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Cited by 358Advanced Cellulose Research StudiesPolysaccharides and Plant Cell WallsNatural Fiber Reinforced Composites

Cellulose nanofibers produced from banana peel by chemical and enzymatic treatment

Open access
Tibolla, Heloisa, Pelissari, Franciele Maria, Menegalli, Florencia Cecilia·2014·LWT - Food Science and Technology
DOI 10.1016/j.lwt.2014.04.011
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Abstract

Cellulose nanofibers were isolated from banana peel bran using chemical treatment (CT—alkaline treatment, bleaching, and acid hydrolysis) and enzymatic treatment (ET—alkaline treatment and hydrolysis with xylanase). Both bran and cellulose nanofibers were characterized by size distribution, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR); the morphological features of the bran and the nanostructures were studied by scanning (SEM) and transmission electron microscopy (TEM), respectively. TEM analysis evidenced that both treatments effectively isolated banana fibers in the nanometer scale. Nanofibers originating from CT and ET had an average diameter of 10.9 and 7.6 nm and a length of 454.9 and 2889.7 nm, respectively. The aspect ratio of all the samples lay in the range of long fibers. In neutral water, the nanofiber suspensions exhibited high and negative zeta potential, which prevented the nanofibers from aggregating and yielded a more stable colloidal suspension. XRD studies revealed that CT afforded more crystalline cellulose nanofibers (58.6%) as compared with ET (49.2%). FTIR confirmed that the treatments removed most of the hemicelluloses and lignin present in the banana fibers. Nanoparticles isolated from the banana peel by both treatments have potential application as reinforcing elements in composites.

AI snapshot

Written from the paper’s full text.

TL;DR

Cellulose nanofibers were isolated from banana peel bran using chemical treatment (alkaline treatment, bleaching, acid hydrolysis) and enzymatic treatment (alkaline treatment, xylanase hydrolysis). Both treatments produced nanoscale fibers, but enzymatic treatment gave longer, higher-aspect-ratio, more stable suspensions, while chemical treatment gave more crystalline nanofibers.

Key findings

  • Both treatments effectively isolated banana fibers in the nanometer scale: CT nanofibers had average diameter 10.9 ± 2.3 nm, length 454.9 ± 6.6 nm, aspect ratio 42.7 ± 7.5, and zeta potential −16.1 ± 0.7 mV; ET nanofibers had diameter 7.6 ± 1.5 nm, length 2889.7 ± 214.3 nm, aspect ratio 353.9 ± 28.2, and zeta potential −25.7 ± 0.6 mV.
  • XRD crystallinity index was 15.0% for bran, 58.6% for CT-treated CNFs, and 49.2% for ET-treated CNFs; bran crystallinity improved by 300% after CT and 200% after ET.
  • ET furnished twice as high yield (10%) as CT (5.1%); nanofiber suspension concentrations were 0.54 and 0.57 g/100 g for CT and ET, respectively.
  • FTIR confirmed that treatments removed most hemicelluloses and lignin, but ET did not remove lignin completely, leaving residual lignin and bundles/impurities; CT was more aggressive and removed amorphous components more effectively.

Methods

  • Bran was prepared from the peel of unripe plantain bananas of the variety “Terra” (*Musa paradisiaca*) from southeastern Brazil, harvested in March 2013; peels were dried, milled, washed with ethanol, and sieved through a 200-mesh sieve.
  • CT used 5% w/v KOH, 1% w/v NaClO₂ bleaching at pH 5.0 and 70 °C, a second KOH treatment, and 1% v/v H₂SO₄ hydrolysis at 80 °C for 1 h; ET used 5% w/v KOH delignification followed by xylanase (50 U/g bran) in acetate buffer pH 5.0 at 45 °C for 24 h, then enzyme denaturation at 80 °C for 30 min.
  • Characterization included SEM, TEM, laser diffraction particle size, zeta potential, XRD crystallinity index, and FTIR; ANOVA and Tukey tests were run at 5% significance.

Limitations

  • The paper states that a future study will investigate the potential reinforcement that nanofibers from both treatments promote in composites; no composite mechanical testing was performed here.
  • The paper states that the samples were compared without the mechanical treatment step, even though a previous study found seven passages through a high-pressure homogenizer most suitable, because the objective was to isolate the effect of chemical versus enzymatic treatment.
  • The paper states that ET did not remove lignin completely and that ET nanofibers contained residual bundles/impurities; CT was more aggressive, produced shorter nanofibers, and had lower zeta potential, making those CNFs more likely to aggregate.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.lwt.2014.04.011

Cites

51 of 51 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 61 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    The aspect ratio of all the nanofiber samples lay in the range of long fibers.

    “The aspect ratio of all the samples lay in the range of long fibers.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Cellulose nanofibers obtained by enzymatic treatment had an average diameter of 7.6 nm.

    “Nanofibers originating from CT and ET had an average diameter of 10.9 and 7.6 nm and a length of 454.9 and 2889.7 nm, respectively.”
    • Also stated in: § 3.3. Scanning (SEM) and transmission electron microscopy (TEM) · plain
      “the CNFs obtained by CT and ET had diameters of 10.9 and 7.6 nm, respectively”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The TEM images processed for diameter measurement are representative of the nanofiber population.
  • Findingown data

    FTIR confirmed that the treatments removed most of the hemicelluloses and lignin present in the banana fibers.

    “FTIR confirmed that the treatments removed most of the hemicelluloses and lignin present in the banana fibers.”
    Quote in the paperSubstantial claim
  • Findingown data

    XRD studies revealed that chemical treatment afforded more crystalline cellulose nanofibers (58.6%) as compared with enzymatic treatment (49.2%).

    “XRD studies revealed that CT afforded more crystalline cellulose nanofibers (58.6%) as compared with ET (49.2%).”
    Quote in the paperSubstantial claim
  • Findingown data

    Both chemical and enzymatic treatments effectively isolated banana fibers in the nanometer scale.

    “TEM analysis evidenced that both treatments effectively isolated banana fibers in the nanometer scale.”
    • Also stated in: § 3.3. Scanning (SEM) and transmission electron microscopy (TEM) · plain
      “In general, the CNFs obtained by CT and ET had diameters of 10.9 and 7.6 nm, respectively, showing that both treatments effectively isolated banana fibers in the nanometer scale (Table 1).”
    Quote in the paperSubstantial claim
  • May combine two claims. 46
  • Classified as probably not a substantial claim. 23
  • The quote only partly states this claim. 2

  • May combine two claims.

    Findingown data

    Cellulose nanofibers were isolated from banana peel bran using chemical treatment (alkaline treatment, bleaching, and acid hydrolysis) and enzymatic treatment (alkaline treatment and hydrolysis with xylanase).

    “Cellulose nanofibers were isolated from banana peel bran using chemical treatment (CTdalkaline treatment, bleaching, and acid hydrolysis) and enzymatic treatment (ETdalkaline treatment and hydrolysis with xylanase).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    The peak at 3337 cm-1 corresponded to OH stretching and was related to specific intramolecular hydrogen bonds of cellulose II.

    “The peak at 3337 cm À1 corresponded to eOH stretching; this band was related to specific intramolecular hydrogen bonds of cellulose II (Yang, Yan, Chen, Lee, & Zheng, 2007;Zuluaga et al., 2009).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Yang, Yan, Chen, Lee, & Zheng, 2007;Zuluaga et al., 2009

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Findingown data

    The crystallinity index (Icr) was 15.0% for the bran, 58.6% for CT-treated CNFs, and 49.2% for ET-treated CNFs.

    “The crystallinity index (I cr ) of the samples (calculated by Eq. ( 1)) was 15.0, 58.6, and 49.2% for the bran, CT-treated CNFs, and ETtreated CNFs, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    ET yielded longer nanofibers and a higher aspect ratio than CT.

    “ET yielded longer nanofibers and higher aspect ratio, and the values lay in the range that made them potentially useful as reinforcing agents in composites.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    The bran sample crystallinity improved by 300% after CT and by 200% after ET.

    “The bran sample crystallinity improved by 300 and 200% after CT and ET, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Both prepared nanofibers presented a larger crystalline region as compared with the initial banana fibers, and their diffraction patterns were similar.

    “Both the prepared nanofibers presented larger crystalline region as compared with the initial banana fibers, and their diffraction patterns were similar.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The light yellowish pulp became lighter, but not totally white, so the enzymatic process did not remove the lignin fractions completely.

    “The light yellowish pulp became lighter, but not totally white (Fig. 1b), so the process did not remove the lignin fractions completely.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The treatments changed the fibers structurally and chemically; the fibers underwent morphological alterations along all the treatment steps.

    “The treatments changed the fibers structurally and chemically; the fibers underwent morphological alterations along all the treatment steps.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    A white material emerged at the end of the acid hydrolysis.

    “A white material emerged at the end of the acid hydrolysis (Fig. 1a).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    CT-treated cellulose nanofibers had a diameter of 10.9 nm and a length of 454.9 nm.

    “Nanofibers isolated from the banana peel had diameters and lengths of 10.9 and 454.9 nm (CT) and 7.6 and 2889.7 nm (ET), respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Both the bran and the cellulose nanofibers obtained by CT exhibited modal distribution.

    “Both the bran and the CNFs obtained by CT exhibited modal distribution.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The chemical composition of banana fibers, on dry basis, was 9.6% total extractives, 0.01% ash, 7.5% cellulose, 7.9% lignin, and 74.9% polysaccharides including hemicelluloses.

    “The chemical composition of banana fibers, on dry basis, was as follows: 9.6% of total extractives, 0.01% of ash, 7.5% of cellulose, 7.9% of lignin, and 74.9% of polysaccharides including hemicelluloses.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    ET-treated cellulose nanofibers had a diameter of 7.6 nm and a length of 2889.7 nm.

    “Nanofibers isolated from the banana peel had diameters and lengths of 10.9 and 454.9 nm (CT) and 7.6 and 2889.7 nm (ET), respectively.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingreasoning

    The alkaline treatment changed the initial brown color of the material to light yellowish brown.

    “The alkaline treatment (first step) was accomplished during both CT and ET, which changed the initial brown color (color in the web version) of the material (many cellulosic pulps appear to be darker when they are in suspension with alkaline solution) to light yellowish brown (color in the web version), due to phenolic groups ionization.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    SEM micrographs of the banana peel bran revealed irregular structure and some residues from the grinding procedure; they also evidenced starch granules resulting from the contact of the banana peel with the pulp.

    “The SEM micrographs of the banana peel bran revealed irregular structure and some residues from the grinding procedure; they also evidenced starch granules (see arrows in Fig. 2) resulting from the contact of the banana peel with the pulp.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The banana peel bran had an average diameter of 24.5 mm.

    “The bran had an average diameter of 24.5 mm.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    The shoulder at 1731 cm-1 in the spectrum of the bran corresponded to vibrations of the acetyl and uronic ester groups of hemicelluloses or to the ester linkage of carboxylic group of the ferulic and p-coumaric acids of lignin.

    “The shoulder at 1731 cm À1 in the spectrum of the bran corresponded to vibrations of the acetyl and uronic ester groups of hemicelluloses or to the ester linkage of carboxylic group of the ferulic and p-coumaric acids of lignin (Cherian et al., 2008).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Cherian et al., 2008 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    TEM images suggested gradual removal of amorphous components such as hemicelluloses, lignin, and pectin; they also showed that a cellulose portion remained after chemical and enzymatic treatment.

    “The images suggested gradual removal of amorphous components such as hemicelluloses, lignin, and pectin; they also showed that a cellulose portion remained after CT and ET.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    The bran contained a large amorphous portion, and its typical B-type pattern peak at 2θ=17 evidenced the presence of starch.

    “The bran contained a large amorphous portion; the typical Btype pattern peak at 2q ¼ 17 evidenced the presence of starch (Pirani & Hashaikeh, 2013).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Pirani & Hashaikeh, 2013

      Not checked in the free run.

  • May combine two claims.

    Findingcitation

    The sharp diffraction peaks at 2θ=16 and 2θ=22 were typical of cellulose I and indicated higher crystallinity of the nanofibers as compared with the initial fibers.

    “The sharp diffraction peaks at 2q ¼ 16 and 2q ¼ 22 were typical of cellulose I and indicated the higher crystallinity of the nanofibers as compared with the initial fibers (Rosa et al., 2010).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Rosa et al., 2010 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    The treatments affected the dimensions and the surface charge of the resulting nanoparticles.

    “The treatments affected the dimensions and the surface charge of the resulting nanoparticles.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    FTIR spectra of the cellulose nanofibers confirmed this finding.

    “FTIR spectra of the cellulose nanofibers confirmed this finding.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    The chemically treated banana fibers had 300% larger crystallinity as compared with the 200% higher crystallinity of the enzymatically treated samples.

    “On the other hand, the chemically treated banana fibers had 300% larger crystallinity as compared with the 200% higher crystallinity of the enzymatically treated samples.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The enzymatic treatment furnished longer nanofibers with higher aspect ratio and a more stable suspension with higher zeta potential than the chemical treatment.

    “The milder method used enzymes and furnished longer nanofibers with higher aspect ratio; nanofibers obtained by this method culminated in a more stable suspension, with higher zeta potential than the nanofibers obtained by chemical treatment.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The performance of cellulose nanofibers as reinforcing agents is associated with surface charge (zeta potential).

  • May combine two claims.

    Findingcitation

    The bleaching (CT) and alkaline treatment (ET) steps removed most of the lignin from the CNFs, as evidenced by the disappearance of bands at 1525 cm-1 and 761 cm-1 after these pretreatments.

    “Fig. 6 evidences that the bleaching (CT) and alkaline treatment (ET) steps removed most of the lignin from the CNFs: the bands at 1525 cm À1 (aromatic ring vibration) and 761 cm À1 (CeH strains) disappeared after these pretreatments (Zuluaga et al., 2009).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Zuluaga et al., 2009 source

      Not checked in the free run.

  • May combine two claims.

    Findingcitation

    The shoulder at 1635 cm-1 in the spectrum of the CT-treated CNFs was associated with adsorbed water; it could also reveal that conjugated carbonyl groups either existed in the polyphenolic structure of lignin or resulted from carbohydrate oxidation.

    “The shoulder that appeared in the spectrum of the CT-treated CNFs at 1635 cm À1 was associated with adsorbed water; it could also reveal that conjugated carbonyl groups either existed in the polyphenolic structure of lignin or resulted from carbohydrate oxidation (Hassan et al., 2010).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hassan et al., 2010

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Acid hydrolysis is corrosive, modifies the cellulose surface, and produces chemical waste.

    “However, acid hydrolysis is corrosive, modifies the cellulose surface, and produces chemical waste (Satyamurthy et al., 2011).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Satyamurthy et al., 2011 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Sulfuric acid is usually the reagent of choice because it efficiently cleaves the glycosidic bonds between cellulose chains and prevents cellulose nanofibers from agglomerating, generating stable colloidal suspensions.

    “Sulfuric acid is usually the reagent of choice: it efficiently cleaves the glycosidic bonds existing between the cellulose chains and prevents the CNFs from agglomerating, to generate stable colloidal suspensions (Pirani & Hashaikeh, 2013).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Pirani & Hashaikeh, 2013

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Isolation of cellulose nanoparticles usually involves three steps: pretreatment of raw materials, partial hydrolysis, and mechanical disintegration.

    “Although various methods yield cellulose nanoparticles, their isolation usually involves three steps: (1) pretreatment of raw materials, (2) partial hydrolysis, and (3) mechanical disintegration (Sun, 2004).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Sun, 2004

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The efficiency of these processes depends on the treatment conditions, the nature of the raw material, and the properties of the hydrolytic agent.

    “The efficiency of these processes depends on the treatment conditions, the nature of the raw material, and the properties of the hydrolytic agent (Sukumaran, Singhania, Mathew, & Pandey, 2009).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Sukumaran, Singhania, Mathew, & Pandey, 2009

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Enzymatic hydrolysis constitutes an environmentally friendly process that can potentially reduce operational costs and improve efficiency.

    “Because it does not involve solvents or chemical reagents, enzymatic hydrolysis constitutes an environmentally friendly process that can potentially reduce operational costs and improve efficiency (Meyabadi & Dadashian, 2012;Siqueira, Bras, & Dufresne, 2010a;Yu, Lou, & Wu, 2008).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Meyabadi & Dadashian, 2012

      Not checked in the free run.

    • cites Siqueira, Bras, & Dufresne, 2010a

      Not checked in the free run.

    • cites Yu, Lou, & Wu, 2008

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Xylanases are hydrolytic enzymes that modify the random amorphous compounds (hemicelluloses) present in the plant fiber.

    “Xylanases are hydrolytic enzymes that modify the random amorphous compounds (hemicelluloses) present in the plant fiber.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Hubbe, Rojas, Lucia, & Sain, 2008

      Not checked in the free run.

    • cites Pääkko et al., 2007 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Plant fibers are rich sources of cellulose, the main component of plant cell walls.

    “plant fibers, which are among the existing natural fibers, are an attractive materialdthey constitute rich sources of cellulose, the main component of plant cell walls (Lavoine, Desloges, Dufresne, & Bras, 2012).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lavoine, Desloges, Dufresne, & Bras, 2012

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Process conditions that lead to nanometric dimensions affect the morphological characteristics of the nanoparticles, thereby influencing how they perform as reinforcement material in composites.

    “The process conditions that lead to nanometric dimensions affect the morphological characteristics of the nanoparticles, thereby influencing how they perform as reinforcement material in composites (Rosa et al., 2010).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Rosa et al., 2010 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The high negative zeta potential prevented the nanofibers from aggregating and yielded a more stable colloidal suspension.

    “In neutral water, the nanofiber suspensions exhibited high and negative zeta potential, which prevented the nanofibers from aggregating and yielded a more stable colloidal suspension.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Acid hydrolysis and enzymatic hydrolysis are the most commonly employed methods for cellulose nanoparticle isolation.

    “Acid hydrolysis (Lu & Hsieh, 2012;Tonoli et al., 2012;Zuluaga et al., 2009) and enzymatic hydrolysis (George, Ramana, Bawa, & Siddaramaiah, 2011;Hassan, Mathew, Hassan, & Oksman, 2010;Pääkko et al., 2007;Satyamurthy, Jain, Balasubramanya, & Vigneshwaran, 2011;Woehl et al., 2010) are the most commonly employed methods.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Lu & Hsieh, 2012

      Not checked in the free run.

    • cites Tonoli et al., 2012 source

      Not checked in the free run.

    • cites Zuluaga et al., 2009 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Cellulose nanofibers are mechanically strong, stiff, and highly crystalline.

    “Cellulose nanofibers (CNFs) offer many advantages: they are mechanically strong, stiff, and highly crystalline, so they find wide applications in the biomedical (Cherian et al., 2008), pharmaceutical (Villanova et al., 2011), and especially the paper industries (Sehaqui, Allais, Zhou, & Berglund, 2011); they can also function as reinforcing agents in polymer matrixes (Lee, Teramoto, & Endo, 2011;S”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Cherian et al., 2008 source

      Not checked in the free run.

    • cites Villanova et al., 2011 source

      Not checked in the free run.

    • cites Sehaqui, Allais, Zhou, & Berglund, 2011

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The enzymatic hydrolysis of cellulose nanofibers has to be fast, to avoid complete cellulose degradation.

    “The enzymatic hydrolysis of CNFs has to be fast, to avoid complete cellulose degradation (Zhu, Sabo, & Luo, 2011).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Zhu, Sabo, & Luo, 2011

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Cellulose nanofibers can function as reinforcing agents in polymer matrixes.

    “they can also function as reinforcing agents in polymer matrixes (Lee, Teramoto, & Endo, 2011;Soykeabkaew, Laosat, Ngaokla, Yodsuwan, & Tunkasiri, 2012).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Lee, Teramoto, & Endo, 2011

      Not checked in the free run.

    • cites Soykeabkaew, Laosat, Ngaokla, Yodsuwan, & Tunkasiri, 2012

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Xylanases can initiate the random hydrolysis of the b-1,4 non-reducing terminal regions located between the glycosidic linkages of the glucose units.

    “They can also initiate the random hydrolysis of the b-1,4 non-reducing terminal regions located between the glycosidic linkages of the glucose units (Hubbe, Rojas, Lucia, & Sain, 2008;Pääkko et al., 2007).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Hubbe, Rojas, Lucia, & Sain, 2008

      Not checked in the free run.

    • cites Pääkko et al., 2007 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    It is more appropriate to use the unripe banana peel instead of the ripe fruit because the enzymatic synthesis of the fruit itself occurs during maturation, partially degrading cellulose to monosaccharides.

    “It is more appropriate to use the unripe banana peel instead of the ripe fruit.This is because the enzymatic synthesis of the fruit itself occurs during maturation, and thus, to partially degrade cellulose to monosaccharides (Happi Emaga, Robert, Ronkart, Wathelet, & Paquot, 2008).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Happi Emaga, Robert, Ronkart, Wathelet, & Paquot, 2008 source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Nanosized particles should have high zeta potential so that the colloidal suspension can resist aggregation, to increase its degree of dispersion in the composite.

    “According to Tholstrup Sejersen et al. (2007), nanosized particles should have high zeta potential, so that the colloidal suspension can resist aggregation, to increase its degree of dispersion in the composite.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Tholstrup Sejersen et al. (2007) source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Higher electrostatic repulsion existed between the fibers in the ET case, providing enough surface charges to stabilize the suspension.

    “Higher electrostatic repulsion existed between the fibers in this case, providing enough surface charges to stabilize the suspension.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The performance of cellulose nanofibers as reinforcing agents is associated with surface charge (zeta potential).

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    According to previous results, the most suitable mechanical treatment condition to prepare cellulose nanofibers was to accomplish seven passages through the high-pressure homogenizer.

    “A previous work by our research group (Pelissari et al., 2014) evaluated how the number of passages (0, 3, 5, and 7 times) affected the structure of the nanofibers.According to these previous results, the most suitable mechanical treatment condition to prepare CNFs was to accomplish seven passages through the high-pressure homogenizer.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Pelissari et al., 2014 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Hydrolysis with sulfuric acid elicited electrostatic repulsion between nanofibers in suspension and introduced natural sulfate groups into the nanofiber surface.

    “Bondeson and Oksman (2007) reported that hydrolysis with sulfuric acid elicited electrostatic repulsion between nanofibers in suspension, and that this process introduced natural sulfate groups into the nanofiber surface.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Bondeson and Oksman (2007)

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The alkaline treatment probably was not efficient enough to totally remove lignin; the remaining lignin may have formed a barrier around hemicelluloses and cellulose.

    “Probably, the alkaline treatment probably was not efficient enough to totally remove lignin; the remaining lignin may have formed a barrier around hemicelluloses and cellulose.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    During bleaching, chlorine and chlorites rapidly oxidized lignin, generating hydroxyl, carbonyl, and carboxylic groups; these groups facilitated lignin solubilization in alkaline medium and hence cellulose purification.

    “During bleaching, chlorine and chlorites rapidly oxidized lignin, generating hydroxyl, carbonyl, and carboxylic groups; these groups facilitated lignin solubilization in alkaline medium and hence cellulose purification (Dufresne, Cavail ̀lé, & Vignon, 1997).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Dufresne, Cavail ̀lé, & Vignon, 1997

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The enzyme xylanase had difficulty in solubilizing hemicelluloses, so it was not able to penetrate the cellulose chains, which made cellulose hydrolysis difficult.

    “In other words, the enzyme xylanase had difficulty in solubilizing hemicelluloses, so it was not able to penetrate the cellulose chains, which made cellulose hydrolysis difficult.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    CT gave rise to less resistant cellulose nanofibers, probably as a result of the shorter length of the nanoparticles.

    “Hassan, Hassan, and Oksman (2011) described that CT gave rise to less resistant CNFs, probably as a result of the shorter length of the nanoparticles.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hassan, Hassan, and Oksman (2011)

      Not checked in the free run.

  • The quote only partly states this claim.

    Interpretationown data

    The aspect ratio values of cellulose nanofibers obtained by CT and ET lay in the range that made them potentially useful as reinforcing agents in composites.

    “ET yielded longer nanofibers and higher aspect ratio, and the values lay in the range that made them potentially useful as reinforcing agents in composites.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    High aspect ratio should favor tension transfer in the nanofiber-matrix interface.

    “George et al. (2011) stated that high aspect ratio should favor tension transfer in the nanofiberematrix interface.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites George et al. (2011) source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The bands relative to cellulose were more intense in the spectra of the treated samples, because lignin removal augmented their crystalline content.

    “The bands relative to cellulose were more intense in the spectra of the treated samples, because lignin removal augmented their crystalline content.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    CT was more aggressive than ET, degrading amorphous zones and partly destroying the crystalline zones of the fibers, to furnish shorter nanofibers.

    “This meant that CT was more aggressivedit degraded amorphous zones and partly destroyed the crystalline zones of the fibers, to furnish shorter nanofibers.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Sun, Xu, Sun, Xiao, and Sun (2005) reported that chemical treatment effectively delignified cellulose and solubilized hemicelluloses in barley straw.

    “Indeed, Sun, Xu, Sun, Xiao, and Sun (2005) reported that CT effectively delignified cellulose and solubilized hemicelluloses in the barley straw.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Sun, Xu, Sun, Xiao, and Sun (2005)

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Enzymatic treatment did not remove these amorphous components as effectively as chemical treatment, which generated a barrier of cementing materials around the fiber bundles and hindered enzyme penetration into the cellulose chains.

    “ET did not remove these amorphous components as effectively as CT, which generated a barrier of cementing materials around the fiber bundles and hindered enzyme penetration into the cellulose chains.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Compared with enzymatic treatment, chemical treatment involved more steps and was more aggressive, promoting greater removal of the amorphous components.

    “Compared with ET, CT involved more steps and was more aggressive, promoting greater removal of the amorphous components.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Cellulose nanofiber isolation involved either acid or enzymatic hydrolysis, and these steps removed amorphous cellulosic domains.

    “CNFs isolation involved either acid or enzymatic hydrolysis, and these steps removed amorphous cellulosic domains (Siqueira et al., 2010a).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Siqueira et al., 2010a

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Incomplete hemicelluloses and lignin removal during treatment and interfibrillar hydrogen bonds formation accounted for the residual nanofiber bundles.

    “On the basis of the study by Pelissari et al. (2014), incomplete hemicelluloses and lignin removal during treatment and interfibrillar hydrogen bonds formation accounted for the residual nanofiber bundles.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Pelissari et al. (2014) source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Nanofibers of mulberry branch barks obtained by CT had an Icr of 58.8%, similar to that found for the CT-treated nanofibers herein.

    “Nanofibers of mulberry branch barks obtained by CT had I cr of 58.8% (Li et al., 2009), similar to that found for the CT-treated nanofibers herein.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Li et al., 2009

      Not checked in the free run.

  • The quote only partly states this claim.

    Interpretationcitation

    The diameters of cellulose nanofibers obtained by chemical and enzymatic treatment were similar to those of nanosized structures derived from other chemically treated sources (rice straw 12-35 nm, sugarcane bagasse 30 nm, sugar beet 30-100 nm) and enzymatically treated sources (bleached kraft bagasse pulp 9-25 nm, bleached soft wood 5-6 nm, cotton lint 30-50 nm).

    “These diameters were similar to those of nanosized structures derived from other chemically treated sourcesdrice straw (12e35 nm) (Abe & Yano, 2009), sugarcane bagasse (30 nm) (Bhattacharya, Germinario, & Winter, 2008), and sugar beet (30e100 nm) (Leitner, Hinterstoisser, Wastyn, Keckes, & Gindl, 2007)dand enzymatically treated sourcesdbleached kraft bagasse pulp (9e 25 nm) (Hassan et al., 2010),”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Abe & Yano, 2009

      Not checked in the free run.

    • cites Bhattacharya, Germinario, & Winter, 2008

      Not checked in the free run.

    • cites Leitner, Hinterstoisser, Wastyn, Keckes, & Gindl, 2007 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Bagasse pulp nanofibers obtained by ET gave much higher Icr (73.9%) as compared with the ET-treated CNFs achieved in this study.

    “In contrast, bagasse pulp nanofibers obtained by ET gave much higher I cr (73.9%) (Hassan et al., 2010) as compared with the ET-treated CNFs achieved in this study.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hassan et al., 2010

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Removal of hemicelluloses and lignin fractions extensively altered the structure of natural fibers, increasing the crystal surface area and the accessibility of the hydrolytic agent to the cellulose.

    “Mussatto, Fernandes, Milagres, and Roberto (2008) stated that removal of hemicelluloses and lignin fractions extensively altered the structure of natural fibers, increasing the crystal surface area and the accessibility of the hydrolytic agent to the cellulose.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Mussatto, Fernandes, Milagres, and Roberto (2008)

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The chemical method removed amorphous components more effectively and enhanced the crystalline content in the sample.

    “Hence, the chemical method removed amorphous components more effectively and enhanced the crystalline content in the sample.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The ET-treated CNFs presented a peak at 1574 cm-1, which attested that the sample contained lignin residues; i.e., ET did not remove lignin completely.

    “Nevertheless, the ET-treated CNFs presented a peak in this region, at 1574 cm À1 , which attested that the sample contained lignin residues; i.e., ET did not remove lignin completely.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Both CT and ET effectively removed the amorphous components from the structure of the bran and permitted CNFs isolation.

    “These results allowed to state that both CT and ET effectively removed the amorphous components from the structure of the bran and permitted CNFs isolation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Both treatments successfully isolated cellulose nanofibers from the banana peel, encouraging the use of this agroindustrial residue as a renewable source of nanofibers.

    “Finally, both treatments successfully isolated cellulose nanofibers from the banana peel, encouraging the use of this agroindustrial residue as a renewable source of nanofibers.”
    Quote in the paperSubstantial claim
66 of 66

  • The paper relies on this without support.

    Enzymatic treatment allows for milder hydrolysis conditions compared with acid hydrolysis.

    “Enzymatic treatment has gained prominence and is developing rapidly: it allows for milder hydrolysis conditions as compared with acid hydrolysis.”

  • The paper relies on this without support.

    The omission of mechanical treatment does not prevent a valid comparison of the chemical and enzymatic treatments.

    “However, because the main objective of this study was to determine how the chemical and enzymatic treatments affected the CNFs isolation, we decided to compare the samples without the mechanical treatment step.”

  • The paper relies on this without support.

    The TEM images processed for diameter measurement are representative of the nanofiber population.

    “To determine the diameters of the fibers, the TEM images were processed using processing analysis software (ImageJ).”

  • The paper relies on this without support.

    The performance of cellulose nanofibers as reinforcing agents is associated with surface charge (zeta potential).

    “The performance of the nanofiber as reinforcing agent is also associated with other features such as surface charge (zeta potential).”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • This is a way to utilize unripe fruit in Brazil, which are discarded as waste.

    “This is a way to utilize unripe fruit in Brazil, which are discarded as waste [137].”

    From Potential Valorization of Banana Production Waste in Developing Countries: Bio-Engineering Aspects (2024) · cites this paper as [137]

    The Materials section says the study used peels from unripe bananas obtained in southeastern Brazil. The Introduction describes banana peel as an agroindustrial residue the study sought to use. It does not say that unripe fruit itself is discarded as waste in Brazil. (LLM, conf=0.87)

    Experimental — accuracy not yet measured

  • Tibolla et al. introduced a composite made with cellulose nanofibers from discarded banana peels; diameter and length were 10.9 nm and 454.9 nm for the chemical process and 7.6 nm and 2889.7 nm for the enzymatic process.

    “Tibolla et al. [137] introduced a composite made with cellulose nanofibers from discarded banana peels. The diameter and length were 10.9 nm and 454.9 nm for the chemical process and 7.6 nm and 2889.7 nm for the enzymatic process, respectively.”

    From Potential Valorization of Banana Production Waste in Developing Countries: Bio-Engineering Aspects (2024) · cites this paper as [137]

    Table 1 reports the stated average diameters and lengths for nanofibers obtained by chemical and enzymatic treatment of banana peels. But the Conclusion says the study isolated nanofibers and that their use as reinforcement in composites would be investigated in a future study; it does not report introducing a composite. (LLM, conf=0.93)

    Experimental — accuracy not yet measured

  • Unripe plantain peels may be used for nanofiber production.

    “Unripe plantain peels may be used for nanofiber production.”

    From Potential Valorization of Banana Production Waste in Developing Countries: Bio-Engineering Aspects (2024) · cites this paper as [137]

Cites

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Related

Authors
Tibolla, H., Pelissari, F. M., & Menegalli, F. C.
Affiliations
Universidade Estadual de Campinas (UNICAMP) (BR)
Corresponding author
Pelissari, Franciele Maria
ORCID
Venue
LWT - Food Science and Technology
Publisher
Elsevier BV
Published
2014-12
Volume
59
Issue
2
Pages
1311-1318
ISSN
0023-6438 (ISSN-L)
DOI
10.1016/j.lwt.2014.04.011
OpenAlex
W1997398631
Semantic Scholar
0c59345e28ecf4bf94dd89971106b8f42a2ebcfa
Cited by
358
References
52
Citations by year
2026: 19 · 2025: 27 · 2024: 36 · 2023: 34 · 2022: 44 · 2021: 39 · 2020: 42 · 2019: 38 · 2018: 28 · 2017: 24 · 2016: 17 · 2015: 10
FWCI
6.43
Type
journal article
Language
en
Open access
Licence
Locations
LWT (publishedVersion, cc-by-nc-nd)
Funders
  • Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (2952/2011)
  • Conselho Nacional de Desenvolvimento Científico e Tecnológico (477842/2011-9)
Topics
  • Physical Sciences › Materials Science › Biomaterials › Advanced Cellulose Research Studies
  • Life Sciences › Agricultural and Biological Sciences › Plant Science › Polysaccharides and Plant Cell Walls
  • Physical Sciences › Materials Science › Polymers and Plastics › Natural Fiber Reinforced Composites
Keywords
cellulose nanofibers, banana peel, alkali treatment, xylanase hydrolysis, acid hydrolysis, bleaching, hemicellulose removal, lignin removal, crystallinity, zeta potential, colloidal stability, nanofiber morphology, composite reinforcement

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-08.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-08.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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