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Human hair, composed primarily of keratin, represents a sustainable waste material suitable for various applications. Synthesizing keratin nanoparticles (KNPs) from human hair for biomedical uses is particularly attractive due to their biocompatibility. In this study, keratin was extracted from human hair using concentrated sulfuric acid as the hydrolysis agent for the first time. This process yielded KNPs in both the supernatant (KNPs-S) and precipitate (KNPs-P) phases. Characterization involved scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Zeta potential analysis, X-ray diffraction (XRD), and thermogravimetric analysis (TG). KNPs-S and KNPs-P exhibited average diameters of 72 ± 5 nm and 27 ± 5 nm, respectively. The hydrolysis process induced a structural rearrangement favoring ß-sheet structures over α-helices in the KNPs. These nanoparticles demonstrated negative Zeta potentials across the pH spectrum. KNPs-S showed higher cytotoxicity (CC50 = 176.67 µg/mL) and hemolytic activity, likely due to their smaller size compared to KNPs-P (CC50 = 246.21 µg/mL), particularly at concentrations of 500 and 1000 µg/mL. In contrast, KNPs-P did not exhibit hemolytic activity within the tested concentration range of 32.5 to 1000 µg/mL. Both KNPs demonstrated cytocompatibility with fibroblast cells in a dose-dependent manner. Compared to other methods reported in the literature and despite requiring careful washing and neutralization steps, sulfuric acid hydrolysis proved effective, rapid, and feasible for producing cytocompatible KNPs (biomaterials) in single-step synthesis.

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Currently, petroleum-derived plastics are widely used despite the disadvantage of their long degradation time. Natural polymers, however, can be used as alternatives to overcome this obstacle, particularly cornstarch. The tensile properties of cornstarch films can be improved by adding plant-derived nanofibers. Sisal (Agave sisalana), a very common low-cost species in Brazil, can be used to obtain plant nanofibers. The goal of this study was to obtain sisal nanofibers using low concentrations of sulfuric acid to produce thermoplastic starch nanocomposite films. The films were produced by a casting technique using commercial corn starch, glycerol, and sisal nanofibers, accomplished by acid hydrolysis. The effects of glycerol and sisal nanofiber content on the tensile mechanical properties of the nanocomposites were investigated. Transmission electron microscopy findings demonstrated that the lowest concentration of sulfuric acid produced fibers with nanometric dimensions related to the concentrations used. X-ray diffraction revealed that the untreated fibers and fibers subjected to acid hydrolysis exhibited a crystallinity index of 61.06 and 84.44%, respectively. When the glycerol and nanofiber contents were 28 and 1%, respectively, the tensile stress and elongation were 8.02 MPa and 3.4%. In general, nanocomposites reinforced with sisal nanofibers showed lower tensile stress and higher elongation than matrices without nanofibers did. These results were attributed to the inefficient dispersion of the nanofibers in the polymer matrix. Our findings demonstrate the potential of corn starch nanocomposite films in the packaging industry.

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Cellulose nanocrystals (CNCs) are crystalline domains isolated from cellulosic fibers. They have been utilized in a wide range of applications, such as reinforcing fillers, antibacterial agents and manufacturing of biosensors. Whitin this context, the aim of this work was to obtain and analyze CNCs extracted from bacterial nanocellulose (BNC) using two distinct methods combined with milling pre-treatment: an acidic hydrolysis using 64 % sulfuric acid and an enzymatic hydrolysis using a commercial cellulase enzyme mixture. The CNCs obtained from the enzymatic route (e-CNCs) were observed to be spherical nanoparticles with diameter of 56 ± 11 nm. In contrast, the CNCs from the acid hydrolysis (a-CNCs) appeared as needle-shaped nanoparticles with a high aspect ratio with lengths/widths of 158 ± 64 nm/11 ± 2 nm. The surface zeta potential (ZP) of the a-CNCs was -30,8 mV, whereas the e-CNCs has a potential of +2.70 ± 3.32 mV, indicating that a-CNCs consisted of negatively charged particles with higher stability in solution. Although the acidic route resulted in nanocrystals with a slightly higher crystallinity index compared to the enzymatic route, e-CNCs was found to be more thermally stable than BNC and a-CNCs. Here, we also confirmed the safety of a-CNCs and e-CNCs using L929 cell line. Lastly, this article describes two different CNCs synthesis approaches that leads to the formation of nanoparticles with different dimensions, morphology and unique physicochemical properties. To the best of our knowledge, this is the first study to yield spherical nanoparticles as a result of BNC enzymatic treatment.

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The study investigated Chenopodium berlandieri to analyze its oleanolic acid (OA) content. Response surface methodology with central composite design was used to improve saponin extraction, varying temperature, ethanol, and sample-to-solvent ratio. Best conditions (65 °C, 50% ethanol, 1:10 ratio) yielded 53.45 ± 0.63 mg/g of extract from Huauzontle seeds. Temperature linearly impacted extract yield, while temperature and ethanol influenced total saponin content. Hydrolyzing saponin-rich extracts produced OA-rich extracts. Characterization via HPLC-ELSD and LC-MS identified OA4 as the most concentrated OA saponin (5.54 ± 0.16 mg/g). OA alone reached 2.02 ± 0.12 mg/g. Acid hydrolysis increased OA content by up to 3.27×, highlighting the potential of hydrolyzed Huauzontle extracts as a natural ingredient for various industries due to enhanced OA content.

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One of the activities most representative of the agricultural sector in Colombia is the production of biodegradable fique fiber. The efficiency of the defiberization process of the fique leaves is very low since a mere 4% of the total weight of the leaf (cabuya) is used and marketed. The remaining 96%, composed of fique juice and bagasse, is considered to be waste and discarded, impacting the environment. The aim of this work was to study fique bagasse as a source of cellulose nanoparticles (CNCs). CNCs were obtained by acid hydrolysis and added at 10% to films made from cassava thermoplastic starch (TPS) by the casting method. Structural changes in the CNCs, TPS, and their mixtures were characterized by FTIR-ATR and their morphology and particle size by SEM and TEM microscopy, respectively. Thermal properties were analyzed using DSC and TGA, along with their effect on mechanical properties. Changes in the FTIR spectra indicated that the chemical method adequately removed hemicellulose and lignin from the fiber surface of fique bagasse. The CNCs showed a diameter and length of 7.5 ± 3.9 and 52.7 ± 18.1 nm, respectively, and TPS 10% CNC obtained an increase in mechanical strength of 116%. The obtainment of CNCs from lignocellulosic materials can thus be viewed as a favorable option for the subsequent reinforcement of a polymeric matrix.

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BACKGROUND: Agaves are mainly used to produce alcoholic beverages such as tequila, mezcal and bacanora. However, the leaves constitute more than 50% of the plant and are not used in the production process, so they are considered waste. This plant material can be used as a source of bioactive compounds such as terpenes, flavonoids and saponins. Therefore, the objective of this study was to characterize the aglycone type of saponins and to quantify three steroidal sapogenins in leaves of five Agave species collected in different regions of Guerrero and Oaxaca, Mexico. RESULTS: Analysis by gas chromatography-flame ionization detection of the hydrolyzed methanolic extracts showed that diosgenin and tigogenin were the most abundant sapogenins identified in the five Agave species. Differences in the content of these sapogenins were found in the same species collected in different localities. The leaves of Agave americana var. oaxacensis L. (Oaxaca) had the highest diosgenin-derived saponin content, while the leaves of A. angustifolia Haw. (Guerrero) had the highest tigogenin-derived saponin content. Only in A. cupreata was sarsasapogenin identified, all three sapogenins occurring in the leaves of this species. For the first time, information is provided on the aglycones of the saponins produced in A. potatorum Zucc. and A. karwinskii Zucc. CONCLUSION: This study made it possible to compare the content of diosgenin and tigogenin-derived saponins in leaves of Agave species from Guerrero and Oaxaca. This information will be useful for better utilization of this plant material and add value to the process of mezcal elaboration. © 2022 Society of Chemical Industry.

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Due to their remarkable characteristics, cellulose nanocrystals are strategic materials that has various industrial applications, and are capable of being produced from vegetable fibers derived from the discards of agricultural practices. Peanut(Arachis hypogaea L.) peel is a residue considered of low commercial value and high polluting potential that needs new applications in order to mitigate these problems. Thus, in this study the feasibility of extracting cellulose nanocrystals was investigated. Two chemical routes were followed for this extraction. In the first, the fibers were bleached before acid hydrolysis whereas mercerization was used in the second. The second route was more efficient, as it enabled the elimination of proteins and phenolic compounds, which could be confirmed through solid-state 13C nuclear magnetic resonance (NMR) that revealed no signs of lignin residues. The cellulose nanocrystals composed of mainly type I cellulose presented a high degree of crystallinity index, 75 %, a thermal stability up to 200 °C, considerable stability in suspension (zeta potential of -48.1 ± 2.1 mV), and an aspect ratio of 125. They represent options that could add value to this residue, which would ease environmental problems.

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A multilevel factorial design of 23 with 12 experiments was developed for the preparation of cellulose nanocrystals (CNC) from Agave tequilana Weber var. Azul bagasse, an agro-industrial waste from tequila production. The studied parameters were acid type (H2SO4 and HCl), acid concentration (60 and 65 wt% for H2SO4, 2 and 8N for HCl) temperature (40 and 60 °C for H2SO4, 50 and 90 °C for HCl), and hydrolysis time (40, 55 and 70 min for H2SO4; and 30, 115 and 200 min for HCl). The obtained CNC were physical and chemically characterized using dynamic light scattering (DLS), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XDR) techniques. The maximum CNC yield was 90 and 96% for HCL and H2SO4, respectively, and the crystallinity values ranged from 88-91%. The size and morphology of A. tequilana CNC strongly depends on the acid type and hydrolysis time. The shortest CNC obtained with H2SO4 (65 wt%, 40 °C, and 70 min) had a length of 137 ± 68 nm, width 33 ± 7 nm, and height 9.1 nm, whereas the shortest CNC obtained with HCl (2 N, 50 °C and 30 min) had a length of 216 ± 73 nm, width 69 ± 17 nm, and height 8.9 nm. In general, the obtained CNC had an ellipsoidal shape, whereas CNC prepared from H2SO4 were shorter and thinner than those obtained with HCl. The total sulfate group content of CNC obtained with H2SO4 increased with time, temperature, and acid concentration, exhibiting an exponential behavior of CSG=aebt.

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In this article, we describe the semi-synthesis of N-alkyl-kappa-carrageenan derivatives and their antibacterial activity against Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 8739), and Pseudomonas aeruginosa (ATCC 9027). Kappa-carrageenan was submitted to partial acid hydrolysis promoting the selective cleavage of α-glycosidic bonds involving 3,6-anhydro-α-D-Galp units, giving rise to reducing low-molecular weight polysaccharide fragments, which were reacted with alkylamines of varying chain lengths by reductive amination. The carrageenan derivatives were characterized by HPSEC-MALLS-RID and 1D and 2D 1H and 13C NMR spectroscopy. The antibacterial activity of N-alkyl-kappa-carrageenan derivatives was compared with N-alkyl-(1-deoxylactitol-1-yl)-amines using a microdilution test, which indicated that inhibitory activity was dependent on the degree of substitution by hydrophobic groups at the polysaccharide structure. Comparing the effect of different N-alkyl chains, those with longer chains showed higher activity.

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This work aimed to produce and characterize cellulose nanofibers obtained from cassava peel with a combination of pre-treatments with acid hydrolysis or TEMPO-mediated oxidation and ultrasonic disintegration. All nanofibers presented nanometric diameter (5-16 nm) and high negative zeta potential values (around -30 mV). Oscillatory rheology showed a gel-like behavior of the aqueous suspensions of nanofibers (1.0-1.8 % w/w), indicating their use as reinforcement for nanocomposite or as a thickening agent. Additionally aqueous suspensions of nanofibers obtained by acid hydrolysis presented higher gel strength than those produced by TEMPO-mediated oxidation. However, ultrasound application increased even more viscoelastic properties. Flow curves showed that suspensions of nanofibers obtained by acid hydrolysis presented a thixotropy behavior and viscosity profile with three regions. Therefore our results showed that it is possible to tune mechanical properties of cellulose nanofibers choosing and modifying chemical and physical process conditions in order to allow a number of applications.

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In present research, Hevea brasiliensis (Rubber Wood) converted into cellulose by pre-treatment with NaOH (5%) and NaClO2 (5%). In addition, the cellulose was converted to nanocellulose (NC) using ionic liquid, acid hydrolysis and TEMPO oxidation accompanied by ultra-sonication. The prepared nanocellulose characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier transformation infrared spectroscopy (FT-IR). Thermal properties have been studied using thermogravimetric and differential thermal Analysis (TGA/DTA). FT-IR results clearly suggested that the synthetic approaches employed did not alter the principle chemical structure of rubber wood cellulose. SEM and AFM monographs reveal that synthetic approaches affect the morphology/surface topology of prepared nanocellulose. Among the three kinds of NC, NC by TEMPO approach had the largest aspect ratio and superior thermal stability.

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Cellulose nanofibers (CNFs) were isolated from unripe banana peel by acid hydrolysis, with different acid concentrations (0.1%, 1.0% and 10% v/v), followed by mechanical treatment with high-pressure homogenizer. Banana starch-based films added with CNFs (0.2% w/w) as a reinforcing agent were produced by the casting method. The rheological behavior of aqueous dispersions of CNFs (1.0% w/w) and their effects on the properties of nanocomposite films were investigated. All aqueous dispersions of CNFs showed gel-like behavior and, when incorporated to the films, CNFs improved their water barrier properties and mechanical resistance as demonstrated by the increase in tensile strength and Young's modulus. Moreover, CNFs were well dispersed in the composite matrix. CNFs prepared at higher concentration, followed by mechanical treatment (FNM1 and FNM10), formed films with low moisture (13.66%) and solubility in water (24.1%). Whereas, CNFs prepared at the lowest acid concentration without mechanical treatment (FN0.1) led to films with high elongation at break (30.6%) and good tensile strength (12.3 MPa). Regardless of the used CNFs, all the nanocomposites displayed lower UV/light transmission than control film. The nanocomposite has potential use in food packaging, since the use of CNFs can promote improvements on barrier, optical and mechanical properties. Cellulose nanofibers isolated from agro-industrial residues offer the potential to reinforce composites of biodegradable polymers, producing a value-added material.

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In recent years, the relationship between humans and companion animals has tightened considerably and resulted in the expansion of the range of pet food industry products available in the market. In this context, snacks have gained greater popularity as pet owners seek to please their animals by providing such foods. Due to the growing importance of the snack segment, a need exists for accurate information on the nutritional composition of these products, such as fat concentration. No studies were found that evaluated the effectiveness of different methods applied for determining the content of this nutrient in dog snacks. In addition, too much mineral content can pose health risks. Thus, the objective of this study was to compare three methodologies for determining fat in pet snack products. The moisture, calcium and phosphorus content of each was also determined to compare the obtained results with each value stated on their product labels. Fat determination methods evaluated were ether extract (EE), ether extract after acid hydrolysis (EEHA), and fat content obtained from Ankom XT15 analyzer (ANKOM). Twenty-four snacks produced by 17 companies were evaluated. The results of the three methodologies were compared using the Tukey test. The comparison between the results of the laboratory analysis and the values stated on the labels was performed using descriptive statistics. There was no difference between the three methods evaluated (p = 0.34) regarding fat content. Regarding the nutritional compliance of the labels, 25% (n = 6) of the snacks presented higher moisture content than the declared amount, 50% (n = 12) presented lower fat content, 25% (n = 6) lower phosphorus content and, in 50% (n = 12), the calcium content was not within the minimum and maximum range stated on the label. Therefore, due to the absence of difference between the results, any of the three fat determination methodologies could be used. Regarding compliance of labels for calcium, phosphorus and fat content, greater control over the nutritional composition of these foods is required since most pet owners tend to supply large quantities of snacks to dogs, leading to excessive daily energy intake.(AU)

Nos últimos anos a relação entre seres humanos e animais de companhia estreitou-se consideravelmente e houve uma expansão da gama de produtos da indústria pet food disponíveis no mercado. Nesse contexto, os petiscos ganharam maior popularidade, uma vez que os tutores buscam agradar seus pets com esse tipo de alimento. Devido à crescente importância do segmento de petiscos, há a necessidade de informações precisas sobre a composição nutricional desses produtos, como o teor de gordura, uma vez que não foram encontrados estudos que avaliassem a eficácia dos métodos de determinação do teor deste nutriente em petiscos destinados a cães e o excesso de minerais pode implicar em riscos para a saúde. Assim, o presente trabalho comparou três metodologias para determinação de gordura em petiscos para cães, e também determinou os seus respectivos teores de umidade, cálcio e fósforo, cujos resultados foram comparados aos valores declarados pelos fabricantes nos rótulos dos produtos. Os métodos de determinação da gordura avaliados foram: extrato etéreo (EE), extrato etéreo após hidrólise ácida (EEHA) e teor de gordura obtido em analisador Ankom XT15 (ANKOM). Vinte e quatro petiscos produzidos por 17 empresas foram avaliados. Os resultados das três metodologias de determinação da gordura foram comparados com o emprego do teste Tukey. A comparação entre os resultados das análises laboratoriais e os valores declarados nos rótulos foi realizada por meio de estatística descritiva. Não houve diferença entre os três métodos avaliados (p = 0,34) em relação ao teor de gordura dos petiscos examinados. Em relação à conformidade nutricional dos rótulos, 25% (n = 6) dos petiscos apresentaram teor de umidade superior ao declarado, 50% (n = 12) apresentaram menor teor de gordura; 25% (n = 6) menor teor de fósforo e, em 50% (n = 12) deles, o teor de cálcio estava fora da faixa mínima e máxima declarada no rótulo. Portanto, devido à ausência de diferença entre os resultados, as três metodologias de determinação de gordura podem ser utilizadas. Quanto à conformidade dos rótulos em relação aos teores de cálcio, fósforo e gordura, é necessário maior controle sobre a composição nutricional desses alimentos, uma vez que a maioria dos tutores fornece petiscos em elevadas quantidades para os cães, que podem determinar excessivo consumo de energia.(AU)

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In recent years, the relationship between humans and companion animals has tightened considerably and resulted in the expansion of the range of pet food industry products available in the market. In this context, snacks have gained greater popularity as pet owners seek to please their animals by providing such foods. Due to the growing importance of the snack segment, a need exists for accurate information on the nutritional composition of these products, such as fat concentration. No studies were found that evaluated the effectiveness of different methods applied for determining the content of this nutrient in dog snacks. In addition, too much mineral content can pose health risks. Thus, the objective of this study was to compare three methodologies for determining fat in pet snack products. The moisture, calcium and phosphorus content of each was also determined to compare the obtained results with each value stated on their product labels. Fat determination methods evaluated were ether extract (EE), ether extract after acid hydrolysis (EEHA), and fat content obtained from Ankom XT15 analyzer (ANKOM). Twenty-four snacks produced by 17 companies were evaluated. The results of the three methodologies were compared using the Tukey test. The comparison between the results of the laboratory analysis and the values stated on the labels was performed using descriptive statistics. There was no difference between the three methods evaluated (p = 0.34) regarding fat content. Regarding the nutritional compliance of the labels, 25% (n = 6) of the snacks presented higher moisture content than the declared amount, 50% (n = 12) presented lower fat content, 25% (n = 6) lower phosphorus content and, in 50% (n = 12), the calcium content was not within the minimum and maximum range stated on the label. Therefore, due to the absence of difference between the results, any of the three fat determination methodologies could be used. Regarding compliance of labels for calcium, phosphorus and fat content, greater control over the nutritional composition of these foods is required since most pet owners tend to supply large quantities of snacks to dogs, leading to excessive daily energy intake.(AU)

Nos últimos anos a relação entre seres humanos e animais de companhia estreitou-se consideravelmente e houve uma expansão da gama de produtos da indústria pet food disponíveis no mercado. Nesse contexto, os petiscos ganharam maior popularidade, uma vez que os tutores buscam agradar seus pets com esse tipo de alimento. Devido à crescente importância do segmento de petiscos, há a necessidade de informações precisas sobre a composição nutricional desses produtos, como o teor de gordura, uma vez que não foram encontrados estudos que avaliassem a eficácia dos métodos de determinação do teor deste nutriente em petiscos destinados a cães e o excesso de minerais pode implicar em riscos para a saúde. Assim, o presente trabalho comparou três metodologias para determinação de gordura em petiscos para cães, e também determinou os seus respectivos teores de umidade, cálcio e fósforo, cujos resultados foram comparados aos valores declarados pelos fabricantes nos rótulos dos produtos. Os métodos de determinação da gordura avaliados foram: extrato etéreo (EE), extrato etéreo após hidrólise ácida (EEHA) e teor de gordura obtido em analisador Ankom XT15 (ANKOM). Vinte e quatro petiscos produzidos por 17 empresas foram avaliados. Os resultados das três metodologias de determinação da gordura foram comparados com o emprego do teste Tukey. A comparação entre os resultados das análises laboratoriais e os valores declarados nos rótulos foi realizada por meio de estatística descritiva. Não houve diferença entre os três métodos avaliados (p = 0,34) em relação ao teor de gordura dos petiscos examinados. Em relação à conformidade nutricional dos rótulos, 25% (n = 6) dos petiscos apresentaram teor de umidade superior ao declarado, 50% (n = 12) apresentaram menor teor de gordura; 25% (n = 6) menor teor de fósforo e, em 50% (n = 12) deles, o teor de cálcio estava fora da faixa mínima e máxima declarada no rótulo. Portanto, devido à ausência de diferença entre os resultados, as três metodologias de determinação de gordura podem ser utilizadas. Quanto à conformidade dos rótulos em relação aos teores de cálcio, fósforo e gordura, é necessário maior controle sobre a composição nutricional desses alimentos, uma vez que a maioria dos tutores fornece petiscos em elevadas quantidades para os cães, que podem determinar excessivo consumo de energia.(AU)

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In recent years, the relationship between humans and companion animals has tightened considerably and resulted in the expansion of the range of pet food industry products available in the market. In this context, snacks have gained greater popularity as pet owners seek to please their animals by providing such foods. Due to the growing importance of the snack segment, a need exists for accurate information on the nutritional composition of these products, such as fat concentration. No studies were found that evaluated the effectiveness of different methods applied for determining the content of this nutrient in dog snacks. In addition, too much mineral content can pose health risks. Thus, the objective of this study was to compare three methodologies for determining fat in pet snack products. The moisture, calcium and phosphorus content of each was also determined to compare the obtained results with each value stated on their product labels. Fat determination methods evaluated were ether extract (EE), ether extract after acid hydrolysis (EEHA), and fat content obtained from Ankom XT15 analyzer (ANKOM). Twenty-four snacks produced by 17 companies were evaluated. The results of the three methodologies were compared using the Tukey test. The comparison between the results of the lab

Nos últimos anos a relação entre seres humanos e animais de companhia estreitou-se consideravelmente e houve uma expansão da gama de produtos da indústria pet food disponíveis no mercado. Nesse contexto, os petiscos ganharam maior popularidade, uma vez que os tutores buscam agradar seus pets com esse tipo de alimento. Devido à crescente importância do segmento de petiscos, há a necessidade de informações precisas sobre a composição nutricional desses produtos, como o teor de gordura, uma vez que não foram encontrados estudos que avaliassem a eficácia dos métodos de determinação do teor deste nutriente em petiscos destinados a cães e o excesso de minerais pode implicar em riscos para a saúde. Assim, o presente trabalho comparou três metodologias para determinação de gordura em petiscos para cães, e também determinou os seus respectivos teores de umidade, cálcio e fósforo, cujos resultados foram comparados aos valores declarados pelos fabricantes nos rótulos dos produtos. Os métodos de determinação da gordura avaliados foram: extrato etéreo (EE), extrato etéreo após hidrólise ácida (EEHA) e teor de gordura obtido em analisador Ankom XT15 (ANKOM). Vinte e quatro petiscos produzidos por 17 empresas foram avaliados. Os resultados das três metodologias de determinação da gordura foram c

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In recent years, the relationship between humans and companion animals has tightened considerably and resulted in the expansion of the range of pet food industry products available in the market. In this context, snacks have gained greater popularity as pet owners seek to please their animals by providing such foods. Due to the growing importance of the snack segment, a need exists for accurate information on the nutritional composition of these products, such as fat concentration. No studies were found that evaluated the effectiveness of different methods applied for determining the content of this nutrient in dog snacks. In addition, too much mineral content can pose health risks. Thus, the objective of this study was to compare three methodologies for determining fat in pet snack products. The moisture, calcium and phosphorus content of each was also determined to compare the obtained results with each value stated on their product labels. Fat determination methods evaluated were ether extract (EE), ether extract after acid hydrolysis (EEHA), and fat content obtained from Ankom XT15 analyzer (ANKOM). Twenty-four snacks produced by 17 companies were evaluated. The results of the three methodologies were compared using the Tukey test. The comparison between the results of the lab

Nos últimos anos a relação entre seres humanos e animais de companhia estreitou-se consideravelmente e houve uma expansão da gama de produtos da indústria pet food disponíveis no mercado. Nesse contexto, os petiscos ganharam maior popularidade, uma vez que os tutores buscam agradar seus pets com esse tipo de alimento. Devido à crescente importância do segmento de petiscos, há a necessidade de informações precisas sobre a composição nutricional desses produtos, como o teor de gordura, uma vez que não foram encontrados estudos que avaliassem a eficácia dos métodos de determinação do teor deste nutriente em petiscos destinados a cães e o excesso de minerais pode implicar em riscos para a saúde. Assim, o presente trabalho comparou três metodologias para determinação de gordura em petiscos para cães, e também determinou os seus respectivos teores de umidade, cálcio e fósforo, cujos resultados foram comparados aos valores declarados pelos fabricantes nos rótulos dos produtos. Os métodos de determinação da gordura avaliados foram: extrato etéreo (EE), extrato etéreo após hidrólise ácida (EEHA) e teor de gordura obtido em analisador Ankom XT15 (ANKOM). Vinte e quatro petiscos produzidos por 17 empresas foram avaliados. Os resultados das três metodologias de determinação da gordura foram c

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Textile manufacturing industries generate large amounts of viscose yarn waste (VW) that causes serious environmental pollution. In this study, VW was used as raw material to successfully extract nanocellulose (NC) in a facile one-step extraction process, without any pretreatment. Different hydrolysis reaction times (5-60 min) were employed, and the extracted material was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning and transmission electron microscopies, atomic force microscopy, and thermogravimetric analysis. Interestingly, it was possible to obtain NC in only 5 min of reaction without any pretreatment and with an increase of 50% in the crystallinity, which was attributed to the pretreatments VW undergone in textile industry that swell cellulose chains and make them more accessible to further reactions. The higher crystallinity index was observed after 30 min of reaction (87%), and through microscopy, it was verified that the morphology of the VW was completely changed to irregular nanoparticles with average size of 42 nm. The obtained NC showed interesting properties to be used in several potential applications, including stabilization of oil/water Pickering emulsions. These results indicate that VW is an attractive source to obtain NC, making the extraction of NC from VW a value-added alternative to recycle this textile waste.

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The effect of dual modification of corn starch, including hydrolysis and succinylation, were evaluated through peak viscosity (PV) analysis, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. This dual modification was shown to increase the reaction efficiency (RE) and degree substitution (DS) compared with starches that were not subjected to acid hydrolysis pretreatment with a 44% and 45% increase respectively. After acid hydrolysis pretreatment, the surface of the corn starch granules exhibited exo-erosion and whitish points due to the accumulation of succinyl groups. The peak viscosity was reduced significantly with the acid hydrolysis pretreatment (between 3 and 3.5-fold decrease), which decreased the pasting temperature and peak time to 20 °C and 100 s respectively. In addition, the dual modification of corn starch altered certain thermal properties, including a reduction in the enthalpy of gelatinization (ΔH) and a higher range of gelatinization (around 6 °C), which may effectively improve industrial applications. Modifications on the FTIR spectra indicated that the dual modification affected the starch crystallinity, while the Raman spectra revealed that the dual modification disrupted the short-range molecular order in the starch. Rearrangement and molecular destabilization of the starch components promoted their granular amphiphilic properties.

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Pineapple crown is an important source of cellulose that is still going to waste because of the lack of knowledge about their economic uses. The isolation of cellulose nanocrystals (CNC) from pineapple crown leaf (PCL) wastes arises as an important alternative to use PCL wastes in high value-added applications, and has not been reported yet. In this study, CNC were successfully extracted from PCL wastes using chemical treatments followed by acid hydrolysis using sulfuric acid. FTIR results confirmed the removal of the non-cellulosic compounds of PCL through the mercerization and bleaching treatments. SEM and AFM showed that the diameter of PCL fibers was reduced from 18 µm to 39 nm after the hydrolysis reaction, resulting in CNC with rod-like shape. The obtained CNC showed cellulose I crystalline structure with high crystallinity index (73%). The thermal degradation of CNC started at 124 °C, what was attributed to the presence of surface sulfate groups identified by elemental analysis. The high hydrophilicity of CNC was verified by its high moisture content and absorption. The results showed that the CNC isolated from PCL have interesting properties to be used in many liquid media applications, besides their use as reinforcement in nanocomposites.

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RESUMEN

Agave tequilana bagasse is the main solid waste of the tequila manufacturing and represents an environmental issue as well as a potential feedstock for biofuel production due to its lignocellulosic composition and abundance. In this contribution, this feedstock was subjected to pretreatments with HCl and H2SO4 for sugar recovery and methane was produced from the hydrolysates in batch and sequencing batch reactors (AnSBR). Sugar recovery was optimized by using central composite designs at different levels of temperature, acid concentration and hydrolysis time. Results showed that at optimal conditions, the HCl pretreatment induced higher sugar recoveries than the H2SO4 one, 0.39 vs. 0.26 g total sugars/g bagasse. Furthermore, the H2SO4 hydrolysate contained higher concentrations of potential inhibitory compounds (furans and acetic acid). Subsequent anaerobic batch assays demonstrated that the HCl hydrolysate is a more suitable substrate for methane production; a four-fold increase was found. A second optimization by using HCl as acid catalyst and methane production as the response variable demonstrated that softer hydrolysis conditions are required to optimize methane production as compared to sugar recovery (1.8% HCl, 119 °C and 103min vs. 1.9% HCl, 130 °C and 133min). This softer conditions were used to feed an AnSBR for 110 days and evaluate its stability at three different cycle times (5, 3 and 2 days). Results showed stable reactor performances at cycle times of 5 and 3 days, obtaining the highest methane yield and production at 3 days, 0.28 NL CH4/g-COD and 1.04 NL CH4/d respectively. Operation at shorter cycle times is not advised due to microbial imbalance.

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