Tecnologia de Alimentos
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11783
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Item Acacia gum as modifier of thermal stability, solubility and emulsifying properties of α-lactalbumin(Carbohydrate Polymers, 2014-12-05) Oliveira, Fabíola Cristina de; Coimbra, Jane Sélia dos Reis; Oliveira, Eduardo Basílio de; Rodrigues, Marina Quadrio Raposo Branco; Sabioni, Rachel Campos; Souza, Bartolomeu Warlene Silva de; Santos, Igor José BoggioneProtein–polysaccharide conjugates often display improved techno-functional properties when compared to their individual involved biomolecules. α-Lactalbumin:acacia gum (α-la:AG) conjugates were prepared via Maillard reaction by the dry-heating method. Conjugate formation was confirmed using results of absorbance, o-phthalaldehyde test, sodium dodecyl sulfate–polyacrilamide gel electrophoresis (SDS–PAGE) and size exclusion chromatography. Techno-functional properties (emulsifying characteristics, solubility, and thermal stability) were evaluated for α-la, α-la/AG mixtures and α-la:AG conjugates. Conjugate thermal stability was improved compared to pure α-la treated at the same conditions of conjugate formation. Response surface methodology was used to establish models to predict solubility and emulsifying activity as functions of the salt concentration, pH and reaction time. α-la:AG conjugate solubility is affected in a complex manner by the three factors analyzed. Emulsifying activity index (EAI) of α-la is significantly affected by pH, while the α-la:AG EAI is affected by the three analyzed factors. Both solubility and EAI are maximized with pH 8.0, NaCl concentration of 0.3 mol L−1 and two days of Maillard reaction.Item Bacterial diversity of artisanal cheese from the Amazonian region of Brazil during the dry and rainy seasons(Food Research International, 2018-03-21) Martins, Mayra Carla de Freitas; Freitas, Rosângela de; Deuvaux, Júlio Cesar; Eller, Monique Renon; Augusto Nero, Luís; Carvalho, Antônio Fernandes deThe microbiota from artisanal cheeses produced in the Amazonian region is evaluated. Samples of artisanal cheeses were obtained from markets in Conceição do Araguaia and Redenção (Pará, Brazil) over rainy and dry seasons, and their biodiversity was assessed by culture-dependent and culture-independent methods. Mean counts of lactic acid bacteria (LAB) in cheeses ranged from 7.32 to 8.84 log CFU/g, for both seasons. Members of genera Lactobacillus, Lactococcus, Weissella, Enterococcus, Pediococcus, and Leuconostoc were predominant. The amplification of the 16S rRNA V6-V9 region, followed by a temporal temperature-gradient gel electrophoresis (TTGE) and sequencing of the TTGE bands revealed important differences in the microbial composition variability between samples from the two seasons and among cheese samples analyzed. TTGE showed the presence of microorganisms that are frequently found in cheese, such as L. lactis subsp. lactis, as well as other non-usual species, such as Macrococcus caseolyticus and Corynebacterium variabile. Moreover, TTGE analysis revealed the presence of microorganisms that have been isolated from other types of foods (Paralactobacillus selangorenses) along with some not usually found in foods, such as Exiguobacterium acetylicum, plus the presence of pathogenic microorganisms (Granulicatella elegans and Aerococcus sanguinicola). The present molecular approaches combined with culture-dependent methods provided a more detailed description of the microbial ecology of traditional cheeses from the Amazonian region in northern Brazil.Item Influence of package and health-related claims on perception and sensory acceptability of snack bars(Food Research International, 2017-08-31) Pinto, Vinícius Rodrigues Arruda; Freitas, Tamara Beatriz de Oliveira; Dantas, Maria Inês de Souza; Lucia, Suzana Maria Della; Melo, Laura Fernandes; Minim, Valéria Paula Rodrigues; Bressan, JosefinaConcerns for health can lead to healthier food choices, especially if the consumer is well informed. This study aimed to evaluate the importance of package and health-related claims on Brazilian consumers' acceptance of snack bars. In order to evaluate package attributes, in focus groups discussions, 19 consumers chose the most important factors that influence their purchase decisions. Next, 102 consumers evaluated six commercial brands of snack bars in a three-session acceptance test: the first with no information about the product, the second containing the product package and the third with information on health-related claims associated with consumption of the bar. In general, package attributes, price and flavor were the most important factors that influence the purchase of snack bars. Health claims positively influenced consumer acceptance, but information concerning the absence of gluten and lactose did not significantly alter sensory acceptance. The presence of omega-3s, sugars, preservatives, flavorings and colorings have the potential to improve acceptability, because they were able to raise the acceptance of the seed bar, removing it from the rejection region. Protein and nut bars are not well known to the general public and the lower mean acceptance of the seed and protein bars demonstrated the need for sensorial improvement.Item Thermodynamic and kinetic analyses of curcumin and bovine serum albumin binding(Food Chemistry, 2017-09-18) Hudson, Eliara Acipreste; Paula, Hauster Maximiler Campos de; Ferreira, Guilherme Max Dias; Ferreira, Gabriel Max Dias; Hespanhol, Maria do Carmo; Silva, Luis Henrique Mendes da; Pires, Ana Clarissa dos S.Bovine serum albumin (BSA)/curcumin binding and dye photodegradation stability were evaluated. BSA/curcumin complex showed 1:1 stoichiometry, but the thermodynamic binding parameters depended on the technique used and BSA conformation. The binding constant was of the order of 105 L·mol−1 by fluorescence and microcalorimetric, and 103 and 104 L·mol−1 by surface plasmon resonance (steady-state equilibrium and kinetic experiments, respectively). For native BSA/curcumin, fluorescence indicated an enthalpic and entropic driven process based on the standard enthalpy change (ΔH○F = −8.67 kJ·mol−1), while microcalorimetry showed an entropic driven binding process (ΔH○cal = 29.11 kJ·mol−1). For the unfolded BSA/curcumin complex, it was found thatp ΔH○F = −16.12 kJ·mol−1 and ΔH○cal = −42.63 kJ·mol−1. BSA (mainly native) increased the curcumin photodegradation stability. This work proved the importance of using different techniques to characterize the protein-ligand binding.