Browsing by Author "Gomes, Francileni Pompeu"
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- Analysis of volatiles of rose pepper fruits by GC/MS: drying kinetics, essential oil yield, and external color analysisPublication . Oliveira, Kênia Borges de; Carocho, Marcio; Finimundy, Tiane C.; Resende, Osvaldo; Célia, Juliana Aparecida; Gomes, Francileni Pompeu; Quequeto, Wellytton Darci; Bastos, Fabiano José de Campos; Barros, Lillian; Ferreira Junior, Weder NunesCondiments and culinary supplements are subjected to long-term storage and may undergo physical, chemical, and biological changes that can influence their quality. )us, the objective of the present study was to analyze the drying kinetics of rose pepper (Schinus terebinthifolius Raddi) fruits in an oven with forced air circulation at different temperatures, namely, 45, 55, 65, and 75°C, and determine the effective diffusion coefficient and activation energy using different mathematical models. Furthermore, the effects of the different drying temperatures were analyzed for external color parameters and yield of essential oil contents by gas chromatography coupled to a mass spectrometer. Of the ten models used for fitting, )ompson’s model was one with the best fitting to represent the drying of rose pepper fruits. )e diffusion coefficient increases with the elevation of drying air temperature, described by the Arrhenius equation, with activation energy of 53.579 kJ·mol− 1. )e color of the fruits decreased in lightness (L∗) with the increase in temperature. Of the thirty-eight terpenes identified, α-pinene and cis-ocimene were the most abundant, with the overall highest yield being found at a drying temperature of 45°C.
- Drying kinetics of cinnamon (Cinnamomum zeylanicum J. Presl) leaves: effects on individual volatile compounds and external colorPublication . Celia, Juliana Aparecida; Resende, Osvaldo; Carocho, Márcio; Finimundy, Tiane C.; Oliveira, Kenia Borges de; Gomes, Francileni Pompeu; Quequeto, Wellytton Darci; Barros, Lillian; Ferreira Junior, Weder NunesThe post-harvest stage of crops aims to minimize losses occuring during storage and commercialization. Drying process are some of the most used methods to minimize those losses. This work aimed at studying the drying kinetics of cinnamon (Cinnamomum zeylanicum), subject to two different drying conditions, one of which in an experimental fixed-bed dryer relying on an ambient air and speed of 0.5 m s-1, and the other with a forced air circulation oven at different temperatures (313.5, 323.15, 333.15 and 343.15 degrees K). The time required to reach the moisture equilibrium contents was 1.42, 3.0, 6.41, 14.0 and 21 h for drying temperatures of 343.15, 333.15, 323.15, 313.5 and 307.95 oK, respectively. The Arrhenius equation described the diffusivity's dependence on temperature, defining the activation energy of 64.77 kJ mol-1. The essential oils of the samples were analyzed through gas chromatography, which identified 23 individual compounds being eugenol the most abundant.
- Optimization and validation of two methods to determine the levels of AFM1 in milk and cheese samples using immunoaffinity columns for extraction and HPLC-FLD for quantificationPublication . Vaz, Andreia; Gomes, Francileni Pompeu; Alves, A.; Rodrigues, Paula; Venâncio, ArmandoConsumption of dairy products has expanded rapidly over the past decade and constitutes an important source of dietary protein. 1 Aflatoxin M1 (AFM1) is a potent carcinogen metabolite that can be present in milk from dairy cows that consume feed contaminated with Aflatoxin B1. Even though it is less toxic than its parent compound, AFM1 is hepatotoxic and carcinogenic, and is stable during milk pasteurization, storage and preparation of various dairy products. 2,3 Due to the toxicity of this molecule, its detection and quantification is extremely important. The objective of this work was to optimize and validate two methods, according to Commission Regulation (EC) nº 401/2006 of 23 February, to determine the levels of AFM1 in milk and in cheese, using immunoaffinity columns (IAC) for extraction and HPLC with fluorescence detection for quantification.4 The method for milk samples was adapted from VICAM – the supplier of the IAC, and for cheese samples was from r-biopharm and VICAM.5,6 For both methodologies, three levels of spiking in triplicate on two different days were performed. The calibration curve was linear from 0.047 to 4.7 μg L⁻¹ and the detection and quantification limits for milk and cheese were 0.001 μg L⁻1 and 0.003 μg L⁻¹, and 0.006 and 0.02 μg kg⁻¹, respectively. For milk samples, average recoveries determined at spiking levels of 0.020, 0.050 and 0.10 μg L⁻¹ were in the range of 62 % – 87 %, with intra-day precision (RSDr) in the range of 3.4 % – 9.5 %, and inter-day precision (RSDr) in the range of 5.4 % – 6.2 %. For cheese samples, average recoveries determined at spiking levels of 0.050, 0.10 and 0.25 μg L⁻¹ were in the range of 47 % – 74 %, with intra-day precision (RSDr) in the range of 3.8 % – 7.0 %, and inter-day precision (RSDr) in the range of 3.8 % – 5.8 %. Results of the validation process indicate that, except for the recovery in cheese samples, both methods are agree with the provisions of Commission Regulation (EC) nº 401/2006. Despite the recovery for cheese, both methods are precise for the quantification of AFM1 in milk and cheese.