FTIR Bands Research Articles

Semisynthesis and characterization of versatile azide intermediates using sodium alginate and its homopolymeric derivatives as starting material

Alginate, a polyuronic biopolymer composed of mannuronic and guluronic acid units, contain hydroxyl and carboxyl groups as targeting modification sites to obtain structures with new and/or improved biological properties. The copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a versatile click reaction for polymer functionalization, but it typically requires a “pre-click” modification to introduce azide or alkyne groups. Here, we described a straightforward chemical path to selectively modify alginate carboxyl groups producing versatile azido derivatives through N-acylation using 3-azydopropylamine. The resulting azide-functionalized polysaccharides underwent click chemistry to yield amino derivatives, confirmed by NMR and FTIR analyses. The 1H NMR spectrum reveals a characteristic triazole group signal at 8.15 ppm. The absence of the azide FTIR band for all amino derivatives, previously observed for the N-acylation products, indicated reaction success. Antibacterial and antioxidant assessments revealed that the initial polysaccharide lacks E. coli inhibition, while the click chemistry-derived amine products exhibit growth inhibition at 5.0 mg/mL. Lower molecular weight derivatives demonstrate superior DPPH scavenging ability, particularly amino-derivatives (24–33 % at 1.2 mg/mL). This innovative chemical pathway offers a promising strategy for developing polysaccharide structures with enhanced properties, demonstrating potential applications in various fields.

Synthesis and Exploring structural, magnetic, morphology and optical properties of La2−xAlxCuO4 (0 ≤ x ≤ 0.25) perovskite nanoparticles by microwave-assisted combustion method

La2CuO4 perovskite nanoparticles doped with aluminum were synthesized through the microwave-assisted combustion technique. Comprehensive studies on the structural, magnetic optical, functional and morphological properties were conducted using various techniques, including XRD, EDX, VSM, DRS-UV, FT-IR and FESEM respectively, .The XRD patterns of pristine La2CuO4 and Al-doped La2CuO4 unequivocally validated the exclusive development of a perovskite structure, devoid of any impurities. Nevertheless, the augmentation in Al3+ content (x = 0–0.25) induced a noteworthy phase shift from orthorhombic to cubic configuration. The average crystallite dimensions spanned from 54 to 41 nm. Distinct FT-IR bands at approximately 687 and 434 cm-1 were intricately linked to the La-O and Cu-O stretching modes inherent to the orthorhombic La2CuO4 phase. The energy gap determined through the Kubelka–Munk (K–M) methodology, experienced an elevation concomitant with the heightened Al3+ content (1.67–1.72 eV), attributable to quantum confinement phenomena. Within the La2-xAlxCuO4 (x = 0 to 0.25) system, the genesis of nanoscaled crystallized grains, interspersed with pores resulting from the amalgamation of grains, was evident. Analysis of hysteresis curves unveiled the emergence of soft ferromagnetic behavior at ambient temperature.

Implementation of plant extracts for cheddar-type cheese production in conjunction with FTIR and Raman spectroscopy comparison

Plant extracts have demonstrated the ability to act as coagulants for milk coagulation at an adequate concentration, wide temperatures and pH ranges. This research is focused on the use of different vegetative extracts such asCitrusaurnatiumflower extract (CAFE), bromelain, fig latex, and melon extract as economical and beneficial coagulants in the development of plant-based cheddar-type cheese. The cheddar-type cheese samples were subjected to physicochemical analysis in comparison to controlled cheese samplesmade fromaceticacid and rennet. The fat, moisture, protein, and salt contents remained the same over the storage period, but a slight decline was observed inpH.The Ferric reducing antioxidant power (FRAP) increased with the passage of the ripening period. The FTIR and Raman spectra showed exponential changes and qualitative estimates in the binding and vibrational structure of lipids and protein in plant-based cheeses. The higher FTIR and Raman spectra bands were observed in acid, rennet, bromelain, and CAFE due to their firm and strong texture of cheese while lower spectra were observed in cheese made from melon extract due to weak curdling and textural properties. These plant extracts are economical and easily available alternative sources for cheese production with higher protein and nutritional contents.

Development and Characterization of Edible Films Based on Cassava Starch Modified by Corona Treatment

Corona treatment (CT), a surface treatment widely used in the plastic industry, can be used to alter the properties of cassava starch. In the present work, CT was performed on dry granular starch (DS), water-suspended humid granular starch (HS), and gelatinized starch (GS). Different properties and structural characteristics of treated starches were studied. A lowering in pH was generally observed after CT and the rheological properties depended on the starch presentation. A reinforcement of DS and HS samples after CT was deduced from higher viscosity values in flow assays and viscoelastic moduli, but weak gels were obtained when CT was applied to GS. Changes in the A-type polymorphic structure, as well as a drop in relative crystallinity, were produced by CT for DS and HS. Additionally, changes in O-H and C-O-C FTIR bands were observed. Therefore, CT can be applied for starch modification, producing predominantly cross-linking in the DS and de-polymerization in the HS. Casting films made from the modified DS showed higher tensile strength and lower hydrophilicity, solubility, water absorption capacity, and water vapor permeability. Thus, the DS cross-linking induced by CT improved mechanical characteristics and hydrophobicity in edible films, which can be better used as packaging materials.

Short-range order and chemical compositions of glasses along the basaltic-rhyolite sub-alkaline join by Raman and FTIR spectroscopies

Six sub-alkaline glasses with compositions progressively shifting from the tholeiitic basalt (B100) end-member to the rhyolite (R100) end-member were investigated and analysed in the same frequency domain by both Raman and FTIR. This approach highlights spectroscopic similarities and differences such as positions, widths and intensities of Raman and FTIR bands, which may also exhibit significant overlapping. Both the Raman and FTIR spectra show several peaks grouped in three main vibrational windows: 200–650 (low frequency region, named F-I in this study), 650–850 (intermediate region, F-II) and 850–1250 cm−1 (high-frequency region, F-III). In line with previous investigations, the F-I interval can be ascribed to vibrational modes involving rings of tetrahedrally coordinated cations linked by bridging oxygens. It can be fitted with three components, whereas F-II involves the motion of Si atoms within its oxygen cage and is adequately represented by two components. Finally, F-III contains different T-O (T = tetrahedrally coordinated network-forming cation) stretching bands that can be tied to the overall degree of polymerization of the glass and are fitted with four components. In some glasses, the three and the two components within F-I and F-II are identifiable in both Raman and FTIR spectra; in cases of strong peak overlap, these peaks can be complementary to one another towards our interpretation of the molecular arrangement(s) in these glasses. Indeed, the positions of the four components in F-III are first constrained in the Raman spectra, which are more identifiable, then further refined using available Raman spectra for corresponding chemically simple silicate systems. The nine fitted components can reproduce the Raman and FTIR spectra extremely well.As a function of the amount of SiO2, the positions and intensities of the three low frequency components progressively shift in both Raman and FTIR. Similarly, the two bands in the F-II intermediate region exhibit a monotonic shifting of their positions. Indeed, the components at high frequency display less significant shifting of their positions as a function of SiO2, while their intensities change more markedly in the Raman spectrum compared to those for FTIR. The vibrational components measured in this study provide a referenced dataset of assignations of the most abundant natural volcanic glasses. Therefore, it provides a diagnostic tool based on the cross-validation of Raman and FTIR spectra to quickly identify the glass chemistry, offering the possibility to expand the applicability of remote investigations.

A novel Z-scheme heterojunction photocatalyst CeO2@WO3 nanocomposite with enhanced visible-light photocatalytic performance for wastewater treatment by cephalexin antibiotic degradation: Process optimization

Considering growing global environmental concerns, there is a heightened focus on expediting the synthesis of highly efficient catalytic materials to address these challenges effectively. Herein, a novel CeO2@WO3 heterojunction photocatalyst was synthesized using an ultrasonic-assisted method for the environmentally friendly degradation of cephalexin (CPX) under visible light. The optimized photocatalyst synthesis condition was achieved by assessing the influence of effective parameters, including the CeO2 content (5–25 wt%) and calcination temperature (300–600 °C), employing the RSM method. The synthesized photocatalysts were comprehensively characterized through XRD, SEM, TEM, EDS-mapping, BET, FTIR, and UV–Vis band gap analysis. Using optimal photocatalyst (CeO2 content: 15.78 %, calcination temperature: 440.59 °C, and ultrasonic power: 80 W), the influence of four critical variables on CPX degradation was thoroughly investigated via RSM-CCD. The maximum CPX degradation efficiency of 98.8 % was attained under the following optimal conditions: CPX concentration: 20.00 mg/L, solution pH: 6.79, photocatalyst dosage: 0.019 g/L, and visible light time: 94.82 min. Statistical analysis confirmed the accuracy of the regression model based on empirical data. The CeO2@WO3 heterojunction demonstrated substantial Chemical Oxygen Demand (COD) removal, reaching 73.26 % during the mineralization of CPX, surpassing the outcomes of previous studies. Trapping experiments and EPR analysis indicated the crucial involvement of hydroxyl radicals and superoxide radicals as highly active species due to their non-selective oxidation capabilities. Furthermore, a Z-scheme charge transfer mechanism was proposed to elucidate the enhanced photocatalytic activity. Identifying degradation intermediates was accomplished through HPLC-MS analysis, leading to a plausible pathway for CPX degradation. Overall, CeO2@WO3 exhibited excellent stability and could endure five cycles with minimal cerium leaching, highlighting its effectiveness in decomposing organic contaminants.

TPGS-modified Chitosan Nanoparticles of EGFR Inhibitor: Physicochemical and In vitro Evaluation against HepG2 Cell Lines.

Gefitinib (GFN) is an Epithelial Growth Factor Receptor (EGFR) inhibitor, and Food and Drug Administration (FDA) has approved medication to treat lung cancer. However, this investigation aimed to produce and characterize Gefitinib (GFN)-loaded chitosan and soy lecithin nanoparticles (NPs) modified with D-α-tocopheryl polyethylene glycol 1000 succinate mono ester (TPGS) and assess their therapeutic potential against HepG2 liver cell lines. Chitosan, a cationic polymer with biocompatible and biodegradable properties, was combined with soy lecithin to develop the NPs loaded with GFN using a self-organizing ionic interaction methodology. The entrapment efficiency and drug loading were found to be 59.04±4.63 to 87.37±3.82% and 33.46±3.76 to 49.50±4.35%, respectively, and results indicated the encapsulation of GEN in NPs. The pH of the formulations was observed between 4.48-4.62. Additionally, all the prepared NPs showed the size and PDI range of 89.2±15.9 nm to 799.2±35.8 nm and 0.179±0.065 to 0.455±0.097, respectively. The FTIR bands in optimized formulation (GFN-NP1) indicated that the drug might be contained within the NP's core. The SEM photograph revealed the spherical shape of NPs. The kinetic release model demonstrated the combination of diffusion and erosion mechanisms. The IC50 value of GFN and GFN-NP1 formulation against the HepG2 cell lines were determined and found to be 63.22±3.36 μg/ml and 45.80±2.53 μg/ml, respectively. DAPI and PI staining agents were used to detect nuclear morphology. It was observed that the optimized GFN-NP1 formulation successfully internalized and inhibited the growth of HepG2 cells. Hence, it can be concluded that the prepared NPs can be a new therapeutic option for treating liver cancer.

Green synthesis of CuO nanoparticles using Jasmin sambac extract: Conditions optimization and photocatalytic degradation of Methylene Blue dye

This investigation utilized an eco-friendly method to produce copper oxide nanoparticles (CuO NPs) through the utilization of Jasminium sambac leaf extract. Optimization of pH, temperature, reaction time, and copper sulfate concentration were performed. Characterization via UV–Vis, SEM, XRD, FTIR, and EDX techniques revealed a peak at 243 nm in UV–Vis, and an FTIR band at 590 cm−1 confirmed Cu(II) ion reduction to CuO NPs. pH, temperature, reaction time, and copper sulfate concentration were identified as crucial synthesis parameters. EDX analysis indicated a composition of 75.94% copper and 24.06% oxygen. CuO NPs were dispersive, monoclinic, crystalline, and pure, with an average particle size of 13.4 nm. Photocatalytic experiments achieved 97% Methylene Blue dye degradation in 210 min, highlighting the efficacy of the green synthesis method for CuO NPs with significant photocatalytic activity in wastewater remediation.

An approach towards identification of leather from leather-like polymeric material using FTIR-ATR technique

AbstractLeather, a by-product of the meat industry, has unique strength, elasticity, water vapor permeability, resistance to abrasion, durability, and longevity. In the background of ISO 15115:2019, the authenticity of leather has become a subject matter of concern. There is a need to distinguish leather (animal origin) from other leather-like materials derived from fossil fuel (PU, faux leather, etc.) and agro-product-driven vegan materials, which are also sold in the market as leather. For this purpose, this work relies on the signature FTIR bands of collagen (the skin-making protein) as a starting point to distinguish between animal origin and rest. A detailed investigation of all types of materials used in lifestyle products has been carried out to assess the boundary lines of this hypothesis. It is reasonably concluded that the signature Amide I, II, and III bands of collagen occurring at 1600, 1500, and 1200 cm−1 could serve as the first line to distinguish against all materials other than nylon and in the case of nylon, and the Amide A band at 3200 cm−1, forms the basis for differentiation from nylon. In essence, the FTIR spectra can be used as a robust, easy and unambiguous technique to distinguish leather from leather-like materials currently available on the market. Graphical Abstract

Structural, morphological, optical and low temperature magnetic studies on SnSeO3/ZnSeO3 nanocomposite

Nanocomposite SnSeO3/ZnSeO3 has been synthesized by hydrothermal method. EDAX and XRD confirm the perfect formation of SnSeO3/ZnSeO3 nano composite. It shows an interesting morphology of rectangular bar. Particle size is determined as 137.3nm. It is an effective applicant for applications in optoelectronic field. The energy gap of SnSeO3/ZnSeO3 nanocomposite is 5.52 eV. Urbach energy value obtained is 0.0635 eV. Refractive index obtained from optical energy gap is 1.926. PL emission spectrum obtains a strong efficient emission in UV (~387.7 nm) region, weak emission in green (~520.7 nm) region, and moderate emission in red (~788.7 nm) region. The UV emission at 387.7 nm shows radiative electron-hole recombination and it makes the candidate suitable for display applications. The emission peaks in the visible range may be attributed to different surface imperfections of Schottky and Frenkel kinds, oxygen vacancies and Sn – interstitials or Zn -interstitials. The FTIR bands are well assigned and confirms Se-O, ZnO, Sn-O bonds in finger print region. The sample exhibits diamagnetic nature at 300K and 5K. It also exhibits interesting super paramagnetic nature at 5K between -0.15Tesla to 0.15Tesla.

A comparative study of Mentha longifolia var. asiatica and Zygophyllum arabicum ZnO nanoparticles against breast cancer targeting Rab22A gene.

Breast cancer is the most frequently diagnosed cancer worldwide, and the incidence rate has increased enormously over the last three decades. Rab proteins are members of the Rab GTPase superfamily. The aberrant function of these proteins leads to the development of tumors. Mentha longifolia var. asiatica and Zygophyllum arabicum have been known for their therapeutic potential for ages. The present study aimed to synthesize ZnO nanoparticles encapsulated with the extracts of M. longifolia var. asiatica and Z. arabicum and evaluating their therapeutic potential against breast cancer, targeting the Rab22A gene and its protein. UV-Vis spectrophotometer showed characteristic absorbance peaks at 295 nm and 345 nm for Z. arabicum and M. longifolia var. asiatica ZnONPs, respectively. The FTIR bands of Z. arabicum nanoparticles suggested the presence of aldehydes, alcohols, and polyols whereas bands of M. longifolia var. asiatica ZnONPs suggested the presence of carboxyl groups, hydroxyl groups, alkynes, and amines. SEM revealed the size of Z. arabicum ZnO NPs to be 25 ± 4 nm with a spherical shape as compared to nanoparticles of M. longifolia var. asiatica having a size of 35 ± 6 nm with a hexagonal shape. EDX determined the elemental composition of both particles. The cytotoxicity of both plant extracts and respective NPs was determined against the MCF-7 breast cancer cell line, which was found to be significant with an IC50 value of 51.68 μM for Z. arabicum and 88.02 μM for M. longifolia var. asiatica ZnO compared to plant extracts (64.01 μM and 107.9 μM for Z. arabicum and M. longifolia var. asiatica). The gene expression and protein levels of Rab22A were decreased in nanoparticle-treated cells as compared to the control group. The apoptotic role of synthesized nanoparticles against the MCF-7 cell line was also determined by the expression of apoptotic pathway genes and proteins (bax, caspase 3, caspase 8 and caspase 9). All samples showed significant apoptotic activity by activating intrinsic and extrinsic pathway genes. The activity of Z. arabicum was more eminent as compared to M. longifolia var. asiatica which was evident by the greater expression of studied genes and proteins as determined by Real-time qPCR and ELISA. This is the first-ever report describing the comparative analysis of the efficacy of Z. arabicum and M. longifolia var. asiatica ZnONPs against breast cancer.

Molybdenum(VI) complexes of N, N′-bis isatin diamine Schiff base: Synthesis and characterization

Schiff base ligand of N, N′-bis isatin diamine was synthesized from various diamine and isatin through condensation reaction in 1:2 molar ratio. Mo(VI) complexes of isatin-diamines were synthesized by the reaction between the sodium molybdate dehydrate and N,N' bis isatin diamines with the reflux method. The synthesized ligand and complexes were characterized using spectroscopic techniques. The FT-IR band of azomethine group at 1600- 1610 cm-1 indicated the formation of the ligand. The UV-vis spectra clearly indicated that the prepared complex is a genuine Mo(VI) with d0 electronic configuration. The formation of a coordination bond was revealed by the downfield chemical shift of the complex in the NMR data as compared to the ligand. The UV results were corroborated by molar conductance data, which demonstrated their non-electrolytic character. The experimental evidence primarily supported the synthesis of both ligands and corresponding Mo(VI) complexes. Bangladesh J. Sci. Ind. Res. 58(4), 201-208, 2023

Innovative Protein Gel Treatments to Improve the Quality of Tomato Fruit.

This study aims to establish the effect of biostimulatory protein gels on the quality of tomato. One of the most consumed vegetables, tomato (Lycopersicon esculentum Mill.) is a rich source of healthy constituents. Two variants of protein gels based on bovine gelatin and keratin hydrolysates obtained from leather industry byproducts were used for periodical application on the tomato plant roots in the early stage of vegetation. The gels were characterized by classical physicochemical methods and protein secondary structure was obtained by FTIR band deconvolution. After ripening, tomato was analyzed regarding its content of quality indicators (sugars and organic acids) and antioxidants (lycopene, β-carotene, vitamin C, polyphenols). The results emphasized the positive effects of the protein gels on the quality parameters of tomato fruit. An increase of 10% of dry matter and of 30% (in average) in the total soluble sugars was noted after biostimulant application. Also, lycopene and vitamin C recorded higher values (by 1.44 and 1.29 times, respectively), while β-carotene showed no significant changes. The biostimulant activity of protein gels was correlated with their amino acid composition. Plant biostimulants are considered an ecological alternative to conventional treatments for improving plant growth, and also contributing to reduce the intake of chemical fertilizers.

CQTDs/SiO2NPs nanocomposite for Pb2+ and Cd2+ remediation and reuse applications in LFP detection and photocatalysis

Due to their propensity to bioaccumulate, lead and cadmium, two hazardous heavy metals, can seriously disrupt the ecosystem. These metals have the potential to cause major environmental and human health problems. Herein, carbon quantum dots were used to coat silica nanoparticles to create a brand-new nanocomposite called CQTDs/SiO2NPs. Cd2+ and Pb2+ ions were effectively removed from water and preconcentrated using the produced nanocomposite. The novel nanocomposite was characterized using SEM, TEM, FT-IR, XRD, and XRF. The bending vibration of Si–O–Si/Si–O–C and Si–OH are responsible for the FT-IR bands that were detected in the nanocomposite at 1041 and 954 cm−1, respectively. XRD demonstrated that the silica nanoparticles were amorphous. Additionally, SEM and TEM analysis revealed the nanocomposite's shape, which was determined to be spherical with minimal agglomeration.While XPS demonstrated the binding energy of the functional group present in the composite and further confirmed the metal loaded onto the adsorbent. On CQTDs/SiO2NPs nanocomposite, the optimum pH and dosage were 8 and 0.2 g respectively. The highest Cd2+ and Pb2+ ion adsorption capabilities are 14.87 and 38.49 mg g −1, respectively. The use of the nanocomposite resulted in an exothermic, physical and non-spontaneous adsorption that closely resembled the Langmuir equilibrium isotherm and the second-order kinetics. The metal loaded adsorbent used as a fingerprint labelling agent displayed clear fingerprint ridges and degraded the sulfamethoxazole (SMX) for up to 90 %. The prepared composite has proven to be coherent in heavy metal removal and can thus be reused in Latent fingerprint and photocatalysis applications. The reuse of the nanocomposite in the above-mentioned applications is an alternative solution to avoid secondary pollution.

Determining the nanostructure and main axis of gly-his-gly fibrils using the amide I’ bands in FTIR, VCD, and Raman spectra

The zwitterionic tripeptide glycyl-histidine-glycine (GHG) has been shown to self-assemble into visible crystalline fibrils that form a gel-supporting network with a very high storage modulus. Here we elaborate on the theory and experimental setup behind our novel approach employed to determining the main fibril axis for these gel-forming fibrils by simulating the amide I band profile for infrared absorption (IR), vibrational circular dichroism (VCD), and visible Raman scattering. We also highlight that combining these three vibrational spectroscopies can help in validating structures that are solved using powder x-ray diffraction analysis (PXRD). The PXRD analysis yielded a GHG fibril unit cell with P21 symmetry containing two peptide monomers and two water molecules. The monomers adopt a conformation reminiscent of the distorted polyproline II conformation obtained for tri-lysine in aqueous solution. Stabilization occurs primarily through peptide-peptide intermolecular hydrogen bond interactions, while the role of water in peptide hydration is minimal. The comparison of simulated and experimental amide I’ band profiles suggests that the xz plane of the crystal unit cell is being predominantly probed in the experimental IR and VCD spectra, with the x axis of the unit cell pointing in the direction of the main fibril axis. The monomer peptide in the unit cell interacts with six adjacent peptides forming hydrophobic channels by edge-to-face and parallel-displaced ππstacking in the y direction. These cores are further stabilized by a plethora of intermolecular interactions in the x and z directions. Our result suggests that the hydrophobic xz-surfaces would be a good target for the adsorption of hydrophobic drugs.

Effect of Basic Amino Acids on Folic Acid Solubility.

To prevent neural tube defects and other cardiovascular diseases in newborns, folic acid (FA) is recommended in pregnant women. A daily dose of 600 µg FA consumption is widely prescribed for women during pregnancy and 400 µg for women with childbearing potential. FA is a class IV compound according to the Biopharmaceutics Classification System (BCS) due to its low permeability (1.7 × 10-6 cm/s) and low solubility (1.6 mg/L); therefore, it must be administered via a formulation that enhances its solubility. Studies reported in the literature have proved that co-amorphization and salt formation of a poorly soluble drug with amino acids (AA) can significantly increase its solubility. Although arginine has been used with FA as a supplement, there is no information on the effect of basic AA (arginine and lysine) on the physical and chemical properties of FA-AA binary formulations. The present study implemented a conductimetric titration methodology to find the effective molar ratio to maximize FA solubility. The results showed that a 1:2.5 FA:AA molar ratio maximized solubility for arginine and lysine. Binary formulations were prepared using different methods, which led to an amorphous system confirmed by the presence of a glass transition, broad FTIR bands, and the absence of an X-ray diffraction pattern. Results of FA:AA (1:2.5) solubility increased in the range of 5500-6000 times compared with pure FA. In addition to solubility enhancement, the binary systems presented morphological properties that depend on the preparation method and whose consideration could be strategic for scaling purposes.

Differentiation of protein types extracted from tilapia byproducts by FTIR spectroscopy combined with chemometric analysis and their antioxidant protein hydrolysates

This research aimed to characterize protein types including sarcoplasmic protein (SP), myofibrillar protein (MP), and alkali-aided protein extract (AP) prepared from tilapia byproducts using water, 0.6 M NaCl, and alkaline solution (pH 11), respectively compared to freeze-dried minced tilapia muscle (CONTROL). Principal component analysis was performed from second derivative FTIR spectra to differentiate protein type. The AP mostly contained β-sheet structure and had low total sulfhydryl content and surface hydrophobicity. SP can be distinguished from MP by the loading plots of the FTIR bands representing the α-helical structure. While the bands for lipids and β-sheet of protein were noted for differentiating AP from CONTROL. After being hydrolyzed by Protease G6, the AP hydrolysate disclosed the highest ABTS radical scavenging activity, while the SP hydrolysate revealed the strongest metal chelating ability. Thus, an understanding of how fish processing waste can be utilized in the production of antioxidant protein hydrolysates has been achieved.

Molecular characterisation, gelation kinetics and rheological enhancement of ultrasonically extracted triggerfish skin gelatine

Improper fish skin disposal raises environmental and health concerns, highlighting the need for sustainable waste management. Turning discarded fish skins into marketable products like gelatine benefits both the economy and ecology. This study aims to investigate the feasibility of employing ultrasonic technique for the recovery of gelatine from the collagen-rich titan triggerfish skin following a preliminary pretreatment. The applied ultrasonic parameters included 100 W power, 40 kHz frequency, and a temperature held at 50 °C over a 3 h duration, resulting in a maximum gelatine yield of 20.5 ± 0.3 % (w/w) based on wet weight measurements. The biochemical and functional attributes of the extracted triggerfish gelatine (TFG) were compared to those of commercial bovine gelatine (CBG). TFG exhibited a substantial protein content (92.2 ± 0.2 %), along with low levels of moisture (7.4 ± 0.1 %), fat (0.2 ± 0.1 %), and ash (0.2 ± 0.04 %). SDS-PAGE showed that the primary elements of TFG were β- and α-chains (MW ∼ 150 to 220 kDa). While both gelatine types displayed predominant FTIR bands in the amide area (amide-I, amide-II and amide-ІІІ), TFG spectra, however, suggested that the ultrasonic treatment had no discernible effect on its triple helical structure. Significant variations in the gross amino acid profiles were found in both TFG and CBG. Nevertheless, compared to CBG, TFG had lower levels of proline and hydroxyproline residues. Additionally, TFG exhibited relatively lower gel strength; however, the optimal inclusion of microbial transglutaminase (MTGase) increased its gel strength (394±4 g) and melting temperature (Tmp = 31.9 °C), while reducing gelation time (<50 min at 20 °C). Functionally, TFG demonstrated higher foaming but marginally lower emulsifying properties than CBG. The finding underscores the potential of ultrasonication to mitigate fish skin waste emissions and efficiently retrieve high-quality gelatine within a shorter time frame.

The assessment of coagulation and flocculation performance and interpretation of mechanistic behavior of suspended particles aggregation by alum assisted by tapioca peel starch

The current study describes the synergistic action of a green starch flocculant extracted from agricultural waste coupled with aluminium sulphate to enhance coagulation and flocculation for surface water treatment. The coagulants and the flocs characteristics were analyzed to better understand the physicochemical properties and the underlying mechanisms of the treatment process. Several elements, including Cl and Ca were observed on the surface of the starch, and the presence of essential functional groups such as hydroxyl and carboxyl that help to promote flocculation function was detected. Superior performance was observed in the treatment using alum+TPS compared to the treatment using alum as a sole coagulant. Maximum turbidity and TSS removals of 90.32% and 88.89%, respectively, were attained within 10 min of settling time using the recommended alum-TPS dosage of 7.5–50 mg/L at pH 7. The flocs generated by the alum+TPS treatment exhibited distinguishable characteristics with bigger and highly compacted flocs matrix in which colloidal particles enmeshed within the flocs clusters. The combination use of alum+TPS showed the microflocs were initially formed by alum through the charge neutralization mechanism. The later addition of the starch into the suspension revealed that the bridging and sweep flocculation mechanism governs the flocculation process reflected through the shifting of FTIR bands that marked the formation of hydrogen bonding between the starch, alum and the suspended particles. Adding starch into the suspension undoubtedly provided effective entrapment and adsorption by larger-sized polymer, which promotes inter-colloidal particle bridging and subsequently improves the water clarity.

Effect of Lithium Salts on the Properties of Cassava Starch Solid Biopolymer Electrolytes.

This study evaluates the effect of lithium salts on the structural, electrochemical, and thermal properties of cassava starch solid biopolymer electrolytes (SBPEs). Films of SBPEs were synthesized using plasticizing agents and lithium salts (LiCl, Li2SO4, and CF3LiSO3) via thermochemical method. The SBPEs with lithium salts exhibited characteristic FTIR bands starch, with slight variations in the vibration oxygen-related functional groups compared to salt-free biopolymer spectra. The RCOH/COC index (short-range crystallinity) was higher in the films synthesized without lithium salt and the lowest value was established in the films synthesized with Li2SO4. Thermal degradation involved dehydration between 40 to 110 °C and molecular decomposition between 245 to 335 °C. Degradation temperatures were close when synthesized with salts but differed in films without lithium salt. DSC revealed two endothermic processes: one around 65 °C linked to crystalline structure changes and the second at approximately 271 °C associated with glucose ring decomposition. The electrochemical behavior of the SBPEs varied with the salts used, resulting in differences in the potential and current of peaks from the redox processes and its conductivity, presenting the lowest value (8.42 × 10-5 S cm-1) in the SBPE films without salt and highest value (9.54 × 10-3 S cm-1) in the films with Li2SO4. It was concluded that the type of lithium salt used in SBPEs synthesis affected their properties. SBPEs with lithium triflate showed higher molecular ordering, thermal stability, and lower redox potentials in electrochemical processes.