Na2CO3 Treatment Research Articles

Changes in Texture and Collagen Properties of Pork Skin during Salt-Enzyme-Alkali Tenderization Treatment.

The effects of salt-enzyme-alkali progressive tenderization treatments on porcine cortical conformation and collagen properties were investigated, and their effectiveness and mechanisms were analyzed. The tenderization treatment comprised three treatment stages: CaCl2 (25 °C/0-30 min), papain (35 °C/30-78 min), and Na2CO3 (25 °C/78-120 min). The textural, microscopic, and collagenous properties (content, solubility, and structure) of pork skin were determined at the 0th, 30th, 60th, 90th, and 120th min of the treatment process. The results showed that the shear force, hardness, and chewability of the skin decreased significantly (p < 0.05), and the elasticity exhibited a gradual increase with the progression of tenderization. The content and solubility of collagen showed no significant change at the CaCl2 treatment stage. However, the soluble collagen content increased, the insoluble collagen content decreased, and the collagen solubility increased by 18.04% during the subsequent treatment with papain and Na2CO3. Meanwhile, the scanning electron microscopy results revealed that the regular, wavy structure of the pig skin collagen fibers gradually disappeared during the CaCl2 treatment stage, the overall structure revealed expansion, and the surface microscopic pores gradually increased during the papain and Na2CO3 treatment stages. The findings of the Fourier transform infrared spectroscopy analysis indicated that the hydrogen bonding interactions between the collagen molecules and the C=O, N-H and C-N bonds in the subunit structure of collagen were substantially altered during treatment and that the breakage of amino acid chains and reduction in structural ordering became more pronounced with prolonged treatment. In the tertiary structure, the maximum emission wavelength was blue-shifted and then red-shifted, and the fluorescence intensity was gradually weakened. The surface hydrophobicity was slowly increased. The salt-enzyme-alkali tenderization treatment considerably improved the physical properties and texture of edible pork skins by dissolving collagen fibers and destroying the structure of collagen and its interaction force.

Exogenous Melatonin Reinforces Photosynthesis, Antioxidant Defense and Gene Expression to Ameliorate Na2CO3 Stress in Maize.

Salt stress can seriously affect the growth and development of maize (Zea mays L.), resulting in a great yield loss. Melatonin (MT), an indole hormone, is a potential enhancer of plant tolerance against salt stress. However, the complex mechanisms of MT application in enhancing maize salt tolerance are still unclear. Herein, three-leaf seedlings of salt-susceptible P138 and its salt-resistant ethyl methane sulfonate (EMS)-104 mutant were cultured with or without 150 μM MT application under 0 and 100 mM Na2CO3 treatments for seven days, to systematically explore the response mechanisms of exogenous MT in improving the salt tolerance of maize. The results showed that salt stress triggered an escalation in reactive oxygen species production, enhanced multiple antioxidant enzymes' activities, impaired cellular membrane permeability, inhibited photosynthetic pigment accumulation, and ultimately undermined the vigor and photosynthetic prowess of the seedlings. While suitable MT application counteracted the detrimental impacts of Na2CO3 on seedlings' growth and photosynthetic capacity, the seedling length and net photosynthetic rate of P138 and EMS-104 were increased by 5.5% and 18.7%, and 12.7% and 54.5%, respectively. Quantitative real-time PCR (qRT-PCR) analysis further showed that MT application activated the expression levels of antioxidant enzyme-related genes (Zm00001d025106, Zm00001d031908, Zm00001d027511, and Zm00001d040364) and pigment biosynthesis-related genes (Zm00001d011819 and Zm00001d017766) in both maize seedlings under Na2CO3 stress; they then formed a complex interaction network of gene expression, multiple physiological metabolisms, and phenotype changes to influence the salt tolerance of maize seedlings under MT or Na2CO3 stress. To sum up, these observations underscore that 150 μM MT can alleviate salt injury of maize seedlings, which may provide new insights for further investigating MT regulation mechanisms to enhance maize seedlings' salt resistance.

Synergistic effects of alkaline and heat treatments on structural and functional properties of mung bean protein isolate: improving physicochemical stability of plant‐based emulsions

SummaryPlant‐based meat alternatives often require fat replacers to mimic the texture of traditional products. This study aimed to develop plant‐based emulsion gels using mung bean protein isolate (MBPI) as a potential fat substitute. However, creating these gels via heat setting requires a high protein concentration, which demands modification of the MBPI structure to enhance emulsifying properties. This study investigated synergistic effects of alkaline treatment (0.3 or 3.5% Na2CO3) and heat treatments (40 or 70 °C) on the functional properties of MBPI at high protein levels, for potential application as a plant‐based emulsion. The combined treatments reduced the zeta potential of protein suspensions from −9 to −19 mV and altered the protein conformation to form smaller particles (from 426 to 166 μm) with increased β‐sheet content. These treatments improved dispersibility of 8% MBPI suspension (58 to 86%), emulsifying activity index (6.34–10.89 m2 g−1), and stability coefficient (43 to 96%). Notably, MBPI samples treated with 0.3% Na2CO3 at 40 and 70 °C exhibited excellent emulsifying properties, forming stable monolayers at the oil–water interface, likely due to the increased surface activity of MBPI. Increasing protein concentration to 11% facilitated heat‐set gel formation; however, addition of 3.5%‐Na2CO3 induced premature gelation, limiting its application in emulsions. At 0.3%‐Na2CO3, increasing the protein content from 8% to 11% and the oil content from 10% to 30% further reduced emulsion droplet size, especially for MBPI treated with 0.3% Na2CO3 at 70 °C (MB‐0.3%‐70 °C) from 5.10 to 2.61 μm, likely due to decreased coalescence. This treatment yielded superior MBPI‐stabilised emulsion gels with enhanced penetration, fluid retention, and stability by possibly reducing protein aggregation. These findings demonstrate the potential of MBPI modified by combined addition of 0.3% Na2CO3 and heat treatment, particularly MB‐0.3%‐70 °C, as a promising ingredient for producing plant‐based emulsions.

MiRNA Sequencing Analysis in Maize Roots Treated with Neutral and Alkaline Salts.

Soil salinization/alkalization is a complex environmental factor that includes not only neutral salt NaCl but also other components like Na2CO3. miRNAs, as small molecules that regulate gene expression post-transcriptionally, are involved in plant responses to abiotic stress. In this study, maize seedling roots were treated for 5 h with 100 mM NaCl, 50 mM Na2CO3, and H2O, respectively. Sequencing analysis of differentially expressed miRNAs under these conditions revealed that the Na2CO3 treatment group had the most differentially expressed miRNAs. Cluster analysis indicated their main involvement in the regulation of ion transport, binding, metabolism, and phenylpropanoid and flavonoid biosynthesis pathways. The unique differentially expressed miRNAs in the NaCl treatment group were related to the sulfur metabolism pathway. This indicates a significant difference in the response patterns of maize to different treatment groups. This study provides theoretical evidence and genetic resources for further analysis of the molecular mechanisms behind maize's salt-alkali tolerance.

Mn-MIL-100 non-thermally derived MnOx catalysts for toluene oxidation

Herein, a novel preparation method via non-thermal derivation by using Mn-MIL-100 as the precursor to synthesize MnOx catalysts was proposed. The synthesized catalysts were applied to toluene oxidation. Characterizations and experiments results showed that the more surface Mn3+, Oads species, large surface area, better low-temperature reducibility and higher lattice oxygen mobility of Mn-Na2CO3 prepared via Na2CO3 treatment induced its great catalytic activity for toluene oxidation.

Technology comparison for sequential extraction of fucoidan and sodium alginate from Ascophyllum nodosum using a glycerol and choline chloride solvent

Brown algae are the main source of polysaccharides such as fucoidan and alginate, which can be used to develop a wide range of bioactive and polymer materials. In this study, sodium alginate and fucoidan were sequentially extracted using thermochemical, microwave, ultrasonic and sub critical water treatments of untreated and ethanol-pre-treated brown algae, Ascophyllum nodosum. Extraction was achieved using a solvent solution consisting of a 1:2 M ratio of choline chloride to glycerol (ChGl) in 70% water (w/w) for initial treatment to extract fucoidan, followed by Na2CO3 treatments for alginate extraction. Microwave extraction was shown to be the most advantageous treatment for alginate extraction, with the greatest biomass extracted (46.2%), purity (33.43% combined mannuronic and guluronic acid content), and molecular weight, whilst indicating an increased bioactive capacity associated with co-extracted polyphenolic content. However, using ChGl for fucoidan extraction resulted in a large fraction of the solvent remaining within the fucoidan. This is evidenced by up to 39% of the fucoidan consisting of glycerol. The extracted alginate has the potential as a bioactive polysaccharide, whilst the fucoidan would require further purification.

Enhancing stimulation of cyaniding, GhLDOX3 activates reactive oxygen species to regulate tolerance of alkalinity negatively in cotton

Anthocyanins belong to flavonoid secondary metabolites that act as plant pigments to give flowers and fruits different colors and as "scavengers" of reactive oxygen species (ROS) to protect plants from abiotic and biotic stresses. Few studies linked anthocyanins to alkaline resistance so far. In this study, anthocyanin synthesis-related gene leucoanthocyanidin dioxygenase (LDOX) was screened as a candidate gene to explore its relationship with alkali stress. The results found that pYL156: GhLDOX3 lines treated with 50 mM Na2CO3 (pH 11.11) for 24 h showed a significant increase in peroxidase (POD) activity, a decrease in total anthocyanin content and an increase in cyanidin content and a decrease in ROS accumulation compared to pYL156. The overexpressed (OE) lines, ldox mutant and wild-type (WT) lines in Arabidopsis were treated with 50 mM Na2CO3, 100 mM Na2CO3 and 150 mM Na2CO3 for 8 d, respectively. The wilted degree of the OE lines was more severe than WT lines, and less severe in the mutant lines in the 150 mM Na2CO3 treatment. After treatment, the expression levels of AtCAT and AtGSH genes related to antioxidant system in OE lines were significantly lower than in WT, and the expression levels of AtCAT and AtGSH in mutant lines were significantly higher than in WT. In conclusion, the above results suggest GhLDOX3 played a negative regulatory role in the mechanism of resisting Na2CO3 stress. Therefore, it can be considered in cotton breeding to improve the alkali tolerance of cotton by regulating the expression of related genes.

Salt adopted in soaking solution controls the yield and starch digestion kinetics of intact pulse cotyledon cells

Intact cellular powders have gained attention as a functional ingredient due to their lower glycemic response and potential benefits in colon. The isolation of intact cells in the laboratory and pilot plant settings is mainly achieved through thermal treatment with or without the use of limited salts. However, the effects of salt type and concentration on cell porosity, and their impact on the enzymic hydrolysis of encapsulated macro-nutrients such as starch, have been overlooked. In this study, different salt-soaking solutions were used to isolate intact cotyledon cells from white kidney beans. The use of Na2CO3 and Na3PO4 soaking treatments, with high pH (11.5–12.7) and high amount of Na ion (0.1, 0.5 M), greatly improved the yield of cellular powder (49.6–55.5 %), due to the solubilization of pectin through β-elimination and ion exchange. Intact cell walls serve as a physical barrier, significantly reducing the susceptibility of cell to amylolysis when compared to white kidney bean flour and starch counterparts. However, the solubilization of pectin may facilitate enzyme access into the cells by enlarging cell wall permeability. These findings provide new insights into the processing optimization to improve the yield and nutritional value of intact pulse cotyledon cells as a functional food ingredient.

The globulin aggregation characteristics induced by salt and alkali and its effects on dough processing quality

The aggregation characteristics of wheat globulin under NaCl or Na2CO3 induction were investigated via SDS-PAGE, disulfide bonds analysis, protein secondary structure and surface hydrophobicity. The results showed that both the NaCl and Na2CO3 treatment promoted the globulin conformation transforming from β-turns and α-helixes to β-sheets and random coils, facilitating the protein aggregation. Moreover, for the NaCl treatment, higher concentrations of NaCl could induce the aggregation of globulin through disulfide bonds. For the Na2CO3 treatment, disulfide bonds aggregation occurred at a lower concentration; while with the increased concentration, the disulfide bonds were destroyed, and non-disulfide bonds covalent aggregation could be produced. Additionally, the surface hydrophobicity was overall lower, further confirming the massive globulin molecules aggregation. Additionally, following creep and stress relaxation test, it was found that the globulin had an increased impact on the dough elasticity with salt treatment. However, under alkali treatment, the globulin's effects on the dough resistance to deformation and flow, and the stiffness and elasticity of dough were all significantly enhanced. These variation may lie in the aggregation characteristics of globulin analyzed above, which could further enhance the structure of protein network and significantly strengthen the functionality of globulin in dough processing.

Improved mechanical and water absorption properties of epoxy-bamboo long natural fibres composites by eco-friendly Na2CO3 treatment

ABSTRACT Epoxy-bamboo long natural fibres composites were prepared by hand lay-up method to study the influence of fibre’s treatment on their characteristics. SEM showed increased surface roughness due to the removal of amorphous compounds from the treated fibre as confirmed by the disappearance of certain peaks in FTIR spectroscopy. Resultantly, ∼52% increase in crystallinity was observed by XRD analysis. TGA results also showed the effectiveness of the treatment as mass loss for treated fibres was ∼15% lesser than the untreated fibres. Moreover, thermogravimetric analysis of composites showed highest mass loss in untreated fibres composites and lowest in neat epoxy. The DSC-DTA curves indicated an early start of initiation temperature in treated fibre composite. Tension tests showed ∼12% and ~16% increase in tensile strength and modulus respectively for treated fibres composite due to increased interfacial strength caused by fibre treatment. Treatment also resulted in decreased impact energy and water absorption level.

Carbonation treatment of gasification fly ash from municipal solid waste using sodium carbonate and sodium bicarbonate solutions

In recent years, slagging-gasification technology has received increasing attention in treating municipal solid waste (MSW). Compared with conventional incineration, the higher temperature in the slagging-gasification process optimizes its residue composition, and gasification fly ash (GFA) is the only unreused solid residue. Although GFA is a potential civil engineering material, its high content of heavy metals, chlorides, and sulfates hinders its practical use. Moreover, although carbonation has proven to immobilize heavy metals in incineration fly ash, the conventional gas carbonation method cannot remove chlorides and sulfates. In this study, sodium bicarbonate (NaHCO3) treatment was studied to treat GFA for the first time, and sodium carbonate (Na2CO3) was used for comparison. Different concentrations of NaHCO3 and Na2CO3 solutions were used to treat the GFA, and comprehensive tests were conducted on the treated samples. The results indicated that NaHCO3 treatment was effective in immobilizing Pb, Zn, Cu, and Ni in GFA, while Na2CO3 treatment could not effectively immobilize Pb and Zn. Both NaHCO3 and Na2CO3 promoted the removal of chlorides and sulfates in GFA. The wastewater from the NaHCO3 treatment contained fewer heavy metals compared with those from water washing or Na2CO3 treatment, benefitting its treatment or reuse.

Valorization of red macroalgae biomass via hydrothermal liquefaction using homogeneous catalysts

Hydrothermal liquefaction of red macroalgae species, Kappaphycus alvarezii (KA) and Eucheuma denticulatum (ED), was performed at 350 °C in the presence of 5 wt% neutral and alkali catalysts like Na2CO3, K2CO3, CaCO3, Na2SO4, NaOH, and KOH. The maximum bio-crude yield of 26.7 wt% and 18.5 wt%, on a dry ash-free basis, was obtained from Na2CO3 treatment of KA and KOH treatment of ED, respectively. The bio-crude from both feedstocks mainly consisted of cyclic oxygenates, whose selectivities were maximum in K2CO3 and CaCO3 treatments. The calorific value of the bio-crude was 38.5 MJ/kg from KA and 30.8 MJ/kg from ED, while that of biochars was 20–24 MJ/kg. A high degree of deoxygenation (64.2%) was observed in bio-crude produced from Na2SO4 treatment of KA biomass. Salts of Cl–, SO42– and K+ constituted the major inorganic portion of the aqueous phase. Maximum energy recovery (99%) was observed from the Na2CO3 treatment of ED.

Effects of Water-Soluble Sodium Compounds on the Microstructure and Combustion Performance of Shengli Lignite.

Different water-soluble sodium compounds (NaCl, Na2CO3, and NaOH) were used to treat Shengli lignite, and the resulting effects on the microstructure and combustion performance of the coal were investigated. The results showed that Na2CO3 and NaOH had a significant impact on combustion performance of lignite, while NaCl did not. The Na2CO3-treated lignite showed two distinct weight-loss temperature regions, and after NaOH treatment, the main combustion peak of the sample moved to the high temperature. This indicates that both Na2CO3 and NaOH can inhibit the combustion of lignite, with the latter showing a greater effect. The FT-IR/XPS results revealed that Na+ interacted with the oxygen-containing functional groups in lignite to form a “–COONa” structure during the Na2CO3 and NaOH treatments. It is deduced that the inhibitory effect on combustion of lignite may be attributed to the stability of the “–COONa” structure, and the relative amount is directly correlated with the inhibitory effect. The XRD/Raman analysis indicated that the stability of the aromatic structure containing “–COOH” increased with the number of “–COONa” structures formed. Additionally, experiments with carboxyl-containing compounds further demonstrated that the number of oxygen-containing functional groups combined with Na was the main reason for the differences in the combustion performance of treated lignite.

Development of organobentonite based on bentonite clay for the purpose of disposing of oil spills on water bodies

Today, oil spill response is an urgent problem for oil-producing countries. This paper researches the elimination of oil pollution using organomineral sorbents. The authors present a scheme for obtaining sorbents based on natural bentonite clays by modifying with a quaternary ammonium salt. Two variants of modification of natural bentonites have been studied: with preliminary Na2CO3 treatment to convert the main component of bentonite into the sodium form and without preliminary treatment. The obtained organobentonites have high sorption and hydrophilic properties. The sorbent obtained from natural bentonite with preliminary treatment with Na2CO3 has better properties in comparison with the sorbent without preliminary treatment. The authors also demonstrated the ability of the obtained organobentonites for oil sorption. Organobentonites upon contact with oil films on the water surface form dense agglomerates that can be easily removed mechanically.

Preparation of a hollow HZSM-5 zeolite supported molybdenum catalyst by desilication-recrystallization for enhanced catalytic properties in propane aromatization

A hollow HZSM-5 supported molybdenum (Mo) catalyst was successfully prepared by desilication-recrystallization method of HZSM-5 in tetrapropylammonium hydroxide (TPAOH) solution. The as-synthesized catalyst exhibiting excellent performance in propane aromatization reaction was thoroughly investigated, along with the mechanism for the formation of hollow structure and mechanism for the deactivation. Results revealed that TPA ​+ ​exerted a controllable desilication and recrystallization effect. Compared with Na2CO3 treatment which led to a mesoporous structure, TPAOH treatment was able to leach out the inner Si species by OH- and then those Si species recrystallized on the external surface, resulting in the hollow structure and a silicon-rich external surface. In addition, the hollow zeolite exposing higher external surface provided more anchoring sites for Mo species, which was beneficial to the Mo related Lewis acid sites but decreased the surface Bronsted acidity. At 823 ​K and a space velocity of 1800 ​mL·g-1·h-1, the hollow Mo/HZSM-5(TPAOH) catalyst behaved a propane conversion of 73.01% and aromatics selectivity of 77.36%, exceeding those of the hierarchical Mo/HZSM-5(Na2CO3) catalyst by 5.97% and 9.96%, respectively. These features of Mo/HZSM-5(TPAOH) granted it superb diffusion ability and optimized Bronsted/Lewis acid ratio (B/L ​= ​1.3), which greatly enhanced the propane conversion and aromatic selectivity together with a preeminent catalytic stability.

In Situ Chemical Locking of Acetates During Xylo-Oligosaccharide Preparation by Lignocellulose Acidolysis.

Xylo-oligosaccharides with high value could be obtained by acidolysis of lignocellulosic biomass with acetic acid, which was an urgent problem to solve for the separation of acetic acid from crude xylo-oligosaccharides solution. Four neutralizers, CaCO3, CaO, Na2CO3, and NaOH, were used for in situ chemically locking the acetic acid in the acidolyzed hydrolysate of corncob. The chemically locked hydrolysate was analyzed and compared using vacuum evaporation and spray drying. After CaCO3, CaO, Na2CO3, and NaOH treatment, the locking rates of acetic acid were 92.62%, 94.89%, 95.05%, and 95.58%, respectively, and 39.55 g, 41.13 g, 41.78 g, and 41.87 g of the compound of xylo-oligosaccharide and acetate were obtained. Sodium neutralizer had lesser effect on xylo-oligosaccharide content, and Na2CO3 was the best chemical for locking acetic acid among these four neutralizers. This process provides a novel method for effectively utilizing acetic acid during the industrial production of xylo-oligosaccharides via acetic acid.

Beneficial effects of endophytic Pantoea ananatis with ability to promote rice growth under saline stress.

Soil salinization severely inhibits plant growth, leading to a low crop yield. The aim of the current study was to isolate endophytic bacteria with the ability to promote rice growth under saline conditions. We isolated eight salt-tolerant endophytic bacteria from rice roots. An isolated strain D1 was selected due to its ability to stimulate rice seed germination in the presence of NaCl, which was identified as Pantoea ananatis D1. It exhibited multiple plant growth-promoting traits including phosphate solubilization, production of indole-3-acetic acid, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and siderophore. Inoculation of P. ananatis D1 obviously enhanced the rice root and shoot growth under normal and saline conditions. It also significantly increased the contents of chlorophyll, total soluble protein, and proline in salt-stressed rice seedlings. Moreover P. ananatis D1 could ameliorate the oxidative stress in rice induced by NaCl and Na2 CO3 treatment. The malondialdehyde content and various antioxidant enzyme activities were decreased by P. ananatis D1 inoculation in salt-affected rice. In addition, P. ananatis D1 showed a positive potential for limiting the Na+ accumulation and enhancing the K+ uptake, leading to an increase of 1·2-1·7 fold in K+ /Na+ ratio under saline environment. Pantoea ananatis D1 has the ability to improve the salt tolerance of rice seedlings. The application of plant growth-promoting bacteria (PGPB) is an eco-friendly strategy to improve plant tolerance towards abiotic stresses. We demonstrated that P. ananatis D1 could be used as an effective halotolerant PGPB to enhance rice growth in different salt-affected soils.

Surface Roughness-Governed Shape Stability of the Coal Fly Ash-Based Phase Change Material: Molten Salt Processing and Thermal Properties

Coal fly ash (FA) valorization is of great significance and sustainable interests to addressing the current environmental challenges faced by coal power industry. Herein, this work attempted a novel molten salt Na2CO3 treatment for processing FA into a robust matrix to support lauric acid (LA) toward construction of latent phase change composite. Their micromorphology, physiochemical, and thermal properties were monitored with scanning and transmission microscopy, X-ray diffraction and FT-IR spectroscopy, differential scanning calorimetry, among others. As Na2CO3 dosage increased from 20% to 40%, the FA experienced firstly higher loss of SiO2 and then substantial loss of Al2O3, and yet exhibited merely varied porosity. Then, both the composites revealed a maximum LA content of 20% that doubled that of pristine FA. Nevertheless, the optimal composite was disclosed with thermal conductivity of 0.5668 W/mK, which was 69% higher than its FA-based counterpart. It was proposed that the surface roughness evidenced by the formation of tremendous grooves and gaps during thermal alkaline processing were accountable for the promoted carrying capacity toward organic component. Furthermore, the latent phase change composite revealed excellent durability, including negligibly varied phase transition temperature and enthalpy even after 1500 thermal cycling, which promised great interest in passive building cooling. Meanwhile, the finds here led to a new understanding into the structural origin of adsorption capacity by inorganic FA, and may provide guidance for better exploration of its characteristics for other applications.

Study on cocoonase, sericin, and degumming of silk cocoon: computational and experimental

BackgroundCocoonase is a proteolytic enzyme that helps in dissolving the silk cocoon shell and exit of silk moth. Chemicals like anhydrous Na2CO3, Marseille soap, soda, ethylene diamine and tartaric acid-based degumming of silk cocoon shell have been in practice. During this process, solubility of sericin protein increased resulting in the release of sericin from the fibroin protein of the silk. However, this process diminishes natural color and softness of the silk. Cocoonase enzyme digests the sericin protein of silk at the anterior portion of the cocoon without disturbing the silk fibroin. However, no thorough characterization of cocoonase and sericin protein as well as imaging analysis of chemical- and enzyme-treated silk sheets has been carried out so far. Therefore, present study aimed for detailed characterization of cocoonase and sericin proteins, phylogenetic analysis, secondary and tertiary structure prediction, and computational validation as well as their interaction with other proteins. Further, identification of tasar silkworm (Antheraea mylitta) pupa stage for cocoonase collection, its purification and effect on silk sheet degumming, scanning electron microscope (SEM)-based comparison of chemical- and enzyme-treated cocoon sheets, and its optical coherence tomography (OCT)-based imaging analysis have been investigated. Various computational tools like Molecular Evolutionary Genetics Analysis (MEGA) X and Figtree, Iterative Threading Assembly Refinement (I-TASSER), self-optimized predicted method with alignment (SOPMA), PROCHECK, University of California, San Francisco (UCSF) Chimera, and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) were used for characterization of cocoonase and sericin proteins. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), protein purification using Sephadex G 25-column, degumming of cocoon sheet using cocoonase enzyme and chemical Na2CO3, and SEM and OCT analysis of degummed cocoon sheet were performed. ResultsPredicted normalized B-factors of cocoonase and sericin with respect to α and β regions showed that these regions are structurally more stable in cocoonase while less stable in sericin. Conserved domain analysis revealed that B. mori cocoonase contains a trypsin-like serine protease with active site range 45 to 180 query sequences while substrate binding site from 175 to 200 query sequences. SDS-PAGE analysis of cocoonase indicated its molecular weight of 25–26 kDa. Na2CO3 treatment showed more degumming effect (i.e., cocoon sheet weight loss) as compared to degumming with cocoonase. However, cocoonase-treated silk cocoon sheet holds the natural color of tasar silk, smoothness, and luster compared with the cocoon sheet treated with Na2CO3. SEM-based analysis showed the noticeable variation on the surface of silk fiber treated with cocoonase and Na2CO3. OCT analysis also exemplified the variations in the cross-sectional view of the cocoonase and Na2CO3-treated silk sheets. ConclusionsPresent study enlightens on the detailed characteristics of cocoonase and sericin proteins, comparative degumming activity, and image analysis of cocoonase enzyme and Na2CO3 chemical-treated silk sheets. Obtained findings illustrated about use of cocoonase enzyme in the degumming of silk cocoon at larger scale that will be a boon to the silk industry.

Greener extraction of highly crystalline and thermally stable cellulose micro-fibers from sugarcane bagasse for cellulose nano-fibrils preparation

This study aims to assess Na2CO3 treatment as a potential pre-treatment for extracting cellulose micro-fibers and subsequently cellulose nano-fibrils (CNF) from sugarcane bagasse. For cellulose micro-fibers extraction, Na2CO3 concentration, reaction time, and temperature were critical factors influencing reaction kinetics. It was concluded from statistical analysis of crystallinity index (CrI) that temperature was the most significant factor. Moreover, reaction time and Na2CO3 concentration were minimized while maximizing temperature to get an increase of 33 % and 115.2 % in the CrI and activation energy of thermal degradation, respectively. FTIR analysis of cellulose micro-fibers indicated the removal of hemicellulose and lignin. For the preparation of CNF, ionic liquid (IL) 1-n-butyl-3-methylimidazolium chloride was used. The CNF diameter was in the range of 4–35 nm, and the length was in a few micrometers. Hence Na2CO3 treatment in the combination of IL treatment is an efficient and environmentally friendly approach to valorize sugarcane bagasse into high-value CNF.