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1.
Environ Pollut ; 355: 124255, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38815894

RESUMO

Polylactic Acid (PLA) based compostable bioplastic films degrade under thermophilic composting conditions. The purpose of our study was to understand whether sample pre-treatment along with bioaugmentation of the degradation matrix could reduce the biodegradation time under a simulated composting environment. Sepcifically, we also explored whether the commercial composts could be replaced by landfill-mined soil-like fraction (LMSF) for the said application. The effect of pre-treatment on the material was analysed by tests like tensile strength analysis, hydrophobicity analysis, morphological analysis, thermal degradation profiling, etc. Subsequently, the degradation experiment was performed in a simulated composting environment following the ASTM D5338 standard, along with bioaugmentation in selected experimental setups. When the novel approach of material pre-treatment and bioaugmentation were applied in combination, the time necessary for 90% degradation was reduced by 27% using compost and by 23% using LMSF. Beyond the improvement in degradation rate, the water holding capacity increased significantly for the degradation matrices. With pH, C: N ratio and microbial diversity tested to be favourable through 16s metabarcoding studies, material pre-treatment and bioaugmentation allow LMSF to not only replace commercial compost in polymer degradation but also find immense application in the agricultural sector of drought-affected areas (for better water retention) after it has been used for PLA degradation.


Assuntos
Agricultura , Biodegradação Ambiental , Compostagem , Solo , Instalações de Eliminação de Resíduos , Compostagem/métodos , Solo/química , Biopolímeros , Agricultura/métodos , Microbiologia do Solo , Poluentes do Solo/metabolismo , Poluentes do Solo/análise , Poliésteres/química , Poliésteres/metabolismo , Eliminação de Resíduos/métodos
2.
Int J Biol Macromol ; 269(Pt 1): 132051, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38777687

RESUMO

The impact of guar gum (GG), crude algae ethanolic extract (CAEE), and turmeric essential oil (TEO) incorporated edible coating formulations on the quality of cut potatoes was investigated at room temperature (27 ±â€¯3 °C, 70-85 % RH) storage using a rotatable central composite design. Besides, 30 % glycerol, 5 % calcium chloride, and 3 % ascorbic acid (w/w) were added to the coating solution as additives. The surface color, respiration rate, water vapor transmission rate, visible mold growth, and sensory analysis were assessed after seven days of storage. The inclusion of ascorbic acid and TEO in edible coating demonstrated a more effective delay in browning. The coated potatoes had lower OTR, CTR, and WVTR values for GG concentrations of 0.5 to 1 g/100 mL than the control. Compared to additives, higher concentrations of GG improved response parameters. The WVTR value of coated potatoes was significantly impacted by the interaction between CAEE and TEO with GG. Incorporating CAEE and TEO into the formulations of guar gum led to a reduction in the permeability of the coating to oxygen and water vapor. The seven days of extended shelf life compared to two days of control were observed with the optimized coating formulation. Furthermore, the application of the coating treatment proved effective in preventing enzymatic browning and creating a barrier against moisture and gases, contributing to prolonged freshness during extended storage periods.


Assuntos
Armazenamento de Alimentos , Galactanos , Mananas , Gomas Vegetais , Solanum tuberosum , Gomas Vegetais/química , Galactanos/química , Mananas/química , Mananas/farmacologia , Solanum tuberosum/química , Armazenamento de Alimentos/métodos , Conservação de Alimentos/métodos
3.
Int J Biol Macromol ; 254(Pt 3): 127489, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37852394

RESUMO

In the present study, the effects of guar gum (0.7 %):chitosan (0.3 %) based composite edible coating functionalized with coconut oil and essential oils like clove bud oil and cinnamon bark oil were investigated on the postharvest shelf life of Khasi mandarins at ambient conditions (25 ± 5 °C, RH 75 ± 5 %) up to 20 days of storage period. The postharvest characteristics such as weight loss, firmness, acidity, total soluble solids (TSS) and reducing sugar of control and treated fruits were evaluated at 5 days intervals throughout the storage period. The obtained results indicated that the application of guar gum/chitosan-based composite edible coating with coconut oil, clove bud and cinnamon bark essential oil was effective in prolonging the postharvest shelf life of Khasi mandarins as compared to control fruits by minimizing the decay and loss of postharvest quality attributes. The treatment of composite such as guar gum/chitosan/coconut oil/clove oil/cinnamon oil (GGCsC-Cl-Cn) was most effective in maintaining postharvest characteristics of fruits compared to other treatments and control. The significant (p < 0.05) lowest weight loss (38 %) with retention of higher firmness (5.9 N), titratable acidity (0.29 %), and total soluble solid (10.8 %) was noticed in the Khasi mandarins treated with GGCsC-Cl-Cn composite coating on 20 days of storage. Furthermore, the present study confirmed the significance of the developed composite formulation in improving the shelf life of Khasi mandarin.


Assuntos
Quitosana , Filmes Comestíveis , Óleos Voláteis , Humanos , Conservação de Alimentos/métodos , Quitosana/farmacologia , Óleo de Coco , Óleos Voláteis/farmacologia , Redução de Peso
4.
Int J Biol Macromol ; 253(Pt 5): 126977, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37739287

RESUMO

The major drawback associated with petroleum-based polymer products is pollution, leading to environmental hazards. Biodegradable polymers and biocomposites have the potential to play a major role in replacing the conventional polymers in specific applications on a case to case basis. In the current study, sawdust reinforced polylactic acid/polycaprolactone (PLA/PCL) biocomposites were developed using the melt extrusion technique. Primary processed fine sawdust was reinforced with PLA/PCL blend in a mini twin screw extruder in different weight fractions (10 %, 20 %, 30 %, and 40 %). The developed biocomposites were subjected to tensile testing, which indicated that the increased weight percent of sawdust reduced the tensile strength. The materials were further characterized, using sophisticated analytical such as field emission scanning electron microscopy, differential scanning calorimetry and thermogravimetry analysis. The composite containing 30 % sawdust concentration presented the best results with tensile strength of 26.5 MPa, tensile strain of 4.4 % and onset degradation temperature of 320 °C. The same formulation was successfully scaled up to the pilot level of 5 kg batch. It was further subjected to secondary processing to produce market ready cutlery items. Biodegradability studies in simulated composting environments revealed that addition of sawdust drastically reduces the lag phase in degradation and total degradation may be obtained in approximately 90 days. Based on the investigation, there is optimism that the PLA/PCL composites, blended with sawdust may ensure commercial application of sustainable polymer blends at affordable prices.


Assuntos
Poliésteres , Polímeros , Poliésteres/química , Polímeros/química , Resistência à Tração
5.
Int J Biol Macromol ; 242(Pt 3): 125126, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37257545

RESUMO

This new investigation deals with the synthesis of an organic-inorganic nanohybrid using SNC with magnificent flower bud-shaped ZnO, termed SNC-ZnO by precipitation method. The nanohybrid (with concentrations 1 wt%, 3 wt%, and 5 wt%) was in situ incorporated into the PLA matrix to prepare the electrospun solution. The functionalized PLA composite nanofibres produced by electrospinning with SNC-ZnO nanohybrid were systematically studied using different structural and morphological analyses to meet the challenging processing requirements. The FESEM analysis gives an average diameter of nanofibres 246 ± 10.2 nm where nanohybrid tends to adhere on the surface of the PLA nanofabric increasing hydrophobicity up to water contact angle 135.3 ± 0.25 °C with 5 wt% nanohybrid incorporation. The nanofabric has significant antibacterial activity against E.Coli and S.Aureus bacteria. Further, an extensive study has been made on thermally stipulated processes using DSC on non-isothermal crystallization kinetics using different models: Avrami, Ozawa, Mo, and Tobin. The results revealed sites for heterogeneous nucleation and improvement in crystallinity, t1/2, and nucleation effects due to the incorporation of crystalline nanohybrid in PLA nanofibres. Further, the Avrami plot has confirmed both primary and secondary crystallization processes thereby considering its potential to utilize functionalized PLA nanofabric for applications in protective textile.


Assuntos
Nanopartículas , Óxido de Zinco , Óxido de Zinco/química , Seda , Poliésteres/química , Antibacterianos/farmacologia , Antibacterianos/química , Escherichia coli
6.
Sci Total Environ ; 851(Pt 2): 158311, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36037904

RESUMO

Growing demand for plastic and increasing plastic waste pollution have led to significant environmental challenges and concerns in today's world. Bioplastics offer exciting new opportunities and possibilities where biodegradable and bio-based plastics are expected to be more eco-friendly and rely on renewable resources. With all its promises, evaluating its real impact and fate on the geoenvironment is paramount for promoting bioplastic use. This paper presents a systematic literature review to understand current bioplastic-soil research and the effects of its residues on the geoenvironment. 632 studies related to bioplastic research in soil since 1973 were identified and categorized into different relevant topics. Publication trend showed bioplastic-soil research grew exponentially after 2010 wherein field studies accounted to 33.1 % of the total studies and only about 9.7 % studied the effects of bioplastic residues on the geoenvironment. Majority of the lab studies were on development and subsequent stability of bioplastics in soil. Short-term studies (in months) dominated the longer-term studies and studies over 4 years were almost non-existent. Lab and field experiments often gave inconsistent results with seasonal, climatic and bio-geographical factors strongly influencing the field results and bioplastic stability in soil. Most existing studies reported significant effects for microbioplastic concentrations at or above 1 % w/w. Bioplastic residues were found to substantially affect soil C/N ratio, impact soil microbial diversity by favouring certain microbial taxa and alter soil physical structure by influencing soil aggregates formation. At higher concentrations, plant health and germination success were also negatively affected. Conclusively, the review found it important to focus more on long-term field experiments to better understand the degree and extent of bioplastic residue impact on soil physico-chemical properties, mechanical properties, soil biology, soil-bioplastic-plant response, nutrients and toxicity. There are also very few studies investigating contaminant transport and migration of micro or nano-bioplastics in soil.


Assuntos
Plásticos , Solo , Plásticos/toxicidade , Plásticos/química , Poluição Ambiental
7.
Sci Rep ; 12(1): 14724, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-36042315

RESUMO

This present study demonstrated the preparation of a highly crystalline anatase (ana) form of titanium oxide (TiO2) doped silk nanocrystal (SNC) nanohybrid (ana-TCS) of diameter (7.5 ± 1.4 nm) by the sol-gel method using titanium (IV) butoxide as the hydrolysis material. This prepared nanohybrid with surface hydroxyl groups acted as a co-initiator for the synthesis of poly(L-lactic acid) (PLLA)-g-ana-TSC nanocomposite with grafted PLLA chains via the in situ polymerization technique, using tin-octoate as a catalyst. The fabricated nanocomposite had a high number average molecular weight of 83 kDa with good processibility. This prepared nanocomposite was hydrophobic in nature, with a contact angle of 105°, which was further enhanced to 122 ± 1° when processed via electrospinning technique into a non-woven fabric. The prepared nanocomposite could degrade up to 43% methylene blue dye in 15 days. This nanocomposite showed no significant molecular weight reduction after 1 h of aqeous treatment, which could be attributed to its hydrophobic nature, inhibiting its degradation. However, 50% degradation was observed for the nanocomoposite whereas, PLLA demonstrated 25% degradation in 15 days, after its end-of-life. Thus, this study revealed that the in situ synthesized PLA-ana-TCS nanocomposite could be targeted for use as a hydrophobic, self-cleaning, dye-degradable fabric.


Assuntos
Nanocompostos , Nanocompostos/química , Poliésteres/química , Polimerização , Têxteis
8.
ACS Appl Bio Mater ; 5(8): 3722-3733, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35853242

RESUMO

Wound dressing materials fabricated using biocompatible polymers have become quite relevant in medical applications, and one such material is bacterial cellulose (BC) with exceptional properties in terms of biocompatibility, high purity, crystallinity (∼88%), and high water holding capacity. However, the lack of antibacterial activity slightly restricts its application as a wound dressing material. In this work, polycaprolactone (PCL) was first impregnated into the BC matrix to fabricate flexible bacterial cellulose-based PCL membranes (BCP), which was further functionalized with antibiotics gentamicin (GEN) and streptomycin (SM) separately, to form wound dressing composite scaffolds to aid infectious wound healing. Fourier transform infrared spectroscopy (FT-IR) results confirmed the presence of characteristic PCL and cellulose peaks in the composite scaffolds at 1720 cm-1, 3400 cm-1, and 2895 cm-1, respectively, explaining the successful interaction of PCL with the BC matrix, which is further corroborated by scanning electron microscopy (SEM) images. X-ray diffraction (XRD) studies revealed the formation of highly crystalline BCP films (∼86%). In vitro studies of the BC and BCP scaffolds against baby hamster kidney (BHK-21) cells revealed their cytocompatible nature; also the wettability studies indicated the hydrophilicity of the developed scaffolds, qualifying the main criterion in wound dressing applications. Energy dispersive X-ray analysis (EDX) of the drug loaded scaffolds showed the presence of sulfur in the composites. The prepared scaffolds also exhibited excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus. The release profiles initially indicated a burst release (6 h) followed by controlled release of GEN (∼42%) and SM (∼58%) from the prepared scaffolds within 48 h. Hence, these results interpret that the prepared drug-functionalized cellulosic scaffolds have great potential as a wound dressing material in biomedical applications.


Assuntos
Bandagens , Celulose , Antibacterianos/farmacologia , Bactérias , Celulose/farmacologia , Escherichia coli , Testes de Sensibilidade Microbiana , Espectroscopia de Infravermelho com Transformada de Fourier , Cicatrização
9.
Int J Biol Macromol ; 219: 384-394, 2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-35850271

RESUMO

An environmentally friendly non-woven nanotextile has been prepared using enantiomeric pairs of poly (lactic acid) PLA by electrospinning technique. Solution blending of synthesized high molecular weight (⁓105 Da) poly (L-lactic acid) PLLA and poly (D-lactic acid), PDLA for prolonged time stirring produce solely stereocrystallites (sc). The high crosslinking effect of sc-PLA has played an important role, with multifunctional behaviour on the addition of anatase-TiO2 (a-TiO2) in three different ways (Case-I-III). The high crystallinity of a-TiO2 (~7.14 nm), has been confirmed from XRD and TEM studies as 98 %. The nanofinish as studied in (Case -III) by dipping and drying has decreased the water contact angle for the electrospun sc-PLA nanotextile from highly hydrophobic (132°) to superhydrophilicity after 8 min. An easy demonstration of high temperature treated nanofabric (at 100 °C) has proven to obtain an anti-shrinkage sc-PLA nanofabric. Even, the presence of a-TiO2 has improved the colour strength ability of sc-PLA as a dark dyed nanofabric. The loading of as-synthesized a-TiO2 nanoparticle has enhanced adsorbent dosages for 5TdipscPLA up to 1.44 mg/g of MB dosage, at contact time (8 h), and 68 % methylene blue (MB) removal efficiency under UV irradiation. Thereby, this a-TiO2 impregnated sc-PLA nanofabric tends to dye removal.


Assuntos
Azul de Metileno , Titânio , Corantes , Ácido Láctico/química , Poliésteres/química , Titânio/química , Água
10.
RSC Adv ; 12(21): 13295-13313, 2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35520137

RESUMO

The concept of sustainability and the substitution of non-biodegradable packaging using biodegradable packaging has attracted gigantic interest. The objective of the present study was to revalorize the biowaste "de-oiled green algae biomass (DAB)" of Dunaliella tertiolecta using a green approach and the development of biodegradable chitosan (CS)-based edible active biocomposite films and coatings for prolonging the shelf life of fresh produce. Ultrasound-assisted green extraction was conducted using food-grade solvent ethanol for obtaining the bio-actives, namely "crude algae ethanolic extract (CAEE)" from DAB. The edible films (CS/CAEE) and coating solutions were developed by incorporating CAEE with varying concentrations (0 to 28%). The CAEE was subjected to MALDI-TOF-MS, NMR, and other biochemical analyses, and was found to be rich in DPPH antioxidant activity (∼40%). The CS/CAEE films were fabricated using a solvent casting method and characterized by several biochemical and physicochemical (FESEM, TGA, FTIR, XRD, WVP, UTM, and rheological) characterization techniques. The addition of CAEE into the CS matrix reduced the maximum film transparency (∼20%), water vapor permeability (∼60%); improved the crystallinity (∼24%), tensile strength (∼25%), and antioxidant activity (∼27%); and exhibited UV-Vis blocking properties as compared to the control film. Besides, the developed coating solutions and CAEE showed biocompatibility with BHK-21 fibroblast cells and antimicrobial activity against common food pathogens. The developed coating solution was applied on green chilli using a dipping method and stored at ambient temperature (25 ± 2 °C, 50-70 % RH) for 10 days. The shelf life of chillies was extended without altering the quality as compared to uncoated green chillies. Therefore, the formulated coating could be applicable for prolonging the shelf life of fresh produce.

11.
Int J Biol Macromol ; 211: 116-127, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35561853

RESUMO

The current work demonstrates a unique approach of utilizing nanochitosan (NCS) based edible nanomodifier for functionalizing starch (ST)/guar gum (GG) biocomposite with superior packaging properties targeting stringent edible food packaging on fresh cuts. The effectiveness of NCS in terms of structure-property-performance analysis of ST/GG biocomposites was done. The inclusion of NCS to the biocomposites of ST/GG converts its hydrophilic surface nature to hydrophobic (contact angle of ~114°) by modifying the surface features. The addition of NCS improved the thermal stability, where the observed 10% weight degradation of ST biocomposites were ~79.36, ~80.49, and ~186.89 °C for neat ST, ST/GG biocomposites, and ST/GG/NCS (3% w/v) (ST-GG-NCS3), respectively. The observed transparency of ST, ST-GG, and ST-GG-NCS3 were 21, 8, and 48%, respectively in the visible region suggesting consumer preference for transparent packaging materials. The wt% of O, C and N elements in ST-GG-NCS3 as observed by EDX spectra were ~ 50.2, ~47.6, and ~ 2.2%, respectively, which confirm the safety of the materials. Additionally, it is noteworthy to mention that the storage quality in terms of microbial growth, pH change, color attributes, and weight loss are better preserved when used as an edible coating on cut apple fruits.


Assuntos
Filmes Comestíveis , Galactanos/química , Mananas , Gomas Vegetais , Amido/química , Propriedades de Superfície
12.
ACS Appl Bio Mater ; 5(5): 2143-2151, 2022 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-35467829

RESUMO

Poly(lactic acid) (PLA) is an emerging biobased implant material. Despite its biocompatibility and the aseptic procedures followed during orthopedic surgery, bacterial infection remains an obstacle to implementing PLA-based implants. To tackle this issue, prodigiosin-incorporated PLA has been developed, which possesses improved hydrophobicity with a contact angle of 111 ± 1.5°. The degradation temperature of the prodigiosin is 215 °C, which is more than the melting temperature of PLA, which supports the processability and sterilization of the PLA-based implants without any toxic gases. Further, prodigiosin improves the transparency of PLA and acts as a nucleation site. The spherulite density increases three times compared to that of neat PLA. The inherent methoxy group of prodigiosin is an active site responsible for the inhibition of bacterial attack and biofilm formation. The in vitro study on biofilm formation shows excellent inhibition activity against implant-associated pathogens such as Klebsiella aerogenes and Staphylococcus aureus.


Assuntos
Poliésteres , Prodigiosina , Biofilmes , Poliésteres/química , Prodigiosina/farmacologia , Staphylococcus aureus
13.
Eur J Pharm Sci ; 173: 106168, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35318131

RESUMO

The present study reports the construction of Gold Nanoparticle (AuNP)-decorated [Zn2+]:[Insulin] condensed assembly which was found to be reversible and biocompatible. At first, Citrate-Capped AuNPs were synthesized using the Turkevich method, and the colloidal solution was co-incubated with [Zn2+]:[Insulin] maintaining an equimolar stoichiometry, at physiological pH, 60 °C and 6 h. Accordingly, the effect of excess Zn2+ and surface sorption events were investigated. The surface chemistry of protein sorption on AuNPs involved interaction of surface citrate with the amyloidogenic residues of insulin Chain A (L13, E17, N18) and Chain B (V12, Y16, L17), and also C7:A, C7:B, C20:A. The surface sorption involved a number of driving forces which were predicted to be covalent, H-bonding and hydrophobic interactions. Upon the capture of a fraction of insulin molecules, the Zn2+ was found to form cross-links between the unbound monomers and insulin bound on AuNP, thus forming nucleating species with dendritic morphology. The dendritic species self-assembled into linear and branched organization, followed by the formation of densely packed AuNP-decorated [Zn2+]:[Insulin] condensed assembly. Subsequently, alteration of pH resulted in changes of local charges, thus destabilizing the intermolecular ionic interactions, and subsequently caused the reversal of the condensed assembly back to monomeric forms. Furthermore, the reversible AuNP-decorated [Zn2+]:[Insulin] condensate was found to be biocompatible, and promoted the growth of the adherent cell line, BHK-21 fibroblasts. The non-cytotoxic and reversible material thus formed might have enormous applications in bioelectronics, cell culture matrices, and drug-delivery systems.


Assuntos
Ouro , Nanopartículas Metálicas , Ácido Cítrico , Ouro/química , Insulina , Nanopartículas Metálicas/química , Zinco
14.
Crit Rev Food Sci Nutr ; 62(7): 1912-1935, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33249872

RESUMO

Consumers increasingly prefer healthy and nutritious diet worldwide, and demands for fresh fruits and vegetables are rapidly growing. Fresh produce are perishable commodities, and physical damage, moisture loss, biochemical changes, and postharvest microbial decay are primary causes of quality loss and reduced shelf-life. Packaging, including plastic films and coatings is an effective strategy to improve postharvest-life of whole and cut fruits and vegetables. However, plastic packaging is a significant environmental concern globally. Biopolymer based films and/or coatings are environment-friendly alternative packaging for food. But, these biopolymers, derived from plant, animal and microbial sources, lack some of the primary physico-chemical and mechanical properties compared to conventional plastic packaging. Reinforcement of biopolymer with nanomaterials addresses these shortcomings, and adds functional properties such as antimicrobial and/or antioxidant activities to the nanocomposites. Organic (e.g. nanocellulose fibrils), and inorganic (e.g. montmorillonite, zinc oxide, silver) nanomaterials are effective in achieving these improvements in biopolymer based nanocomposite. Plant-extracts and compounds derived from plant (e.g. essential oil) are also effective in imparting antimicrobial and antioxidant properties to biopolymer based nanocomposites. This is an extensive review of research works on effectiveness of biopolymer based nanocomposite films and coatings used for packaging of whole and cut fruits and vegetables to extend their shelf-life. Numerous reports have demonstrated effectiveness of biopolymer based nanocomposites in improvement in shelf-life of packaged and/or coated whole and cut fruits and vegetables by at least 4-5 days to as much as a few months.HighlightsFresh produce are perishable commodities requiring package or coating.Conventional plastics and waxes are major environmental and health concerns.Biopolymer based nanocomposites are environment-friendly alternatives.These nanocomposite films and coatings are effective in enhancing shelf-life.


Assuntos
Nanocompostos , Verduras , Biopolímeros , Embalagem de Alimentos , Conservação de Alimentos , Frutas
15.
Chemosphere ; 287(Pt 3): 132282, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826941

RESUMO

The discharge of effluents from the textile industry is a multidimensional problem that affects the ecosystem in many ways. Though many new technologies are being developed, it remains to be seen which of those can be practiced in a real scenario. The current investigation attempts to absorb the Malachite Green, an effluent from textile dye using Chinese Fan Palm Seed Biochar. Accordingly, biochar was prepared using fruits of Chinese Fan Palm (Livistona chinensis) tree. The fruit also yielded a significant amount of biochar and bio-oil. 1.346 kg of fresh and cleaned fruit was fast pyrolyzed at 500 °C in a laboratory-scale Pyrolyzer resulting in 0.487 kg of biochar and 0.803 L of bio-oil. The remaining fruit matter was converted to gaseous products. The kinetics of dye removal were studied and the parameters were determined. The study advocates that the Langmuir isotherm model simulates the adsorption experiment, to a good extent. From the plot, the maximum (monolayer) adsorption capacity, Qm was determined to be 21.4 mg/g. The suitability of the Langmuir isotherm model onto biochar was established by the high correlation coefficient, R2 that was higher than 0.97.


Assuntos
Ecossistema , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , China , Concentração de Íons de Hidrogênio , Cinética , Corantes de Rosanilina
16.
Int J Biol Macromol ; 193(Pt B): 1623-1634, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34742836

RESUMO

The holo form of Cytochrome-C which is involved in the electron transfer chain of aerobic and anaerobic respiration remains structurally intact by its complex with heme. However, when a prolonged thermal and pH stress was applied, heme was found to abruptly dissociate from the holo protein, resulting in complete collapse of the three-dimensional functional structure. Interestingly, two distinct structures were formed as the consequence of the dissociation event: (i) A macromolecular amyloid-network formed by the collapsed protein fragments, generated by self-oxidation, and (ii) Fe-containing Quantum-Dots (FeQDs) with 2-3 nm diameter formed by heme reorganization. Further adding to intrigue, the FeQDs were re-adsorbed on the surface of the amyloid network leading to FeQD-decorated macromolecular amyloid matrix. The heme-interactant Met80, constituting the amyloidogenic region, initiates the amylogenic cascade, and gradual exposure of Trp59 synergistically emit intrinsic fluorescence alongside FeQDs. The development of the aforementioned events were probed through a multitude of biophysical, chemical and computational analyses like ThT/ANS/intrinsic fluorescence assays, CD-spectroscopy, FETEM/STEM/elemental mapping, Foldamyloid/Foldunfold/Isunstruct/H-protection/LIGplot analyses, etc. The FeQD-decorated amyloid-network was found to exhibit gel-like property, which supported the growth of BHK-21 fibroblast without cytotoxicity. Further studies on FeQD-decorated Cytochrome C amyloid network might open possibilities to design advanced biomaterial for diverse biological applications.


Assuntos
Citocromos c/química , Amiloide/química , Dicroísmo Circular/métodos , Heme/química , Concentração de Íons de Hidrogênio , Oxirredução , Dobramento de Proteína , Teoria Quântica
17.
Int J Biol Macromol ; 191: 521-530, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34560151

RESUMO

Exploration of biodegradable materials for conventional application has taken a rising interest across the world. The presented work primarily focused on exploring the effectiveness of isolated CNCs from marine de-oiled green algae biomass residue (Dunaliella tertiolecta) in synthesized poly(ɛ-caprolactone) (PCL). The washed algae biomass residue (WABR) and algae derived CNCs were explored as two different bio-fillers incorporated into PCL for comparison and development of biodegradable and flexible bio-composites with varying bio-filler loading. FTIR, XRD, TGA, UTM, DSC, POM, and SAXS characterized the developed PCL/WABR and PCL/CNC bio-composites. Improved thermal stability was observed in PCL/CNC bio-composites by ~10 °C rise. Besides, increased modulus of 18.38 MPa and tensile strength was obtained in PCL/CNC/1 bio-composites. However, the isothermal kinetics study (at 45 °C) revealed the reduction in the degree of crystallinity of bio-composites, and the axialite formation was visualized via POM. Moreover, CNCs was found as an excellent nucleating agent and effective bio-filler as compared to WABR.


Assuntos
Celulose/química , Microalgas/química , Nanocompostos/química , Nanopartículas/química , Poliésteres/química , Resistência à Tração
18.
Bioresour Technol ; 337: 125478, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34320758

RESUMO

In this work, an effort has been made to develop an integrated system (ozonation followed by biodegradation) for the treatment of Acid orange 7 (AO 7) dye. The process parameters such as pH (3.0-11) and ozone dosage (5-25 mg/L) were optimized and obtained as 3.0 and 25 mg/L, respectively to treat the AO 7 by ozonation. Similarly, the process parameters, namely pH (5.0-9.0) and temperature (25-45 °C) were optimized and found to be 7.0 and 35 °C, respectively by biological treatment. Bacillus sp. was found to be the most effective bacteria to remove the AO 7. An integrated system obtained an overall 98.7% removal of AO 7 under optimum conditions. Andrews-Haldane model was best to predict the experimental data and the bio-kinetic constants; µmax: 0.1875 day-1; Ks: 49.53 mg/L; Ki: 133.32 mg/L were obtained. The developed integrated system can be a promising option for the treatment of azo dye containing-wastewaters.


Assuntos
Ozônio , Águas Residuárias , Compostos Azo , Benzenossulfonatos , Biodegradação Ambiental , Corantes
19.
Int J Biol Macromol ; 184: 936-945, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34153361

RESUMO

The developed edible coating with curcumin facilitated iron functionalized cellulose nanofiber (f-CNF) reinforced chitosan (CS) were applied on kiwifruits for maintaining the quality during storage life. The f-CNF was fabricated via anchoring iron particles onto the surface of CNF as evident by FESEM, FETEM, and XRD analysis. The inclusion of f-CNF and curcumin as a component of edible coating can provide a synergistic effect in maintaining the quality of kiwifruits. The f-CNF (1.5 wt%) dispersed CS edible coating assisted by curcumin provided a lamellar and heterogonous surface morphology with a hazy appearance. The used edible coating materials were effective in reducing mass loss, firmness loss, respiration rate, and microbial count of the kiwifruits during storage life (10 days at 10 °C). Additionally, color, and physiological properties of kiwifruits can be modified by using the addressed edible coating materials.


Assuntos
Actinidia/química , Celulose/química , Quitosana/química , Curcumina/química , Filmes Comestíveis , Conservação de Alimentos , Armazenamento de Alimentos , Nanofibras , Difração de Raios X
20.
Food Chem ; 360: 130048, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34034054

RESUMO

This paper demonstrates the fabrication of silk nanodisc (SND) dispersed chitosan (CS) based new edible coating as a candidate for superior thermal, hydrophobic, optical, mechanical, and physicochemical properties, which further provide remarkable storage quality for banana fruits. Fabrication of SND is attained following acid hydrolysis of silk fibroin (SF), where the successful nanostructures formulations are analyzed by FESEM, FETEM and XRD analysis delivering disc shaped morphology with amplified crystallinity (~95.0%). The SF has been fabricated from waste muga cocoons using the degumming process. The superior thermal stability of SND compared to SF portray a new era in required heat resistant packaging. The effectiveness of SND is investigated on packaging properties of CS biocomposites including thermal, wettability, mechanical, color, surface morphology, and others. Wettability of SND incorporated CS biocomposite enhanced by ~ 10° suggesting improved hydrophobicity. The edible coatings are a new candidate to improve the shelf life of bananas over 7 days at 25 °C for prevailing original weight, optical property, firmness, and others.


Assuntos
Quitosana , Filmes Comestíveis , Conservação de Alimentos/métodos , Frutas , Nanocompostos/química , Seda , Fibroínas , Interações Hidrofóbicas e Hidrofílicas , Musa
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