Tecnologia de Alimentos
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11783
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Resultados da Pesquisa
Item Desenvolvimento e avaliação de filme antimicrobiano aromatizado para aplicação em massa de pastel(Ciência Rural, 2011-03) Moraes, Allan Robledo Fialho e; Vidigal, Márcia Cristina Teixeira Ribeiro; Soares, Nilda de Fátima Ferreira; Moraes, Luana Pereira de; Melo, Nathália Ramos de; Gonçalves, Maria Paula JunqueiraA indústria de alimentos, buscando atender à crescente demanda dos consumidores, vem desenvolvendo embalagens ativas para proporcionar qualidade e segurança aos produtos acondicionados. Este trabalho objetivou desenvolver e avaliar a aplicação de filmes ativos aromatizados em contato com a massa de pastel. Os filmes foram preparados pelo método casting, adicionados de ácido sórbico e aroma de pizza e avaliados in vitro frente ao microrganismo Penicillium sp. Também foram estudadas suas propriedades mecânicas, migração de ácido sórbico, avaliação sensorial do produto e análise microbiológica in vivo. Os filmes ativos apresentaram atividade antimicrobiana tanto in vitro como no alimento. A caracterização mecânica mostrou que os filmes ativos aromatizados apresentaram valores de carga máxima na ruptura, inferiores ao filme controle e, durante a migração, a adição de aroma contribuiu para uma maior liberação do ácido sórbico. Além disso, as massas de pastel em contato com os filmes ativos aromatizados apresentaram melhores resultados sensoriais.Item Revestimento ativo de amido na conservação pós-colheita de pera Williams minimamente processada(Ciência Rural, 2010-08) Botrel, Diego Alvarenga; Soares, Nilda de Fátima Ferreira; Camilloto, Geany Peruch; Fernandes, Regiane Victória de BarrosA pera é uma das frutas de clima temperado mais consumidas no Brasil, no entanto sua conservação é limitada devido ao seu escurecimento quando sofre danos ou tratamentos físicos. Os revestimentos comestíveis interagem favoravelmente com o alimento, aumentando sua vida de prateleira. Este trabalho objetivou avaliar a ação de revestimento de amido adicionado de lactato de cálcio e L-cisteína na inibição do escurecimento enzimático, na redução do crescimento de psicrotrófilos e enterobactérias e na manutenção da textura. As peras fatiadas foram cobertas com revestimentos comestíveis à base de amido incorporados com cisteína e lactato de cálcio, exceto o controle - sem revestimento (C). Os tratamentos foram: apenas revestimento (T1); 2,0% lactato de cálcio e 1,0% L-cisteína (T2) e 2,0% lactato de cálcio e 1,5% L-cisteína (T3). As amostragens foram feitas nos tempos zero, dois, quatro e seis dias. As amostras foram mantidas sob refrigeração (7°C±2°C). As peras submetidas aos tratamentos T2 e T3 apresentaram-se significativamente mais firmes (P<0,05) que as dos tratamentos C e T1. A ação da cisteína sobre a inibição do escurecimento enzimático foi observada nos tratamentos T2 e T3, que não apresentaram diferença significativa (P≥0,05) entre si para os valores de ∆E, no entanto esses valores foram significativamente menores em relação ao controle. No tempo 6, a redução decimal na contagem de psicrotrófilos chegou a 3,03 e 2,43 para T3 e T2, em comparação com o controle. A contagem de enterobactérias apresentou comportamento semelhante, sendo o valor da redução de 3,16 e 3,05 para T2 e T3 em relação ao controle. Verificou-se que a vida de prateleira de pera minimamente processada pode ser mantida por mais tempo com o uso desse revestimento.Item Rheological properties of aqueous dispersions of xanthan gum containing different chloride salts are impacted by both sizes and net electric charges of the cations(Food Biophysics, 2018-03-27) Galván, Zoila Rosa Nieto; Soares, Lucas de Souza; Medeiros, Eber Antonio Alves; Soares, Nilda de Fátima Ferreira; Ramos, Afonso Mota; Coimbra, Jane Sélia dos Reis; Oliveira, Eduardo Basílio deXanthan gum (XG) is one of the most effective thickener agents used worldwide. In foods products, one of the factors affecting its physical properties is the ionic strength of the medium. Though it is well known that XG rheological properties in aqueous media depend on both type and concentration of electrolytes, correlations between such dispersion properties and molecular aspects of dispersed XG chains are still to be more deeply studied. Thus, in the present study, aqueous XG dispersions [200 mg⋅(100 mL)^−1] added of Na, K, Mg or Ca chlorides (ionic strength 50 mM or 100 mM) were rheologically characterized, and the corresponding results were explained based on different physicochemical analyses. Comparing to the control (unsalted XG dispersion), KCl and CaCl2 tended to produce a more drastic decrease of apparent viscosities of XG dispersions than NaCl and MgCl2. In dynamic-oscillatory assays, the predominance of elastic character over viscous character was more evident for XG dispersions containing KCl and CaCl2, in particular at frequencies > 0.1 Hz. XG dispersions containing KCl or CaCl2 also presented smaller pH and |ζ-potentials| values, as well as greater densities and average hydrodynamic diameters of dispersed XG chains, when compared to respective counterparts containing NaCl or MgCl2. As the decreasing order of the cations radii is K+ > Ca2+ ≈ Na+ > Mg2+, our results allowed deducing that not only the net electric charges of the cations, but also their sizes, should be considered when analyzing the effect of chloride salts on rheological properties of XG aqueous dispersions, according to the desired for this hydrocolloid (weak thickener, strong thickener or pro-gelling agent).Item Aflatoxin M 1 occurrence in ultra high temperature (UHT) treated fluid milk from Minas Gerais/Brazil(Food Control, 2013-03) Soares, Nilda de Fátima Ferreira; Oliveira, Cristiane Patrícia de; Oliveira, Taíla Veloso de; Baffa Júnior, José Carlos; Silva, Washington Azevedo daAflatoxin M1 (AFM1) was determined in 75 samples of ultra-high-temperature (UHT)-treated fluid commercial milk from Minas Gerais, Brazil, from July to November 2009. AFM1 determinations were carried out by HPLC. Results showed that 23 (30.7%) positive samples for AFM1 at levels of 1000–4100 ng L^−1, which were above the tolerance limit for AFM1 in milk as adopted by Brazilian regulations. It was concluded that the incidence of AFM1 in milk marketed in Minas Gerais state is higher, warrants concern about AFM1 in milk and milk products.Item Multiple headspace-solid-phase microextraction as a powerful tool for the quantitative determination of volatile radiolysis products in a multilayer food packaging material sterilized with γ-radiation(Journal of Chromatography A, 2012-06-29) Oliveira, Cristiane Patrícia de; Rodriguez-Lafuente, Angel; Soares, Nilda de Fátima Ferreira; Nerin, CristinaA method consisting of multiple headspace solid-phase microextraction followed by gas chromatography–mass spectrometry analysis was developed and used to determine the main volatile radiolysis products formed by γ-irradiation of flexible multilayer food packaging samples. The developed method allows the use of solid-phase microextraction in the quantification of compounds from plastic solid samples. A screening of volatiles in the γ-irradiated and non-irradiated films was performed and 29 compounds were identified in the irradiated packaging, 17 of which were absent in the non-irradiated samples. The main volatile radiolysis products identified were: 1,3-di-tert-butylbenzene; 2,6-di-tert-butyl-1,4-benzoquinone; 4-tert-butyl-phenol and the off-odor compounds butanoic acid and valeric acid. These volatile radiolysis compounds were determined with the proposed method and the results are shown and discussed. Solid–liquid extraction and headspace solid-phase microextraction methods were also studied for comparative purposes. The automated solvent-free multiple HSPME technique here presented can be used to quantify the radiolysis compounds in irradiated plastic solid samples in a simple way with the advantages of being free from matrix influence and environmentally friendly.Item Behaviour of polydiacetylene vesicles under different conditions of temperature, pH and chemical components of milk(Food Chemistry, 2012-12-01) Oliveira, Cristiane Patrícia de; Soares, Nilda de Fátima Ferreira; Fontes, Edimar Aparecida Filomeno; Oliveira, Taíla Veloso de; Maradini Filho, Antônio ManoelBlue polydiacetylene vesicles were studied with regard to their behaviour under variations in storage temperature, heating, potentiometric titration and in the presence of chemical components of milk, to evaluate their application as a sensor in the food industry. Vesicles were prepared using 10,12-pentacosadienoic acid (PCDA)/1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC). Their changes were monitored using UV–Vis absorption. Temperatures not exceeding 25 °C did not cause colour change in PCDA/DMPC vesicles for a period of up to 60 days of storage. Heating for 10 min at 60 and 90 °C, exposure to pH higher than 9.0 and the simulant solutions of the whey proteins, β-lactoglobulin and α-lactalbumin, promoted colour change from blue to red for the vesicles studied. The effects of routine factors on the characteristics and stability of polydiacetylene vesicles is important in defining the parameters related to their application as a sensor for the food industry.Item Antimicrobial edible coating in post-harvest conservation of guava(Revista Brasileira de Fruticultura, 2011-10) Soares, Nilda de Fátima Ferreira; Silva, Danielle Fabíola Pereira; Camilloto, Geany Peruch; Oliveira, Cristiane Patrícia; Pinheiro, Neuma Maria; Medeiros, Eber Antonio AlvesThis study aimed to develop an antimicrobial edible coating and to evaluate its efficiency in preserving guava. Guava samples were submitted to five treatments: without coating, coating of cassava starch, coating of cassava starch added with acetic acid, coating of cassava starch added with 1.0% and 1.5% chitosan. The following characteristics were analyzed: color of pulp and peel, texture, mass loss, total soluble solids, filamentous fungi and yeast counting. Peel green color of the fruits treated with antimicrobial coatings was preserved and the pulp color of all treatments changed from pink to intense red during the storage. Fruits treated with antimicrobial coatings presented lower mass loss, when compared with the control fruits. There was a decrease in the total soluble solid values of the control group during storage, whereas in the other treatments, the sugar content was preserved until the 8^th day. Fruits treated with 1.0% and 1.5% of chitosan showed the lower filamentous fungi and yeast counting when compared with the control. The use of antimicrobial edible coatings contributes to the preservation of guava, reducing microbial growth and increasing its post-harvest life.Item Packaging properties and control of Listeria monocytogenes in bologna by cellulosic films incorporated with pediocin(Brazilian Journal of Food Technology, 2013-08-29) Espitia, Paula Judith Pérez; Pacheco, Jhon Jairo Reina; Melo, Nathália Ramos de; Soares, Nilda de Fátima Ferreira; Durango, Alba ManuelaListeria monocytogenes is a foodborne pathogen, able to survive and proliferate at refrigeration temperatures. As a result, ready-to-eat meat products have been associated with major outbreaks. Producing meat products involves lethal preservation treatments, e.g. thermal treatments. Listeria contamination, however, may be introduced when products are sliced and packaged at retail businesses or delicatessens. In Brazil, sliced bologna is very popular at retail markets. After slicing, however, bologna has a short shelf-life. The aim of this work was to study the effects of pediocin incorporation on the load at break, water vapor permeability rate and structure, by microscopic analysis, of antimicrobial cellulosic packaging. The potential application of the developed packaging for the preservation of bologna and inhibition of Listeria biofilm formation was also studied. Cellulosic antimicrobial packaging films were produced with cellulose acetate and acetone. Pediocin (commercially available concentrate ALTATM 2341) was incorporated at 30, 40 and 50 % w/w. The load at break of films was studied using the Universal Testing Machine (Instron) at 10 °C and 25 °C. The water vapor permeability was determined by gravimetric method. A scanning electron microscope was used to study the developed packaging structure. Antimicrobial activity of films against Listeria innoucua and L. monocytogenes was tested both in vitro and in bologna samples. Results showed that values of load at break decreased with increasing concentrations of pediocin at 10 °C and 25 °C. Regarding water vapor permeability, only the control and 50 % pediocin films presented statistical difference, with the 50 % pediocin film being more permeable. In vitro tests showed antimicrobial activity against L. innocua. Cellulosic film with 50 % pediocin reduced L. monocytogenes growth on sliced bologna by 1.2 log cycles after 9 days and prevented biofilm formation on packaging and bologna surfaces. Hence, active cellulosic films made with 50 % pediocin in the form of commercially available concentrated ALTATM 2341 have the potential of being used in a system of hurdle technologies as a final obstacle for L. monocytogenes control in bologna preservation.Item Sachês antimicrobianos em pós-colheita de manga(Revista Brasileira de Fruticultura, 2011-10) Medeiros, Eber Antonio Alves; Soares, Nilda de Fátima Ferreira; Polito, Tiago de Oliveira Sales; Sousa, Miriane Maria de; Silva, Danielle Fabíola PereiraObjetivou-se com este trabalho desenvolver sachês incorporados com óleos essenciais avaliando as propriedades físico-químicas e microbiológicas de mangas armazenadas em saco de papel contendo estes sachês em seu interior. Os óleos essenciais de orégano (Origanum vulgaris) e capim-limão (Cymbopogon citratus) foram incorporados em saches, e sua atividade antimicrobiana foi testada nos fungos Colletotrichum gloeosporides, Lasiodiplodia theobromae, Xanthomonas campestris pv. mangiferae indica, Alternaria alternata. Frutos de manga 'Tommy Atkins' foram acondicionados individualmente em sacos de papel contendo em seu interior um sachê antimicrobiano e mantidos a 25 °C ± 2 °C e UR 80% ± 5% por nove dias. Os parâmetros cor da epiderme, firmeza de polpa, sólidos solúveis, acidez titulável e pH sofreram pouca influência dos óleos essenciais de orégano e capim limão, indicando que a presença do óleo essencial não altera as características físico-químicas da polpa de manga. Os sachês ativos incorporados com óleos essenciais de orégano e capim limão apresentaram controle no crescimento dos microrganismos testados, sendo o capim-limão mais eficiente, reduzindo em aproximadamente 2 ciclos Log a contagem de mesófilos aeróbios e fungos filamentosos e leveduras em relação ao tratamento controle empregado.Item Desenvolvimento e caracterização de filmes de base celulósica incorporados com aldeído cinâmico(Brazilian Journal of Food Technology, 2014-03) Lopes, Franceline Aparecida; Soares, Nilda de Fátima Ferreira; Lopes, Cristiane de Cássia Pires; Silva, Washington Azevedo daFilmes antimicrobianos foram desenvolvidos com a incorporação de aldeído cinâmico nas concentrações de 5%, 10% e 20% v/p. Suas atividades de inibição do crescimento foram avaliadas para as bactérias Staphylococcus aureus, Listeria monocytogenes e Escherichia coli e para os fungos Fusarium oxysporum e Aspergillus flavus. As propriedades mecânicas dos filmes também foram avaliadas. Para as bactérias, à exceção de E. coli, foram observados halos de inibição que aumentaram proporcionalmente ao aumento da concentração de aldeído cinâmico no filme. A espessura média dos filmes utilizados, independentemente da concentração, foi de 32,47 µm e a média de deformação relativa na carga máxima dos filmes foi de 2,05% a 8 ºC e 1,73% a 25 ºC. O filme contendo 10% de aldeído cinâmico apresentou carga máxima de deformação de 108,27 N (Newton), significativamente menor (p<0,05) que os filmes com 0% e 5%. Os resultados mostraram que o uso de filmes incorporados com aldeído cinâmico é uma alternativa como embalagem ativa para o controle do crescimento de micro-organismos em produtos alimentícios.