Acid Hydrolysis Treatment Research Articles

Structural investigation of cellulose nanocrystals extracted from chili leftover and their reinforcement in cariflex-IR rubber latex

The morphology and chemical composition of chili fibres were investigated. Unusual low lignin content was found when compared to other annual plants. High aspect ratio cellulose nanocrystals (CNCs) were prepared from these fibres by an acid hydrolysis treatment. CNCs extracted from chili leftover were characterized using FT-IR, AFM, TGA and XRD to access their functional, structural, thermal and crystallinity properties, respectively. The length and diameter of the chili leftover CNC were 90–180nm and 4–6nm, respectively, resulting in an average aspect ratio of 26. This high aspect ratio ensures percolation at low filler content which in turn results in high thermal and mechanical properties of the nanocomposites. These CNCs were used to prepare nanocomposite films using the highly marketing commercial latex called Cariflex-Isoprene (IR) by casting/evaporation in order to investigate their reinforcing effect. The mechanical properties of nanocomposite films were investigated in both the linear and nonlinear range by DMA and tensile test, respectively, and their morphology was studied using scanning electron microscopy.

Preparation and Characterization of Cellulose Nanofibers from Cassava Pulp

SummaryIn this study, cassava pulp (CP) was used to prepare cellulose nanofibers. CP was treated with sodium hydroxide and then bleached by sodium chlorite solution in acetate buffer solution. Finally, acid hydrolysis treatment was conducted by using two different acid type (H2SO4 and HCl). The morphological structure of the ensuing fibers was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM images showed diameter and length of cellulose nanofibers obtained from sulphuric acid treatment in the range of 8‐15 nm and 200‐800 nm, respectively. Fourier transform infrared (FTIR) spectroscopy showed the progressive removal of non‐cellulosic constituents. X‐ray diffraction (XRD) revealed an increase in crystallinity of the nanofibers after successive treatments. The thermal properties of cassava pulp and cellulose nanofibers were also investigated using thermogravimetric analysis (TGA). Cellulose nanofibers showed higher thermal stability than cassava pulp.

Processing of Soju Industrial Bioresidue to Extract Microcrystalline Cellulose and Characterization

AbstractSoju industrial biomass residue (SIBR) is a lignocellulosic agro-industrial biowaste available in large quantities in soju producing countries. In this study, an attempt was made to extract microcrystalline cellulose (MCC), a biopolymer from SIBR by controlled acid hydrolysis. X-ray diffraction analysis indicated the presence of cellulose I structure with two peaks around 2θ = 15 and 22.5° and increase in crystallinity after acid hydrolysis treatment. Fourier transform infrared analysis showed no significant chemical affect of the cellulose fragment. Thermo-gravimetric analysis reveals that the extracted MCC have a good thermal stability (319°C). Dynamic light scattering studies confirmed the presence of MCC in micro range (126.4 nm) which was supported by transmission electron microscopy. The results of this work are useful for extracting valuable and widely applicable cellulose, and help solve management of SIBR in terms of disposal and pollution problems.

Antioxidant property of solvent extract and acid/alkali hydrolysates from rice hulls

Abstract In the present study, the extracts were prepared from rice hulls using solvent, acid and alkali hydrolysis treatments and their in vitro antioxidant potential was evaluated. Among various solvent extraction methods used to recover the polyphenolic extract, grinding in morter and pestle with 75% ethanol yielded maximum total phenolic concentration (240.14 mg FAE/L). Between acid and alkali treatments, alkali hydrolysis (932.14 mg FAE/L) is more effective than acid hydrolysis (674.29 mg FAE/L) in recovering phenolic compounds. Moreover, alkali hydrolysate exhibited higher antioxidant potential in terms of radical scavenging against DPPH (78.96%), superoxide (85.22%), hydroxyl (71.54%) radicals and hydrogen peroxide (78.64%). Further, the ferric reducing power (0.739 absorption units) and phosphomolybdate assays (1458 AEAA/mg sample) also indicated the high antioxidant activity of alkali hydrolysate of rice hulls when compared to acid hydrolysate and solvent extract. Hence, alkali hydrolysis treatment could be recommended for the maximum recovery of total phenolic compounds from rice hulls.

PATI RESISTEN SAGU HASIL PROSES HIDROLISIS ASAM DAN AUTOCLAVING-COOLING

The aim of this study was to produce resistant starch (RS) from a combination of acid hydrolysis and autoclaving-cooling processes of sago starch. This study compared two methods of starch modification to produce RS, i.e. (1) acid hydrolysis treatment followed by autoclaving-cooling cycles (AH-AC), and (2) autoclaving-cooling cycles followed by acid hydrolysis treatment (AC-AH). The acid hydrolysis used 1 and 2% HCl while autoclaving-cooling process consisted of three-cycle of autoclaving at 121°C for 30 min followed by cooling at 4°C for 72 hrs. Both AH-AC and AC-AH modification methods decreased starch content, altered amylose and amylopectin ratio, and increased RS contents. Both modification methods also yielded nearly flat pasting profiles at both heating and cooling phases as compared to that of native sago starch. At the same HCl concentration, the AH-AC process yielded a higher RS content than that of AC-AH. Among all treatments, the acid hydrolysis treatment using 1% HCl followed by three cycles of autoclaving-cooling process yielded the highest RS content (74.28%). The crystallinity of RS was also lower than of native sago starch, but its A crystalline type remained the same.

Mechanical and thermal properties of Posidonia oceanica cellulose nanocrystal reinforced polymer

In the present study, cellulose nanocrystals (CNC) were isolated from Posidonia oceanica balls and leaves. CNC was prepared from this marine biomass by sulfuric acid hydrolysis (H2SO4) treatment. The raw fibers were firstly isolated by a delignification-bleaching process then the acid hydrolysis treatment was performed at 55°C during 40min under mechanical stirring. The ensuing CNCs were characterized by their morphological and thermal properties using transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA), respectively. Nanocomposite materials using the CNC extracted from marine biomass were obtained by casting and evaporating a mixture of this suspension with poly(styrene-co-butyl acrylate). The effect of CNC loading on mechanical and thermal properties was studied. Dynamic mechanical analysis (DMA) results showed a strong reinforcing effect of CNC that depends on their origin (balls or leaves). The difference was attributed not only to differences in the aspect ratio of CNC but also to the stiffness of the percolating network of nanoparticles.

Fabrication and Characterization of Sisal Cellulose Nanowhiskers

There is growing interest in cellulose nanowhiskers from renewable sources for several industrial applications. In this work, sisal cellulose nanowhiskers (SCNW) are produced from sisal fiber by the combinations of acid hydrolysis and dialysis treatment. The structure of SCNW is characterized by Fourier transform infrared spectroscopy (FTIR), the morphology of SCNW is observed using field emission scanning electron microscopy (FESEM), and the thermal properties of SCNW is investigated by differential thermogravimetric analysis (DTG). The FTIR study displays that the chemical structures of SCNW are consistent with those of cellulose, indicating the removal of most of hemicelluloses during the acid hydrolysis process. The DTG result suggests the initial decomposition temperature of SCNW is 280 °C and the terminal decomposition temperature is 356 °C, the residual rate is 10% or so, indicating favorable thermal performance. The SEM results show that the sisal cellulose microcrystals exhibit an average length of 50 μm and a diameter of 5~10 μm, and SCNW displays a diameter of 5~60 nm and a length of several micrometers, revealing that the size of SCNW is much smaller than that of cellulose microcrystal. All above results illustrate that SCNW has a great promise for many potential applications, such as pharmaceutical, liquid filtration, catalysts, bio-nanocomposites, and tissue engineering scaffolds.

Synthesis of 4’,5,7-trihydroxyflavanone and 3’,4’,5,7-tetrahydroxyflavanone and antioxidant activity

Natural flavonoids, 4’,5,7-trihydroxyflavanone and 3’,4’,5,7-tetrahydroxyflavanone were synthesised via their respective chalcone. The initial step wasto synthesise derivatives of 2-hydroxyacetophenone and benzaldehyde by protecting the phenolic hydroxyl groups. The chalcone was synthesised byClaisen-Schmidt condensation. Acid hydrolysis and subsequent treatment with sodium acetate of 2’-hydroxy-4,4’-6’-tris(methoxymethyloxy)chalconeand 2’-hydroxy-3,4,4’,6’-tetrakis(methoxymethyloxy)chalcone, gave 4’,5,7-trihydroxyflavanone and 3’,4’,5,7-tetrahydroxyflavanone, respectively.3’,4’,5,7-Tetrahydroxyflavanone was found to be more potent as an antioxidant agent than 4’,5,7-trihydroxyflavanone with 83.11% inhibition and SC508.57 μg/mL in the radical scavenging activity by ESR method.

Determination of plant stanols and plant sterols in phytosterol enriched foods with a gas chromatographic-flame ionization detection method: NMKL collaborative study.

This collaborative study with nine participating laboratories was conducted to determine the total plant sterol and/or plant stanol contents in phytosterol fortified foods with a gas chromatographic method. Four practice and 12 test samples representing mainly commercially available foodstuffs were analyzed as known replicates. Twelve samples were enriched with phytosterols, whereas four samples contained only natural contents of phytosterols. The analytical procedure consisted of two alternative approaches: hot saponification method, and acid hydrolysis treatment prior to hot saponification. As a result, sterol/stanol compositions and contents in the samples were measured. The amounts of total plant sterols and total plant stanols varying from 0.005 to 8.04 g/100 g product were statistically evaluated after outliers were eliminated. The repeatability RSD (RSDr) varied from 1.34 to 17.13%. The reproducibility RSD (RSDR) ranged from 3.03 to 17.70%, with HorRat values ranging from 0.8 to 2.1. When only phytosterol enriched food test samples are considered, the RSDr ranged from 1.48 to 6.13%, the RSD, ranged from 3.03 to 7.74%, and HorRat values ranged from 0.8 to 2.1. Based on the results of this collaborative study, the study coordinator concludes the method is fit for its purpose.

Exergy analysis of pretreatment processes of bioethanol production based on sugarcane bagasse

Bioethanol produced from LB (lignocellulosic biomass) is a renewable option to decrease fossil fuel demand. LB is considered the future feedstock for bioethanol production because of its low cost and availability. The production of bioethanol from LB involves different steps: pretreatment, hydrolysis, fermentation, and bioethanol recovery. Some pretreatments such as SE (steam explosion), LHW (liquid hot water), ammonia fiber explosion and acid hydrolysis treatment have been used frequently to remove lignin and to improve the saccharification of cell wall carbohydrates. In this work via exergy analysis biomass pretreatment methods to prepare LB for bioethanol production using two typical chemical compositions of sugarcane bagasse are evaluated. Four case studies for the following pretreatment technologies (A) SE, (B) Organosolv, (C) LHW and (D) SE + LHW are studied. Although high exergy values are obtained in all cases of this study (A) 93.2%, (B) 85.4%, (C) 94.1%, and (D) 95.1%, the values of destroyed exergy rate found for the cases analyzed using the raw material 2 are high compared to the input bagasse exergy rate, (A) 7.2%, (B) 24.8%, (C) 6.0%, and (D) 5.5%, highlighting the relevance of such processes in the overall exergy efficiency of second-generation bioethanol production routes.

Stability-indicating densitometric high-performance thin-layer chromatographic method for the quantitative analysis of biomarker naringin in the leaves and stems ofRumex vesicariusL.

A simple, sensitive, and stability-indicating high-performance thinlayer chromatography (HPTLC)-densitometric method was developed for the quantification of biomarker naringin in the methanol extracts of stems and leaves of Rumex vesicarius. Chromatography was performed on glass-backed silica gel 60 F254 high-performance thin-layer chromatography (HPTLC) plates with ethyl acetateglacial acetic acid-MeOH-H2O (30:10:5:1, ½/½) as mobile phase. Scanning and quantification were done at 275 nm. The system was found to give compact spot for naringin at RF = 0.46 ± 0.001. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.998 with respect to area in the concentration range of 100–1000 ng. The regression equation of standard was found to be Y = 3.438X + 38.485. Naringin was subjected to acid and alkali hydrolysis, peroxide oxidation, photodegradation, dry heat, moist heat, and ultraviolet (UV) treatment. The drug undergoes complete degradation under acidic tre...

A common strategy to extracting cellulose nanoentities from different plants

In order to obtain cellulose nanoentities like nanofibres (CNF) and nanocrystals (CNC) from sisal (S), hemp (He) and flax (F) fibres, a new succession of specific chemical treatments including extractives (E), prealkalization (PA), alkalization (A), acetylation (Ac) and acid hydrolysis (H) treatments have been developed. Cellulose nanoentities obtained have been characterized by different techniques. FTIR spectra confirmed the removal of non-cellulosic components after chemical treatments. XRD results showed that all samples exhibited cellulose I crystalline structure and the crystallinity index of cellulose nanoentities was increased about 30% relative to raw fibres owing to removal of non-cellulosic components. The thermal stability of samples decreased after using an acid medium. AFM images confirmed that cellulose nanofibres and nanocrystals were obtained.

Enzyme and acid deconjugation of plasma sulfated metanephrines

BackgroundTotal (i.e. free+sulfated) metanephrines in plasma is a biomarker for the diagnosis of pheochromocytoma/paraganglioma. Sulfated metanephrines must be completely deconjugated by perchloric acid hydrolysis or sulfatase treatment prior to analytical measurement to enable quantification by current techniques. In this report, we compare the yield and efficiency of both methods. MethodsThe deconjugation rate of synthetic sulfated metanephrines (normetanephrine (S-NMN), metanephrine (S-MN) and methoxytyramine (S-MT)) spiked in charcoal-stripped plasma was determined by boiling perchloric acid and compared to sulfatase treatment. Total plasma metanephrines (MN, NMN and MT) were also determined in patient samples by both methods. ResultsThe complete deconjugation of sulfated metanephrines is achieved after 30min incubation with 0.1M boiling perchloric acid or upon sulfatase treatment. Ten minutes of acid hydrolysis (gold-standard) leads to a 30% underestimation of metanephrine concentrations. The enzyme hydrolysis is time and amount of sulfatase dependent. The rate of hydrolysis is analyte-dependent (MT>>NMN>MN), although it must contain at least 0.8 U/ml of sample. The Deming regression curves comparing acid versus enzyme hydrolysis on patient samples assessed that both methods gave similar unbiased concentrations. ConclusionEnzyme and acid treatments are equivalent and efficient for removing sulfate from metanephrines as long as the optimal protocol is used for each method. However, the gold standard method for acid hydrolysis at 10min established more than 20 years ago was not satisfactory regarding the hydrolysis of metanephrines in plasma.

Methodology for quantitative determination of the carbohydrate composition of brown seaweeds (Laminariaceae)

The monosaccharide composition of four different samples of brown seaweeds Laminaria digitata and Saccharina latissima were compared by different high performance anion exchange chromatography (HPAEC) methods after different acid hydrolysis treatments or a cellulase treatment.

The Effect of Chemical and High‐Pressure Homogenization Treatment Conditions on the Morphology of Cellulose Nanoparticles

Cellulose nanoparticles were fabricated from microcrystalline cellulose (MCC) through combined acid hydrolysis with sulfuric and hydrochloric acids and high‐pressure homogenization. The effect of acid type, acid‐to‐MCC ratio, reaction time, and numbers of high‐pressure homogenization passes on morphology and thermal stability of the nanoparticles was studied. An aggressive acid hydrolysis was shown to lead to rod‐like cellulose nanocrystals with diameter about 10 nm and lengths in the range of 50–200 nm. Increased acid‐to‐MCC ratio and number of homogenization treatments reduced the dimension of the nanocrystals produced. Weak acid hydrolysis treatment led to a network of cellulose nanofiber bundles having diameters in the range of 20–100 nm and lengths of a few thousands of nanometers. The high‐pressure homogenization treatment helped separate the nanofiber bundles. The thermal degradation behaviors characterized by thermogravimetric analysis at nitrogen atmosphere indicated that the degradation of cellulose nanocrystals from sulfuric acid hydrolysis started at a lower temperature and had two remarkable pyrolysis processes. The thermal stability of cellulose nanofibers produced from hydrochloric acid hydrolysis improved significantly.

Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

조사처리한 건조수산품의 전처리 방법에 따른 Luminescence 판별 특성

건조수산품의 조사여부 확인을 위하여 PSL-TL 방법으로 분석하였다. 비 조사 시료에서는 모두 700보다 낮은 PCs를 나타내었고 조사된 홍합 5, 10 kGy에서만 5,000 이상의 PCs를 나타내었으나 조사된 오징어, 한치, 꼴뚜기, 홍합, 가자미, 꽁치는 비 조사값과 중간값을 나타내었다. TL분석에 이용되는 광물질을 얻기 위해 비중분리법(DS)과 산가수분해법(AH)을 이용하였으며, 그 결과 비 조사시료에서는 250°C 이상의 범위에서 낮은 intensity와 peak를 나타났으며 조사된 시료에서는 150~250°C 범위에서 높은 intensity와 peak를 나타내었다. 그러나 특히 AH 방법으로 미네랄을 분리하였을 때 TL ratio(TL₁/TL₂)와 TL glow curve 결과가 보다 정확한 결과를 얻을 수 있었다. 따라서 PSL 방법은 홍합시료에서만 적용 가능하였으며, TL 방법은 실험에 사용된 모든 건조수산품에 적용 가능하였으나, AH 방법으로 처리한 판별결과가 DS 방법보다 더 정확한 결과를 나타내었다.

Determination of Free and Total Myo-Inositol in Infant Formula and Adult/Pediatric Nutritional Formula by High-Performance Anion Exchange Chromatography with Pulsed Amperometric Detection, Including a Novel Total Extraction Using Microwave-Assisted Acid Hydrolysis and Enzymatic Treatment: First Action 2012.12

After an assessment of data generated from a single-laboratory validation study published in J. AOAC Int. 95, 1469-1478 (2012), a method for determining total myo-inositol in infant formula and adult/ pediatric nutritional formula by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), including extraction by using microwave-assisted acid hydrolysis and enzymatic treatment was presented for consideration by AOAC during the AOAC Annual Meeting held in Las Vegas, NV, from September 30 to October 3, 2012. The Expert Review Panel on Infant Formula and Adult Nutritionals concluded that the method met the criteria set by the standard method performance requirements (SMPRs) for the determination of free myo-inositol and approved the method as AOAC Official First Action. The method also determines total myo-inositol, but includes bound sources that the SMPRs exclude. The method involves using HPAEC-PAD for free myo-inositol and a total myo-inositol determination by two different techniques. The first technique uses the conventional acid hydrolysis with 6 h incubation in an autoclave. The second uses a microwave-assisted acid hydrolysis with enzymatic treatment that decreases the extraction time.

A validated stability-indicating TLC-densitometric method for the determination of stanozolol in pharmaceutical formulations

BackgroundStanozolol is a synthetic derivative of dihydrotestosterone (DHT), and one of the frequently detected anabolic steroids in doping analysis. The current work describes the development and validation of the stability-indicating TLC-densitometric method for sensitive and specific estimation of stanozolol even its degradation product being there. Precoated silica gel TLC aluminium plates were utilized as the stationary phase and the eluent comprised of petroleum ether: acetone (6:4, v/v). Densitometric analysis of stanozolol was achieved at λmax 750 nm in the absorbance mode after staining with phosphomolybdic acid (PMA). Stress degradation of stanozolol was carried out under various reaction conditions including acid, base and neutral hydrolysis, wet and dry heating treatment, oxidation, and photo-degradation. Resulted stress samples and pharmaceutical products were analyzed with the developed TLC method.ResultsThis system showed a compact spot for stanozolol at Rf value of 0.46 ± 0.02. The data of linear regression analysis indicated a good linear relationship over the range of 200–1200 ng/spot concentrations. The method was validated for robustness, precision and recovery. The LOD and LOQ were 1.6 and 5.1 ng/spot, respectively. Under various stressed conditions, stanozolol showed degradation only under acidic hydrolysis. Peak of a degraded product was well resolved from the stanazolol with reasonably different Rf value and identified as 17, 17-dimethyl-l8-nor-5α-androst-13(14)-eno [3,2c] pyrazole through 1D- and 2D-NMR spectroscopic techniques and ESI-QqTOF-MS/MS analysis.ConclusionResult reflected that the stanozolol is majorly affected by the acidic condition. Statistical analysis indicated the application of the developed stability-indicating TLC-densitometric method for routine analysis of stanozolol in the presence of its degradation product.

Suppression of Umami Aftertaste by Polysaccharides in Soy Sauce

Umami is one of 5 basic tastes that make foods savory and palatable. The umami aftertaste is a long-lasting taste sensation that is important for Japanese broth (dashi) utilized for various Japanese foods. Soy sauce is usually added when making dashi-based dishes; however, different soy sauces produce distinct effects on the umami aftertaste. In this study, we attempted to identify the substances that cause the suppression of the umami aftertaste in soy sauce by combining sensory analysis, size fractionation, chemical analysis, and enzymatic treatment. The suppressive substance was revealed to be polysaccharides with molecular weights between 44900 and 49700. The results of acid hydrolysis and enzymatic treatment suggested that the polysaccharides were cellulose. These results indicate that a type of water-soluble cellulose derived from soybean, wheat, or microorganisms has a suppressive effect on the umami aftertaste of soy sauce. Future studies should focus on developing a strategy that regulates the amount of these polysaccharides generated during soy sauce production, to maintain or enhance the umami aftertaste.