ABSTRACT: European market regulates that poultry electronarcosis stunning in abattoirs must be performed with a minimal required current (mA per animal) and correlative frequency (Hz), to promote animal welfare and meat quality. In this way, Brazilian abattoirs must adjust the stunning parameters so that they can meet the requirements of that market. This study evaluated the effect of stunning parameters using frequency and duty cycle variables. For this, nine treatments were performed, whose results showed that the analyzed frequencies (700, 1100, and 1500 Hz) had a higher incidence of indicators of animal welfare (AW). Thus, stunning had low efficiency in AW terms. However, the 25% and 40% duty cycles had the best stunning efficiency. There was no significant difference (P > 0.05) for pH 24 h, bruises, and drip loss. Color and pH 2 h were significantly affected (P < 0.05). The shear force was higher in birds subjected to higher frequencies and interaction between 1500 Hz and 15% and 25% duty cycles. Water-holding capacity was lower at 1100 Hz and in the 25% duty cycle interactions. The treatments affected the evaluated indicators, except for the 40% duty cycle, which had a positive influence. Therefore, the duty cycle applicability must be elucidated due to its direct influence on stunning efficiency.

RESUMO: O mercado europeu regulamenta que a insensibilização de aves por eletronarcose nos abatedouros deva acontecer com uma corrente mínima necessária (mA por animal) e frequência correlata (Hz), com corrente e frequência alta. O intuito é promover o bem estar animal e qualidade de carne. Desta forma, os abatedouros brasileiros devem ajustar os parâmetros de insensibilização para que possam atender este mercado. O objetivo do trabalho foi avaliar o efeito dos parâmetros de insensibilização usando as variáveis frequência e duty cycle. Foram realizados nove ensaios. Os resultados demostraram que as frequências avaliadas (700 Hz, 1100 Hz e 1500 Hz) apresentaram maior incidência nos indicadores de Bem Estar Animal (BEA). Assim, houve baixa eficiência na insensibilização das aves para este fator. Entretanto, o duty cycle 25% e 40% promoveu a melhor eficiência na insensibilização das aves. Não foi observada diferença significativa (P > 0,05) para pH 24h, hematomas e a perda por gotejamento. A cor e o pH 2h foram afetados significativamente (P < 0,05) nos ensaios avaliados. A força de cisalhamento foi maior nas frequências mais altas e na interação da frequência de 1500 Hz com o duty cycle de 15% e 25% A capacidade de retenção de água foi menor na frequência de 1100 Hz, e na interação duty cycle 25%. Os ensaios estudados apresentaram comprometimento dos indicadores avaliados, exceto a variável duty cycle a 40%, que demonstrou influência positiva nos indicadores avaliados. Portanto, a aplicabilidade do duty cycle deve ser elucidada devido a sua influência direta na eficiência da insensibilização.

ABSTRACT Ultra-refined yerba mate (URYM), with a final particle size of 5 to 12 microns, is an innovation in the market that aims to diversify and increase the consumption of yerba mate ( Ilex paraguariensis St. Hil) through its practicality and versatility of preparation. The present work seeks to evaluate the potential for applying naturally colored URYM in food products. The nature of this study was exploratory, adopting a chemical approach (analysis of the antioxidant potential); physical approach (color stability) and sensory perception. URYM is a suitable naturally colored food ingredient with natural antioxidant appeal. Methanolic extraction of URYM (MEUR) was more efficient in scavenging DPPH radicals compared with aqueous extract of URYM (AEUR) (959.5 vs . 638.1 µmol Trolox g–1). No differences were found between AEUR and MEUR for total phenolic content in mg GAE g–1 (266.4 and 339.0, respectively) and scavenging of ABTS radicals in µmol Trolox g–1 (1008.9 and 1053.8, respectively). Water was able to extract phenolic compounds with antioxidant activity. Ice cream, juice, cake, and cookies emerged as the food products in which consumers used URYM in their homemade foods. With good color stability (no difference between L*, a* and b* parameters during the six-day) and good acceptance, cake with URYM added has a profile described as tasty, sweet, soft, and mate flavor. The results also demonstrated consumer interest in food products and ingredients with a healthy appeal.

ABSTRACT Remote sensing has proven to be a promising tool allowing crop monitoring over large geographic areas. In addition, when combined with machine learning methods, the algorithms can be used for estimating crop yield. This study sought to estimate soybean yield through the enhanced vegetation index and normalized difference vegetation index. These vegetation indices were obtained using moderate-resolution imaging spectro-radiometer (MODIS) sensors on AQUA and TERRA satellites and multispectral instrument (MSI) sensor on Sentinel-2 satellite. Random forest (RF) algorithm was used to predict soybean yield and the estimation models were compared with the actual plot’s yield. The RF algorithm showed good performance to estimate soybean yield with our models (R2 = 0.60 and RMSE = 0.50 for MSI; R² = 0.63 and RMSE = 0.59 for MODIS). Vegetation indices with imaging dates corresponding to the crop’s maturation had a higher degree of importance in its predictive ability. However, when comparing the actual and predicted soybean production values, differences of 145 kg ha-1 in contrast to 4 kg ha-1 were found for the MODIS and MSI models, respectively. Therefore, the MSI sensor integrated with machine learning algorithms accurately estimated crop yields.

RESUMO O Sensoriamento Remoto orbital (SR) tem se mostrado uma ferramenta promissora, pois permite o monitoramento de culturas em grandes áreas geográficas. Além disso, quando métodos de Aprendizado de Máquina (AM) são combinados, os algoritmos podem ser usados para estimativas de produtividade de culturas. Assim, o estudo teve como objetivo estimar a produtividade da soja por meio dos índices de vegetação EVI (Enhanced vegetation index) e NDVI (Normalized Difference vegetation index), obtidos por meio dos sensores MODIS (Moderate-Resolution Imaging Spectroradiometer) dos satélites ACQUA e TERRA e MSI (Multispectral Instrument) do satélite orbital Sentinel-2. Neste estudo, o algoritmo Random Forest (RF) foi usado por ser amplamente difundido no estudos previsão de safras, e os modelos de estimativa de rendimento da soja foram comparados com o rendimento real da parcela. Os resultados mostraram bom desempenho do algoritmo de RF para estimar a produtividade da soja, obtendo R2 de 0,60 e RMSE de 0,50 para MSI; e R² de 0,63 e RMSE de 0,59 para MODIS na validação. Na modelagem, os índices de vegetação com datas de imagem correspondentes à maturação da cultura tiveram maior grau de importância na previsão. No entanto, ao comparar os valores reais e previstos de produção de soja, houve uma diferença de 145 kg ha-1 para o modelo gerado pelo MODIS e apenas 4 kg ha-1 para o MSI. Portanto, o sensor MSI integrado aos algoritmos de aprendizado de máquina estima com precisão o rendimento das culturas.

Chlorophyll is the most abundant green pigment on the planet, it is unstable and decomposes naturally. Mate-herb is a traditional native plant in the southern region of South America, and its tea is part of the local culture and extractive agriculture. The mate-herb industry generates as a by-product a resinous material rich in chlorophyll whose use is proposed to be a natural pigment. The chlorophyll extraction method uses ethanol as a solvent; its structural modification leads to the obtainment of derivatives like pheophytin, Co-pheophytin, Ni-pheophytin, and Zn-pheophytin. The samples were analyzed by electronic (VISIBLE) and vibrational (FTIR) spectroscopy, and energy-dispersive X-ray fluorescence spectrometry (EDXRF). Color analysis (CIE L*a*b*) was performed by decomposition in grayscale and the classification of the samples by the supervised machine learning (ML) algorithm Random Forest (RF), showing adequate accuracy for this type of matrix. The pigments were dispersed in synthetic enamel paint to study color stability when exposed to lighting. It was verified that Co-pheophytin and Ni-pheophytin are the most stable. The chlorophyll extracted from the resin presents an economically viable use for residues from mate-herb industries, whose family farmers benefit, with the bias of environmental and social sustainability, within the circular economy.

Resumo O alto valor nutricional e o baixo custo de comercialização têm impulsionado o consumo de raízes de batata-doce. Adicionalmente, a grande variabilidade genética levanta questionamentos sobre a qualidade pós-colheita dos acessos cultivados. Assim, o presente estudo objetiva caracterizar e avaliar as características físico-químicas e os compostos bioativos de raízes de batata-doce. Os tratamentos consistiram na avaliação de 11 acessos (UGA 34, UGA 37, UGA 49, UGA 73, UGA 76, UGA 81, UGA 110, UGA 125, UGA 126, UGA 127 e Parcela 49). Os atributos físico-químicos de firmeza (FI) e massa seca (MS) foram avaliados em delineamento experimental em blocos casualizados. Avaliaram-se ainda pH, teor de sólidos solúveis (SS), acidez titulável (AT), relação entre sólidos solúveis e acidez titulável (SS/AT), e parâmetros colorimétricos L*, saturação de cor croma e tonalidade da cor pelo ângulo Hue obtidos da casca (externa) e da polpa (interna) das raízes. Avaliou-se também a concentração de compostos bioativos: carotenoides totais (CAR), compostos fenólicos (FEN) e teor de ácido ascórbico (AA), além da capacidade antioxidante hidrofílica e lipofílica (CAH e CAL) de amostras de batata-doce congelada. As análises foram realizadas em triplicata sob delineamento inteiramente casualizado. Os resultados indicaram grande variabilidade entre os acessos estudados, com maior rendimento de raízes de UGA 125 e UGA 127. Os acessos UGA 126 e UGA 34 sobressaíram-se quanto aos teores de sólidos solúveis, à capacidade antioxidante hidrofílica e lipofílica, à firmeza e à matéria seca; seus parâmetros colorimétricos também se destacaram dos demais acessos. Os acessos UGA 73 e UGA 81 apresentaram maiores teores de compostos fenólicos. Dessa forma, identificou-se o potencial produtivo dos acessos estudados que nos permite indicar os acessos mais promissores ao cultivo e ao consumo.

Abstract The high nutritional value and low marketing costs have increased the consumption of sweet potato roots. In addition, the great genetic variability highlights questions about the nutritional quality of the cultivated accessions. Thereby, this study aimed to characterize and evaluate the physical-chemical characteristics as well as the bioactive compounds of sweet potato roots. The treatments consisted of the use of eleven cultivated accessions (UGA 34, UGA 37, UGA 49, UGA 73, UGA 76, UGA 81, UGA 110, UGA 125, UGA 126, UGA 127 and Parcela 49). The physical-chemical characteristics of Firmness (FI) and Dry Mass (DM) were evaluated in a randomized block design. Indeed, the pH, Soluble Solids (SS), Titratable Acidity (TA), (SS / TA), colorimetric parameters L*, Color Index (C), Chroma (A), Hue angle (B) from peel (external) and pulp (internal) of roots were evaluated. The concentrations of bioactive compound were also evaluated: Total Carotenoid Contents (TCC); Phenolic Compounds (PCs); Ascorbic Acid Contents (AAC); and also, Hydrophilic and Lipophilic Antioxidant Activity (HAA and LAA) of frozen sweet potato. The analysis was performed in triplicate under a completely randomized design. The results indicated a high variability among the cultivated accessions, consisting of a superior root yield for UGA 125 and UGA 127. The genotypes UGA 126 and UGA 34 stood out for SS, LAA and HAA, FI, and DM; however, their colorimetric parameters stood out from the other genotypes. The genotypes UGA 73 and UGA 81 showed higher PCs. In this way, it could be identified the productive potential of the genotypes studied that allows us to indicate the most promising genotypes for cultivation and consumption.

Abstract Food antioxidants are a core topic of food science due mainly to the consumption of ultra-processed foods, which cannot be overlooked, and represent an importance to modern society. At the same time, natural food antioxidants are gaining attention in studies due to its food safety aspects, that commonly affect food choices. Based on this, the present study aimed to explore the cognitive evaluation of food antioxidants by consumers using the qualitative consumer technique Word Association. Two stimuli were given. Respondents were first asked to write down the first four words that came to mind; descriptions, associated thoughts, or feelings when reading “Food Antioxidants”. Secondly the word Natural was added and the stimulus was “Natural Food Antioxidants”. The Word Association technique has been shown to be an important tool for cognitive evaluation of the perception of food antioxidants, and the dimensions, Health, Food Safety, Preservatives, Source and Preference which arose and differentiated the stimuli. The results revealed some prior knowledge about issues related to food antioxidants, natural or not. Additionally, showed a clear potential use for natural food antioxidants by the food industry, judging by consumer perception that primarily related cognitively to positive aspects of healthy and food safety.

RESUMO: O presente trabalho apresenta uma metodologia analítica baseada em Cromatografia Líquida de Alto Desempenho (CLAE) e Análise de Componentes Principais (ACP) para quantificação simultânea e diferenciação analítica de ácidos orgânicos e açúcares em amostras comerciais de suco de frutas (laranja, uva, maçã e tangerina). Além do desenvolvimento do método que gerou parâmetros de validação adequados para aplicações analítica quantitativas, a análise de catorze amostras comerciais e o uso da ACP indicaram a relação entre os analitos e a natureza química constitucional do suco. Em geral, nos sucos de uva e maçã não foi quantificado ácido ascórbico sendo o conteúdo de ácido cítrico muito baixo, no entanto, as concentrações de frutose e glicose foram as mais altas em ambos sucos. Nos sucos de laranja e tangerina, o conteúdo de todos os analitos, exceto o ácido ascórbico, não diferiram estatisticamente entre si. No entanto, diferiram significativamente dos demais, principalmente em relação ao conteúdo de sacarose. Finalmente, as amostras de suco de maçã diferiram de acordo com o teor de frutose e ácido málico, constituinte predominante da maçã. Os resultados mostraram que o método comatográfico simultâneo associado à análise de componentes principais gera informações importantes sobre as características dos sucos comerciais, com potencialidade para ser utilizado em sistemas de controle de qualidade e identificação de adulterações.

ABSTRACT: The present research presents an analytical methodology based on High Performance Liquid Chromatography (HPLC) and Principal Component Analyses (PCA) for simultaneous quantification and analytical differentiation of organic acids and sugars in commercial fruit juice samples (orange, grape, apple and tangerine). In addition to the development of the method that generated suitable validation paramters for quantitative analytical applications, the analysis of fourteen commercial samples and the use of Principal Component Analysis indicated the relationship between the constituents and the very constitutional chemical nature of the juice. In general, in grape and apple juices, ascorbic acid was not quantified and the citric acid content was very low; however, the concentrations of fructose and glucose were the highest in both juices. In orange and mandarin orange juices, the content of all analytes, except acorbic acid, did not differ statistically from each other. However, these differed significantly from the others, mainly in relation to sucrose content. Finally, the apple juice samples differed according to the content of fructose and malic acid, the predominant constituint of the apple. Results showed that the simultaneous chromatographic method associated with principal component analysis generated important information about characteristics of commercial juices, with the potential to be used in systems of quality control and identification of adulterations.

Abstract Eragrostis plana (Nees) (Tough Lovegrass) shows ability to interfere with other plants, a phenomenon known as allelopathy. This chemical interaction between plants occurs due to the release of compounds into the environment. Thus, a phytotoxicity study was carried out with E. plana roots collected during each season throughout the year, and the compounds were extracted with solvents of increasing polarity. The data from the bioassays were analyzed by GLM and PCA. In addition, a fingerprint of these extracts was obtained by HPLC-DAD. The extracts in petroleum ether from roots collected in the winter and summer showed greater phytotoxicity on Ipomoea grandifolia germination and growth. The PCA obtained from the chromatogram of the crude extract showed that the extracts in petroleum ether were chemically different from the extracts in ethyl acetate and methanol. Thus, continuing this study in order to develop a new generation of bio-herbicides is essential.

Resumo O açaí é uma fruta popular brasileira, porém já faz parte dos hábitos alimentares saudáveis da população mundial, devido às suas propriedades antioxidantes. O objetivo deste estudo foi determinar o efeito do solvente na extração de compostos fenólicos com potencial antioxidante em açaí juçara (Euterpe edulis Mart.), utilizando um Delineamento Inteiramente Casualizado (DIC). O perfil dos compostos fenólicos foi quantificado por Cromatografia Líquida de Alta Eficiência (CLAE) e o conjunto de dados foi analisado por Análise de Componentes Principais (PCA). O PCA foi aplicado para evidenciar as relações entre a concentração de compostos fenólicos e os solventes. Além disso, a atividade antioxidante também foi determinada pelos métodos DPPH, ABTS e FRAP. O solvente etanol:água a 70% foi mais eficiente na extração de compostos fenólicos com alta atividade antioxidante. Neste extrato, o ácido salicílico foi encontrado em alta concentração, além de catequina, epicatequina e ácido cumárico. Com base no consenso de que os compostos fenólicos são os principais compostos relacionados à atividade antioxidante das frutas, o açaí juçara da Mata Atlântica é uma fonte potencial de compostos fenólicos e poderia ser usado como antioxidante natural para aplicação nas indústrias alimentícia e farmacêutica, em substituição aos antioxidantes sintéticos.

Abstract The açaí is a popular Brazilian fruit, however, already part of the world's healthy eating habits owing to its antioxidant properties. The study aimed to determine the effect of solvent in extracting phenolic compounds with antioxidant potential in açaí juçara (Euterpe edulis Mart.) using a Completely Randomized Design (CRD). The phenolic compound profile was quantified by High-Performance Liquid Chromatography (HPLC), and the data set was analyzed by Principal Component Analysis (PCA). The PCA was applied to evidence the relationships between the concentration of phenolic compounds and the solvents. Furthermore, the antioxidant activity was also determined by 2,2’-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and Ferric Reducing Antioxidant Power (FRAP) methods. The solvent ethanol: water 70% was more efficient in extracting phenolic compounds with high antioxidant activity. In this extract, salicylic acid was found in high concentrations as well as catechin, epicatechin, and coumaric acid. Based on a consensus that phenolic compounds are associated with the most powerful antioxidant activities of fruits, the “açaí juçara” from the Atlantic Forest is a potential source of polyphenols. They could be used as natural antioxidants for application in the food and pharmaceutical industry in order to substitute the synthetic antioxidants.

Abstract The consumption of fish in Brazil is below the world average. In order to change this scenario, considering the high nutritional value of this meat, one of the strategies is to turn fish into a convenient product, such as burgers. Since fish burgers are not yet established in the market, it requires investigation of the shelf life. To that end, survival analysis and cut-off point (COP) methodologies access the perception of consumers and trained panels. Thus, the objective of this study was to estimate the shelf life of grass carp burgers, by means of the survival analysis and cut-off point. A trained sensory panel and consumers evaluated the burgers during a refrigerated storage of 30 days. Simultaneously, the pH and the reactive substances of thiobarbituric acid (TBARS) were evaluated. The TBARS results corroborated rancidity observed both with exponential growth and with correlation coefficients above 0.98. The survival analysis determined the end of the shelf life of the fish burgers after 21 days, with the COP technique indicating 17 days. Both methodologies were efficient in estimating the shelf life of the product analyzed, considering the lower result from COP adequate, since it establishes the value were the acceptability begins to decrease.

The extraction process of bioactive compounds from grape and apple pomaces was optimized using a response surface methodology to evaluate the effect of ethanol concentration, time and temperature on the extraction of total phenolic content, antioxidant activity by radical scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) method and individual phenolics by high performance liquid chromatography (HPLC). Optimizing suggests that the best condition for total phenolic and gallic acid extraction from grape pomace was obtained in intermediate level (60% ethanol, 60 °C, 30 min) while 80% ethanol, 75 °C and 39 min was more efficient for p-coumaric acid extraction. For apple pomace the extract obtained with 50% ethanol at 75 °C and 39 minutes was more active by DPPH method and content of caffeic acid. Therefore, these abundant and inexpensive agro-industrial residues produced in Southern Brazil, are an important source of bioactive compounds that may be used as antioxidant substances in food and pharmaceutical industries.

Abstract The aim of the work was to study the mechanical properties of extruded starch/polyvinyl alcohol (PVA)/glycerol biodegradable blends using multivariate analysis. The blends were produced as cylindrical strands by extrusion using PVAs with different hydrolysis degrees and viscosities, at two extrusion temperature profiles (90/170/170/170/170 °C and 90/170/200/200/200 °C) and three conditioning relative humidities of the samples (33, 53, and 75%). The mechanical properties showed a great variability according to PVA type, as well as the extrusion temperature profile and the conditioning relative humidity; the tensile strength ranged from 0.42 to 5.40 MPa, elongation at break ranged from 10 to 404% and Young’s modulus ranged from 0.93 to 13.81 MPa. The multivariate analysis was a useful methodology to study the mechanical properties behavior of starch/PVA/glycerol blends, and it can be used as an exploratory technique to select of the more suitable PVA type and extrusion temperature to produce biodegradable materials.

The extraction process of bioactive compounds from propolis produced by selected bees was optimized using a 2³ factorial design planning to evaluate the effect of ethanol concentration, time and temperature on the extraction of total phenolic compounds and antioxidant activity. Analysis of total flavonoids, antioxidant activity and chemical characterization performed by high-performance liquid chromatography with photodiode array (HPLC-PDA) detection were carried out in optimal conditions of extraction. Optimizing results suggest that the best condition for extraction of bioactive compounds was obtained in higher levels: time (45 min), temperature (70 °C) and concentration of ethanol (80%). The extract evaluated in optimal conditions presented good antioxidant activity by the radical scavenging 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) methods and chromatographic analysis identified phenolic acids: para-coumaric, ferulic and caffeic, indicating that this material is a potential source of bioactive compounds.

The investigation of the chemical properties of soil organic matter (OM), by the use of some spectroscopic techniques, requires the removal of the mineral impurities of the samples. Therefore, the objective of this study was to evaluate the influence of the pretreatment of samples and, also, the influence of instrumental conditions on the qualitative and quantitative results obtained by Fourier transform infrared (FTIR) spectroscopy to soil and humic acid (HA) samples. The obtained results showed that: the mass of potassium bromide (KBr) used on the background pellet influenced the characteristics of samples spectra; the baseline correction changes the intensity of the absorptions; both the extraction of HA as the hydrofluoric acid (HF) treatment were not efficient in removing the mineral impurities of the samples. The scanning electron microscopy (SEM) analysis showed differences due to the extraction, but not due to the HF treatment. The present study shows the importance of the use of adequate treatments, before, during and after the spectroscopic study of soil OM, providing valuable information for future works.

Agroindustrial waste in general presents significant levels of nutrients and organic matter and has therefore been frequently put to agricultural use. In this context, the objective of this study was to determine the chemical composition, nitrogen, phosphorus, potassium, calcium, magnesium and carbon content, as well as the qualitative characteristics through Fourier transform infrared spectroscopy of four samples of poultry litter and one sample of cattle manure, from the southwestern region of Paraná, Brazil. Results revealed that, in general, the poultry litter presented higher amount of nutrients and carbon than the cattle manure. The infrared spectra allowed identification of the functional groups present and the differences in degree of sample humification. The statistical treatment confirmed the quantitative and qualitative differences revealed.