Lisiane dos Santos Freitas
@ufs.br
Chemistry
Federal University of Sergipe
EDUCATION
Chemistry
Scopus Publications
Scopus Publications
Claudia Zubiolo, Hortência E. P. de Santana, Lucas L. Pereira, Denise Santos Ruzene, Daniel Pereira Silva, and Lisiane S. Freitas
American Chemical Society (ACS)
Jonatas de Oliveira S. Silva, José Felipe dos Santos, Honnara S. Granja, Wandson S. Almeida, Thiago F.L. Loeser, Lisiane S. Freitas, Márcio F. Bergamini, Luiz H. Marcolino-Junior, and Eliana Midori Sussuchi
Elsevier BV
Jonatas Silva, Honnara Granja, José dos Santos, Lisiane Freitas, and Eliana Sussuchi
Sociedade Brasileira de Quimica (SBQ)
In this review, we present the versatility of biomass and its derivatives obtained through thermal conversion processes (biochar and hydrochar) for applications in the development of electrochemical devices. This work highlights the generation of carbonaceous materials through pyrolysis and hydrothermal carbonization, in addition to proposing strategies to modify their physicochemical properties through activation methodologies to enhance their application as electrode materials. The processes of monitoring and degrading chemical species are discussed based on the diversity of electrodes that can be obtained with these bioderived coals, according to recent contributions available in the literature (2020-2023), which show the wide applicability of these materials in the field of electrochemistry
Lays C. de Almeida, Erikles L. O. Andrade, Jefferson C. B. Santos, Roberta M. Santos, Alini T. Fricks, Lisiane dos S. Freitas, Álvaro S. Lima, Matheus M. Pereira, and Cleide M. F. Soares
MDPI AG
The present research aims to study the process of immobilization of lipase from Burkholderia cepacia by physical adsorption on graphene oxide derived (GO) from grape seed biochar. Additionally, the modified Hummers method was used to obtain the graphene oxide. Moreover, Fourier transform infrared spectroscopy, Raman spectrum, X-ray diffraction, and point of zero charge were used for the characterization of the GO. The influences of pH, temperature, enzyme/support concentration on the catalytic activity were evaluated for the immobilized biocatalyst. The best immobilization was found (543 ± 5 U/g of support) in the pH 4.0. Considering the biochemical properties, the optimal pH and temperature were 3.0 and 50 °C, respectively, for the immobilized biocatalyst. Reusability studies exhibited that the immobilized lipase well kept 60% of its original activity after 5 cycles of reuse. Overall, these results showed the high potential of graphene oxide obtained from biochar in immobilization lipase, especially the application of nanobiocatalysts on an industrial scale.
Solange Cerqueira, Laryssa Santos, Antonia Gois, Cleide Soares, Brenno DaSilveira Neto, and Lisiane Freitas
Sociedade Brasileira de Quimica (SBQ)
The liquid product of the pyrolysis of biomass is a mixture of an organic phase and other aqueous, being the last one rich in phenol monomers which can be used in industrial chemistry as input for plastic and resin production. This work aimed to develop a method for extracting phenols present in the aqueous fraction obtained from the pyrolysis of guava seeds, using ultrasonic assisted liquid-liquid extraction (UALLE) with ethyl acetate and ionic liquids (ILs) as co-solvents (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) amide (BMIM.NTF2) and 1-butyl-3-methylimidazolinium hexafluorophosphate (BMIM.PF6)). The percentage IL, ultrasonic bath potency, temperature, and pH were studied. Quantification of twelve phenol monomers was performed using gas chromatography-mass spectrometry (GC-MS) and the total phenol concentration (TPC) was performed using UV-Vis spectrophotometer. The ionic liquid BMIM.NTF2 was more efficient for phenol extraction than BMIM.PF6. The phenolic extractions were influenced by the pH of the aqueous fraction (higher extraction yields at pH ≤ 7), and thus, presented recoveries above 80% for both ionic liquids.
Lays C. de Almeida, Felipe A. de Jesus, Flávia M. S. Wiltshire, Roberta M. Santos, Alini T. Fricks, Lisiane dos S. Freitas, Matheus M. Pereira, Álvaro S. Lima, and Cleide M. F. Soares
MDPI AG
Enzymes are promising tools for achieving an environmentally benign process. However, enzymes are required to be immobilized on economically competent supports to be reusable and maintain their activity. In this work, the aim was to evaluate the application of the biochar for immobilization of Burkholderia cepacia lipase (BCL) by physical adsorption (PA) and covalent binding (CB). Additionally, it was observed that regarding the biochemical properties, the optimal pH was 4.0 for the BCL immobilized by PA and pH 7.0 for the BCL free and immobilized by CB. Among the kinetic parameters, the maximal velocity (Vmax) for the free enzyme was 2500 µmol g−1·min−1, and for the PA- and CB-immobilized biocatalyst the values of Vmax were 2000 and 3333 µmol g−1·min−1, respectively. The Michaelis-Menten constant (Km) value for the free lipase was 665 mM and for the biocatalysts immobilized by PA and CB the Km values were 219 and 369 mM, respectively. Immobilized LBC exhibited superior thermal stability. The reusability tests showed that the LBC immobilized by PA preserved 50% of the initial activity after 16 cycles. Thus, biochar is a by-product of a renewable source; therefore, it is a promising alternative for lipase immobilization demonstrating its potential for use in a wide range of greener industrial processes.
Rebeca Dantas Xavier Ribeiro, Ronaldo Lopes Oliveira, Gleidson Giordano Pinto de Carvalho, Thadeu Marinello Silva, Jonival Barreto Costa, Vinicius da Silva Oliveira, Lisiane Santos Freitas, Claudio Vaz Di Mambro Ribeiro, and Leilson Rocha Bezerra
CSIRO Publishing
Context Crude glycerin (CG) is an energetic byproduct that generates glycerol, an energy product that is absorbed by the ruminal wall and conducted to the liver, where it is metabolised and it is converted to glucose, by the action of the enzyme glycerol kinase, in a gluconeogenesis process. Aims The study objective was to determine the effect of CG inclusion, replacing corn bran, in a total mixed ration to lambs, on carcass traits, physicochemical properties and the fatty acid (FA) profile of lamb meat. Methods Forty-four uncastrated crossbred Santa Ines × indigenous lambs were distributed in a completely randomised study, with four CG inclusion levels (0, 70, 140 and 210 g/kg in the lamb diet). Key results The addition of CG up to a level of 70 g/kg to the lamb diets promoted greater slaughter bodyweight, hot and cold carcass weight, carcass traits, and meat lipid content, and improved Warner–Bratzler shear force in meat. Inclusion of CG in the diet did not affect (P > 0.05) the pH and colour parameters (lightness, redness, yellowness and chroma) of meat. The FA composition of the longissimus lumborum of lambs C14:0, C15:1, C16:0, C18:1 cis and ΣFA medium-chain were greater, and FA meat concentration of C14:1, C15:0, C17:1, C18:0, C18:2 n−3, C18:2 n−6, ΣPUFA, ΣFA-old-chain and elongase enzymatic activity were lower in lambs fed without CG and with 70 g/kg CG, compared with lambs mainly fed 140 and 210 g/kg CG. The heath indexes, atherogenicity index and desirable FAs improved by dietary CG inclusion of 210 g/kg to the diet of lambs. Conclusions CG obtained from biodiesel production can be incorporated in lamb diets up to 70 g/kg total mixed ration, replacing corn bran to improve the weight gain, meat lipid content, Warner–Bratzler shear force and FA profile of lamb meat. Meat fat-related consumers health indices improved from the biggest inclusions of CG to the diet of lambs However, the use of CG at levels 140 and 210 g/kg total mixed ration reduces the performance, carcass weight and morphometric measurements. Implications It is recommended the inclusion at a maximum level of 70 g of CG/kg DM as total mixed ration replacing corn bran improves the weight gain, cooking weight loss, Warner–Bratzler shear force, meat lipid content and consequently FA meat composition.
Sílvia R. S. Martins, Suellen M. S. Andrade, Alini T. Fricks, Álvaro S. Lima, Daniel P. Silva, Renan T. Figueiredo, Lisiane S. Freitas, Rebeca Y. Cabrera-Padilla, Cleide M. F. Soares, and Ranyere L. Souza
Springer Science and Business Media LLC
The present work aims to evaluate the synergistic effect of imidazolium-based ionic liquids (IL) in the preparation and immobilization of Burkholderia cepacia lipase in a new hybrid support of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and silica. In addition, these biocatalysts were applied in transesterification reactions of crude coconut oil for the production of ethyl esters. Lipase immobilized on hybrid support with [C4min][NTf2] or [C6min][NTf2] ionic liquid exhibited nearly ≈ 1.6-fold immobilization yield greater than IB-Control. The use of IL during the preparation of the hybrid support promoted changes in its morphological structure as presented by B.E.T. and FTIR. Thermogravimetric analyzes were used to characterize the prepared derivatives and support the results of immobilization yields and the synergic effect of IL used. Transesterification reactions applying biocatalysts showed that the conversion maximum in esters (59%) was found under conditions of molar ratio 1:7 (oil:ethanol) in 72 h of reaction. These results were obtained using [C4min][NTf2] during the preparation of the hybrid support for the immobilization of Burkholderia cepacia lipase, thus showing the potential of these new biocatalysts.
Lays C. Almeida, Milson S. Barbosa, Felipe A. Jesus, Roberta M. Santos, Alini T. Fricks, Lisiane S. Freitas, Matheus M. Pereira, Álvaro S. Lima, and Cleide M. F. Soares
Wiley
Guava seed biochar appears as a new alternative of the effective support to the immobilization of Burkholderia cepacia lipase (BCL) by physical adsorption. The objective of this work was to evaluate the potential of this immobilized biocatalyst in the transesterification reaction of crude coconut oil and ethanol and to understand the mechanism of the reaction through the study of molecular docking. The best loading of BCL was determined to be 0.15 genzyme/gsupport having a hydrolytic activity of 260 U/g and 54% immobilization yield. The products of transesterification reaction produced a maximum yield at 40 °C under different reaction conditions. The monoacylglycerols (MAGs) conversion of 59% was using substrate molar ratio oil:ethanol of 1:7 with the reaction time of 24 H. In addition, the highest ethyl esters yield (48%) had the molar ratio of 1:7 with the reaction time of 96 H and maximum conversion of diacylglycerols (DAGs) was 30% with the molar ratio of 1:6 with the reaction time of 24 H. Molecular Docking was applied to clarify the mechanisms of transesterification reaction at the molecular level. MAGs and DAGs are compounds with excellent emulsifying properties used in industrial production of several bioproducts such as cosmetic, pharmaceuticals, foods, and lubricants.
Diego Bispo, Roberta Santos, Honnara Granja, and Lisiane Freitas
Sociedade Brasileira de Quimica (SBQ)
Ultrasonic pretreatment of cowpea bean pod biomass with addition of tripotassium phosphate (K3PO4) was used to induce the production of bio-oil enriched in phenolic compounds. An ultrasound bath operating at 40 kHz, 154 W power, and constant biomass:K3PO4 ratio of 5:1 (m/m) was used for pretreatments with different durations: 0.5, 1.5, 3, 6, 8, and 12 h. After the pretreatment, the biomass was pyrolyzed in a fixed bed reactor at 600 °C, under a flow of N2 at 5 mL min-1. The pyrolysis results indicated that the use of K3PO4 reduced the bio-oil yield, when compared to non-catalytic pyrolysis, and that the use of ultrasound caused increased biomass devolatilization, increasing the gas yield and reducing the formation of biochar. Gas chromatography mass spectrometry (GC-MS) analysis of the bio-oils indicated that pretreatment of the biomass led to significant increases of the phenolics contents, as well as alteration of the chemical profile of these compounds. The highest phenolics content of 8.12% m/m was obtained for the biomass submitted to 1.5 h of ultrasonic pretreatment, compared to 4.89% m/m for the untreated biomass.
Josefa Grasiela Silva Santana, Priscilla Santana Santos, Lisiane Santos Freitas, Fabiano Silva Soares, Moisés Ambrósio, Evandro Neves Muniz, Ana Silva Ledo, and Ana Veruska Cruz Silva Muniz
Informa UK Limited
ABSTRACT Mangaba (Hancornia speciosa Gomes) is a native fruit of Brazil that has high antioxidant activity and may benefit human health. The goal of this study was to discriminate between accessions in the germplasm bank of mangaba to improve its management. Eight morpho-agronomic traits were analysed in the ripe fruit of 36 genotypes taken from six accessions, and descriptive analyses were undertaken using Pearson correlation analysis, principal component analysis (PCA) and cluster analysis. The highest correlation coefficients were obtained between fruit size traits, and there was also a moderate correlation between the vitamin C content and number of seeds. PCA showed that 80.6% of the variability was explained by the first three principal components, to which all eight traits made significant contributions, while cluster analysis revealed considerable germplasm variation among the genotypes, which formed five distinct clusters: one cluster with a lower fresh mass (FM) and a mean vitamin C content of 410.09 mg·100 g−1 FM; one cluster with a higher FM and a mean vitamin C content of 363.85 mg·100 g−1 FM; and a further three clusters with a high FM, vitamin C content and soluble solids content, respectively. These findings on the vitamin C content and FM of these accessions will be useful for the agro-economic development of this native Brazilian species.
Roberta Santos, Diego Bispo, Honnara Granja, Eliana Sussuchi, André Luis Ramos, and Lisiane Freitas
Sociedade Brasileira de Quimica (SBQ)
The use of agricultural residues for the production of bio-oil is an important alternative to the use of fossil fuels. In this study, the Caupi bean pod (Vigna unguiculata) was characterized and used as biomass in the production of bio-oil. This biomass was evaluated in terms of physicochemical, morphological (scanning electron microscopy (SEM)), and thermal (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC)) characterization, lignocellulosic composition, and pyrolysis processes. The pyrolysis was carried out in a stainless steel fixed-bed reactor (260 mm in length and 60 mm in diameter) under atmospheric nitrogen pressure. Pyrolysis was conducted at 550, 600, and 700 °C and N2 gas flow of 2, 5, and 7 mL min. The chemical composition of the bio-oils was studied through CHN, TGA, Fourier-transform infrared spectroscopy (FTIR), and gas chromatography-mass spectrometry (GC-MS). The results confirmed the bean pod’s potential in the thermochemical process. The thermogravimetric analyses demonstrate that there can be a relationship between the components of the principal biomass (cellulose, hemicellulose, and lignin) and the compounds present in the bio-oil. The obtained bio-oils represent bio-products that are rich in compounds of several chemical classes with relevant commercial value such as acids (palmitic, linoleic, oleic, and stearic), alcohols (ethylene glycol), sugars (levoglucosan), and phenols (guaiacol, catechol, phenol, and pyrocatechol).
Juliana L. Santana, Juliana M. Oliveira, Jamily S. Nascimento, Silvana Mattedi, Laiza C. Krause, Lisiane S. Freitas, Eliane B. Cavalcanti, Matheus M. Pereira, Álvaro S. Lima, and Cleide M. F. Soares
Wiley
Here, we have assessed the use one packed bed or two packed bed reactors in series in which Burkholderia cepacia lipase (BCL) was immobilised on protic ionic liquid (PIL)-modified silica and used as a biocatalyst for the transesterification of crude coconut oil. Reaction parameters including volumetric flow, temperature and molar ratio were evaluated. The conversion of transesterification reaction products (ethyl esters) were determined using gas chromatography and the quantities of intermediate products (diglyceride and monoglyceride) were assessed using high performance liquid chromatography. Packed bed reactors in series produced ethyl esters with the greatest efficiency, achieving 65.27% conversion after 96 h at a volumetric flow rate of 0.50 mL min-1 at 40°C and a 1:9 molar ratio of oil to ethanol. Further, within the first 24 h of the reaction, increased monoglyceride (54.5%) production was observed. Molecular docking analyses were performed to evaluate the catalytic step of coconut oil transesterification in the presence of BCL. Molecular docking analysis showed that triglycerides have a higher affinity energy (-5.7 kcal mol-1 ) than the smallest monoglyceride (-6.0 kcal mol-1 ), therefore BCL catalyzes the conversion of triglycerides rather than monoglycerides, which is consistent with experimental results. This article is protected by copyright. All rights reserved.
Rafaely N. Lima, Alan Diego C. Santos, Adauto S. Ribeiro, Lucio Cardozo-Filho, Lisiane S. Freitas, Andersson Barison, Emmanoel V. Costa, and Péricles B. Alves
Elsevier BV
Abstract Supercritical carbon dioxide (SC−CO2) extraction of dry leaves of Piper hispidum was employed to optimize the selective extraction of cinnamoyl pyrrolidine amides. Taguchi L-9 method and 32 factorial experiments were used in the methodology optimization. The extraction yield (1.92 %, 353 K/ and 20 MPa) was improved significantly to 3.62 % with organic solvents addition (5 % of methanol in the extraction). The chemical composition investigation of supercritical extracts led to the isolation of four compounds, not initially identified by GC–MS. The compound 2 (Z,E) and 3 (E,Z) were identified as the major cinnamoyl pyrrolidine amides (up to 74.11 %). Antioxidant activity assay of the extract obtained at 333 K/ 20 MPa presented an IC50 of 228 μg/mL and AAI of 0.087. The amide 2 and 5 % co-solvent extracts were also capable of inhibiting HL-60 cells grow up to 73 %. The newly developed methodology was suitable to obtain selectively metabolites with biological potential.
V.da S. Oliveira, R.L. Oliveira, R.H.T.B. Goes, T.M. Silva, L.F. Silva, L.S. Freitas, E.S. Pereira, and L.R. Bezerra
Elsevier BV
Abstract The use of agroindustrial waste to feed ruminants can change the microbial ecology of the animal, affect the fatty acid biohydrogenation extent and improve the profile of fatty acid of tissues. This study was conducted to determine the amount of sunflower cake in the diet of bulls that had the best effects on the physicochemical characteristics, fatty acid composition and sensory attributes of meat. To do so thirty-two intact Nellore bulls with an initial average body weight of 374 ± 42.5 kg that were used 24 months of age in a design completely randomized (four treatments). Animals were fed 400 g/kg Tifton 85 hay and 600 g/kg concentrate. The inclusion levels of sunflower cake (0, 9, 18, and 27% in DM basis) were the experimental treatments. Sunflower cake inclusion in the diet linearly increased the following characters (P
Milson S. Barbosa, Cintia C. C. Freire, Lays C. Almeida, Lisiane S. Freitas, Ranyere L. Souza, Ernandes B. Pereira, Adriano A. Mendes, Matheus M. Pereira, Álvaro S. Lima, and Cleide M. F. Soares
Wiley
Alternative strategies are required to develop the optimized production of fatty acids using biocatalysis; molecular docking and response surface methodology are efficient tools to achieve this goal. In the present study, we demonstrate a novel and robust methodology for the sustainable production of fatty acids from Moringa oleifera Lam oil using lipase‐catalyzed hydrolysis (without the presence of emulsifiers or buffer solutions). Seven commercial lipases from Candida rugosa (CRL), Burkholderia cepacia (BCL), Thermomyces lanuginosus (TLL), Rhizopus niveus (RNL), Pseudomonas fluorescens (PFL), Mucor javanicus (MJL), and porcine pancreas (PPL) were used as biocatalysts. Initial screening showed that CRL had the highest hydrolytic activity (hydrolysis degree of 81%). Molecular docking analysis contributed to the experimental results, showing that CRL displays more stable binding free energy with oleic acid (C18:1), which is the fatty acid of highest concentration in Moringa oleifera Lam oil. To evaluate and optimize the hydrolysis process, response surface methodology (RSM) was used. The effect of temperature, mass ratio oil:water, and hydrolytic activity on enzymatic hydrolysis was evaluated by central composite design using RSM. Under the optimized conditions (temperature of 37 °C, mass ratio oil:water of 25%, and hydrolytic activity of 550 U goil−1), the maximum hydrolysis degree (100%) was achieved. The present study provides a robust method for the enzymatic hydrolysis of different oils for efficient and sustainable fatty acid production.
Rafaely N. Lima, Adauto S. Ribeiro, Gilvandete M.P. Santiago, Cinara O. d´S. Costa, Milena B. Soares, Daniel P. Bezerra, Saravanan Shanmugam, Lisiane dos S. Freitas, and Pericles B. Alves
SAGE Publications
The chemical constituents of essential oils extracted by hydrodistillation from Piper klotzschianum, P. hispidum, and P. arboreum, collected from the remaining Atlantic forest in Sergipe State, were characterized and submitted to cytotoxic and larvicidal activity assays. The major constituents identified (stems, fresh, and dried leaves) were ( E)-caryophyllene (16.8%) and bicyclogermacrene (21.6%). Germacrene D (22.8%) was identified only in P. klotzschianum and P. hispidum. A high percentage of β-pinene (27.2%) and α-pinene (7.2%) were present in P. klotzschianum stems and δ-3-carene in the fresh and dried leaves of P. hispidum (17.4% and 19.1%, respectively). Piper klotzschianum showed the best cytotoxic activity, inhibiting human hepatocellular carcinoma (27.3 µg/mL), human promyelocytic leukemia (33.8 µg/mL), and murine melanoma (37.9 µg/mL) cell lines. Larvicidal activity was also tested and the essential oil from the dried leaves of P. klotzschianum was the most potent against Aedes aegypti larvae, with an LC50 value of 122.4 µg/mL.
M.C. Lisboa, C.A. Rodrigues, A.S. Barbosa, S. Mattedi, L.S. Freitas, A.A. Mendes, C. Dariva, E. Franceschi, ÁS. Lima, and C.M.F. Soares
Elsevier BV
Abstract The increased demand for biotechnological processes in industrial applications requires the development of highly active and stable heterogeneous biocatalysts. For this reason, the present work aimed to study the immobilization process by physical adsorption of lipase from Burkholderia cepacia (BCL) on aerogel modified with protic ionic liquid (2-hydroxy-N-methylethanaminium pentanoate – C5). The adsorption study of BCL on aerogel modified with protic ionic liquid (Aerogel-IL) has been performed and compared with unmodified support (Aerogel-Control). It was observed that the modification of aerogel allowed a greater retention of BCL (337 mg.gsupport –1 or 977.7 U.gsupport –1) than the unmodified support (297 mg.gsupport –1 or 863.5 U.gsupport –1). Experimental data obtained in physical adsorption of BCL on Aerogel-IL and Aerogel-Control were well-fitted to Sips and Redlich-Peterson isotherm models, respectively. BCL adsorption on both supports was found to be a spontaneous process. Immobilized BCL on Aerogel-IL has shown a better thermal stability than free and immobilized BCL on unmodified support being active for more than 14 days. These results reveal that the modified aerogel prepared in this work can be a promising support to prepare stable and active biocatalysts.
Nayára Carvalho, Bruna Vidal, Anderson Barbosa, Matheus Pereira, Silvana Mattedi, Lisiane Freitas, Álvaro Lima, and Cleide Soares
MDPI AG
Treated silica xerogel with protic ionic liquid (PIL) and bifunctional agents (glutaraldehyde and epichlorohydrin) is a novel support strategy used in the effective immobilization of lipase from Burkholderia cepacia (LBC) by covalent binding. As biocatalysts with the highest activity recovery yields, LBC immobilized by covalent binding with epichlorohydrin without (203%) and with PIL (250%), was assessed by the following the hydrolysis reaction of olive oil and characterized biochemically (Michaelis–Menten constant, optimum pH and temperature, and operational stability). Further, the potential transesterification activity for three substrates: sunflower, soybean, and colza oils, was also determined, achieving a conversion of ethyl esters between 70 and 98%. The supports and the immobilized lipase systems were characterized using Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), elemental analysis, and thermogravimetric (TG) analysis.
Priscilla Santana Santos, Lisiane dos Santos Freitas, Josefa Grasiela Silva Santana, Evandro Neves Muniz, Allívia Rouse Carregosa Rabbani, and Ana Veruska Cruz da Silva
Elsevier BV
Abstract The mangaba is a native Brazilian species of socioeconomic importance and with a great appeal for the conservation of its genetic resources. The fruit is rich in nutrients, especially ascorbic acid. Because the species’ areas of natural occurrence have decreased rapidly, the Embrapa Coastal Tablelands has maintained it in the Mangaba Active Germplasm Bank (AGBMangaba), in Itaporanga D’Ajuda, Sergipe, Brazil, since 2006, in an attempt to conserve its genetic resources. The objective of the present study was to estimate the genetic diversity and fruit quality of six bank accessions (BI, CA, LG, PR, PT, and TC) from the states of Bahia and Sergipe, aiming at the selection of promising material for genetic improvement. Twenty ISSR markers were tested, and 12 were selected to evaluate genetic similarity, which allowed the identification of three distinct groups. The longitudinal and transversal diameters were measured, and fresh mass content, the number of seeds, pH, soluble solids content, titratable total acidity, and vitamin C content were evaluated. The quality of these accessions was evident; the BI, CA, PR, and PT accessions showed the highest values of vitamin C content, which is a characteristic of interest in both genetic improvement programs and agroindustry.
Simonise F. Amarante, Maikon A. Freire, Douglas T.S.L. Mendes, Lisiane S. Freitas, and André L.D. Ramos
Elsevier BV
Abstract Metal-organic frameworks represent a new class of hybrid inorganic-organic materials which are characterized by high stability, high porosity and well-defined crystalline structures. One of their applications is in Catalysis, where bifunctional catalysts may be developed, with both acidic and basic sites. Zeolitic imidazole framework (ZIF) is a subfamily of MOFs which combines the advantages of MOFs with high thermal and chemical stability of zeolites. The objective of this work is to evaluate the basic character of synthetized ZIFs (ZIF-8 and ZIF-67). Samples were characterized by N 2 adsorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA). The Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate was chosen as model reaction to evaluate the basic sites. The reaction was conducted at 40 °C and aniline was used as homogeneous catalyst for comparison. Characterization has shown high crystallinity, the presence of functional groups typical of ZIFs structures and high thermal stability. Both ZIF catalysts have shown good catalytic activity (around 90% at 8 h of reaction), similar to the activity of aniline, a homogeneous catalyst. So the presence of basic sites of ZIF-8 and ZIF-67 and their activity were proven in this work.
Rosane Gomes de OLIVEIRA, Sona JAIN, Alexandre Cândido LUNA, Lisiane dos Santos FREITAS, and Edilson Divino de ARAÚJO
FapUNIFESP (SciELO)
Honey from stingless bees of the genus Melipona is a well sought product. Nevertheless lack of legal frameworks for quality assessment complicates the evaluation of food safety and marketing of these products. Seeking to assess the quality of honey from the bees of this genus, physical and chemical analyses, identification of phenolic compounds, and microbiological evaluation from six species of stingless bees was performed. The honey samples showed high reducing sugars, low protein levels and a balanced microbiota. High total phenols and flavonoids and higher antioxidant activity were also recorded. Different phenolic compounds of great biotechnological potential were identified and of these apigenin, kaempferol and luteolin were identified for the first time in honey. To the best of our knowledge, this is one of the few works describing a detail characterization of melipona honey together with identification of the phenolic compounds of significant therapeutic value.
Lays C. Almeida, Anderson S. Barbosa, Alini T. Fricks, Lisiane S. Freitas, Álvaro S. Lima, and Cleide M.F. Soares
Elsevier BV
Abstract The objective of this work was to evaluate the influence of dichloromethane (CH2Cl2), potassium hydroxide (KOH) and phosphoric acid (H3PO4) in the treatment of biochar from guava seeds on conventional and non-conventional techniques (ultrasound and microwave) for the immobilization of Burkholderia cepacia lipase (BCL) by physical adsorption. The effects of the different treatments on the physical and chemical properties of the biochar were evaluated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The immobilization of the BCL on the biochar was evaluated in hydrolysis reactions of olive oil. The conventional treatment of the biochar with KOH showed increased modification on the surface of the biochar, which presented a highly porous surface, and a greater activity for the immobilized biocatalyst compared with the other treatments. The results revealed the potential of biochar as a support novelty for the immobilization of enzymes and for their application in biocatalysis.
Maikon A. Freire, Douglas T.S.L. Mendes, Lisiane S. Freitas, Rolf Beerthuis, Simonise F. Amarante, and André L.D. Ramos
Elsevier BV
Abstract Alkylation of phenolic compounds with olefins is an important industrial reaction to increase the chemical stability of bio-oil. In this study, the liquid-phase alkylation of phenol with linear (1-octene) and branched (diisobutylene) olefins was studied, in a batch reactor using homogeneous (sulfuric acid) and heterogeneous (Amberlyst-15) acid catalysts. Conversion and selectivity trends were compared and the effects of different operational conditions (temperature, phenol/olefin molar ratio and catalyst content) were evaluated employing factorial experimental design. The Amberlyst-15 solids acid resin was characterized by nitrogen physisorption and Bronsted acid sites titration. The heterogeneous catalyst showed satisfactory conversions with both olefins, albeit being less active than sulfuric acid. Higher conversions were obtained with diisobutylene than with 1-octene. C-alkylation was dominant in the diisobutylene reaction, including some product formation resulting from fragmentation of the diisobutylene olefin. However, mainly O-alkylation was observed under mild reaction conditions in the 1-octene reaction. Factorial experimental design showed that temperature was the variable that most influenced the conversion and selectivity trends, and the highest yields of di- and tri-alkylated products were obtained at elevated temperatures. A mechanistic model was proposed for both reactions.