Acid Hydrolysis Treatment Research Articles

Chrysin Nano Formulation Using Cellulose of Rumex vesicarius Herb Leaf Waste: Isolation, Characterization and in-Vitro Evaluation

In this work, for the first time to our knowledge, cellulose was isolated from the Rumex vesicarius herb leaf waste, and cellulose nanospheres (CNS) were developed from this cellulose. Alkali, bleaching, acid hydrolysis, and ultrasonication treatments were used for fabrication of the CNS. The resulting CNS were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), zeta potential and thermogravimetric analysis (TGA). CNS is considered as an effective nanocarrier to alleviate the problems of some drugs like instability, low water solubility and bioavailability. We used the CNS as an effective nanocarrier for the entrapment of chrysin (CHR), a flavonoid secondary metabolite of the flavone class. By adjusting the solvent composition ratio and processing method, the CHR was entrapped in the CNS and a CNS-CHR nano-formulation was developed. An entrapment efficiency of 88.11% was achieved. FTIR, TGA, XRD and TEM confirmed the entrapment of the CHR in the CNS. The in-vitro dissolution investigation demonstrated an 86.53% release of CHR from the CNS-CHR complex when subjected to a release study and 47.14% of CHR release after 24 h, as the pure CHR is poorly soluble in its pure form. These findings indicate that CNS is a highly effective natural carrier at the nanoscale for CHR owing to easy availability and cost-effectiveness.

Biowaste Valorization of Palm Tree Phoenix dactylifera L. for Nanocellulose Production.

The desire to reduce reliance on oil resources arises from the concerns about carbon footprint and nonrenewability. Conversely, the global presence of over 100 million palm trees poses a significant challenge due to the substantial amount of biowaste generated annually. Additionally, the use of nanocellulose (NC) as a cost-effective material is steadily gaining recognition for its growing adaptability over time. The main goal of this study is to biosynthesized NC from Iraqi date palm Phoenix dactylifera leaves waste with low-concentration acid-alkali treatment. The date palm leaves waste yields 20 g of NC from 100 g of leaves before acid hydrolysis treatment. The chemical components of biosynthesized NC were 47.90%, 26.78%, and 24.67% for α-cellulose, hemicellulose, and lignin, respectively. In order to study their properties, NC from raw date palm leaves was studied by microscopic techniques such as scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and atomic force microscope (AFM). SEM results revealed rod-like structured NC as well as combined long-fine fibrous structures rather than compacted bundles with sizes ranging between 31 and 74 nm. With EDX, all spectra exhibit the peaks of carbon and oxygen as the main elements with 63.8% and 10.44%, respectively, in their compositions, which relate to the typical composition of cellulose. The 3D image of AFM NC with a tapping mode presented a highly uniform distribution of NC with a size of ∼15 nm. The statistical roughness analysis shows that the obtained roughness average is 7.20 nm with the root-mean-square roughness value of 21.56 nm, which corresponded relatively with the micrographs of SEM. The results of this study demonstrate the promise of using date palm waste as raw material to produce NC as green nanocomposite from biodegradable nanomaterials for water purification and sustained drug delivery for biomedical applications. In this regard and because of the insufficient reports about the extraction of NC from palm tree leaves waste, the objective of this study was designed to fabricate NC biologically from fibers sourced from the waste of Iraqi date palm P. dactylifera leaves that left in agricultural lands or burned, which can be an ecological and health problem as a bionanocomposites in the medical and industrial field and as alternative resources of wood materials.

Development of a protocol for fractionating and characterising fibres from lignocellulosic food waste

This study aims to explore an advanced protocol for characterising dietary fibre (DF) fractions to meet the growing demand for accurate and reliable data. Although current enzymatic-gravimetric approaches, e.g., AOAC and Van Soest analysis, provide information about soluble and insoluble DF quantification, they present limitations related to the lack of fractions characterisation. To overcome these limitations, the proposed protocol integrates the official AOAC 991.43 method with the sequential fibre fractionation by exploiting the different resistance of the fibre fractions to acid hydrolysis treatments (TFA and H2SO4), utilising hazelnut shells as a case-study. Each hydrolysed fraction was quantified and characterised through GC–MS analysis of monosaccharides. The data obtained for hemicellulose, cellulose, and lignin fractions were then discussed and compared with the Van Soest method. This approach yields a comprehensive procedure applicable to different food and nutraceutical products, emphasising the importance of DF characterisation for a deeper understanding of their bio-functional properties.

Green banana resistant starch: A promising potential as functional ingredient against certain maladies.

This review covers the significance of green banana resistant starch (RS), a substantial polysaccharide. The food industry has taken an interest in green banana flour due to its 30% availability of resistant starch and its approximately 70% starch content on a dry basis, making its use suitable for food formulations where starch serves as the base. A variety of processing techniques, such as heat-moisture, autoclaving, microwaving, high hydrostatic pressure, extrusion, ultrasound, acid hydrolysis, and enzymatic debranching treatments, have made significant advancements in the preparation of resistant starch. These advancements aim to change the structure, techno-functionality, and subsequently the physiological functions of the resistant starch. Green bananas make up the highest RS as compared to other foods and cereals. Many food processing industries and cuisines now have a positive awareness due to the functional characteristics of green bananas, such as their pasting, thermal, gelatinization, foaming, and textural characteristics. It is also found useful for controlling the rates of cancer, obesity, and diabetic disorders. Moreover, the use of GBRS as prebiotics and probiotics might be significantly proved good for gut health. This study aimed at the awareness of the composition, extraction and application of the green banana resistant starch in the future food products.

Development of eco-friendly biofilms by utilizing microcrystalline cellulose extract from banana pseudo-stem

Banana pseudo-stem, often considered as an underutilized plant part was explored as a potential reinforced material to develop an eco-friendly biofilm for food packaging applications. In this study, Microcrystalline cellulose (MCC) was extracted from banana pseudo-stem by alkali and acid hydrolysis treatment. The extracted MCC was used as a reinforced material in different concentrated polyvinyl alcohol (PVA) matrix alone as well as both PVA and Carboxymethyl Cellulose (CMC) matrix to develop biofilm by solvent casting method. The synthesized MCC powder was characterized by scanning electron microscope to ensure its microcrystalline structure and to observe surface morphology. The biofilms composed of MCC, PVA, and CMC were assessed through Fourier-transform infrared spectroscopy (FTIR), mechanical properties, water content, solubility, swelling degree, moisture barrier property (Water Vapor Permeability - WVP), and light barrier property (Light Transmission and Transparency). The FTIR analysis showed the rich bonding between the materials of the biofilms. The film incorporating a combination of PVA, CMC, and MCC (S6) exhibited the highest tensile strength at 26.67 ± 0.152 MPa, making it particularly noteworthy for applications in food packaging. MCC incorporation increased the tensile strength. The WVP content of the films was observed low among the MCC-induced films which is parallel to other findings. The lowest WVP content was showed by 1% concentrated PVA with MCC (S4) (0.223 ± 0.020 10−9 g/Pahm). The WVP content of S6 film was also considerably low. MCC-incorporated films also acted as a good UV barrier. Transmittance of the MCC induced films at UV range were observed on average 38% (S2), 36% (S4) and 6% (S6) which were almost 6% lower than the control films. The S6 film demonstrated the lowest swelling capacity (1.42%) and water content, indicating a significantly low solubility of the film. The film formulated with mixing of PVA, CMC and MCC (S6) was ahead in terms of food packaging characteristics than other films. Also, the outcomes of this study point out that MCC can be a great natural resource for packaging applications and in that regard, banana pseudo-stem proves to be an excellent source for waste utilization.

Extraction and preparation of cellulose nanocrystal from Brewer's spent grain and application in pickering emulsions

In recent years, the search for novel Pickering stabilizers has attracted much interest in the food, cosmetic and pharmaceutical industries. In this work, brewer's spent grain cellulose (BSGC) was successfully extracted by diluted acid, alkaline and bleaching treatments, and then brewer's spent grain cellulose nanocrystal (BSGCNC) were obtained by acid hydrolysis treatment of BSGC. The properties of the BSGCNC were characterized, and the results showed that the BSGCNC had a rod-like structure with high crystallinity (67.09%). Then the emulsification properties of BSGCNC were evaluated by different concentrations and water-oil ratios, and the results showed that BSGCNC were able to form stable Pickering emulsions. This study suggested that cellulose nanocrystal (CNC) could be extracted from brewer's spent grain which was used as food waste, as a stabilizer for Pickering emulsions.

Production of derivatives from wheat straw as reinforcement material for paper produced from secondary fibers

Nowadays, a high percentage (> 50%) of the paper produced in Europe uses recovered paper (secondary fibers) as raw material. In order to improve the mechanical properties of the paper produced, different kinds of additives are usually incorporated into the paper. Emerging renewable materials based on agricultural or forest residues, such as cellulose nanomaterials, have recently proved good capacities as reinforcing agents for different applications. In this work, pulp from wheat straw with a content of cellulose nanomaterial has been produced and tested as a mechanical reinforcing agent for paper production. A soda semi-chemical process was applied for the delignification of straw, to produce pulp with high cellulose content. Posteriorly, pulps with cellulose nanofibers were obtained in a high-pressure homogenizer, applying three different pretreatments to the cellulose pulp (acid hydrolysis, enzymatic hydrolysis and thermal treatment with glycerol) in order to facilitate the obtention of cellulose nanomaterial. Handsheets of paper were prepared from two sources of secondary fiber (fluting paper and old corrugated containers), adding different percentages of wheat straw derivatives (0, 3.5, 5 and 7%). The fibers' morphology and the papers' mechanical properties were investigated. Noticeable improvement rates (up to 25%) were observed for some mechanical properties of paper containing nanocellulose produced after the enzymatic and acid pretreatments. The quality of the secondary fibers source also affected the improvement rates achieved, with higher percentage changes for the lower-quality recycled paper.

Synthesis of cellulose nanofibers from jute fiber by using chemomechanical method.

Jute fiber is one of the most versatile natural fibers that is widely used as a raw material for packaging, textiles, and construction; and as a reinforcement in composite materials for heavy-duty applications. In the past, acid hydrolysis and mechanical treatment via the ball milling method were common in the extraction of cellulose nanofiber (CNFs) from natural plant fibers. However, there are some drawbacks of using those methods where there will be a huge quantity of acidic wastewater generated when the acid hydrolysis method is performed. This study investigated the potential use of a combination of chemical and mechanical methods in the extraction of jute CNFs. Through this method, the jute fibers were first chemically treated using sodium hydroxide (NaOH), sodium chlorite (NaClO 2) and sulphuric acid (H 2SO 4) to remove the non-cellulosic elements followed by mechanical milling by using a planetary ball mill. The shape and size of the obtained CNFs were observed under a field emission scanning electron microscope (FESEM). This study revealed that jute CNFs were successfully extracted through the combination of chemical and mechanical treatment methods where the obtained CNFs reveal themselves in smooth fibrous morphology with a diameter of 23 nm and 150-200nm in length. Jute cellulose nanofibers were successfully drawn out from raw jute fibers by means of a combination of chemical and mechanical treatment. The results obtained confirmed that the chemomechanical method is an effective technique for isolating the CNFs and its potential use as reinforcement material was explained.

Effect of Glycerol Concentrations on the Characteristics of Cellulose Films from Cattail (Typha angustifolia L.) Flowers.

Plastic waste has become a big problem for the environment globally. Biodegradable polymers are a potential replacement for plastics that can have a positive outcome both environmentally and economically. In this work, we used acid hydrolysis and alkaline treatment to extract cellulose fibers from cattails. The obtained cellulose was used as a substrate for the fabrication of cellulose film using a casting technique on plastic plates. Different concentrations of the plasticizer, glycerol, were used to prepare films for comparison, and its effects on the film's characteristics were observed. The morphology, chemical structure, and thermal stability of the cattail cellulose (CTC) films were studied using techniques such as scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and thermogravimetric analysis (TGA), respectively. Measurements of transparency, moisture content (MC), water solubility (MS), and water contact angle (WCA) were also performed. Introducing glycerol into the films increased the transparency, MC, and WS values, as well as the gap width between film textures. However, it resulted in a decrease in the WCA of the films, showing that the hydrophilicity of the films is increased by the addition of glycerol. The interaction between the functional groups of cellulose and glycerol was established from the ATR-FTIR and XRD data. The obtained results indicated that glycerol affected the thermal stability and the degree of crystallinity of the produced films. Accordingly, the hydrophilicity of the cellulose film was increased by increasing the glycerol content; therefore, cattail cellulose films can be used as a biodegradable alternative to plastic in the future.

Bound form terpenes in sweet potatoes and their distribution in flesh and peel of different cultivars

SummarySix prevalent sweet potato cultivars, New Orleans, Beauregard, Japanese, Hannah, Garnet and Jewel, were selected to determine the distribution of terpenes in their flesh and peel. Free‐form terpenes were not detected in both flesh and peel in all the cultivars by using a solid phase microextraction (SPME) and gas chromatography–mass spectrometer (GC–MS) method. Major terpenes in the sweet potatoes were linalool and α‐terpineol and existed in bound form in flesh and peel. They were released as free‐form and determined after acid hydrolysis treatment. However, ultrasonication‐assisted acid hydrolysis decreased the levels of terpenes with increased treatment time because the broken‐down free‐form terpenes were volatile and rapidly evaporated or oxidised. For the selected cultivars, the Garnet, Jewel and Japanese cultivars had the greatest levels of linalool, while the Beauregard and New Orleans cultivars had the greatest level of α‐terpineol. Also, the concentration of linalool or α‐terpineol in the peel of each cultivar was approximately two times greater than in its flesh. This study revealed the bound form terpenes and their distribution in sweet potatoes. The results explored the potential utilisation of sweet potato peel as a natural source of terpenes.

Effects of acid hydrolysis level prior to heat-moisture treatment on properties of starches with different crystalline polymorphs

Highly crystalline starches find applications as resistant starch because of their improved thermal stability and reduced enzyme susceptibility. Both acid hydrolysis (AH) and heat-moisture treatment (HMT) have been used to alter starch gelatinization properties and digestibility. This study investigated the effects of varying AH levels (0–9%) prior to HMT on the structures and properties of starches with different crystalline polymorphs, including the A-type corn starch, the B-type potato starch, and the C-type pea starch. HMT resulted in significant increases in gelatinization temperatures and significant decreases in gelatinization enthalpy and α-amylase digestion for all three starches. When combined AH with HMT, all three starches generally displayed increases in gelatinization temperatures, gelatinization enthalpy and relative crystallinity with increasing AH level, but the susceptibility to α-amylase varied with starch type and AH level. Acid preferentially hydrolyzed the amorphous regions involving amylose and amylopectin branch points, and increased hydrolysis levels yielded greater amounts of linear chains that were capable of reorganizing into crystallites during HMT. The greater AH level, up to 9%, combined with HMT promoted the formation of more thermally stable crystallites for starches with different crystalline polymorphs.

INVESTIGATION OF MICROCRYSTALLINE CELLULOSES EXTRACTED FROM Thaumatococcus danielli and Ficus exasperata LEAVES

Cellulose is a vital raw material used in various industrial applications. Microcrystalline celluloses were extracted from de-waxed Thaumatococcus danielli and Ficus exasperata leaves through acid hydrolysis (1.5ml nitric acid), bleaching (12g sodium chlorite) and mercerization treatments (17.5% w/v sodium hydroxide). The properties of the extracted microcrystalline celluloses were examined with Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy-Energy/Dispersive X-ray Spectroscopy (SEM-EDX), Thermogravimetry/Differential Thermogravimetry (TGA/DTA) and X-ray Diffraction (XRD). The leaves were found to have appreciable amount of cellulose of 30 and 37.26 % for Thaumatococcus danielli and Ficus exasperata leaves respectively. The FT-IR results showed absorption peaks at 1017-1010 cm-1 which confirmed stretching vibration of C-O-C in Thaumatococcus danielli and Ficus exasperata celluloses. This corresponds to the SEM micrograph results that proved the removal of non-cellulosic components from the surface of the celluloses. EDX results revealed predominant intrinsic elements of the celluloses as carbon, oxygen with traces of silicon and iodine. Thermal analysis showed apparent weight loss of 78.37 and 81.31% at 380oC for Thaumatococcus danielli and Ficus exasperata celluloses correspondingly. XRD results revealed high crystallinity index of 91.5 and 84.8 % with an average crystallite size of 1.015 and 1.454 nm respectively. The properties of microcrystalline celluloses obtained suggest their applications as a potential stabilizer in cosmetic, pharmaceutical and biocomposite reinforcement.

Kenaf bast nanocrystalline cellulose: Analysis of morphological, chemical, crystalline, and thermal

Cellulose nanocrystals (CNC) were prepared from delignified kenaf bast fiber by using alkaline pulping, based on soda anthraquinone, hydrogen peroxide bleaching, and acid hydrolysis treatment with H2SO4. The size and morphology of the fibers were characterized by scanning electron microscopy (SEM), and the isolated fiber from unbleached and bleached pulp had a diameter between 9 to 30 µm. Fourier transform infrared (FTIR) spectroscopy exhibited that the content of lignin decreased in the pulping process, and the lignin was almost completely removed during hydrogen peroxide bleaching. Moreover, fibers were characterized for crystallinity using X-ray diffraction (XRD). The fiber crystallinity gradually increased at each stage of the process (raw kenaf bast, unbleached pulp, bleached pulp, and acid hydrolysis). The fiber was characterized by atomic force microscopy (AFM), which showed that the isolated pulp nanofibers had diameters of approximately 30 nm.

Preparation of Nanocellulose from Coffee Pulp and Its Potential as a Polymer Reinforcement.

Coffee is one of the most valued agricultural products regarding its high commercialization rate. During the production of coffee beans, coffee pulp is obtained as one of the main byproducts with a cellulose content of more than 30% of dry weight. This research focused on the value-added potential of coffee pulp fiber as the reinforcement in composite materials. The nanocellulose coffee pulp (NCP) from the coffee pulp (CP) was prepared and subsequently used as a filler to reinforce the polyvinyl alcohol (PVA) matrix for the improvement of PVA composite properties. The CP was treated via alkali and bleaching treatment before the production of NCP using the acid hydrolysis treatment. The TEM result of NCP showed the successful preparation of NCP with an average diameter of 16.03 ± 4.70 nm with increasing crystallinity size and crystallinity index. The effect of glycerol (G) in the PVA matrix was observed. The result showed that glycerol had a play-role as a plasticizer for increased flexibility and decreased hardness and brittleness of PVA nanocomposite film. The nanocomposite film of PVA/G/NCP was fabricated with various ratios of NCP through the casting method. It was shown that the physical properties were improved with the presence of NCP in the PVA matrix compared to the neat PVA film.

Strong and biodegradable films from avocado peel fiber

Plastics are desirable as packaging materials due to their strong, flexible, and low-cost properties. However, their lack of biodegradability is environmentally detrimental. To this end, plant-based natural fiber is a viable option for creating plastic replacing and biodegradable materials. This study aimed to extract lignocellulosic fiber from avocado peel and make films. Acid hydrolysis and alkali treatment were used to obtain the fiber from avocado peel and ZnCl2 to solubilize it and make films by crosslinking the polymer chains through Ca2+ ions. The results reveal that increasing the Ca2+ ions amount significantly reduces moisture content, moisture absorption, water vapor permeability, water solubility, transparency, and elongation at the break of films but improves tensile strength. The films biodegrade within 30 days at the soil moisture content of 22% with a half-life of 3.19–4.63 days. Overall, extract from avocado peel fiber could aid in designing and developing plastic replacement and biodegradable packaging films.

The Effect of Buckwheat Resistant Starch on Intestinal Physiological Function.

Resistant starch appears to have promising effects on hypertension, cardiovascular and enteric illness. The influence of resistant starch on intestinal physiological function has drawn great attention. In this study, we first analyzed the physicochemical characteristics, including the crystalline properties, amylose content, and anti-digestibility among different types of buckwheat-resistant starch. The influence of resistant starch on the physiological functions of the mouse intestinal system, contained defecation, and intestinal microbes were also evaluated. The results showed that the crystalline mold of buckwheat-resistant starch changed from A to B + V after acid hydrolysis treatment (AHT) and autoclaving enzymatic debranching treatment (AEDT). The amylose content in AEDT was higher than in AHT and raw buckwheat. Moreover, the anti-digestibility of AEDT was also stronger than that in AHT and raw buckwheat. The buckwheat-resistant starch can promote bowel intestinal tract movement. The quantity of intestinal microbe was regulated by buckwheat-resistant starch. Our research demonstrates an effective preparation method for improving the quality of buckwheat-resistant starch and found that buckwheat-resistant starch has the role of adjusting the distribution of the intestinal flora and maintaining the health of the body.

Discard the dross and select the essence: Purified orange peel with coupled alkali-acid hydrolysis as potential Cd(II)-capturing adsorbent

Turning agricultural wastes into green adsorbents is a compatible and cost-effective strategy for solid waste disposal and environmental pollution control. Herein, the discarded orange peel (OP) sample was purified via coupled alkali-acid hydrolysis and the obtained adsorbents were applied for eliminating toxic cadmium (Cd(II)) from the liquid phase. Based on the single factor experiments, the optimal Cd(II)-capturing adsorbent (i.e., OP-OH-H-25) was generated under the purification condition of soaking raw OP in 2.0 M NaOH solution at 25 °C followed by an acid hydrolysis treatment with 2.5 M HCl solution at 25 °C. Spectral analyses reflected the efficient elution of hemicellulose/pectin and lignin impurities, the transformation of cellulose type I to cellulose type II, and the exposure of sulfhydryl functional groups. The kinetics removal process of Cd(II) by OP-OH-H-25 reached equilibrium after 0.5 h with a removal efficiency of ∼88%. The maximum Cd(II) sorption capacity of OP-OH-H-25 (i.e., 124.90 mg/g) was higher than a series of previously reported adsorbents. The sorption behavior of Cd(II) onto the prepared OP-OH-H-25 material was mostly interfered with by the coexisting Mg2+, Ca2+, and heavy metals. The desorption data and spectroscopic analysis jointly pointed to the inner-sphere binding of Cd(II) with OP-OH-H-25 functional groups. Overall, the extracted OP-OH-H-25 sample could act as a promising decontaminant for the remediation of Cd(II)-polluted water environment.

Session IX:

Turning agricultural wastes into green adsorbents is a compatible and cost-effective strategy for solid waste disposal and environmental pollution control. Herein, the discarded orange peel (OP) sample was purified via coupled alkali-acid hydrolysis and the obtained adsorbents were applied for eliminating toxic cadmium (Cd(II)) from the liquid phase. Based on the single factor experiments, the optimal Cd(II)-capturing adsorbent (i.e., OP-OH-H-25) was generated under the purification condition of soaking raw OP in 2.0 M NaOH solution at 25 °C followed by an acid hydrolysis treatment with 2.5 M HCl solution at 25 °C. Spectral analyses reflected the efficient elution of hemicellulose/pectin and lignin impurities, the transformation of cellulose type I to cellulose type II, and the exposure of sulfhydryl functional groups. The kinetics removal process of Cd(II) by OP-OH-H-25 reached equilibrium after 0.5 h with a removal efficiency of ∼88%. The maximum Cd(II) sorption capacity of OP-OH-H-25 (i.e., 124.90 mg/g) was higher than a series of previously reported adsorbents. The sorption behavior of Cd(II) onto the prepared OP-OH-H-25 material was mostly interfered with by the coexisting Mg2+, Ca2+, and heavy metals. The desorption data and spectroscopic analysis jointly pointed to the inner-sphere binding of Cd(II) with OP-OH-H-25 functional groups. Overall, the extracted OP-OH-H-25 sample could act as a promising decontaminant for the remediation of Cd(II)-polluted water environment.

Preparation of Higher Purity Cellulose from Kenaf Core by Acid Hydrolysis

For sustainable industries based renewable biomass, secure of raw material is important. Kenaf is a good candidate with fast-growing and high biomass productvity. Acid hydrolysis treatment of kenaf woody core is capable produced high purity cellulose for fine chemical production, which was hydrolyzed hemicelluloses (mainly xylan) to monosaccharides. The effects of various reaction temperatures (110-130℃), and reaction times (60-120 min) were investigated to get the optimum condition. 1H NMR spectroscopy was used to quantitative analysis of polysaccharide composition based on hydrolzed monosaccharides analysis. The results showed that optimum conditions for acid hydrolysis treatment was 1.00N sulfuric acid, 130℃, and 60 min for higher purity cellulose production with cellulose as 50.0%, hemicellulsoe as 1.2%) and lignin as 0.3% based on raw kenaf core biomass.

High Cellulose Purity by Acid Hydrolysis Pretreatment on Kenaf Outer Bast

Acid hydrolysis treatment of kenaf outer bast fiber can produce pure cellulose content and hydrolyzed hemicellulose to monosaccharides. The effects of various reaction temperatures (110–130 °C), acid concentrations of sulfuric acid (0.25–1.00 N), and reaction times (60–120 min) were investigated as the optimum condition to gain pure cellulose content. A 1H NMR spectroscopy was used to analyze the carbohydrate content in the reaction of acid hydrolysis treatment. The results showed that optimum conditions for acid hydrolysis refer to two treatment prospects. First, a higher reaction temperature of 130 °C was necessary to increase the reaction for the hydrolyzes of hemicellulose—the high yield content produced by 0.25 N sulfuric acid with a short reaction time of 60 min. to improve the purity of cellulose, provided by the high sulfuric acid solution of 1.00 N for 120 min. Hemicellulose was hydrolyzed at almost 100% based on the two optimal conditions. The analysis revealed that a high temperature of acid hydrolysis was the primary treatment to hydrolyze hemicellulose to increase high pure cellulose from the kenaf outer bast fiber.