Maria Isabel Queiroz

Caracterização da fração protéica da cianobactéria Aphanothece Microscopica Nägeli cultivada no efluente da parboilização do arroz

The objective of the present work was to evaluate the protein fraction of Aphanothece microscopica Nageli cyanobacteria cultivated in the parboiled rice effluent, submitted to different drying conditions. The production of the biomass was done by using wastewater from the process of rice parboiling in a bubble column bioreactor. The biomass was separated from the effluent by centrifugation and dehydrated in a tray dryer at 40, 50 and 60oC and thicknesses of 5 and 7 mm. The eletroforetic profile of proteins of the biomass was analysed by SDS-PAGE and presented bands with molecular weight between 62.5-15kDa. The amino acid profile was higher than the concentrations recommended by standard FAO, with the exception of the amino acids (LYS) and the sulphurated (MET+CYS). The functional properties characterisation in terms of protein solubility and emulsification capacity demonstrated the influence of the drying condition in the protein functionality of the biomass.

Seleção e treinamento de julgadores para avaliação do gosto amargo em queijo prato

SUMMARY SELECTION AND SCREENING OF A DESCRITIVE PANEL FOR EVALUATION OF BITTER TASTE IN BRAZILIAN PRATO CHEESE. The bitter taste defect in Brazilian prato cheese was evaluated by sensorial tests, using a panel of 6 selected and trained panelists. A procedure for the sample preparation was proposed and a determination of bitter taste intensity in cheese was performed. Cheese samples with thickness of 1.25 cm were immersed in caffeine solutions, at a range of 0 to 0,28% (p/v) for 12 hours at 5oC, and dried for 24 hours at the same temperature. The judges’ selection was achieved by triangular test and Wald sequential analysis. Ranking tests and 9 cm non structured scale was used for judges’ training and the results were evaluated by Friedman test, analysis of variance, and test averages according to Tukey at a level of 5% probability. The bitter taste was detected in different samples, and the samples with highest intensity obtained a score of 5.89±1.86, which corresponds to the sensation produced by cheese samples immersed in caffeine 0.07 % (p/v). The results showed that the immersion of sample cheese in caffeine solution was an adequate procedure to detect the bitter taste in Brazilian prato cheese.

Caracterização sensorial de ovos de codornas alimentadas com dietas modificadas

The eggs are a reliable source of many compounds, such as vitamins, mineral, and proteins. That is the reason why their consumption has been increasing significantly, mainly quail eggs. Descriptive sensorial analysis, which has a pre-defined terminology for the description of the sensorial perceptions, can be considered the first step in the characterization of a nutritious product. Due to the lack of information on the sensorial characterization for quail eggs, the objective of this work was to evaluate the flavor and aroma of these eggs, whose birds were fed diets containing semi-purified oil of fish and the solid fraction of the chemical silage of fish residues. Firstly, the sensorial team was selected and trained, the terminology for quail eggs was surveyed, and the evaluation of different samples was carried out. 10 judges were selected for flavor evaluation and 10 for aroma analyses. Based on the survey of terms, four different groups were described: sweet, farinaceous, oleaginous, and penetrating. It was verified that the diet of the birds can influence in the sensorial characteristics of the quail eggs. Interference of some flavors and aroma of higher intensity was observed. The solid fraction of the chemical silage of fish provides less sensorial modifications than the commercial semi-purified fish oil; when the silage has antioxidants, it does not affect the aroma and flavor of the eggs

Avaliação funcional de bases proteicas desidratadas de anchoita (Engraulis anchoita)

Considerou-se neste trabalho a avaliacao funcional de bases proteicas desidratadas de anchoita (Engraulis anchoita) foi considerada neste trabalho. A polpa do pescado foi separada mecanicamente e submetida a lavagem com dois solventes, agua e acido fosforico. A secagem em camada delgada das bases proteicas foi conduzida em temperaturas de 40, 60 e 70°C e espessuras de amostra de 5mm. O produto foi avaliado considerando a determinacao de proteinas soluveis, composicao centesimal e propriedades funcionais, expressas pela solubilidade proteica, capacidade de retencao de agua, capacidade de retencao de gordura e capacidade emulsificante. Os resultados indicaram que a obtencao da base proteica de anchoita usando acido fosforico como solvente de lavagem apresentou melhores caracteristicas, se consideradas as operacoes de extracao de proteinas soluveis, secagem e propriedades funcionais do produto final. Com relacao a secagem, verificou-se que esta operacao origina um produto com melhores caracteristicas funcionais quando sao empregadas temperaturas de 40 e 60°C.

Influência dos compostos nitrogenados na concentração de proteína da cianobactéria Aphanothece microscopica Nägeli

This study aimed to evaluate the influence of nitrogen compounds on the protein concentration of the cyanobacterium Aphanothece microscopica Nageli cultivated in BG11 medium and fish processing effluent. The experimental conditions were 200 mg L-1 inoculum, 30 °C, pH 7.6, and C/N ratio 20. Each culture was harvested during the early, mid-log, and late logarithmic growth phase and during the stationary phase and analyzed in terms of total nitrogen, non-protein nitrogen, ammonium nitrogen, nitrate, nitrite, and nucleic acid. It can be said that in all cultures the ammonium ion and the nucleic acids account for great portion of the non-protein nitrogen in the biomass. The results show that the culture medium influences the nitrogen content, and that the Kjeldahl method overestimates the real protein concentration in cyanobacteria.