Chemical Composition Of Wheat Straw Research Articles

Feed intake and growth performance of crossbred dairy calves fed on a basal diet of wheat straw treated with urea-molasses, urea-lime, and effective microorganisms

ABSTRACT The effects of various treatment options on the nutritional value of wheat straw as well as the growth performance of crossbred calves fed the treated wheat straw were evaluated. Twenty-four female calves (75% Friesian-Borana), weighing 99.3 ± 19.7 kg (aged 6–9 months), were divided into four groups of six animals using a randomized complete block design. The feeding trial lasted approximately 104 days. The dietary treatments were: untreated wheat straw (control T1), wheat straw treated with urea-molasses (T2), urea-lime (T3), and effective microorganisms (T4). Results showed that the treatment options affected the physical silage quality and chemical composition of wheat straw. Calves in the T3 and T4 groups had a higher daily DM intake (3.7 and 3.5 kg/head, respectively) than those in T2 (3.1 kg/head) and T1 (3.02 kg/head) groups. Calves in the T3 (422.7 g/d) and T4 (391 g/d) groups gained greater weight than those in the T2 (281.7 g/d) and T1 (204.4 g/d) groups (P < 0.001). Thus, improving the feed value of wheat straw with urea-lime or effective microorganisms treatment options suggested in this trial could result in cost-effective and significant growth performances when crossbred calves were supplemented with concentrate at a rate of 1.2% of their live weights.

Microbial Degradation of Plant Residues Rapidly Causes Long-Lasting Hypoxia in Soil upon Irrigation and Affects Leaching of Nitrogen and Metals

With this study, we aim to relate the substrate quality of different organic materials derived from plant residues to the respiratory activity of soil microorganisms after amendment, the formation of oxygen gradients upon irrigation, and the leaching of macronutrients and metals in soil. Elemental analyses were performed to determine the chemical composition of wheat straw, green compost, and a biochar product, showing that carbon availability, C/N ratio, and metal contents varied markedly. Consequently, after application to well-aerated sandy loam soil at 1% w/w, only straw increased microbial activity substantially, and nitrate was depleted within one week. Upon intense irrigation of soil columns packed with differently amended soils, strong hypoxia formed only in straw–soil, where microbial oxygen demand for straw degradation was high. This was enhanced after the application of mineral fertilizers, and nitrate leaching was mitigated. With the decreasing redox potential in straw–soil, the leaching of Fe, Mn, Al, Ni, Co, and As was increased. However, nitrate from mineral fertilizer mitigated the reduction of redox potential and, thus, the leaching of these metals. Measuring oxygen at different depths revealed near anoxic conditions at −15 cm of straw–soil with NP-fertilizer applied within 12 h after the start of irrigation and remained for at least 60 h, while oxygen showed extensive fluctuations in the upper few centimeters. This study showed that organic soil amendments with high carbon availability induce microbial respiration to the extent that causes strong and long-lasting hypoxia upon irrigation, even in sandy soil, which leads to substantial effects on the mobility of nutrients and toxic metals. In contrast, organic soil amendments with low carbon availability did not cause such effects.

Growth and Influence of White-Rot Fungi on the Chemical Composition of Wheat Straw Inoculated under Varying Pre-Conditions

Solid-state fermentation with white-rot fungi is an interesting alternative to chemical straw treatment for ruminant nutrition. However, for practical implementation on farms, feasible handling and its effect on nutritional characteristics have to be tested beforehand. Chopped wheat straw was either soaked and drained or just remoistened to about 24% dry matter without subsequent sterilization. Moist straw was inoculated with Pleurotus ostreatus, Ceriporiopsis subvermispora, or Volvariella volvacea. Fermentation lasted up to 42 d with weekly or shorter sampling intervals. Fiber fractions, minerals and elements, and non-starch polysaccharides were analyzed, and microflora was plate counted. Lactic acid bacteria of selected samples were identified by MALDI-TOF. All inoculated fungi grew well under the selected conditions expressed by the visible mycelium and specific smell. P. ostreatus developed fruiting bodies in the given time. Initial numbers of lactic acid bacteria were &gt;8.0 log cfu/g. In the beginning, Weissella confusa/cibaria dominated. However, neither decrease in lignin nor cellulose concentration was observed during the period in either of the treatments, thus seeming to be inappropriate for ruminant nutrition purposes. Some elements and minerals peaked, especially towards the second and third week (Na, Cl, Mg, Fe, and Mn). Growth conditions for mushrooms were optimized by remoistening the straw with a defined amount of water.

Evaluation of effects of freezing pretreatment on the grindability, energy consumption and chemical composition of wheat straw

In biomass utilisation, size reduction caused by grinding is a critical procedure because it greatly changes the particle size and shape of the biomass sample, which greatly influences its energy conversion efficiency. Raw biomass is difficult to grind due to its fibrous nature and therefore needs to be pretreated before grinding. Traditional torrefaction pretreatment consumes more energy and changes the chemical composition of biomass. In this study, we select wheat straw with abundant yield in northern China as the biomass sample for testing and introduce a new freezing pretreatment method into the grinding procedure. This method incorporates the freezing of wheat straw with liquid nitrogen. We evaluate the performance of freeze grinding in terms of grindability, energy consumption, chemical composition and energy conversion efficiency, and compare it with that of torrefaction grinding to investigate the effects of pretreatment methods on wheat straw. Particle size and shape distribution are used to characterise grindability. Moreover, we improve sample preparation, image acquisition and segmentation methods to reduce the impact of particle agglomeration. Experimental results demonstrate that freezing as pretreatment improves the grindability and energy conversion efficiency, whilst reducing energy consumption and maintaining chemical composition of wheat straw.

The effect of atmospheric pressure plasma pretreatment with various gases on the structural characteristics and chemical composition of wheat straw and applications to enzymatic hydrolysis

The effects of atmospheric pressure plasma pretreatment (PT) on the enzymatic hydrolysis (EH) of wheat straw were investigated, applying air, N2 and CO2 as the plasma gases onto wet substrate environment for varying durations. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and compositional analyses were all used to characterize changes in the structure and composition of the wheat straw. The composition, structure, and surface of the straw were changed considerably through pretreatment, all of which promoted enzymatic hydrolysis. The optimal conditions (90 s, air plasma) merged advantages both very high biomass/sugars recoveries as well as high conversation yield of glucan and xylan with the overall production of 358.4 and 135.8 mg g−1 respectively following 24 h EH. Considering the feasibility of PT at the optimum with subsequent EH to glucose and xylose production process of wheat straw, PT showed a positive impact on the energy balance of the process with an only input energy of 189.97MJ/t that led to net energy gain of 1297.8 MJ/t of the process. Energy-processing costs of PT and subsequent EH estimated to be $ 0.052 MJ/kg glucose and xylose, demonstrating the significant potential of PT to be scaled to industrial-level in biorefineries.

Treatment using white rot fungi changed the chemical composition of wheat straw and enhanced digestion by rumen microbiota in vitro

Treatment with white rot fungi can effectively remove lignin and decompose the structure of biomass to enhance its nutritional value. The aim of this study is to identify high-performance fungi to improve the rumen degradability of wheat straw. In this study three species of white rot fungi (Phanerochaete chrysosporium, Pleurotus ostreatus, Irpex lacteus) were inoculated and incubated under solid state conditions at 28 °C for 0–28 days to determine changes in chemical composition. Samples obtained after 28 days of incubation were assessed for in vitro gas production and rumen fermentation products. Results showed that P. chrysosporium and I. lacteus had similar ability to degrade lignin, while P. ostreatus and I. lacteus had similar selectivity in lignin degradation. After 28 days of incubation, I. lacteus resulted in moderate losses of dry matter, hemicellulose, and cellulose, which were 22%, 46% and 20%, respectively. But the straw treated with I. lacteus had the lowest (P < 0.001) content of lignin (sa) and a 5% increase in the absolute amount of neutral detergent solute. After 96 h of in vitro fermentation, the total volume of gas production from the straw treated with P. chrysosporium dropped by 24%, but that from the straw treated with P. ostreatus and I. lacteus respectively had a 5% and 33% increase. What’s more, the straw treated with I. lacteus not only improved the production of volatile fatty acids (P = 0.047) but also lowered the acetate:propionate ratio (P < 0.001) in the fermentation fluid. However, all the treatments resulted in significantly lower (P < 0.001) concentration of ammonia nitrogen. It is concluded that I. lacteus has a great potential to improve the rumen fermentability and energy utilization of wheat straw, but the effect of fungal treatment on the utilization efficiency of nitrogen needs further research attention.

Isolation and identification of termite gut symbiotic bacteria with lignocellulose-degrading potential, and their effects on the nutritive value for ruminants of some by-products

The termite gut contains different kinds of lignin and lignocellulose degrading microbes. This study was conducted to isolate and identify termite gut symbiotic bacteria with lignocellulose-degrading potential, and evaluate their effects on the chemical composition and in vitro digestibility of wheat straw and date leaves. Termite gut contents were extracted and cultured in 9 different culture media containing lignin and lignocellulosic materials that had been prepared from water-extracted sawdust and wheat straw. Three superior bacteria capable of growing on all media, and with higher lignin peroxidase activity, were selected and subjected to molecular identification. Following this, wheat straw and date leaves were incubated with the isolated bacteria in liquid medium for 6 weeks. 16S rRNA sequence analysis showed that these isolates possessed 97, 99 and 97% similarity with Bacillus licheniformis, Ochrobactrum intermedium and Microbacterium paludicola, respectively. The highest (P<0.05) dry matter (DM) loss in wheat straw and date leaves was observed following treatment with B. licheniformis. In the case of wheat straw, the organic matter (OM) and neutral detergent fiber (NDF), and for date leaves OM, NDF and acid detergent lignin (ADL) contents were not influenced by the treatments (P>0.05). The greatest and lowest (P<0.05) ADF content of wheat straw was observed as a result of treatment with B. licheniformis and O. intermedium, respectively. However, bacterial treatments decreased (P<0.05) ADF content of date leaves when compared to the control. Acid detergent lignin content of wheat straw was decreased (P<0.05) by bacterial treatments in comparisons to the control. For wheat straw, the highest and lowest (P<0.05) value of crude protein (CP) was observed in the case of M. paludicola and O. intermedium treatments, respectively. For date leaves, the CP content of the control treatment was highest (P<0.05) among treatments. For wheat straw, bacterial treatments enhanced (P<0.05) DM, OM and ADF digestibility when compared to the control. However, highest and lowest (P<0.05) CP digestibility was observed using O. intermedium and M. paludicola, respectively. For date leaves, treatment with B. licheniformis significantly increased (P<0.05) digestibility of DM, OM and NDF when compared to the others. However, CP and ADF digestibility was not different (P>0.05) between experimental groups. Overall, the results of this study showed that the isolated bacteria partially changed the chemical composition of wheat straw and date leaves while, they improved digestibility of nutrients. These bacteria are suitable candidates for increasing nutritive value of by-products for ruminants.

Variation in the chemical composition of wheat straw: the role of tissue ratio and composition.

BackgroundWheat straw is an attractive substrate for second generation ethanol production because it will complement and augment wheat production rather than competing with food production. However, like other sources of lignocellulosic biomass, even from a single species, it is heterogeneous in nature due to the different tissues and cell types, and this has implications for saccharification efficiency. The aim of this study has been to use Fourier transform infrared (FTIR) spectroscopy and Partial least squares (PLS) modelling to rapidly screen wheat cultivars for the levels of component tissues, the carbohydrate composition and lignin content, and the levels of simple cross-linking phenolics such as ferulic and diferulic acids.ResultsFTIR spectroscopy and PLS modelling was used to analyze the tissue and chemical composition of wheat straw biomass. Predictive models were developed to evaluate the variability in the concentrations of the cell wall sugars, cell wall phenolics and acid-insoluble lignin. Models for the main sugars, phenolics and lignin were validated and then used to evaluate the variation in total biomass composition across 90 cultivars of wheat grown over two seasons.ConclusionsWhilst carbohydrate and lignin components varied across the varieties, this mainly reflected differences in the ratios of the component tissues rather than differences in the composition of those tissues. Further analysis indicated that on a mol% basis, relative levels of sugars within the tissues varied to only a small degree. There were no clear associations between simple phenolics and tissues. The results provide a basis for improving biomass quality for biofuels production through selection of cultivars with appropriate tissue ratios.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-014-0121-y) contains supplementary material, which is available to authorized users.

Involvement of ligninolytic enzymes in degradation of wheat straw by Trametes trogii.

Wheat straw is generated in billions of tons around the world every year and has not been fully used. This study sought to evaluate the delignification capacity and enzyme production of Trametes trogii MT strain and to clarify the changes of structure and chemical composition of wheat straw during the decay process. The results obtained revealed that the T.trogii MT strain has the ability to degrade lignin, cellulose as well as hemicellulose of wheat straw simultaneously. The strain can produce high activities of laccase, manganese peroxidase, xylanase, carboxymethylcellulase and feruloyl esterase but no lignin peroxidases during the decay process of a 60-day incubation period on wheat straw. Scanning electron microscopy observation and infrared spectroscopy analysis showed the lignin and carbohydrate of wheat straw were degraded with no obvious different levels. The low molecular mass fractions collected from the culture of the MT strains grown in wheat straw powder liquid medium showed high Fe(3+) chelating, reducing capacity and hydroxyl radical and hydrogen peroxide generation. Trametes trogii MT has a complex mechanism to degrade lignocellulose, in addition to the extracellular enzymatic systems, and has great potential as an attractive micro-organism used for the biological degradation of waste straws. This study revealed the dynamic changes of the ligninolytic enzymes of T.trogii MT during the degradation of wheat straw, and suggested that the decay patterns of wheat straw by T.trogii MT had some simultaneous type characteristics.

Variation in the chemical composition of wheat straw: the role of tissue ratio and composition

BackgroundWheat straw is an attractive substrate for second generation ethanol production because it will complement and augment wheat production rather than competing with food production. However, like other sources of lignocellulosic biomass, even from a single species, it is heterogeneous in nature due to the different tissues and cell types, and this has implications for saccharification efficiency. The aim of this study has been to use Fourier transform infrared (FTIR) spectroscopy and Partial least squares (PLS) modelling to rapidly screen wheat cultivars for the levels of component tissues, the carbohydrate composition and lignin content, and the levels of simple cross-linking phenolics such as ferulic and diferulic acids.ResultsFTIR spectroscopy and PLS modelling was used to analyze the tissue and chemical composition of wheat straw biomass. Predictive models were developed to evaluate the variability in the concentrations of the cell wall sugars, cell wall phenolics and acid-insoluble lignin. Models for the main sugars, phenolics and lignin were validated and then used to evaluate the variation in total biomass composition across 90 cultivars of wheat grown over two seasons.ConclusionsWhilst carbohydrate and lignin components varied across the varieties, this mainly reflected differences in the ratios of the component tissues rather than differences in the composition of those tissues. Further analysis indicated that on a mol% basis, relative levels of sugars within the tissues varied to only a small degree. There were no clear associations between simple phenolics and tissues. The results provide a basis for improving biomass quality for biofuels production through selection of cultivars with appropriate tissue ratios.

Sulphate Acid Catalyzed Ethanol Pulping of Wheat Straw

In order to produce paper from agricultural residues such as wheat straw, it is necessary to delignify the wheat straw. Ethanol cooking is a novel process for the fractionation of biomass components. This study evaluated the effectiveness of sulphate acid catalyzed ethanol pulping on pulp yield, chemical composition of wheat straw, strength properties of the resulted paper sheet. The raw wheat straws, which were impregnated with 1.0% sulphate acid for about 12 h at room temperature, were subjected to ethanol cooking. The results showed that total pulp yield and kappa number decreases while screened pulp yield and brightness increases as the cooking severity increases. The optimal conditions of pulping were determined. Under the optimal condition, the screened pulp yield was up to 55.4%, with the kappa number of 66.35, brightness of 16.1 SBD, and the maximum paper sheet strength.

Binderless Particleboard from Steam Exploded Wheat Straw

Wheat straw is one of the most abundant and cheap lignocellulosic waste materials in the world. Nowadays, field burning is the major practice for removing wheat straw due to lack of effective utilization, but it increases the air pollution and consequently affects public health. Wheat straw is an attractive lignocellulosic raw material for binderless particleboard production. In this study, steam explosion was adopted as pretreatment method for wheat straw. The pretreated wheat straw was used to produce binderless particleboard panels. The influence of both pretreatment temperature and residence time on chemical composition of wheat straw, and modulus of rupture, internal bond and water absorption of panel boards was investigated. The results showed that defiberation of wheat straw raw material occurred during steam explosion pretreatment. The modulus of rupture and internal bond increased while water absorption of panels decreased as pretreatment severity increased. The optimum pretreatment condition, with 19.8 MPa of modulus of rupture, 0.2572 MPa internal bond and 61.5% of water absorption of panels, occurred under 170°C temperature and 10 minute residence time.

Near Infrared Spectroscopy as a Screening Tool for Sugar Release and Chemical Composition of Wheat Straw

Bioethanol production would benefit from a rapid screening method to determine the ability of feedstock to be processed into fermentable sugars. The aim of this study was to relate near infrared (NIR) spectra of straw to the release of sugars for ethanol production from cultivars of winter wheat, and to establish a calibration model to quickly determine the content of structural carbohydrates, lignin, and ash. We applied a high-throughput pretreatment and enzymatic hydrolysis (HTPPH) assay, involving hydrothermal pretreatment (180 � C for 17.6 min) and enzymatic hydrolysis, to establish the release of glucose and xylose from 20 cultivars grown in two replicates at two sites; in total 79 samples were measured. The NIR spectra could explain 56% of the variance in sugar release with a root mean square error of cross-validation (RMSECV) of 0.014 g g −1 dm. NIR calibrations predicting content of structural carbohydrates and lignin could explain only about 25% of total variance, whereas calibrations predicting ash content could explain 94% of total variance. The relatively low percentage of explained variance of sugar release was due mainly to uniformity of samples, which rendered the uncertainty of HTPPH method to be large compared with variance between samples. NIR spectroscopy, therefore, has potential to assess sugar release of wheat straw. Improved prediction of carbohydrates and lignin require better compositional analysis for homogeneous material. Despite successful prediction of ash content, site-specific cross-validation indicated that there might be problems with model transferability from site to site.

Enhancement in in vitro digestibility of wheat straw obtained from different geographical regions during solid state fermentation by white rot fungi

The study was carried out to find out the differences in the chemical composition of wheat straw obtained from three different regions of India, to compare their susceptibility to fungal degradation, and subsequently to evaluate the correlation between lignin loss and improvement in in vitro digestibility. Four Phlebia species were used to degrade different wheat straw samples during 30 days of incubation. In wheat straw obtained from central zone of India, most of the fungi were more selective in ligninolysis, with a moderate loss in total organic matter. The best found fungus, P. brevispora,enhanced the in vitro digestibility from 172 to 287 g/kg in north western, 165 to 275 g/kg in north eastern, and 145 to 259 g/kg in central zone with a respective loss of 163, 129, and 105 g/kg in total organic matter. Other three fungi P. fascicularia, P. floridensis, and P. radiata were also able to enhance the in vitro digestibility of all the wheat straw samples up to a significant extent. The study demonstrated that selective ligninolytic behaviour of fungi is influenced by the overall composition of wheat straw as governed by geographic location.

Nitrogen Retention and Chemical Composition of Urea Treated Wheat Straw Ensiled with Organic Acids or Fermentable Carbohydrates

The influence of varying levels of urea and additives on nitrogen (N) retention and chemical composition of wheat straw was studied. The wheat straw was treated with 4, 6 and 8% urea and ensiled with 1.5, 2 and 2.5% of acetic or formic acid and 2, 4 and 6% of corn steep liquor (CSL) or acidified molasses for 15 days. The N content of wheat straw was significantly different across all treatments. The N content of urea treated wheat straw was increased with the increasing level of urea. The N content was higher in urea treated wheat straw ensiled with acetic or formic acid as compared to urea treated wheat straw ensiled without these organic acids. The N content of urea treated wheat straw was further enhanced when it was ensiled with CSL or acidified molasses. This effect was significant across all levels of urea used to treat the wheat straw. Nitrogen retention in urea treated wheat straw was decreased linearly as the urea level was increased to treat the wheat straw. The N content was increased linearly when higher levels of CSL or acidified molasses were used to ensile the urea treated wheat straw. Most of the N in urea treated wheat straw was held as neutral detergent insoluble N (NDIN). The NDIN content was increased linearly with the increasing levels of urea and additives. The neutral detergent fiber (NDF) contents were higher in urea treated wheat straw ensiled with acetic or formic acid as compared to urea treated wheat straw ensiled without additive. The NDF content further increased in urea treated wheat straw ensiled with CSL and acidified molasses. The entire increase in NDF content was because of fiber bound N. The hemicellulose content of urea treated wheat straw ensiled with CSL or acidified molasses was higher as compared to urea treated wheat straw ensiled with acetic or formic acid. The acid detergent fiber content of urea treated wheat straw ensiled with or without additives remained statistically non-significant. The cellulose contents of wheat straw was linearly reduced when urea level was increased from 4 to 6 and 8% to treat the wheat straw. This effect was further enhanced when urea treated wheat straw was ensiled with different additives. The results of the present study indicated that fermentable carbohydrates might improve the Nitrogen retention and bring the favorable changes in physiochemical nature of wheat straw. However, biological evaluation of urea treated wheat straw ensiled with fermentable carbohydrates is required.

The effect of sodium hydroxide and alkaline hydrogen peroxide on chemical composition of wheat straw and voluntary intake, growth and digesta kinetics in store lambs

Wheat straw was treated with alkaline hydrogen peroxide (AHP) by either spraying (spray AHP,E) 250 ml of AHP solution containing 20 g H 2O 2 and 8.3 g NaOH kg −1 straw dry matter (DM) or by soaking (dip AHP, F) straw in 2% AHP solution to give a final concentration of 57 g H 2O 2 and 19 g NaOH kg −1 DM. The AHP-treated straws were compared with A, B, C and D straws treated respectively with 0, 8.3, 25 and 50 g kg −1 DM of NaOH alone in a feeding trial using 36 Dorset Down × Mule store lambs. A digestibility trial using 7 wethers, selected from the feeding trial, in a 7 × 4 incomplete Latin square was also conducted to examine the effects of these treatments on the extent of nutrient digestion and rates of passage (k 1 and k 2). Neutral-(NDF), Modified acid-(MADF), Acid-detergent fibre (ADF) and Acid-detergent lignin (ADL) in the straw organic matter (OM) changed quadratically with increasing NaOH alone from 0 to 50 g kg −1 DM. AHP had different effects on composition depending upon the mode of application. Spray treatment (E v B) did not alter composition but the dip treatment F had less NDF and more MADF, ADF and especially ADL than treatment C. Voluntary straw intake (VSI), liveweight gain (LWG), LWG/W 0.75 and digestibility increased linearly ( P < 0.001) with the increase in NaOH alone from 0 to 50 g kg −1. Spray AHP did not affect VSI, LWG or digestibility compared with either untreated straw or straw treated with the same amount of NaOH alone. Dip AHP tended to increase ( P > 0.05) VSI, LWG and LWG/W 0.75 but decreased DM, MADF ( P < 0.05), OM ( P < 0.01) and NDF ( P > 0.05) digestibility compared with untreated control and reduced VSI, LWG and LWG/W 0.75 ( P < 0.05) and all digestibility parameters ( P < 0.001) compared with treatment with NaOH alone (C). Spray AHP treatment increased ( P < 0.05) rate of passage (k 1 measured with Yb) compared with NaOH-treated control. Dip AHP treatment showed a similar trend ( P > 0.05). AHP did not result in any gross ill effects on animal health.

Effect of Steam Treatment on the Chemical Composition of Wheat Straw

A study was carried out on the effects of steam treatment at 120°C/2 bar for different periods of time on the chemical composition of wheat straw cell wall material. The contents of weakly acidic pectic polysaccharide (WAPP), 80% ethanol soluble material, lignin, hemicelluloses and α-cellulose were determined by successive extractions with 0.25% ammonium oxalate solution, 80% ethanol, acidic sodium chlorite solution and 24% potassium hydroxide with 2% boric acid solution from the residues of 15, 30, 60, 120, 180 and 300min steam treated wheat straw, respectively. The yields of WAPP, hemicellulose, cellulose and lignin extracted from the treated straw ranged from 1.8 to 2.6%, 29.8 to 34.0%, 42.1 to 45.6% and 20.0 to 22.7%, respectively. The neutral sugars in the extracts were measured by gas chromatography. The contents of phenolic acids and aldehydes resulting from alkaline nitrobenzene oxidation of lignin remaining in hemicellulose and cellulose extracted from steam treated wheat straw ranged between 0.14 and 0.33%. The results showed that steam treatment removed some portion of pectic substances and hemicelluloses. In addition, for treatment periods greater than 120min, the treated straw contained higher amounts of lignin and cellulose than untreated straw.

Chemical composition of wheat straw as influenced by urea and alkali treatments at different moisture levels

Chemical composition of wheat straw as influenced by urea and alkali treatments at different moisture levels