Manuel Salvador Vicente Plata-Oviedo

Study of the Rheological Parameters of Honey Using the Mitschka Method

In this work the rheological behavior of two varieties of honey were evaluated using a Brookfield viscometer R.V.T in a temperature range of 5-20°C. In order to interpret the experimental results in terms of viscosity, the torque-speed data and scale readings were converted into shear stress-shear rate relations using numerical conversion values proposed by Mitschka. This method offers excellent potential for quality control testing in the food industry. Samples exhibited Newtonian behavior and the temperature effect on the viscosity followed an Arrhenius-type relationship.

A erva-mate (Ilex paraguariensis Saint Hilaire) como substituto parcial do lúpulo amargor na fabricação de cerveja artesanal

A cerveja e uma bebida obtida da fermentacao de um mosto de agua, malte, lupulo e adjuntos pela acao de leveduras do genero Saccharomyces. Diversos sao os fatores que influenciam as caracteristicas finais de uma cerveja, dentre eles, a metodologia aplicada e principalmente os ingredientes utilizados, pois, cada ingrediente e responsavel por caracteristicas particulares da cerveja, como sabor, odor e corpo. O presente trabalho teve como objetivo avaliar a substituicao parcial do lupulo amargor por erva-mate na fabricacao de cerveja artesanal. Foram elaboradas cinco formulacoes diferentes de cerveja, sendo uma isenta de substituicao do lupulo por erva-mate e outras quatro formulacoes, com respectivamente 0,5g; 1,0g; 2,0g e 3,0g de erva-mate. Foram realizadas analise de teor alcoolico (% v/v), pH, acidez (g de acido lactico,% m/v), °Brix, extrato real (% m/v), extrato primitivo (%m/m) e grau real de fermentacao. As cervejas elaboradas foram classificadas com base nas analises fisico-quimicas como Puro Malte , de alta fermentacao, extra e com alto teor alcoolico.

Cassava starch (Manihot esculenta Crantz) esterified with stearic acid

The objective of this study was to esterification cassava starch with stearic acid, to obtain starches with emulsifying properties, stabilizing and encapsulant of oleic acid. The cassava starch was treated with stearic acid in an alkaline medium (pH 8.0, 9.0, 11.0 and 13.0) and catalyzed by microwave radiation, to obtain the saturated ester starch. The percentage of esterification and degree of substitution (DS), the swelling power and solubility, the apparent viscosity of gels, emulsifying activity and the stability of the emulsions prepared with the modified starches were determined. The use of modified starch in the encapsulation of oleic acid and salad dressings was assessed. The pH of the reaction influences the content and esterification in the GS, only sample evaluated at pH 13.0 showed no percentage esterification. The modification reduced apparent viscosity, the swelling power and the solubility of the granules. Esterification at pH 8.0, 9.0 and 11.0 increased the emulsifying stability and encapsulation efficiency of the starches. Could not find correlation between encapsulation efficiency and the hydrophobicity of the starches. The application of modified starch in sauces like mayonnaise for salads did not show favorable results since the emulsion formed was not stabilized. The emulsion stability was compromised due to low viscosity of the starches after modification

Craft Beer elaboration from partial replacement of malt by honey

In recent years, two trends has excelled in the universe Brewer: getting beer from concentrated musts and the elaboration of beer using special assistants, which may or not aromatize the same, in order to obtain unique sensory attributes in products obtained. The honey of Apis mellifera, is raw material quite favorable to the alcoholic fermentation for being rich in carbohydrates, minerals and low acidity. The present study aimed to develop artisanal beer, using honey as malt and partial substituent as natural flavouring of craft beers. Four different formulations were made of beer, being a replacement for malt-free honey and three other formulations, with respectively 10%, 20% and 30% of honey. Based on the results observed it was concluded that the use of honey in the three levels of substitution allowed obtaining higher-alcohol beers (5.21, 5.76 and 5.57% v/v) in respect of conventional beer (4.86%, v/v). According to the sensory tests the drink proved with consumption potential, since the beers showed distinct features and samples containing honey were the most accepted. Considering that this type of beer is not traditionally consumed in Brazil, this work aims to broaden scientific knowledge in the area of manufacturing technology of honey beers, since the subject is of great importance to enlarge the market of this product.

ESTUDO DO COMPORTAMENTO REOLÓGICO DE SUCOS COMBINADOS DE FRUTAS VERMELHAS

O objetivo deste trabalho foi avaliar o comportamento reologico de sucos combinados de morango, amora-preta e framboesa em duas diferentes temperaturas de interesse em processos industriais na industria de alimentos, usando analises reologicas em regime nao-oscilatorio e a metodologia de superficie de resposta (MSR). Os dados reologicos foram ajustados pelo modelo de Casson. Todas as amostras de sucos combinados de frutas vermelhas apresentaram um comportamento newtoniano, sendo que os parâmetros reologicos tensao inicial (K oc ) e viscosidade plastica de Casson (K oc ) tiveram uma reducao em seus valores com o aumento da temperatura. Pela analise dos diagramas ternarios ficou evidente como o suco de framboesa contribuiu efetivamente para os maiores valores da tensao inicial e viscosidade plastica de Casson em ambas as temperaturas estudadas.