RESUMO
ABSTRACT This study aimed to evaluate the influence of the drying air temperature (140 and 160°C) and the concentration of encapsulating agents gum Arabic and polydextrose (10 and 15%) on the physicochemical characteristics of the red cabbage extract obtained through extraction in acidulated water and drying using a spray dryer. The anthocyanin retention, antioxidant activity, water activity, solubility, color and microstructure of the final product were analyzed. Results showed that increase in the temperature did not cause significant changes in the anthocyanin quantity and antioxidant activity. The microscopic analysis revealed that for both the encapsulating agents, the absence of fissures and porosity in the particle surfaces produced powder with high solubility in water. The principal component analyses showed a strong correlation between the anthocyanin content and the antioxidant activity (r = 0.82) and luminosity (r = 0.81).
RESUMO
Red cabbage aqueous extract acidified with 2 % citric acid was spray-dried using gum Arabic as encapsulating agent. The concentration of anthocyanin in the powder was 253.45 ± 10.82 mg/100 g of dry basis and antioxidant activity of 4.6 ± 0.2 mmol trolox/kg of dry basis. The sorption isotherms were determined at 15, 25 and 35 °C, and the GAB model was the one that best adjusted to the experimental data. The differential enthalpy and entropy for moisture levels up to 2 g of water/g of dry basis decreased to a minimum value of -4.36 kJ/mol and -0.019 kJ/molK respectively, and then increased in magnitude with the rise in moisture content to levels close to the free moisture with a spontaneous process, governed by the entropy. The spreading pressure increased with the rise in water activity for all temperatures, while net integral enthalpy and entropy decreased with the rise in moisture content reaching levels close to 10 kJ/mol and 0.025 kJ/molK, respectively.
RESUMO
No desenvolvimento de produtos, é de suma importância o conhecimento da influência das modificações da formulação nas propriedades sensoriais, físicas e químicas destes. O objetivo deste trabalho foi caracterizar sobremesas à base de soja com e sem adição de mucilagem de chia, utilizada como espessante alimentar. As formulações foram caracterizadas quanto as suas propriedades reológicas, °Brix, pH e cor. O perfil sensorial foi determinado por Análise Descritiva Quantitativa (ADQ), utilizando-se uma equipe de 10 julgadores treinados. Os resultados mostraram que as amostras não diferiram quanto aos valores de pH, °Brix e coordenada cromática a*. Quanto aos outros parâmetros de cor e reológicos, foram detectadas diferenças significativas entre as amostras, o que mostra a influência do tipo de espessante nestas características. Os resultados da ADQ mostraram que as amostras não apresentaram diferenças estatísticas quanto aos atributos, cor rosa, sabor de goiaba, sabor de soja e cremosidade, porém diferiram quanto à consistência. Com isso, conclui-se que a adição da mucilagem de chia pode ser feita sem causar grandes modificações ao produto.
In product development is important to study the influence of ingredients in the physical, chemical and sensory properties of the product. The aim of this study was to characterize soy-based desserts with and without addition of chia mucilage, used as food thickener. The formulations were characterized for their rheological properties, °Brix, pH and color. The sensory profile was determined by Quantitative Descriptive Analysis (QDA) using 10 trained judges. The results regarding to pH, ° Brix and color coordinate a* did not differ. Unlike these parameters, the other chromaticity coordinates and the rheological properties presented significant statistical differences between the samples. The QDA results showed that the samples did not differ as to the attributes, color, pink guava flavor, creaminess and flavor of soy, but differed in consistency. Thus, it is concluded that the addition of mucilage chia can be made without causing major changes to the product.
