RESUMEN

We address the hypothesis that at early and late lactation milk presents low ethanol stability due to high acidity and ionic calcium values. Our aim was to evaluate the functional traits of milk (milk ethanol stability: MES, acidity and ionic calcium: iCa) according to lactation stage in different genetic groups. Raw milk samples were collected from Jersey (n = 271), Holstein (n = 248) and Jersey × Holstein crossbred cows (n = 82), raised on five commercial farms located in the state of Paraná, Brazil. Milk composition, somatic cell count (SCC), milk urea nitrogen (MUN), MES, pH, acidity and iCa were determined. Days in milk (DIM) were categorized into four classes: 1-60, 61-150, 151-305 and over 305 DIM. Data were submitted to analysis of variance. Fixed and random effects were incorporated into the model, in a repeated measures in time arrangement using the mixed models methodology. Significant interactions between DIM class and genetic groups were detected. The comparison between each combination of genetic group and DIM class showed that at the beginning of lactation, Holsteins produced milk with higher MES than Jersey and crossbreds. At 105-305 DIM Holstein milk presented higher MES than Jersey, while beyond 305 DIM Holstein milk showed higher MES than crossbred cows. At the beginning of lactation acidity was higher in Holstein milk and crossbreds compared with Jersey, while acidity was lower in Holstein milk compared with Jersey and crossbreds in the other lactation stages. Ionic calcium was highest after lactation peak for Holstein, but did not vary between lactation stages for Jersey and crossbreds. Functional characteristics of bovine raw milk such as MES, iCa and acidity varied between lactation stages in a distinct manner according to genetic groups. Early and end lactation stages are challenging in terms of low stability, especially for Jersey and crossbreds.

RESUMEN

In Mexico, there is a deficit in the production of pine resin, because it relies on natural forests only. Therefore, it is necessary to select provenances and phenotypes of potential species such as P. oocarpa. The objective was to determine the difference between provenances and the variation in resin components and quality, as well as the effect of geographic and climatic factors. Resin from five provenances was collected from southern Mexico. The percentage of rosin, turpentine and water was obtained, as well as the acidity and saponification index. P. oocarpa resin had 80.94% rosin, 7.7% turpentine and 11.49% water. The saponification and acidity index was 125.47 and 117.49 mg KOH.g-1, respectively. All variables showed differences (p ≤ 0.0001) between provenances. The provenance contributed between 6.44 and 11.71% to the total variance, the error contributed between 88.29 and 93.56%. Geographic and climatic variables only had an effect on the percentage of turpentine; the correlation was negative with altitude and longitude, but positive with temperature and precipitation. The results allow defining seed collection sites for resin plantations and orienting the selection for a P. oocarpa improvement program.

RESUMEN

The performance of catalysts prepared from hierarchical Y zeolites has been studied during the conversion of vacuum gas oil (VGO) into higher-value products. Two different catalysts have been studied: CatY.0.00 was obtained from the standard zeolite (Y-0.00-M: without alkaline treatment) and CatY.0.20 was prepared from the desilicated zeolite (Y-0-20-M: treated with 0.20 M NaOH). The cracking tests were carried out in a microactivity test (MAT) unit with a fixed-bed reactor at 550 °C in the 20-50 s reaction time range, with a catalyst mass of 3 g and a mass flow rate of VGO of 2.0 g/min. The products obtained were grouped according to their boiling point range in dry gas (DG), liquefied petroleum gas (LPG), naphtha, and coke. The results showed a greater conversion and selectivity to gasoline with the CatY.0.20 catalyst, along with improved quality (RON) of the C5-C12 cut. Conversely, the CatY.0.00 catalyst (obtained from the Y-0.00-M zeolite) showed greater selectivity to gases (DG and LPG), attributable to the electronic confinement effect within the microporous channels of the zeolite. The nature of coke has been studied using different analysis techniques and the impact on the catalysts by comparing the properties of the fresh and deactivated catalysts. The coke deposited on the catalyst surfaces was responsible for the loss of activity; however, the CatY.0.20 catalyst showed greater resistance to deactivation by coke, despite showing the highest selectivity. Given that the reaction occurs in the acid sites of the zeolite and not in the matrix, the increased degree of mesoporosity of the zeolite in the CatY.0.20 catalyst facilitated the outward diffusion of products from the zeolitic channels to the matrix, thereby preserving greater activity.

RESUMEN

This study has innovative aspects related to the use of sequential inoculation technique in the coffee bean fermentation process: the inoculation of Lactiplantibacillus plantarum followed by Saccharomyces cerevisiae, in the fermentation of coffee fruit for the production of specialty natural coffees. The objective was to evaluate the effect of this technique and of the total fermentation time on the sensory attributes of the coffee beverage and on the organic acid profile, bioactive compounds, and fatty acid profile of the beans. The fermentation of coffee fruit with sequential inoculation resulted in greater acidity of the beverage and contributed to increases of up to 2 points in coffee fermented. The total fermentation time was directly related to the organic acid content, and the longer the total fermentation time was, the greater the organic acid content. The fatty acid content and bioactive compound content showed little variation among treatments.

Asunto(s)

RESUMEN

The metataxonomic diversity and microbial composition of microorganisms during the coffee fermentation process as well as their relationship with coffee quality were determined across 20 farms in the department of Cesar, Colombia, by sampling coffee fruits from Coffea arabica; Var. Castillo General®, Var. Colombia, and Var. Cenicafé 1. In each farm, the fruits were processed and the fermentation process took place between 10 and 42 h following this. Three samples of mucilage and washed coffee seeds were collected per farm during the fermentation process. The microorganisms present in the mucilage were identified using metataxonomic methods by amplifying the 16S rRNA gene for bacteria and ITS for fungi. The microorganisms' morphotypes were isolated and identified. The analysis of bacteria allowed for the identification of the following genera: Gluconobacter, Leuconostoc, Acetobacter, Frateuria, Pantoea, Pseudomonas, Tatumella, and Weisella, as well as unclassified enterobacteria; the Lactobacillacea and Secundilactobacillus families were only identified in the Var. Cenicafé 1. For fungi, the top 11 genera and families found included Hanseniaspora, Candida, Meyerozyma, Wickerhamomyces, Pichia, f-Saccharomycodaceae, f-Nectriciae, unclassified fungi, and Saccharomycetaceae, which were only found in Cenicafé 1. A total of 92% of the coffee samples obtained scored between 80.1 and 84.9, indicating "Very Good" coffee (Specialty Coffee Association (SCA) scale). Farms with the longest fermentation times showed better coffee attributes related to acidity, fragrance, and aroma. During coffee fermentation, there is a central microbiome. The differences between the microorganisms' genera could be influenced by the coffee variety, while the specific conditions of each farm (i.e., altitude and temperature) and its fermentation processes could determine the proportions of and interactions between the microbial groups that favor the sensory characteristics responsible for coffee cup quality.

RESUMEN

The standard method used to quantify free acidity (FA) in vegetable oil is neutralization titration, which requires many toxic chemicals and depends on an analyst's experience in detecting endpoints. Here, a digital image colorimetry (DIC) method using a smartphone camera was developed to measure FA in vegetable oils. A cupric acetate solution was used to produce the colorimetric reaction. The coloured solutions were imaged, and R values (from the RGB colour system) were calibrated against the respective FAs in the standards. The FA values of the samples were determined by standard addition calibration. These results were compared to measurements of FA obtained by the standard titrimetric method. An excellent correlation was obtained, with an R2 of 0.98 and a mean absolute error of 0.06%. The chemicals needed for analysis were reduced by approximately 90%. Thus, DIC is a less subjective and more economical method for determining FA in vegetable oils.

Asunto(s)

RESUMEN

N-Acylhydrazones are a versatile class of organic compounds with a diversity of potential applications. In this study, two new structure-related 3,4,5-trimethoxybenzoyl-containing N-acylhydrazones were synthesized and fully characterized, both in solution and in the solid state. The compounds differ with respect to the carbonyl precursors, i.e., 3-substituted salicylaldehydes with either a methyl or a nitro group. Single crystals of both compounds were isolated from the respective mother liquors and, in both cases, XRD confirmed the obtention of the (E)-isomer, in an anti-conformation. Computational calculations (gas and water phases) were performed in order to confirm some of the structural and vibrational aspects of the compounds. An important intramolecular H bond involving the phenolic hydroxy group and the azomethine nitrogen was identified in the solid state and seems to be maintained in solution. Moreover, the presence of the electron-withdrawing nitro substituent makes this interaction stronger. However, the contact should probably not subsist for the nitro compound under physiological conditions since the presence of this substituent significantly affects the pKa of the phenol: an apparent value of 5.68 ± 0.02 was obtained. This also impacts the basicity of the azomethine nitrogen and, as a consequence, increases the hydrazone's susceptibility to hydrolysis. Nevertheless, both compounds are stable at physiological-like conditions, especially the methyl-derived one, which qualifies them for further toxicological and activity studies, such as those involving trivalent metal ions sequestering in the context of neurodegenerative diseases.

RESUMEN

Brazil nut oil is highly valued in the food, cosmetic, chemical, and pharmaceutical industries, as well as other sectors of the economy. This work aims to use the Fourier transform infrared (FTIR) technique associated with partial least squares regression (PLSR) and principal component analysis (PCA) to demonstrate that these methods can be used in a prior and rapid analysis in quality control. Natural oils were extracted and stored for chemical analysis. PCA presented two groups regarding the state of degradation, subdivided into super-degraded and partially degraded groups in 99.88% of the explained variance. The applied PLS reported an acidity index (AI) prediction model with root mean square error of calibration (RMSEC) = 1.8564, root mean square error of cross-validation (REMSECV) = 4.2641, root mean square error of prediction (RMSEP) = 2.1491, R2cal (calibration correlation coefficient) equal to 0.9679, R2val (validation correlation coefficient) equal to 0.8474, and R2pred (prediction correlation coefficient) equal to 0, 8468. The peroxide index (PI) prediction model showed RMSEC = 0.0005, REMSECV = 0.0016, RMSEP = 0.00079, calibration R2 equal to 0.9670, cross-validation R2 equal to 0.7149, and R2 of prediction equal to 0.9099. The physical-chemical analyses identified that five samples fit in the food sector and the others fit in other sectors of the economy. In this way, the preliminary monitoring of the state of degradation was reported, and the prediction models of the peroxide and acidity indexes in Brazil nut oil for quality control were determined.

Asunto(s)

RESUMEN

Currently, catalytic pyrolysis has become a versatile and highly useful technology in the treatment of different plastic wastes. Thus, the development of selective catalysts to carry out cracking reactions and obtain a greater fraction of the desired products is essential. This study focuses on the synthesis of monometallic (Ni) and bimetallic (Ni-Zn) catalysts supported on ZSM-5 zeolite using an impregnation and co-impregnation method, respectively. The obtained catalysts were characterized by FTIR spectroscopy, N2 adsorption/desorption measurements, scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDS), temperature programmed NH3 desorption (TPD-NH3) and thermogravimetric analysis (TGA). In this way, a mixture of polystyrene and polypropylene recycled with a catalyst/plastic waste ratio of 1:500 was used for pyrolysis tests. The best results were obtained using the Ni-Zn/ZSM-5 catalyst, which included better impregnation, increased surface acidity, decreased dispersion and a shorter reaction time in the catalytic pyrolysis process. Under the optimized conditions, catalytic pyrolysis showed an excellent performance to generate hydrocarbons of greater industrial interest.

RESUMEN

Objetivo: o presente estudo teve como objetivo avaliar, in vitro, o potencial erosivo para o esmalte dentário de bebidas ácidas, comumente ingeridas pela população e encontradas com frequência no comércio da grande Florianópolis, SC, Brasil. Método: a mensuração do potencial erosivo das bebidas foi realizada através da detecção do potencial hidrogeniônico (pH) e acidez titulável (AT). A amostra foi composta por refrigerantes à base de cola, Coca-Cola® e Pepsi®; isotônicos Gatorade®-morango e maracujá e Powerade®-mix de frutas; Chás industrializados Natural Tea®-limão e Chá Matte Leão®-natural; energéticos Red Bull® e Monster Energy®; sucos naturais de Laranja Pera e de Limão Taiti; água saborizada H2OH!®-sabor limão; e água mineral, para o grupo controle. O pH foi aferido com pHmetro digital (Sensoglass SP1800) e para a AT foi utilizado o método padronizado pelo Instituto Adolfo Lutz, todos os ensaios foram realizados em triplicata. Para a análise estatística descritiva, foram empregados teste t e a ANOVA. Resultados: os menores valores de pH foram encontrados para a bebida Coca-Cola® e suco de limão com 2,3. Para AT, as amostras que apresentaram os maiores valores foram os sucos naturais, com 35,1 para o suco de limão e 13,5 para o suco de laranja. Todas as bebidas analisadas possuem potencial erosivo ao esmalte dental, por apresentarem valores de pH menores que 5,5. Quanto as mensurações de AT, os sucos naturais apresentaram os maiores valores. Conclusão: todas as bebidas do estudo foram consideradas iminentemente erosivas à estrutura dental.(AU)

Objetivo: o presente estudo teve como objetivo avaliar, in vitro, o potencial erosivo para o esmalte dentário de bebidas ácidas, comumente ingeridas pela população e encontradas com frequência no comércio da grande Florianópolis, SC, Brasil. Método: a mensuração do potencial erosivo das bebidas foi realizada através da detecção do potencial hidrogeniônico (pH) e acidez titulável (AT). A amostra foi composta por refrigerantes à base de cola, Coca-Cola® e Pepsi®; isotônicos Gatorade®-morango e maracujá e Powerade®-mix de frutas; Chás industrializados Natural Tea®-limão e Chá Matte Leão®-natural; energéticos Red Bull® e Monster Energy®; sucos naturais de Laranja Pera e de Limão Taiti; água saborizada H2OH!®-sabor limão; e água mineral, para o grupo controle. O pH foi aferido com pHmetro digital (Sensoglass SP1800) e para a AT foi utilizado o método padronizado pelo Instituto Adolfo Lutz, todos os ensaios foram realizados em triplicata. Para a análise estatística descritiva, foram empregados teste t e a ANOVA. Resultados: os menores valores de pH foram encontrados para a bebida Coca-Cola® e suco de limão com 2,3. Para AT, as amostras que apresentaram os maiores valores foram os sucos naturais, com 35,1 para o suco de limão e 13,5 para o suco de laranja. Todas as bebidas analisadas possuem potencial erosivo ao esmalte dental, por apresentarem valores de pH menores que 5,5. Quanto as mensurações de AT, os sucos naturais apresentaram os maiores valores. Conclusão: todas as bebidas do estudo foram consideradas iminentemente erosivas à estrutura dental.(AU)

Asunto(s)

RESUMEN

Aim: The study evaluated the influence of tucupi on enamel surface roughness, microhardness, ultramorphology, and mass variation. Materials and Methods: Ninety healthy bovine incisors were divided into three experimental groups, according to the acidic challenge adopted, being: G1- tucupi, G2- cola-based soft drink, G3-distilled water. The enamel properties (surface roughness, microhardness, ultramorphology and mass variation) of all specimens were evaluated at times T0 (before any intervention), T10 (10 days after the proposed treatments), T20 (20 days after the proposed treatments) and T30 (30 days after the proposed treatments). After confirming the normality of the data (Shapiro-Wilk test), a two-way ANOVA (α = 5%) was performed, followed by Sidak post-test, with results described as mean and standard deviation. Results: The roughness means increased for all tested groups, with no statistical difference only in G3 for all evaluated times. Microhardness of all groups showed a significant decrease over the time, with the lowest average observed in G1 in T30. Considering enamel mass variation, the lowest average was in G2 at time T3, with no statistical difference only in G3 (distilled water) over the time. Regarding ultramorphology (scanning electron microscopy - SEM), only groups G1 and G2, that were exposed to acidic challenges, showed disorganization of the enamel surface layer. Conclusion: It was possible to conclude that tucupi has low pH and high titratable total acidity, being able to gradually decrease enamel microhardness, increasing surface roughness and causing loss of dental enamel.

RESUMEN

Introducción. El grado de acidez Dornic (AD), medida indirecta del grado de contaminación de la leche humana cruda (LHC), proporciona información sobre la calidad de esta. Recién extraída, el valor oscila entre 1,0° y 4,0° (óptimo). Descalifica el consumo si es >8,0 °D. Se evaluó la correlación de la AD de la LHC de donantes internas (DI) y externas (DE) según el tiempo de conservación hasta la pasteurización, y se determinó la prevalencia de AD ≤4 ºD. Población y método. Estudio retrospectivo analítico. Resultados. Sobre 13 203 muestras, la AD a partir del día 14 de conservación fue menor en las donantes internas, de 2,92; (IC95% 2,69-3,15) versus 4,01 (IC95%: 3,94-4,08); p <0,001] con mayor proporción de AD ≤4 ºD (88 % en DI versus 76 % en DE); OR: 2,30 (IC95%: 1,25-4,24); p = 0,003. Coeficiente de correlación para las DI: R 2 :0; p = 1). Conclusión. La AD a partir del día 14 fue menor en DI, presentando mayor prevalencia de AD ≤ 4ºD. No existió correlación entre el tiempo de conservación y la AD en las DI.

Introduction. The degree of Dornic acidity (DA) is an indirect measure of milk contamination and quality. In freshly expressed milk, DA ranges between 1.0 and 4.0 (optimal). If DA is > 8.0 °D, it should be discarded. The correlation between DA in raw breast milk from internal donors (ID) and external donors (ED) based on storage time until pasteurization was assessed. Population and method. Retrospective, analytical study. Results. In 13 203 samples, DA was lower in IDs as of 14 days of storage: 2.92 (95% CI: 2.69­3.15) versus 4.01 (95% CI: 3.94­4.08), with a higher proportion of DA ≤ 4 °D (88% in IDs versus 76% in EDs); odds ratio: 2.30 (95% CI: 1.25­4.24). Conclusion. DA as of 14 days of storage was lower in IDs, with a higher prevalence of DA ≤ 4 °D. No correlation was observed between storage time and DA in ID samples.

Asunto(s)

RESUMEN

The acidity of a solution is associated with the concentration of Brønsted acids. This work proposes a new non-titrimetric potentiometric method using citrate buffer for the determination of vinegar acidity. The difference between the pH values before and after the addition of a diluted vinegar sample to 10 mmol L-1 citrate buffer (pH 5.5) was related to the acetic acid concentration. The dynamic range of the quadratic analytical curve was from 3.5 to 20 mmol L-1 (R2 = 0.998). The repeatability was 0.8% for acetic acid at 0.01 mol L-1. Comparison with the conventional titration method showed an error between 0.7% and 4.64% (n = 9) for analysis of commercial vinegar samples The behaviour of the system could be explained using the buffering function.

Asunto(s)

RESUMEN

Introduction. The degree of Dornic acidity (DA) is an indirect measure of milk contamination and quality. In freshly expressed milk, DA ranges between 1.0 and 4.0 (optimal). If DA is > 8.0 °D, it should be discarded. The correlation between DA in raw breast milk from internal donors (ID) and external donors (ED) based on storage time until pasteurization was assessed. Population and method. Retrospective, analytical study. Results. In 13 203 samples, DA was lower in IDs as of 14 days of storage: 2.92 (95% CI: 2.69-3.15) versus 4.01 (95% CI: 3.94-4.08), with a higher proportion of DA ≤ 4 °D (88% in IDs versus 76% in EDs); odds ratio: 2.30 (95% CI: 1.25-4.24). Conclusion. DA as of 14 days of storage was lower in IDs, with a higher prevalence of DA ≤ 4 °D. No correlation was observed between storage time and DA in ID samples.

Introducción. El grado de acidez Dornic (AD), medida indirecta del grado de contaminación de la leche humana cruda (LHC), proporciona información sobre la calidad de esta. Recién extraída, el valor oscila entre 1,0° y 4,0° (óptimo). Descalifica el consumo si es >8,0 °D. Se evaluó la correlación de la AD de la LHC de donantes internas (DI) y externas (DE) según el tiempo de conservación hasta la pasteurización, y se determinó la prevalencia de AD ≤4 ºD. Población y método. Estudio retrospectivo analítico. Resultados. Sobre 13 203 muestras, la AD a partir del día 14 de conservación fue menor en las donantes internas, de 2,92; (IC95% 2,69-3,15) versus 4,01 (IC95%: 3,94-4,08); p <0,001] con mayor proporción de AD ≤4 ºD (88 % en DI versus 76 % en DE); OR: 2,30 (IC95%: 1,25-4,24); p = 0,003. Coeficiente de correlación para las DI: R 2:0; p = 1). Conclusión. La AD a partir del día 14 fue menor en DI, presentando mayor prevalencia de AD ≤ 4ºD. No existió correlación entre el tiempo de conservación y la AD en las DI.

Asunto(s)

RESUMEN

This study aimed to determine Patulin (PAT) in samples of organically and conventionally grown tomato varieties, to correlate it with their phenolic profile and at evaluating effects of phenolic extracts of tomato samples against the Penicillium expansum CCT 7549 strain. Four varieties of tomatoes (Cherry, Khaki, Italian and Long Life) subject to conventional and organic management were collected in markets in the south of Brazil. PAT was determined in samples by validated method Matrix Solid Phase Dispersion (MSPD) with detection in HPLC-PDA. Titratable acidity, phenolic profile and antifungal activity (minimum inhibitory concentration - MIC and minimum fungicidal concentration - MFC) against P. expansum were determined. In most tomatoes PAT was found at levels that were below the Maximum Recommended Level (MRL = 50 µg/kg). Samples of conventionally grown Cherry tomato showed high acidity and PAT contamination, whose correlation was confirmed by the Principal Component Analysis (PCA). Phenolic extracts of tomatoes subject to conventional management were more efficient to inhibit P. expansum, a fact that may be explained by the content of caffeic acid. However, since PAT production was not inhibited in fruit, it is recommended that PAT should be monitored and a new management strategy should be investigated.

Asunto(s)

RESUMEN

Vineyard soils normally do not provide the amount of nitrogen (N) necessary for red wine production. Traditionally, the N concentration in leaves guides the N fertilization of vineyards to reach high grape yields and chemical composition under the ceteris paribus assumption. Moreover, the carryover effects of nutrients and carbohydrates stored by perennials such as grapevines are neglected. Where a well-documented database is assembled, machine learning (ML) methods can account for key site-specific features and carryover effects, impacting the performance of grapevines. The aim of this study was to predict, using ML tools, N management from local features to reach high berry yield and quality in 'Alicante Bouschet' vineyards. The 5-year (2015-2019) fertilizer trial comprised six N doses (0-20-40-60-80-100 kg N ha-1) and three regimes of irrigation. Model features included N dosage, climatic indices, foliar N application, and stem diameter of the preceding season, all of which were indices of the carryover effects. Accuracy of ML models was the highest with a yield cutoff of 14 t ha-1 and a total anthocyanin content (TAC) of 3900 mg L-1. Regression models were more accurate for total soluble solids (TSS), total titratable acidity (TTA), pH, TAC, and total phenolic content (TPC) in the marketable grape yield. The tissue N ranges differed between high marketable yield and TAC, indicating a trade-off about 24 g N kg-1 in the diagnostic leaf. The N dosage predicted varied from 0 to 40 kg N ha-1 depending on target variable, this was calculated from local features and carryover effects but excluded climatic indices. The dataset can increase in size and diversity with the collaboration of growers, which can help to cross over the numerous combinations of features found in vineyards. This research contributes to the rational use of N fertilizers, but with the guarantee that obtaining high productivity must be with adequate composition.

RESUMEN

Carcinogenic metabolites of fungi such as aflatoxins play a toxic role in some tree nuts and need to be monitored in their by-products, such as oil. In this context, Brazil nut (Bertholletia excelsa) oil, which is a commodity of great economic importance to Brazil, requires attention to monitor the presence of these toxic agents. Therefore, this study aimed to evaluate the presence of aflatoxins in Brazil nut oil and relate it to the presence of fatty acids in the oil as a surveillance tool for food safety. Brazil nut oil samples (n= 25) were acquired in northern Brazil as (a) non-branded products (n= 07) produced by local farmers using artisanal methods from nuts to be discarded by the industry and (b) industrialized products (n= 18). The samples were analyzed for total aflatoxin content by high-performance liquid chromatography and fatty acid content by nuclear magnetic resonance imaging. Seven (28%) samples were positive for the aflatoxin fractions (B1 + B2 + G1 + G2), ranging from undetected (<2.32) to 50.87 µg/kg. Of the aflatoxin positive samples evaluated by NMR analysis, it was not possible to state that the presence of a particular fatty acid can interfere or influence aflatoxin contamination. This was the first study with data on aflatoxin occurrence in Brazil nut oil. Nevertheless, further research is required to relate saturated or unsaturated fatty acid content with aflatoxin levels. We also suggest the implementation of systems to prevent contamination of the raw materials (seed) and detoxification of the oil to guarantee the product's safety and quality.

Asunto(s)

RESUMEN

The influence of processing intumescent bio-based poly(lactic acid) (PLA) composites by injection and fused filament fabrication (FFF) was evaluated. A raw (ANa) and two acidic-activated (AH2 and AH5) montmorillonites were added to the intumescent formulation, composed by lignin and ammonium polyphosphate, in order to evaluate the influence of the strength and the nature (Brønsted or Lewis) of their acidic sites on the fire behavior of the composites. The thermal stability and the volatile thermal degradation products of the composites were assessed. The injected and 3D-printed composites were submitted to cone calorimeter (CC), limit oxygen index (LOI), and UL-94 flammability tests. A similar tendency was observed for the injected and 3D-printed samples. The high density of strong Lewis sites in AH2 showed to be detrimental to the fire-retarding properties. For the CC test, the addition of the intumescent composite reduced the peak of heat released (pHRR) in approximately 49% when compared to neat PLA, while the composites containing ANa and AH5 presented a reduction of at least 54%. However, the addition of AH2 caused a pHRR reduction of around 47%, close to the one of the composite without clay (49%). In the LOI tests, the composites containing ANa and AH5 achieved the best results: 39% and 35%, respectively, for the injected samples, and 35 and 38% for the 3D-printed samples. For the composite containing AH2 the LOI values were 34% and 32% for injected and 3D-printed samples, respectively. Overall, the best performance in the flammability tests was achieved by the composites containing clays with only weak and moderate strength acidic sites (ANa and AH5).

RESUMEN

The diagnosis of unstable non-acid milk (UNAM) in Brazil is overlooked due to the lack of information about this problem available to dairy farmers, mainly in the North region of the country. This report describes the occurrence of UNAM in three dairy farms of family farmers in northern Tocantins state, Brazil, who use animal feed based on Urochloa brizantha without mineral supplementation. The animals had been subjected to a poor feeding practice, with low quantity and quality, due to the dry period in the region and inappropriate nutritional management. Fourteen animals that presented alterations in milk characteristics were subjected to 72% alizarol test, California mastitis test, strip cup test, somatic cell count (SCC), boil test, physical-chemical and microbiological analyses, and search for undesirable substances. The time of lactation, udder health, and serum glucose level of animals, and soil and forage quality were also evaluated. The results showed 42% animals diagnosed with mastitis, 21% of them with clinical and 21% with subclinical mastitis; and 78% of animals with samples positive for the alizarol and boil tests, and Dornic acidity between 14° and 18°, characterizing positive cases for UNAM. Only one animal presented SCC above the limit established by the Brazilian legislation. The animals presented undamaged teats and no alteration in glycemia. Changes in nutritional management were recommended and done and the alizarol tests were redone after 14 days, showing all negative results for UNAM. The conclusion is that incorrect nutritional management is the main cause of UNAN in the studied cases.(AU)

O diagnóstico do leite instável não ácido (LINA) no Brasil ainda é negligenciado devido à falta de informação dos produtores acerca do problema, principalmente na região norte do país. Este relato descreve a ocorrência de leite instável não ácido (LINA) em três propriedades de agricultura familiar localizadas no norte do Tocantins cuja alimentação dos animais era à base de Urochloa brizantha e sem suplementação mineral. Os animais passavam por restrição alimentar, com quantidade e qua-lidade prejudicadas em função do período de seca e de um manejo nutricional inadequado. Foi realizado teste do Alizarol 70%, California Mastitis Tests, Teste de Caneca Telada, CCS, teste da fervura, além de análises físico-químicas, microbiológicas e pes-quisa de substâncias indesejáveis em 14 animais que apresentaram alterações em seu leite. Também foram avaliados o tempo de lactação, a saúde do úbere e os níveis de glicose sérica dos animais, além da qualidade do solo e das forrageiras oferecidas. 42% dos animais foram diagnosticados com mastite, destes, 21% clínica e 21% subclínica. 78% dos animais obtiveram amostra com resul-tado positivo no teste do alizarol e no teste da fervura e acidez Dornic entre 14° e 18, caracterizando casos positivos para LINA. Apenas um animal apresentou CCS acima do preconizado pela legislação. Os animais apresentaram tetos íntegros e não altera-ção da glicemia. Foram sugeridas mudanças no manejo nutricional, e após 14 dias foram refeitos os testes do Alizarol com todos resultados negativos para LINA. Concluiu-se que os casos estudados têm como principal causa o manejo nutricional incorreto.(AU)

Asunto(s)

RESUMEN

Introduction: although reports on dental erosion have appeared in literature for a long time, there is currently a growing interest among researchers and clinicians about this matter. Potential risk factors for loss of dental hard tissue are changed lifestyle and eating patterns, with increased consumption of acid foods and beverages. Case report: an atypical tooth wear on the buccal surfaces of the mandibular teeth in a 45-year-old woman referred for orthodontic treatment, associated with the frequent consumption of whiskey and lemon, is reported. A comprehensive approach, such as the recognition of dental erosion joined with a careful investigation about eating habits was performed. Ultrastructural examination of replicas of the teeth showed practically structureless enamel and dentin surfaces. Conclusion: the screening for dental erosion in patients seeking orthodontic treatment is advisable to be a usual procedure. Recommendations for treatment and prophylactic measures are made emphasizing the need of multiprofessional attention.

Introdução: embora relatos sobre erosão dentária já apareçam há bastante tempo na literatura, existe atualmente interesse crescente entre pesquisadores e clínicos sobre esse assunto. Fatores que representam riscos potenciais para a perda de tecido duro do dente são as mudanças no estilo de vida e no padrão de alimentação, com o aumento no consumo de alimentos e bebidas ácidas. Relato de caso: lesões atípicas de desgaste dentário na superfície vestibular das unidades inferiores, em uma mulher com 45 de idade, encaminhada para tratamento ortodôntico, associadas ao consumo frequente de uísque e limão, foram relatadas. Uma abordagem abrangente, como o reconhecimento da erosão dentária, em conjunção com a investigação cuidadosa dos hábitos alimentares, foi realizada. O exame por meio da microscopia eletrônica de varredura, realizada em réplicas dos dentes, revelou superfícies de esmalte e dentina praticamente desprovidos de elementos estruturais. Conclusão: sugere-se que uma avaliação direcionada à busca por erosão dentária em pacientes que procuram por tratamento ortodôntico seja um procedimento rotineiro. A atenção multiprofissional, envolvendo o tratamento e o uso de medidas preventivas, é essencial para a adequada atuação junto ao paciente.

Asunto(s)