Acid Hydrolysis Conditions Research Articles

Determination Of Optimal Conditions For Template Sol-Gel Synthesis For The Formation Of Antibacterial Materials

One of the current global problems is the increasing resistance of microorganisms to antibacterial agents and the emergence of associated infections. Therefore, the synthesis of new hybrid materials capable of resisting bacteria is necessary. In this work, loading platforms for antibacterial material based on tetraethoxysilane were formed using yeast cells Ogataea polymorpha BKM Y-2559 and Cryptococcus curvatus VKM Y-3288 as templates under conditions of acid and alkaline hydrolysis. Using scanning electron microscopy, it was shown that an alkaline environment is most optimal when using yeast cells as templates for the formation of a porous material. The surface-active properties of a number of quaternary ammonium compounds were studied using the tensometry method to select the optimal template for the production of antibacterial materials in one stage.

Extraction of cellulose nanofibers from sugarcane bagasse at different hydrolysis conditions

This study investigated the effect of alkaline treatment and various acid hydrolysis conditions on the extraction of cellulose nanofibers from sugarcane bagasse. Alkaline treatments were conducted using sodium hydroxide and sodium hypochlorite solutions. After the alkaline treatment, acid hydrolysis was performed in solutions containing 60, 64, and 68% wt. of sulfuric acid at temperatures of 30 ± 1 °C and 45 ± 1 °C. The effectiveness of the alkaline treatment in removing non-cellulosic components was assessed by infrared spectrometry and scanning electron microscopy, which demonstrated satisfactory results in eliminating non-cellulosic components. Transmission electron microscopy revealed the impact of temperature on the dimensions of the extracted cellulose nanofibers, with acid hydrolysis at 45 °C yielding smaller nanofibers compared to hydrolysis at 30 °C. X-ray diffraction analysis showed a higher percentage of crystallinity for hydrolysis at 45 °C, which can be attributed to the removal of a substantial amount of amorphous cellulose content.

Soy whey and brewer’s spent grain hydrolysates wholly replace conventional medium for microalgae growth: Process performance and economic considerations

To enhance circularity in heterotrophic microalgal bioprocesses, this study completely substituted glucose and Bold’s basal medium (BBM) with brewer’s spent grain (BSG) and soy whey (SW) hydrolysates. Mild acid hydrolysis conditions of BSG (0.2 M H2SO4, 130 °C, 36 min) and SW (0.1 M HCl, 95 °C, 30 min) were optimised for glucose release, and their hydrolysates were optimally mixed (15 % SW-85 % BSG) to obtain a medium that best supported Auxenochlorella protothecoides growth. Maximum biomass production (Xmax) and productivity (PXmax) obtained in the hydrolysate medium containing 50.75 g/L endogenous glucose (Xmax: 22.17 g/L; PXmax: 7.06 g/L/day) were comparable to that in BBM containing 50.44 g/L exogenous glucose (Xmax: 20.02 g/L; PXmax: 6.34 g/L/day). Moreover, estimated hydrolysate medium production costs were within an order of magnitude to BBM. Overall, the integrated approach of tailored hydrolytic treatments and complementary side-streams presents a promising technical and economic feasibility, with applications extending beyond A. protothecoides.

Isolation, Identification, and Characterization of Forced Degradation Products of Bosentan by Using Advanced Analytical Techniques

ABSTRACTThe present study explains the degradation behavior of bosentan (BOS), active pharmaceutical ingredient (API) (BOS monohydrate), a Food and Drug Administration (FDA)–approved drug used for the treatment of chronic heart failure, subarachnoid hemorrhage, and Raynaud's syndrome pulmonary hypertension. The stress study was performed under various stress conditions such as acid hydrolysis, base hydrolysis, oxidation, thermal degradation, and photolysis as per International Council for Harmonization (ICH) guidelines and found three degradation products (DPs) under acid hydrolysis conditions (1 N HCl/4 h/60°C reflux conditions) (the net degradation of API ∼ 21.39%). The drug was found to be stable under the remaining conditions (thermal, photolytic, oxidative, and basic hydrolytic conditions). Mechanisms for forming the three acid DPs were also proposed and discussed. The DPs were initially detected by ultrahigh‐performance liquid chromatography–mass spectrometry analysis. These DPs were isolated by preparative HPLC and then characterized by high‐resolution mass spectrometry and nuclear magnetic resonance spectroscopy techniques. Based on the structural characterization study, all these DPs are new and not reported elsewhere in the literature to my knowledge. Many reports were found in the literature for the quantification of the drug in the APIs and formulation products. However, there is no report published yet for the identification and characterization of DPs of the BOS drug.

Optimisation of acid hydrolysis conditions of choline esters and mass spectrometric determination of total choline in various foods

Determining the content of the nutrient choline in foods and obtaining the required amount from the diet are crucial. One way to measure choline in foods is by converting choline esters to free choline via acid hydrolysis, followed by quantifying the total choline, as adopted by the AOAC method (AOAC-Choline); however, certain choline esters are difficult to hydrolyse. Here, we investigated various acid hydrolysis conditions to establish a reliable method for determining the total choline in foods by detecting free choline using highly sensitive and selective mass spectrometry. Hydrolysis in 0.055 mol/L HCl for 8 h in an autoclave (121 °C) was found to be optimal for the hydrolysis of choline esters in various foods. Twenty-four foods, including grains, seed, vegetables, fruits, mushroom, algae, fish, meats, beverage, processed foods, and egg, were measured. The trends in the total choline content were consistent with previous reports; however, the choline content was 10–20% higher than that measured using AOAC-Choline. Therefore, re-evaluation of the total choline content in foods using our constructed method is recommended. This reassessment will allow for a more reliable determination of choline intake for maintaining health.

Identification and Characterization of Rotigotine Degradation Products by HPLC Coupled DAD and CAD Detectors and HRMS Through Q-Orbitrap and Electrospray Ionization

Rotigotine (RTG) is a dopamine agonist used in the treatment of Parkinson's disease. As it is susceptible to oxidation, stability studies must be carefully designed for the identification and characterization of all possible degradation products. Here, RTG degradation was evaluated according to the International Conference on Harmonization guidelines under various stress conditions, including acidic and basic hydrolysis, oxidative, metallic, photolytic, and thermal conditions. Additionally, more severe stress conditions were applied to induce RTG degradation. Significant degradation was only observed under oxidative and photolytic conditions. The samples were analyzed by high performance liquid chromatography coupled to photodiode array detectors, charged aerosol, and high-resolution mass spectrometry. Chromatographic analyses revealed the presence of eight substances related to RTG, four of which were already described and were qualified impurities (impurities B, C, K and E) and four new degradation products (DP-1 – DP-4), whose structures were characterized by high-resolution mass spectrometry through Q-Orbitrap and electrospray ionization. In the stress testing of the active pharmaceutical ingredient in solid form, significant RTG degradation was observed in the presence of the oxidative matrix. The results corroborate the literature that confirm the high susceptibility of RTG to oxidation and the importance of using different detectors to detect degradation products in forced degradation studies.

The study of galactomannans with different molecular weights and their ability to form microparticles suitable for pulmonary delivery

The influence of locust bean gum (LBG) galactomannans (GMs) molecular weight (Mw) to assemble microparticulate systems was evaluated, and carriers for deep lung delivery were developed. A commercial batch of LBG with a mannose/galactose (M/G) ratio of 2.4 (batch 1) was used to study the influence of different microwave partial acid hydrolysis conditions on carbohydrate composition, glycosidic linkages, and aqueous solutions viscosity. The microwave treatment did not affect the composition, presenting 4-Man (36–42 %), 4,6-Man (27–35 %), and T-Gal (24–25 %) as the main glycosidic linkages. Depolymerization led to a viscosity reduction (≤0.005 Pa·s) with no major impact on polysaccharide debranching. The structural composition of the LBG galactomannans were further elucidated with sequence-specific proteins using carbohydrate microarray technologies. A second batch of LBG (M/G 3.3) was used to study the impact of GMs with different Mw on microparticle assembling, characteristics, and insulin release kinetics. The low-Mw GMs microparticles led to a faster release (20 min) than the higher-Mw (40 min) ones, impacting the release kinetics. All microparticles exhibited a safety profile to cells of the respiratory tract. However, only the higher-Mw GMs allowed the assembly of microparticles with sizes suitable for this type of administration.

Acid-hydrolyzed phenolic extract of parsley (Petroselinum crispum L.) leaves inhibits lipid oxidation in soybean oil-in-water emulsions

The antioxidant activity of the natural phenolic extracts is limited in particular food systems due to the existence of phenolic compounds in glycoside form. Acid hydrolysis post-treatment could be a tool to convert the glycosidic polyphenols in the extracts to aglycones. Therefore, this research investigated the effects of an acid hydrolysis post-treatment on the composition and antioxidant activity of parsley extracts obtained by an ultrasound-assisted extraction method to delay lipid oxidation in a real food system (i.e., soybean oil-in-water emulsion). Acid hydrolysis conditions were varied to maximize total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. When extracts were exposed to 0.6 M HCl for 2 h at 80 ℃, TPC was 716.92 ± 24.43 µmol gallic acid equivalent (GAE)/L, and DPPH radical scavenging activity was 66.89 ± 1.63 %. Not only did acid hydrolysis increase the concentrations of individual polyphenols, but it also resulted in the release of new phenolics such as myricetin and gallic acid. The extract's metal chelating and ferric-reducing activity increased significantly after acid hydrolysis. In soybean oil-in-water emulsion containing a TPC of 400 µmol GAE/L, the acid-hydrolyzed extract had an 11-day lag phase for headspace hexanal compared to the 6-day lag phase of unhydrolyzed extract. The findings indicated that the conversion of glycosidic polyphenols to aglycones in phenolic extracts can help extend the shelf-life of emulsion-based foods.

Exploration and Improvement of Acid Hydrolysis Conditions for Inulin-Type Fructans Monosaccharide Composition Analysis: Monosaccharide Recovery and By-Product Identification.

Acid hydrolysis serves as the primary method for determining the monosaccharide composition of polysaccharides. However, inappropriate acid hydrolysis conditions may catalyze the breakdown of monosaccharides such as fructans (Fru), generating non-sugar by-products that affect the accuracy of monosaccharide composition analysis. In this study, we determined the monosaccharide recovery rate and non-sugar by-product formation of inulin-type fructan (ITF) and Fru under varied acid hydrolysis conditions using HPAEC-PAD and UPLC-Triple-TOF/MS, respectively. The results revealed significant variations in the recovery rate of Fru within ITF under different hydrolysis conditions, while glucose remained relatively stable. Optimal hydrolysis conditions for achieving a relatively high monosaccharide recovery rate for ITF entailed 80 °C, 2 h, and 1 M sulfuric acid. Furthermore, we validated the stability of Fru during acid hydrolysis. The results indicated that Fru experienced significant degradation with an increasing temperature and acid concentration, with a pronounced decrease observed when the temperature exceeds 100 °C or the H2SO4 concentration surpasses 2 M. Finally, three common by-products associated with Fru degradation, namely 5-hydroxymethyl-2-furaldehyde, 5-methyl-2-furaldehyde, and furfural, were identified in both Fru and ITF hydrolysis processes. These findings revealed that the degradation of Fru under acidic conditions was a vital factor leading to inaccuracies in determining the Fru content during ITF monosaccharide analysis.

LC-HRMS and NMR studies for the characterization of degradation impurities of ubrogepant along with the in silico approaches for the prediction of degradation and toxicity

Ubrogepant is the first oral calcitonin gene-related peptide (CGRP) receptor antagonist which is used for the acute treatment of migraine in adults. The present study employs liquid chromatography-high resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance spectroscopy (NMR) techniques for the identification and characterization of degradation impurities of ubrogepant. The forced degradation study of ubrogepant was performed as per the International Council for Harmonisation (ICH) Q1A and Q1B guidelines. The in silico degradation profile of ubrogepant was predicted by Zeneth. It was observed that ubrogepant was labile to acidic hydrolysis, basic hydrolysis, and oxidative degradation conditions (H2O2), although it was stable in neutral hydrolysis and photolytic (UV light and visible light) conditions. Eight degradation impurities were formed, which were separated on reversed-phase HPLC with a gradient program on an InertSustain C8 column (4.6 × 250 mm, 5 µm) using 10 mM ammonium formate (pH unadjusted) and acetonitrile as the mobile phase. The structures of all the degradation impurities were characterized using the exact masses obtained from the HRMS/MS. Further, NMR studies were conducted on two major degradation impurities (UB-4 and UB-7). A plausible mechanism was proposed to support the structures of all the degradation impurities of UBR. In silico toxicity and mutagenicity assessment were done by DEREK Nexus, SARAH Nexus, and ProTox-II.

Monosaccharide composition of lignocellulosic matrix—Optimization of microwave-assisted acid hydrolysis condition

Compositional analysis of polysaccharides is crucial in many applications of analytical chemistry, and typically involves hydrolysis as initial step, to break glycosidic bonds and release individual monosaccharide units. We developed a new method for the microwave-assisted acid hydrolysis of polysaccharides, here applied for determining the composition of the polysaccharide fraction within the lignocellulosic matrix of Pinus sylvestris. The optimisation of reaction conditions was carried out using a GC–MS method after a double-step sugar derivatization process.Under the optimized conditions, specifically, employing 2 M TFA, 40 min, and 120 °C, a high depolymerisation yield was achieved with minimal degradation. Furthermore, the amount of polysaccharides detected in pine wood aligns with the results in existing literature, substantiating the determined chemical composition.The synergy of microwave-assisted acid hydrolysis and full factorial design not only facilitated the determination of the optimal hydrolysis conditions but also enabled the assessment of the parameters influencing the polysaccharide hydrolysis process and their relationships. This approach made it feasible to achieve maximum hydrolysis efficiency while minimizing analyte degradation, employing a method that reduces environmental impact through the use of microwave energy. This strategy effectively reduced the required reaction temperature, time, and reagent quantities.

Discerning the stability behaviour of mavacamten availing liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy: In silico toxicity and mutagenicity prediction of degradation products.

The present study aimed to separate, identify, and characterise the degradation products formed when mavacamten is exposed to stress degradation as well as the stability of the drug in various environments and also to understand its degradation chemistry. Prediction of in silico toxicity and mutagenicity was aimed at the observed degradation products. Stress degradation along with stability studies and degradation kinetics were performed on mavacamten, and separation of degradation products was carried out by high-performance liquid chromatography. Tandem mass spectrometry studies were executed to characterise the structures of degradation products using product ion fragments. Orthogonally, nuclear magnetic resonance experiments were conducted to elucidate the structures having ambiguity in characterising them. Deductive Estimation of Risk from Existing Knowledge and Structure Activity Relationship Analysis using Hypotheses software were used to establish in silico toxicity and mutagenic profiles of mavacamten and its degradation products. Two degradation products of mavacamten found in acidic hydrolytic stress conditions were separated, identified, characterised, and proposed as 1-isopropylpyrimidine-2,4,6(1H,3H,5H)-trione and 1-phenylethanamine. Mavacamten was found to be stable under different pH and gastrointestinal conditions. The degradation kinetics of mavacamten under 1 N acidic condition followed zero-order kinetics, and it was degraded completely within 6 h. In silico toxicity and mutagenicity studies revealed that 1-phenylethanamine can be a skin sensitiser. A high-performance liquid chromatography method was developed for the separation of degradation products of mavacamten and characterised by liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance. During the manufacturing and storage of drug product, precautions need to be taken when dealing with acidic solutions as the drug is prone to hydrolysis in acidic conditions. The formation of 1-phenylethanamine under these conditions is to be monitored as it is a skin sensitiser.

Development of an insulin-like growth factor-1 certified reference material by SI-traceable isotope-dilution mass spectrometry

In this study, an insulin-like growth factor-1 (IGF-1) certified reference material (CRM) was developed by the National Institute of Metrology (NIM), and two different principles for evaluating the IGF-1 CRM were established. After optimisation of the acid hydrolysis conditions (110 °C, 36 h), quantitative determination of peptide purity, and chromatographic separation and mass spectrometric detection, amino acid analysis-based high-performance liquid chromatography combined with isotope-dilution tandem mass spectrometry (AAA-HPLC-IDMS/MS) and peptide analysis-based HPLC-IDMS/MS (Peptide-HPLC-IDMS/MS) were used for certified value assignment; the results obtained were 136.28 and 135.01 μg/g, respectively, which were in good agreement. These results were subjected to the normal distribution test, outlier test, and method consistency test. The homogeneity and stability of the reference materials were also examined, and the uncertainty introduced in the experimental process was calculated. The final certified value was (136 ± 15) μg g−1 (k = 2). The CRM was found to be stable for at least six months when stored at −70 °C and for 7 d when stored at higher temperatures (−20 °C, 4 °C, 25 °C, or 40 °C). The CRM is expected to be used as a primary calibrator for quality control in biopharmaceutical production and clinical diagnostics.

Isolation and identification of forced degradation products of Febuxostat

AbstractThe current study explains the degradation behavior of Febuxostat API, a non‐purine xanthine oxidase inhibitor used to treat hyperuricemia. A degradation study was carried out as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines, and the study confirms that the Febuxostat is largely stable in thermal, photolytic, oxidative, and basic hydrolytic conditions and labile in acid hydrolysis conditions. There were four different degradation products (DPs) found during acid hydrolysis; of these, DPs 2, 3, and 4 are new and have never been reported before, while DP 1 is known and has already been published. All these DPs were identified using ultra‐high‐performance liquid chromatography‐mass spectrometry (UHPLC‐MS) analysis, purified by using preparative HPLC, and characterized using high‐resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy techniques. The formed DPs are by the hydrolysis of the cyano functional group of Febuxostat and the esterification of DP‐1 under acidic conditions. All DP's structural characterization was carried out using NMR spectroscopy and HRMS. The present study describes concrete confirmation of DP structures and it explains the stability behavior of the Febuxostat. The current method is also used to identify DPs with shorter runtime in the future.

Ethanol production from sugarcane bagasse by modified PDMS membrane in a membrane bioreactor: pervaporation technique

AbstractBACKGROUNDBioethanol is considered a highly promising alternative to fossil fuels due to its derivation from renewable sources. Reducing the disadvantages of conventional fermentation requires removing the product from the fermentation broth after its formation. Therefore, coupling the membrane separation with a biological process in a single unit leads a reduction of substrate and product inhibitions.RESULTSIn this work, bioethanol production was investigated in a membrane bioreactor (MBR) with sugarcane bagasse (lignocellulose waste) as a renewable source by the sulfuric acid hydrolysis process. Firstly, the optimum conditions to produce the maximum amount of sugar by acid hydrolysis were determined. Second, the membrane bioreactor and pervaporation unit equipped with poly(dimethyl siloxane) carbon nanotube/Tetrazole membrane (PDMS‐CNT/Tetrazole) was fabricated. Third, bioethanol production in a conventional batch reactor (CBR) and the novel MBR was implemented. The outcomes of the two kinds of reactors were then compared. The results illustrated that the optimum conditions for acid hydrolysis are at a temperature of 199.4 °C, an operation time of 30.77 min, and an acid concentration of 1.12%. The obtained data shows that the ethanol production in MBR was increased by 103.6% over conventional fermentation. Furthermore, the pervaporated ethanol concentration was higher than that of the broth because of the high membrane selectivity, where a maximum ethanol concentration of 165.7 g L−1 in the cold trap was achieved.CONCLUSIONFinally, the results illustrate that the MBR can decrease the cell density growth rate and dominate any substrate and product inhibitions, while keeping process productivity for ethanol quite high. © 2024 Society of Chemical Industry (SCI).

Liquid fertilizers produced by microwave-assisted acid hydrolysis of livestock and poultry wastes and their effects on hot pepper cultivation.

Liquid fertilizers (LFs) produced by microwave-assisted acid hydrolysis of livestock and poultry wastes were applied to potted hot pepper (Capsicum annuum L.) to evaluate their potential to be used as amino acid LFs. A preliminary experiment was conducted to determine the optimum acid-hydrolysis conditions for producing LFs from a mixture of pig hair and faeces (P) and another mixture of chicken feathers and faeces (C). Two LFs were produced under the optimum acid-hydrolysis conditions (acidification by sulphuric acid (7.5 mol L-1) in a microwave (200 W) for 90 minutes), and a commercial amino acid LF (Guo Guang (GG)) was used for comparison. P, C and GG fertilizers were tested in potted hot pepper cultivation at two doses, whereas no fertilizer application served as the control (CK). P and C fertilizers significantly increased the fruit yield compared with GG fertilizer, particularly at the higher dose. Moreover, the treatments improved the fruit vitamin C and soluble sugar contents in the order of C > P > GG compared with CK. These results could be attributed to more types of amino acids in C fertilizer than in P and GG fertilizers. The results also indicated that the prepared fertilizers could significantly increase the shoot and root dry weight, soil available nitrogen and phosphorus contents and nitrogen, phosphorus, and potassium (NPK) uptake by plants compared with CK. In conclusion, microwave-assisted acid hydrolysis could effectively convert unusable wastes into valuable fertilizers comparable or even superior to commercial fertilizers.

A newly developed and validated environmentally friendly RP-HPLC stability indicating method for the COVID-19 antiviral Molnupiravir: Application to degradation kinetics structure suggestion using LC-MS and the effect on viable cells of the major degradation products

The SARS-CoV-2 coronavirus pandemic also referred to as COVID-19 is a severe respiratory illness. Molnupiravir (Moln) is a frequently prescribed antiviral medication used in the treatment regimen for mild to moderate cases of COVID-19. Since medications might experience chemical deterioration over time it is crucial to create a stability-indicating technique to evaluate the drug's stability. This study presents the development and validation of a novel stability-indicating approach employing reversed-phase high-performance liquid chromatography. The purpose of this method is to accurately quantify Moln in the presence of its degradation products. The technique was determined to be linear throughout the concentration range of 10–200 μg/mL. It exhibited precision accuracy and specificity. Moln was shown to be susceptible to oxidative acidic and basic hydrolysis. The proposed structure of the degradants was determined using LC-MS. The degradation kinetics were examined revealing that both acidic and oxidative hydrolysis conditions adhere to first-order kinetics. The sulforhodamine B (SRB) test was used to assess the impact of these degradants on Human skin fibroblast cell. The method was assessed using four green metric scales; National environmental metric index (NEMI) Analytical-ECO scale Green Analytical Procedure Index (GAPI) and Analytical GREEnness Metric Approach (AGREE); and it was determined to be ecologically friendly.

Optimization, Scale-Up, and Economic Analysis of the Ethanol Production Process Using Sargassum horneri

Recently, the extensive spread of some algae along coastlines has surged into unmanageable thick decomposition layers. This study aimed to demonstrate the use of Sargassum horneri as a biomass resource for ethanol production through the continuous hydrolysis, enzymatic saccharification, and fermentation process. Sugars from S. horneri were obtained using a combination of thermal acid hydrolysis and enzymatic saccharification. The optimal conditions for thermal acid hydrolysis involved a 10% (w/v) S. horneri slurry treated with 100 mM H2SO4 at 121 °C for 60 min; enzymatic saccharification using 16 U/mL Cellic CTec2 further boosted the monosaccharide concentration to 23.53 g/L. Fermentation experiments were conducted with mannitol-adapted Saccharomyces cerevisiae BY4741 using S. horneri hydrolysate. Enhanced ethanol production was observed in the hydrolysate, particularly with mannitol-adapted S. cerevisiae BY4741, which yielded 10.06 g/L ethanol. Non-adapted S. cerevisiae produced 8.12 g/L ethanol, as it primarily utilized glucose and not mannitol. Regarding ethanol fermentation using 5 L- and 500 L-scale fermenters, the ethanol concentrations reached 10.56 g/L and 7.88 g/L with yields of 0.51 and 0.45, respectively, at 48 h. This study confirmed the economic viability of ethanol production using waste seaweed with optimized pretreatment conditions and the adaptive evolution of S. cerevisiae to mannitol.

Optimized acid hydrolysis conditions for better characterization the structure of inulin-type fructan from Polygonatum sibiricum

Polygonatum sibiricum is an edible plant species in China known for its abundant polysaccharides. However, correlations between its analytical methods and fine structure have not been established. This is usually due to incomplete cleavage of the glycosidic linkages and instability of hydrolysis. In this study, a new optimal acid hydrolysis method for monosaccharide composition (2 M H2SO4 for 1 h) and methylation analysis (2 mol TFA hydrolysis at 100 °C for 1 h) was developed for characterization of inulin-type fructans, resulting in significantly improved monosaccharide recovery and providing more reliable methylation data. The effectiveness of this method was demonstrated through its application to the study of polysaccharide from P. sibiricum (IPS-70S). The results showed that IPS-70S with a molecular weight of 3.6 kDa is an inulin-type fructans consisting of fructose and glucose in a molar ratio of 27:1. Methylation and NMR analysis indicated that IPS-70S contains →2)-Fruf-(6 → or →2)-Fruf-(1 → with branching →1,6)-Fruf-(2 → and terminates in Glcp-(1 → or Fruf-(2→. In conclusion, optimal acid hydrolysis applicable to the specific polysaccharides contribute to its structurally characterized. The newly optimized acid hydrolysis method for monosaccharide composition and methylation analysis offers a reliable and effective approach to the structural characterization of inulin-type fructans from P. sibiricum. Providing reliable basis for the overall work of NMR analysis and structural analysis, which have potential significance in the field of polysaccharides structural characterization.

Acid hydrolysis conditions do affect the non-extractable phenolic compounds composition from grape peel and seed

This study aimed to evaluate the effect of hydrolysis conditions on non-extractable phenolic compounds (NEPC) composition of grape peel and seed powder. The effect of temperature (50–90 °C), hydrochloric acid concentration (0.1–15.0 %), and time (5–20 min) were evaluated to understand their impact on NEPC release/extraction and degradation. The use of 1.0 and 8.0 % of HCl concentrations (v/v) and temperatures of 65 and 80 °C produced extracts with higher concentrations and a larger set of compounds. These conditions promoted a balance between release/extraction and degradation processes, thereby maximizing the NEPC content in the extracts. Furthermore, the results suggest that hydrolysis conditions can be set to modulate the release of specific classes. Non-extractable proanthocyanidins showed higher concentrations when intermediate values of temperature and acid concentration were applied. Hydrolysable tannins and hydroxybenzoic acids, on the other hand, were better extracted using higher acid concentrations and higher temperatures. The results suggest that the concentration and composition of NEPC are influenced by the hydrolysis conditions and the type of matrix. Hence, it is crucial to account for this compositional variation when conducting research on the biological effects of NEPC and when using this fraction as supplements or food ingredients.