textural analysis, drug-carrying properties evaluation, and in vitro and in vivo controlled release analysis in the gastrointestinal environment. Results indicated that higher sodium alginate concentrations led to smaller pore sizes and denser networks on the surface of hydrogel spheres. The textural properties of hydrogel spheres improved, and their water-holding capacity increased from 93.01 % to 97.97 %. The HP-PC-SA (1.0 %) formulation achieved the highest encapsulation rate and drug loading capacity, at 96.87 % and 6.22 %, respectively. Within the gastrointestinal tract, the composite hydrogel's structure significantly enhanced and protected the phycocyanin's digestibility, achieving a bioaccessibility of up to 88.03 %. In conclusion, our findings offer new insights into improving functionality and the effective use of phycocyanin via pectin-based hydrogel spheres.

Ultrasonic-microwave technique promotes the physicochemical structure of hydrogel and its release characterization of curcumin in vitro.

In this study, soybean protein isolate and hawthorn pectin were mixed to prepare binary hydrogels using ultrasound and microwave techniques. Moderate treatment can not only significantly improve the mechanical strength of the hydrogel, but also increase the tightness of the internal cross-linking. The strengthening of interactions (hydrogen bonds, hydrophobic interactions, and disulfide bonds) was the main reason for this trend. Especially, the ultrasonic-microwave (80 s) treatment hydrogel possessed excellent hardness (33.426 N), water-holding capacity (98.26%), elasticity (G' = 1205 Pa), and a more homogeneous and denser microstructure. In addition, the hydrogel minimized the extent of curcumin loss (21.23%) after 5 weeks of storage. In general, the ultrasonic-microwave technique could significantly promote the physicochemical structure and curcumin bioaccessibility of hydrogels, which showed excellent market prospects in the food industry.

Hawthorn pectin/soybean isolate protein hydrogel bead as a promising ferrous ion-embedded delivery system.

In this study, hydrogel beads [SPI/HP-Fe (II)] were prepared by cross-linking soybean isolate protein (SPI) and hawthorn pectin (HP) with ferrous ions as a backbone, and the effects of ultrasound and Fe2+ concentration on the mechanical properties and the degree of cross-linking of internal molecules were investigated. The results of textural properties and water-holding capacity showed that moderate ultrasonic power and Fe2+ concentration significantly improved the stability and water-holding capacity of the hydrogel beads and enhanced the intermolecular interactions in the system. Scanning electron microscopy (SEM) confirmed that the hydrogel beads with 60% ultrasonic power and 8% Fe2+ concentration had a denser network. X-ray photoelectron spectroscopy (XPS) and atomic absorption experiments demonstrated that ferrous ions were successfully loaded into the hydrogel beads with an encapsulation efficiency of 82.5%. In addition, in vitro, simulated digestion experiments were performed to understand how the encapsulated Fe2+ is released from the hydrogel beads, absorbed, and utilized in the gastrointestinal environment. The success of the experiments demonstrated that the hydrogel beads were able to withstand harsh environments, ensuring the bioactivity of Fe2+ and improving its bioavailability. In conclusion, a novel and efficient ferrous ion delivery system was developed using SPI and HP, demonstrating the potential application of SPI/HP-Fe (II) hydrogel beads as an iron supplement to overcome the inefficiency of intake of conventional iron supplements.

Encapsulation and sustained release of curcumin by hawthorn pectin and Tenebrio Molitor protein composite hydrogel.

In this study, the effects of pH value, mixing ratio and the Ca2+ concentration on the complex gelation of hawthorn pectin (HP) and Tenebrio Molitor protein (TMP) were investigated. The turbidity results showed that the composite gel had the maximum polymer concentration when the mixing ratio was 2:1 and the pH value was 3.35. The rheological measurement results showed that TMP/HP (15 mmol/L) hydrogel (THIH) had the highest storage modulus and loss modulus, indicating that the properties of the hydrogel at this Ca2+ concentration had been significantly improved. The results of scanning electron microscope and pore size also proved that the network structure prepared under this condition was compact and uniform, the pore size was small, which was beneficial to the entrapment of active components. Subsequently, in order to explore the storage stability and antioxidant activity of THIH-loaded curcumin in simulated gastrointestinal environment, in vitro simulated digestion experiment was carried out and satisfactory results were obtained. To sum up, THIH was a promising delivery system with broad application prospects, which was expected to provide a novel idea for the entrapment and delivery of active components.

Comparative study of HG-type low-ester hawthorn pectin as a promising material for the preparation of hydrogel.

Homogalacturonan (HG)-type pectin has been considered suitable for the formation of hydrogel, but it is unknown whether the less side chain will limit the properties of hydrogel. The current study successfully obtained low methoxyl HG-type hawthorn pectin (LMHP) from hawthorn by sequential hot water extraction and alkaline de-esterification. The proportion of HG domain, the proportion of rhamnogalacturonan-I (RG-I) domain, molecular weight, and particle size of LMHP were 81.13 %, 4.04 %, 348.43 kDa, and 1386.92 nm, respectively. Compared with commercial citrus pectin (CP), LMHP was more suitable for the preparation of hydrogel. The hydrogel with the densest network structure and relatively stable performance in digestion simulation environment can be obtained as the concentration of LMHP increases to 2.5 %, which is lower than the consumption of commercial citrus pectin. Overall, these findings highlight the potential of hawthorn pectin as a novel hydrogel raw material.

Gill histopathologies following exposure to nanosilver or silver nitrate.

Fish gill is the site for many crucial physiological functions. It is among the first sites of xenobiotic exposure, and gill histopathological alterations may be detected soon after toxicant exposure. Silver (Ag) is one of the most toxic metals to aquatic organisms mainly due to its ability to disrupt ionic regulation. The goal of this study was to determine the effect of ionic and nanoscale Ag on fathead minnow gills by examining gill histology and Na(+)/K(+)-ATPase immunoreactivity. Fathead minnows were exposed to two measured concentrations of silver nitrate (AgNO3: 1.3 or 3.7 µg/L as Ag(+)), citrate silver nanoparticles (citrate-AgNP: 15 or 39 µg/L), and polyvinylpyrrolidone-AgNP (PVP-AgNP) (AgNP: 11 or 50 µg/L). Circulatory disturbances were the most prevalent gill alterations detected and were significantly increased in all Ag treatment groups compared to control. AgNO3 (1.3 µg/L) was the only treatment that significantly elevated the number of total mucous goblet cells present. In all other Ag treatments, the percent of degenerated goblet cells was significantly increased compared to control. When the sum of all histopathological abnormalities (weighted index) was calculated, all Ag groups displayed a significantly higher index, with citrate-AgNP having the highest toxicity (index of 10 ± 0.32 versus 2.4 ± 0.6 in controls). Gill Na(+)/K(+)-ATPase immunoreactivity was decreased by Ag. These results indicated that both AgNO3 and AgNP created similar disruptions in gill structure and ionic regulation, possibly due to the ionic Ag portion of each treatment.

Elemental fingerprinting of soils using ICP-MS and multivariate statistics: a study for and by forensic chemistry majors.

Students in an instrumental analysis course with a forensic emphasis were presented with a mock scenario in which soil was collected from a murder suspect's car mat, from the crime scene, from adjacent areas, and from more distant locations. Students were then asked to conduct a comparative analysis using the soil's elemental distribution fingerprints. The soil was collected from Lafayette County, Mississippi, USA and categorized as sandy loam. Eight student groups determined twenty-two elements (Li, Be, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Cs, Ba, Pb, U) in seven samples of soil and one sample of sediment by microwave-assisted acid digestion and inductively coupled plasma-mass spectrometry (ICP-MS). Data were combined and evaluated using multivariate statistical analyses. All eight student groups correctly classified their unknown among the different locations. Students learn, however, that whereas their results suggest that the elemental fingerprinting approach can be used to distinguish soils from different land-use areas and geographic locations, applying the methodology in forensic investigations is more complicated and has potential pitfalls. Overall, the inquiry-based pedagogy enthused the students and provided learning opportunities in analytical chemistry, including sample preparation, ICP-MS, figures-of-merit, and multivariate statistics.

Plutonium concentration and (240)Pu/(239)Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS.

Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and Amchitka Island underground nuclear test site cannot be ruled out.

Effects of glyphosate on the mineral content of glyphosate-resistant soybeans (Glycine max).

There are conflicting claims as to whether treatment with glyphosate adversely affects mineral nutrition of glyphosate-resistant (GR) crops. Those who have made claims of adverse effects have argued links between reduced Mn and diseases in these crops. This article describes experiments designed to determine the effects of a recommended rate (0.86 kg ha(-1)) of glyphosate applied once or twice on the mineral content of young and mature leaves, as well as in seeds produced by GR soybeans (Glycine max) in both the greenhouse and field using inductively coupled plasma mass spectrometry (ICP-MS). In the greenhouse, there were no effects of either one application (at 3 weeks after planting, WAP) or two applications (at 3 and 6 WAP) of glyphosate on Ca, Mg, Mn, Zn, Fe, Cu, Sr, Ba, Al, Cd, Cr, Co, or Ni content of young or old leaves sampled at 6, 9, and 12 WAP and in harvested seed. Se concentrations were too low for accurate detection in leaves, but there was also no effect of glyphosate applications on Se in the seeds. In the field study, there were no effects of two applications (at 3 and 6 WAP) of glyphosate on Ca, Mg, Mn, Zn, Fe, Cu, Sr, Ba, Al, Cd, Cr, Co, or Ni content of young or old leaves at either 9 or 12 WAP. There was also no effect on Se in the seeds. There was no difference in yield between control and glyphosate-treated GR soybeans in the field. The results indicate that glyphosate does not influence mineral nutrition of GR soybean at recommended rates for weed management in the field. Furthermore, the field studies confirm the results of greenhouse studies.