Acid Hydrolysis Research Articles

Synthesis and characterization of nanocelluloses isolated through acidic hydrolysis and steam explosion of Gliricidia sepium plant fiber

Synthesis and characterization of nanocelluloses isolated through acidic hydrolysis and steam explosion of Gliricidia sepium plant fiber

Value addition of mango kernel for development and characterization of starch with starch nanoparticles for packaging applications

The present research was conducted to explore the potential of mango kernel starch from the Chaunsa variety to develop starch and starch nanoparticles (SNPs) based films. The investigation included starch isolation from mango kernel followed by the preparation of SNPs by acid hydrolysis and a thorough examination of various physicochemical properties for film formation. The properties of SNPs were found to be distinctly different from those of native starch. SNPs exhibited an aggregated form with an irregular surface, whereas native starch had an oval and elongated shape with a smooth surface. X-ray diffraction (XRD) analysis confirmed that the starch type in SNPs was of the A-type. Additionally, the pasting properties of SNPs were minimal due to the acid hydrolysis process. SNP-based composite film was developed with (5 %) SNP concentration added. This successful incorporation of SNPs enhanced biodegradability, with complete degradation occurring within three weeks. Moreover, the composite films displayed increased burst strength, measuring 1303.51 ± 73.7 g, and lower water vapor transmission rates (WVTR) at (7.40 ± 0.50) × 10−3 g per square meter per second and reduced water solubility at 35.32 ± 3.0 %. This development represents a significant advancement in the field of eco-friendly packaging materials.

Fractionation and characterization of Dunaliella microalgal biomass and extraction of carotenoids

This paper presents findings on the application of two fractionation protocols of Dunaliella microalgal biomass with the aim to separate and recover the lipid, pigment and protein fraction, leaving as “residue” the fraction that contains carbohydrates. The first protocol (LPC) is based on the initial extraction of lipids, followed by extraction of proteins, while in the second protocol (CLP), the pigments are first extracted followed by lipids extraction. With the LPC protocol the recovered lipid fraction was 34 and 32 wt%, while the recovered proteinic fraction was 46 and 50 wt% for the two samples under study, i.e. 1120 (D. granulata) and 1220 (D. minutissima). The CLP protocol led to the initial extraction of the pigment fraction with a percentage of 10–15 wt% while the subsequently recovered lipidic fraction was 16–24 wt%. The initial biomass was characterized for its moisture (<0.7 wt% for both samples), ash (approx. 45 wt% for both samples), organic matter, elemental composition and higher heating value (HHV) which was 23 and 30 MJ/kg (organic matter based-OMB). The composition of the lipid fraction was analyzed via esterification and gas chromatography (GC-FID) showing C16 and C18 as the predominant acids in the samples. The residue/carbohydrate fraction was analyzed via acid hydrolysis and analysis by high pressure liquid chromatography (HPLC) showing about 20 wt% (-OMB) content of carbohydrates. The high ash content of the biomass was found to be co-extracted during the fractionation protocols at a percentage of ≈49 % in the lipidic fraction and 45 % in the proteinic fraction. Furthermore, emphasis was given on pigment extraction and recovery using various solvents and quantification methods. Measurements of β-carotene, carotenoids, and chlorophyll content through UV and HPLC analyses is presented with chlorophyl and carotenoid content being ≈12 wt% and ≈9 wt% for samples 1120 and 1220 (-OMB). Additionally, a comparison between three solvents (THF, dichloromethane, acetone) was performed regarding their ability to extract the pigments from the microalgal biomass showing that acetone is capable of extracting pigments when concentration of the pigments is not high. The comparison of the HPLC with the UV method, suggested that UV spectroscopy is a reliable and rapid alternative for pigments determination, while HPLC enables identification and quantitative determination of specific pigments and chlorophyll species. The study provides insights for different fractionation protocols applied in two not yet fully studied Dunaliella species as well as the chlorophyl and carotenoid content.

Effectiveness of Starch Nanocrystals on Mechanical and Shape Memory Behaviour of Smart Rubber

Shape memory rubber (SMR) is a type of smart rubber that can undergo reversible changes when exposed to external stimuli such as temperature, solvent, pH, light, magnetic field and oxidation. Lightly crosslinked rubber demonstrated shape memory behaviour without any initial heat treatment. However, the strength of lightly crosslinked natural rubber latex (NRL) film cured by sulphur is relatively low. With the concept of sustainability in mind, the idea of fabricating green smart material for continuous development has motivated researchers to explore the realms of sustainable materials. This research aims to investigate the mechanical behaviour of starch nanocrystals (SNC) reinforced rubber composite films. To this end, the emphasis is laid on evaluating the effectiveness of SNC on shape memory effect (SME) of rubber nanocomposite films. In the current work, up to 8 wt% of SNC synthesized by acid hydrolysis was incorporated into NRL and the mixture was cast to form rubber nanocomposite films. SNC effectively increased the modulus and energy-storing potential of the rubber nanocomposite films. Moreover, the shape memory behaviour of the rubber nanocomposite films improved significantly with SNC content, leading to increased shape fixity (Sf) and full shape recovery (Sr).

Amino Acids Isolation from α-keratin of Javanese Goat (Capra hircus) Hair and Garut Sheep (Ovis aries) Hair Waste Using Acid Hydrolysis Method as BCAA Supplement

Javanese goat and Garut sheep hair contain α-keratin, a protein that can be broken by hydrolysis to produce simpler amino acids. Feather waste generates millions of tons of α-keratin biomass originating from animal slaughterhouses, thereby raising health concerns. The utilization of acid hydrolysis is considered to be more cost-effective compared to enzymatic hydrolysis, and it provides a broader range of amino acid cleavage sites compared to enzymes, which exhibit specific cleavage. This study aimed to isolate amino acids from Javanese goat and Garut sheep hair through acid hydrolysis. The methods included hair sample preparation, acid hydrolysis used 6 M HCL at 110°C, reflux isolation, amino acid separation based on isoelectric pH 4.9 –5.4, functional groups analysis using FTIR, and analysis of amino acid content by HPLC methods. The results showed that the yield produced after isolation on Javanese goat hair samples was 0.92% and Garut sheep hair 0.32%, respectively. The FTIR spectrum showed amino acid functional groups in both samples, including carboxyl (COOH), amine (C-N primer), (C-S disulfide), and amide I (-CONH2). Successful breakdown of α-keratin proteins into simpler amino acids was achieved for Javanese goat and Garut sheep hair. Amino acid analysis of Javanese goat hair isolates revealed the presence of aspartic acid, threonine, serine, glutamate, proline, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, histidine, lysine, and arginine amino acids, respectively. The highest content was isoleucine at 0.60% w/w. In conclusion, the isolated amino acids from Javanese goat hair can be used as a halal supplement that serves as nutrition in the body.

Synthesis of cellulose nano fiber from palmyrah fruit fiber and its applicability as a reinforcement agent on starch based biodegradable film

The global trend in packaging is shifting towards environmentally friendly, natural materials that decompose easily. Among the bio-based packaging materials, starch is a renewable, biodegradable, bio-compatible, and easily accessible source. However, starch-based biodegradable films depict weak mechanical properties compared with synthetic polymers. This problem can be solved by incorporating reinforcement fillers into the starch matrix. Palmyrah fruit (Borassus flabellifer L.) waste can be a good source to obtain fillers due to its high cellulose content. The aim of the study was to investigate the reinforcement of starch-based biodegradable films with the incorporation of pure cellulose nanofiber (CNF) obtained from palmyrah fruit fiber (PFF). Chemical treatments such as alkaline treatment (4% NaOH), bleaching [1% Ca(OCl)2], and acid hydrolysis (10 moldm-3 H2SO4) were done successively to obtain pure CNF from PFF. CNF was characterized using FTIR and particle size distribution (PSD) was analyzed by granulometry. The yield of CNF from PFF was 37.890±0.008 %. The results of FTIR depicted CNF was synthesized successfully. Five different biodegradable films were prepared by varying the amount of palmyrah tuber starch (4.5-2.5 w/w %) and CNF (0.0-2.0 w/w %) while the amount of glycerin (1.5 w/w %) and gelatin (1 w/w %) were kept constant. PSD results revealed that nano-sized CNF (10-100 nm) was synthesized successfully. The optimized film was selected based on the tensile strength and low water vapor transmission rate. Optimized film formulation, with palmyra tuber starch (3 w/w %) and CNF (1.5 w/w %) showed desirable physical, mechanical and optical properties, including the thickness, moisture content, water vapor transmission rate, water uptake, transparency at 600 nm, water activity, water solubility and tensile strength of 0.192±0.004 mm, 11.07±0.04 %, 3.870±0.005 g/m2.day, 22.34±0.05 %, 3.97±0.01 %, 0.440±0.001, 51.68±0.140 % and 9.55 MPa respectively. All films showed excellent soil biodegradability within two weeks. In conclusion, palmyra fruit CNF can be effectively used to reinforce starch-based biodegradable packaging films.

Synthesis Chitosan nanoparticles from Animal Byproducts (Shrimp Shells) Characterization, Physical Properties and Toxicity of Polymeric Nanoparticles in vivo

The study included the extraction of Chitin (Ch) from shrimp shells and preparation of Chitin nanoparticles (NCh) using acid hydrolysis and ultrasound method. In addition, the preparation of chitosan (Chs) and Chitosan nanoparticles (NChs) by Deacetylation method, then we study some of the characteristics, including yield, diameter by Size Analyzer, Field Emission Scanning Electron Microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, X-Ray Diffractometer (X-RD), Viscosity, Water Binding Capacity (WBC) and Fat Binding Capacity (FBC). The results showed, (a) decreased the percentage of yield of NChs to 8.20%, (b) the effective diameter of the natural chitosan using a Size Analyzer and was 28121.5 nm, (c) FESEM analysis revealed that the NChs displayed a nanoscale structure with diameters ranged from 20.93 - 30.20 nm (d) the degree of deacetylation (DD%) using FT-IR spectroscopy device, of NChs was (80.21%) compared to Chs 71.45%, and in addition, from the X-ray spectrum, two peaks in spectra of (Ch, NCh) and (Chs, NChs) were observed at the diffraction angles (2θ) which are (10.70-10.99) and (19.99-20.37). Results show increasing the crystallization coefficient of NCh and NChs, while viscosity, WBC and FBC of NChs decreased compared to Chs. The NChs did not show any toxic effect on human blood cells at concentrations of 100-1000 µg. ml-1.

Absolute Configuration of 4-Chloroisoleucine in Cyclolithistide A: An Antifungal Peptide Lactone Discovered in Marine Lithistid Sponges.

Cyclolithistide A is a peptide lactone isolated from marine lithistid sponges. Its entire structure, including absolute configurations, has been reported except the relative and absolute configurations of its characteristic residue, 4-chloroisoleucine (4-CIle). We synthesized four isomers of 4-CIle from furfural-derived N-Boc imine and propionaldehyde. Analysis of the acid hydrolysate of cyclolithistide A and the synthetic samples of 4-CIle after derivatization with l- and d-FDAA permitted us to propose the absolute configuration of the 4-chloroisoleucine residue in cyclolithistide A as 2S,3R,4R.

High‐efficiency modification of PET by the low addition of a self‐assembled functional nanocellulose film prepared from waste paper

AbstractPolyethylene terephthalate (PET) is a conventional packaging material. Its modification has attracted immense attention in the industry and academia. Here, office waste paper, white cardboard waste, and waste corrugated paper were first employed as raw materials for cellulose nanocrystal (CNC) extraction by acid hydrolysis. Thereafter, CNC/PET composite films with various CNC additions were prepared via a self‐assembly technique. The results revealed that the CNCs formed a self‐assembled film on the PET surface via the synergistic effect of the complex interactions among the CNCs as well as between the CNCs and PET. Moreover, the CNCs improved the barrier property of PET and decreased the oxygen and water vapor transmittances of CNC/PET by 30.7% and 21.7%, respectively. Additionally, the coating of the PET surface with 0.2 wt.% CNCs extracted from the waste paper decreased the surface wettability of PET, exhibiting application potentials in the hydrophobic modification of polymers. This study realized waste paper recycling and provided a basis for constructing self‐assembled functional films on PET surfaces. The findings and insights of this study could exhibit application potentials in the fields of waste recycling and packaging materials.Highlights A functional cellulose nanocrystal (CNC) film is prepared from waste paper. Self‐assembled CNC is coated on a PET surface to form a CNC/PET composite film. The synergistic interactions among CNCs and between CNC and PET modified PET. The low addition of CNCs realized the efficiency modification of PET. The study achieves waste paper recycling and high‐value utilization.

Influence of Starch Admixtures and Silver Colloids Stabilised with Starch Hydrolysates on the Course of Electrochemical Potential Difference of Reinforcing Steel in High-chloride Environment

The purpose of the conducted study was to verify whether the use of concrete admixtures with modified starches and starches modified with stabilised silver colloids affects the course of electrochemical potential difference, and hence corrosion, of reinforcing steel in a chloride environment. In the tests, cross-linked starches and products of acid hydrolysis of starch (dextrins) were used as admixtures. The 1-molar aqueous solution of sodium chloride was used as an aggressive environment. The tests consisted of measuring the potential difference generated in the reinforcement corrosion cell on the surface for a period of 60 days and then assessing the risk of corrosion. The effect of the addition of starch derivatives on the properties of cement paste was investigated through a one-way ANOVA analysis of variance followed by post hoc tests. The test results showed that the use of concrete admixtures with cross-linked starches positively affects the passivation of the steel. The likelihood of reinforcing steel corrosion when using distarch phosphate, acetylated distarch phosphate and acetylated distarch adipate admixtures is less than 5%. The results obtained showed an improved effect on the passivation of reinforcing steel in cement composites. Additionally, concrete samples may have microbicidal properties.

The role of lysosomal phospholipase A2 in the catabolism of bis(monoacylglycerol)phosphate and association with phospholipidosis

Bis(monoacylglycerol)phosphate (BMP) is an acidic glycerophospholipid localized to late endosomes and lysosomes. However, the metabolism of BMP is poorly understood. Because many drugs that cause phospholipidosis inhibit lysosomal phospholipase A2 (LPLA2, PLA2G15, LYPLA3) activity, we investigated whether this enzyme has a role in BMPcatabolism. The incubation of recombinant human LPLA2 (hLPLA2) and liposomes containing the naturally occurring BMP (sn-(2-oleoyl-3-hydroxy)-glycerol-1-phospho-sn-1’-(2′-oleoyl-3′-hydroxy)-glycerol (S,S-(2,2′,C18:1)-BMP) resulted in the deacylation of this BMP isomer. The deacylation rate was 70 times lower than that of dioleoyl phosphatidylglycerol (DOPG), an isomer and precursor of BMP. The release rates of oleic acid from DOPG and four BMP stereoisomers by LPLA2 differed. The rank order of the rates of hydrolysis were DOPG>S,S-(3,3′,C18:1)-BMP>R,S-(3,1′,C18:1)-BMP>R,R-(1,1′,C18:1)>S,S-(2,2′)-BMP. The cationic amphiphilic drug amiodarone (AMD) inhibited the deacylation of DOPG and BMP isomers by hLPLA2 in a concentration-dependent manner. Under these experimental conditions, the IC50s of amiodarone-induced inhibition of the four BMP isomers and DOPG were less than 20 μM and approximately 30 μM, respectively. BMP accumulation was observed in AMD-treated RAW 264.7 cells. The accumulated BMP was significantly reduced by exogenous treatment of cells with active recombinant hLPLA2 but not with diisopropylfluorophosphate-inactivated recombinant hLPLA2. Finally, a series of cationic amphiphilic drugs known to cause phospholipidosis were screened for inhibition of LPLA2 activity as measured by either the transacylation or fatty acid hydrolysis of BMP or phosphatidylcholine as substrates. Fifteen compounds demonstrated significant inhibition with IC50s ranging from 6.8 to 63.3 μM. These results indicate that LPLA2 degrades BMP isomers with different substrate specificities under acidic conditions and may be the key enzyme associated with BMP accumulation in drug-induced phospholipidosis.

Nanocellulose extraction from acai bagasse through mixed acid hydrolysis and oxidative techniques

Exploring new biomass sources for nanocellulose (NC) extraction is crucial in elevating the economic value of readily available renewable resources. This study compares NC extracted from acai (Euterpe oleracea) bagasse using different methods: mixed acid hydrolysis, 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) mediation, and ammonium persulfate (APS) oxidations. A comprehensive analysis investigates the impact of each treatment on the physical-chemical properties of the nanoparticles, including chemical structure, crystallinity, morphology, and thermal and suspension stability. NCs obtained through mixed acid hydrolysis exhibit the highest crystallinity (62 %) and low sulfate groups on their surfaces. Consequently, they demonstrate excellent thermal stability but poor colloidal stability in water. Oxidized NCs undergo chemical modification, converting alcoholic groups into carboxyl, resulting in NCs with zeta potentials ranging between −25.30 ± 0.81 and − 27.49 ± 1.07 mV. APS oxidation produces nanoparticles with superior thermal stability compared to TEMPO oxidation. Atomic Force Microscopy (AFM) images reveal that all nanocelluloses share characteristics of nanofibers (CNFs). This comprehensive characterization highlights the potential of acai bagasse for yielding high-added-value bioproducts suitable for versatile applications.

RGB-algorithm whiteness appraisal approach for quantitative determination of clopidogrel and aspirin in presence of salicylic acid as a degradation product based on proton NMR technique

A rapid, precise, and selective spectroscopic method based on the quantitative proton nuclear magnetic resonance (1H-qNMR) was developed to estimate aspirin and clopidogrel in their pharmaceutical dosages for the first time. The evolved method was utilized to estimate both drugs in presence of the aspirin degradation product, salicylic acid. Moreover, aspirin and clopidogrel were subjected to various stress conditions such as acid hydrolysis, alkali hydrolysis, water hydrolysis, H2O2 oxidation, and photodecomposition for studying the stability of both compounds under these stress conditions. The 1H-qNMR analyses of the analytes of interest were conducted using the internal standard phloroglucinol and the solvent dimethyl sulfoxide-d6. The NMR spectra showed a quantitative doublet of doublets (dd) signal of aspirin at 7.945 ppm, a doublet signal of clopidogrel at 6.875 ppm, and a dd signal of salicylic acid at 7.810 ppm. The internal standard phloroglucinol exhibited a singlet signal at 5.690 ppm. The results demonstrated the linearity (r2 > 0.999), accuracy, precision (RSD < 2.0 %), stability, selectivity, and specificity of the evolved method. Linearity was confirmed in the ranges of 0.05–3.0 mg/mL for aspirin, 0.15–10.0 mg/mL for clopidogrel, and 0.1–5.0 mg/mL for salicylic acid. The evolved method was efficiently applied to analyse aspirin and clopidogrel in their dosages with high %recovery. Moreover, The RGB algorithm technique was used to evaluate the whiteness profile of the suggested method; the findings confirmed the sustainability of the evolved method, which employed an ecological solvent, followed a simple and straightforward procedure, and avoided any pretreatment or labelling stages for the samples. All the aforementioned advantages gave the technique the privilege.

Isolation and Characterization of Spherical Cellulose Nanocrystals Extracted from the Higher Cellulose Yield of the Jenfokie Plant: Morphological, Structural, and Thermal Properties.

Scholars are looking for solutions to substitute hazardous substances in manufacturing nanocellulose from bio-sources to preserve the world's growing environmental consciousness. During the past decade, there has been a notable increase in the use of cellulose nanocrystals (CNCs) in modern science and nanotechnology advancements because of their abundance, biocompatibility, biodegradability, renewability, and superior mechanical properties. Spherical cellulose nanocrystals (J-CNCs) were successfully synthesized from Jenfokie micro-cellulose (J-MC) via sulfuric acid hydrolysis in this study. The yield (up to 58.6%) and specific surface area (up to 99.64 m2/g) of J-CNCs were measured. A field emission gun-scanning electron microscope (FEG-SEM) was used to assess the morphology of the J-MC and J-CNC samples. The spherical shape nanoparticles with a mean nano-size of 34 nm for J-CNCs were characterized using a transmission electron microscope (TEM). X-ray diffraction (XRD) was used to determine the crystallinity index and crystallinity size of J-CNCs, up to 98.4% and 6.13 nm, respectively. The chemical composition was determined using a Fourier transform infrared (FT-IR) spectroscope. Thermal characterization of thermogravimetry analysis (TGA), derivative thermogravimetry (DTG), and differential thermal analysis (DTA) was conducted to identify the thermal stability and cellulose pyrolysis behavior of both J-MC and J-CNC samples. The thermal analysis of J-CNC indicated lower thermal stability than J-MC. It was noted that J-CNC showed higher levels of crystallinity and larger crystallite sizes than J-MC, indicating a successful digestion and an improvement of the main crystalline structure of cellulose. The X-ray diffraction spectra and TEM images were utilized to establish that the nanocrystals' size was suitable. The novelty of this work is the synthesis of spherical nanocellulose with better properties, chosen with a rich source of cellulose from an affordable new plant (studied for the first time) by stepwise water-retted extraction, continuing from our previous study.

Application of Microwave Energy to Biomass: A Comprehensive Review of Microwave-Assisted Technologies, Optimization Parameters, and the Strengths and Weaknesses

This review article focuses on the application of microwave-assisted techniques in various processes, including microwave-assisted extraction, microwave-assisted pyrolysis, microwave-assisted acid hydrolysis, microwave-assisted organosolv, and microwave-assisted hydrothermal pretreatment. This article discusses the mechanisms behind these techniques and their potential for increasing yield, producing more selectivity, and lowering reaction times while reducing energy usage. It also highlights the advantages and disadvantages of each process and emphasizes the need for further research to scale the processes and optimize conditions for industrial applications. A specific case study is presented on the pretreatment of coffee waste, demonstrating how the choice of microwave-assisted processes can lead to different by-products depending on the initial composition of the biomass.

Metal Ion-Induced Acid Hydrolysis Strategy for the One-Step Synthesis of Tough and Highly Transparent Hydrolyzed Polyacrylamide Hydrogels.

Polyacrylamide (PAM) hydrogel is hard to enhance through coordination bonds because amide groups rarely coordinate with metal ions strongly in an aqueous solution. It is known that the aqueous solution of ZrOCl2.8H2O can be strongly acidic depending on its concentration. Consequently, through a facile one-step metal ion-induced acid hydrolysis strategy (MIAHS), tough and highly transparent hydrolyzed PAM physical hydrogels are prepared by using ZrOCl2.8H2O in this work. The formation of the partially hydrolyzed PAM physical hydrogels elucidates that the side reaction of imidization during common acid hydrolysis of PAM can be perfectly overcome because the structure of the Zr(IV) ion and its interaction with amide groups promote selective acidic hydrolysis from amide to carboxyl groups. Compared to most coordination cross-linked hydrogels, which need at least two-step fabrication, the hydrolyzed PAM hydrogel via MIAHS can be obtained by one-step synthesis due to the weak interaction between amide groups and Zr(IV). The obtained PAM hydrogel cross-linked by hydrogen bonds and coordination bond between Zr(IV) and carboxyl is a multibond network (MBN) and can achieve hierarchical energy dissipation, which exhibits excellent mechanical properties (tensile strength of 3.15 MPa, elongation at break of 890%, and toughness of 17.0 MJ m-3), high transparence (transmittance of 95%), and outstanding conductivity (5.6 S m-1) at water content of 80 wt %. The high gauge factor (from 2.24 to 12.8 as the strain increases from 0 to 400%) endows the hydrolyzed PAM hydrogels with promising application as strain sensors. Furthermore, in addition to ZrOCl2.8H2O, the fact that various hydrolyzable compounds of Ti(IV), Zr(IV) Hf(IV), and Sn(IV) can also fabricate tough hydrolyzed PAM hydrogels verifies the universality of MIAHS. Therefore, the simple, efficient, and universal MIAHS will shed new light on preparing functional PAM-based hydrogels.

NMR Spectroscopy as an Alternative Analytical Method for Biopolymers Without Chromophore: Example of Hyaluronic Acid in Dietary Supplements

To respond to the increasing demand for hyaluronic acid (HA) in dietary supplements (DSs) and nutricosmetics marketed for the treatment of osteoarthritis or moistening, it is essential to have an accurate and reliable method for its analysis in the final products. The study aimed to develop and validate alternative method for the quality control of HA in DSs using low-field (LF) and high-field (HF) nuclear magnetic resonance (NMR) spectroscopy at 80 MHz and 600 MHz, respectively. Moreover, chondroitin sulphate (CH), another active ingredient in DSs, can be simultaneously quantified. The 1H-NMR methods have been successfully validated in terms of limit of detection (LOD) and limit of quantitation (LOQ), which were found to be 0.1 mg/mL and 0.2 mg/mL (80 MHz) as well as 0.2 mg/mL and 0.6 mg/mL (600 MHz). Recovery rates were estimated to be between 92 and 120% on both spectrometers; precision including sample preparation was found to be 4.2% and 8.0% for 600 MHz and 80 MHz, respectively. Quantitative results obtained by HF and LF NMR were comparable for 16 DSs with varying matrix. HF NMR experiments at 70 ℃ serve as a simple and efficient quality control tool for HA and CH in multicomponent DSs. Benchtop NMR measurements, upon preceding acid hydrolysis, offer a cost-effective and cryogen-free alternative for analyzing DSs in the absence of CH and paramagnetic matrix components.

An alternative process for bioethanol production from marine and freshwater algae using yeast for hydrolysis

This research develops a new process for production of bioethanol from marine and freshwater algae based on hydrolysis using yeast rather than the established methods of enzyme and acid hydrolysis. Yeast were isolated and adapted specifically for this process and the effectiveness of this hydrolysis was evaluated. This method was then evaluated within a full ethanol production process involving ozone pretreatment, and both hydrolysis and fermentation using yeast, under different nutrient supplementation regimes. The process effectiveness was evaluated for species of freshwater (Spirogyra hyalina) and marine (Kappaphycus alvarezii) algae. The yeast-based hydrolysis method outperformed acid and enzyme hydrolysis for both species of freshwater and marine algae, with particularly significant results for the freshwater algae. In the whole of process treatment, the yeast-based hydrolysis approach was effective when combined with ozone pretreatment for marine algae, and without any pretreatment for freshwater algae. The highest ethanol yield was achieved through fermentation with a yeast extract supplement present. These results indicate that ozone pretreatment, hydrolysis using yeast, and fermentation with the use of yeast extract as a nutrient are promising methods for economic ethanol production from seawater algae, and for freshwater algae where ozone pretreatment is not required.

Characterization and isolation method of Gigantochloa scortechinii (Buluh Semantan) cellulose nanocrystals

This study explored the impact of sodium hydroxide and benzoylation treatment on the production of cellulose nanocrystals from Semantan bamboo (Gigantochloa scortechinii). Bamboo cellulose nanocrystals (BCNs) were obtained via acid hydrolysis, with the effectiveness of an isolation method and chemical treatments demonstrated in removing non-cellulosic constituents. X-ray diffraction analysis revealed a crystalline cellulose II structure for benzoylated BCN (B) and a crystalline cellulose I structure for NaOH-treated BCN (S), with BCN (S) exhibiting a higher crystallinity index (80.55 %) compared to BCN (B) (67.87 %). The yield of BCN (B) (23.68 ± 1.10 %) was higher than BCN (S) (20.65 ± 2.21 %). Transmission electron microscopy images showed a mean diameter of 7.95 ± 2.79 nm for BCN (S) and 9.22 ± 3.38 nm for BCN (B). Thermogravimetric analysis indicated lower thermal stability for BCN (B) compared to BCN (S), with charcoal residues at 600 °C of 31.06 % and 22 %, respectively. Zeta potential values were −41.60 ± 1.97 mV for BCN (S) and −21.80 ± 2.54 mV for BCN (B). Gigantochloa scortechinii holds significant potential for sustainable and eco-friendly applications in the construction, furniture, and renewable energy industries. These findings highlight the versatility and potential of BCNs derived from Gigantochloa scortechinii for various applications.

Synergistic effect and microbial community structure of waste-activated sludge and kitchen waste solids residue mesophilic anaerobic co-digestion.

Anaerobic co-digestion was conducted on the solid residues after three-phase separation of kitchen waste (KWS) and waste-activated sludge (WAS), the synergistic effects and process performance were studied during co-digestion at different ratios of KWS to WAS. KWS and WAS mix ratios of 0:1, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1 and 1:0 (based on TS). The results showed that a ratio of KWS to WAS of 1:1 got a very high methane recovery with a methane yield of 310.45 ± 30.05 mL/g VSadded. The highest concentration of free ammonia among all reaction systems was only 70.23 ± 5.53 mg/L, which was not enough to produce ammonia inhibition in the anaerobic co-digestion system. However, when the KWS content exceeded 50%, methane inhibition and prolongation of the lag phase were observed due to the accumulation of volatile fatty acids (VFAs), and during the lag phase. Microbial community analysis showed that various bacterial groups involved in acid production and hydrolysis were mainly dominated by phylum Firmicutes, Chloroflexi, Proteobacteria and Bacteroidetes. Hydrogenotrophic methanogen was found to dominate all archaeal communities in the digesters. Co-digestion of KWS with WAS significantly increased the relative abundance of Methanobacterium compared with anaerobic digestion of WAS alone.