Abstract The objective was to produce flour from sorghum grains, to determine the physicochemical and microbiological characteristics, and to develop different formulations of cookies, with total and partial replacement of rice flour, evaluating the moisture content, color, expansion factor and texture profile - TPA. Five formulations were processed, as follows: control - 0%; F1 - 25%; F2 - 50%; F3 - 75% and F4 - 100% sorghum flour. The sorghum flour showed physical, chemical and microbiological characteristics in accordance with current legislation, and can be inserted into human food. The different cookie formulations after baking had a moisture content below 7%. With the addition of sorghum flour, the cookies showed lower light F4 – 32.35 L*. The addition of sorghum flour did not affect the expansion factor of the cookies, with average value of 2.13. The different concentrations of sorghum flour, showed interference in analysis of the Texture-TPA profile, the F3 formulation, presented higher values of hardness 25594.44 N, fracturability 251 N, cohesiveness 0.27. Elasticity has not been compromised. The highest values of gumminess 53.08 N, chewability 1471.15 mJ were found in the formulation F4 – 100% FS. These results may help improve the quality of sorghum-based gluten-free foods for celiac consumers.

Resumo As embalagens ativas podem liberar substâncias para inibir a microbiota e as reações na superfície dos alimentos. Dentre essas substâncias a curcumina pode ser usada pois apresenta atividade antimicrobiana e antioxidante. A difusão de compostos ativos em filmes de acetato de celulose pode ser estendida por longos períodos a taxa controlada. Sua adição pode afetar as propriedades mecânicas e de barreira dos filmes, tornando-se necessário mensurar estas alterações. Assim, objetivou-se preparar filmes ativos de acetato de celulose e tween 80 incorporados com mistura simples de curcumina e nanosuspensão de curcumina e avaliar cor, propriedades mecânicas, permeabilidade ao CO2 e migração do componente ativo. A curcumina influenciou as características mecânicas, ópticas e não afetou a permeabilidade dos filmes. O tween 80 favoreceu a migração da curcumina e a redução do tamanho das partículas não aumentou a migração de curcumina.

Abstract Active packaging can release substances to inhibit microbiota and reactions on the surface of foods; among these substances, curcumin can be applied for its antimicrobial and antioxidant activity. The diffusion of active compounds in cellulose acetate films can be extended for long periods at controlled rate. The addition may affect the mechanical and barrier properties of films, requiring the measurement of the alterations. The purpose of this study was to prepare active films of cellulose acetate and tween 80 incorporated with a simple mixture of curcumin and curcumin nanosuspension as well as assess color, mechanical properties, permeability to CO2 and migration of the active component. Curcumin influenced the mechanical and optical characteristics of the films but had no effect on the permeability to CO2. Tween 80 favored the migration, and the reduction in particles size did not increase the migration of curcumin.

Pearl millet flour was utilized in kibbeh formulations instead of whole-wheat flour. Physicochemical properties, oxidation stability and sensorial characteristics of control kibbeh made with whole-wheat flour (CT) were compared with kibbehs prepared with millet flour (roasted or wet) and stored for 90 days (–18 °C). Kibbeh prepared with millet flour presented good oxidation stability (TBARS concentration). Baked kibbehs (with roasted millet flour) presented good acceptability and kibbeh samples did not differ significantly (p > 0.05) from the whole-wheat flour sample, when global appearance, texture and flavor were evaluated. Millet flour could be a suitable ingredient for kibbeh formulations, maintaining their nutritional value and sensorial quality in addition to being a gluten-free product.

Curcumin is a powerful bioactive agent and natural antioxidant, but it is practically water-insoluble and has low bioavailability; a possible solution to this obstacle would be formulations of curcumin nanoparticles. Surfactants such as tween 80 can be used to stabilize low-solubility molecules preventing particle aggregation. The objectives of this study were the preparation of a suspension with curcumin nanoparticles in tween 80, the testing of pure curcumin solubility and of a simple mixture of curcumin with tween 80 and nanosuspension in water and ethanol as solvents, and finally the assessment of the antioxidant activity. We prepared the nanosuspension by injecting a curcumin solution in dichloromethane at low flow in water with tween 80 under heating and ultrasound. The analysis of particles size was conducted through dynamic light scattering; the non-degradation of curcumin was verified through thin-layer chromatography. The analyses of antioxidant activity were carried out according to the DPPH method. The method applied to reduce the particles size was efficient. Both the curcumin suspension and nanosuspension in tween 80 increased its solubility. Curcumin and the formulations presented antioxidant activity.

Cultivos da cianobactéria Spirulina platensis vêm sendo conduzidos utilizando-se ureia como fonte de nitrogênio, em processo descontínuo alimentado, para obtenção de biomassa desidratada para ser incorporada em alimentos visando enriquecimento nutricional e conferir caráter funcional em virtude da composição rica em proteínas, vitaminas e diversos componentes bioativos. Neste trabalho, foi estudada a substituição da farinha de trigo pela mandioca, além da adição de biomassa de Spirulina platensis e açúcar invertido, para desenvolver um 'sonho' com elevada taxa da Reação de Maillard para mascarar a coloração verde da biomassa, por meio da metodologia de superfície de resposta. As formulações foram avaliadas em relação aos aspectos de composição centesimal, sensoriais e tecnológicos que, quando comparados com o padrão, sem adição de biomassa de S. platensis e açúcar invertido, demonstraram a viabilidade da adição da biomassa para conferir enriquecimento nutricional sem afetar, de forma significativa, a aceitação sensorial e as características típicas do produto obtido.

The cyanobacteria Spirulina platensis has been cultivated in a fed batch process with urea as the nitrogen source, in order to obtain dehydrated biomass for incorporation into food, aiming at nutritional enrichment and the production of a functional character, due to the amount of proteins, vitamins and several bioactive compounds found in this cyanobacterium. In this study, response surface methodology was used to analyze the substitution of wheat flour by cassava in the development of doughnuts with added Spirulina platensis biomass and inverted sugar, in order to increase the rate of the Maillard's reaction and mask the green colour of the biomass. The formulations were evaluated in relation to their proximate, sensory and technological compositions, which, when compared to the standard formulation, without the addition of S. platensis biomass and inverted sugar, showed the feasibility of adding the biomass to bestow nutritional enrichment without significantly affecting the sensory acceptance of the product or its typical characteristics.

The aim of this work was to study the enrichment of Spirulina platensis in wheat flour to prepare fresh pasta to evaluate the green color and nutritional enrichment in addition to functional properties due to the presence of the bioactive compounds in the cyanobacterium. The pastas were evaluated for the centesimal composition, microbiological contamination, sensorial acceptance and technological characteristics such as cooking time, water absorption, volume displacement and loss of solids. The superior protein contents and the satisfactory technological and sensorial attributes compared with the control with no cyanobacterium showed the usefulness of incorporating S. platensis biomass in the fresh pastas. The microbiological quality was in compliance with the legislation in force. The sensorial quality was considered satisfactory (“liked very much”) and purchase intention high (“probably would buy”).

Cereais matinais são produtos extrusados, tradicionalmente consumidos com leite e o principal componente é o amido. A característica de crocância destes produtos está associada a frescor e qualidade do produto e a sua perda é uma das causas de rejeição de consumo. Mudanças indesejáveis na textura podem ocorrer quando os cereais são expostos a determinadas condições ambientais ou quando imersos em meio líquido. A estrutura física dos cereais tem uma grande influência na difusão do líquido, pois sua alta porosidade e higroscopicidade implicam em aumento da difusividade da umidade e conseqüente aumento da atividade de água, ganhando umidade rapidamente e perdendo sua textura quebradiça desejável, tornando-se amolecido. Neste trabalho, o comportamento de três cereais matinais comerciais foi analisado e os coeficientes de difusão foram determinados, além do estudo da alteração da textura destes produtos, através das propriedades mecânicas, em relação ao tempo de imersão em leite. A variação dos valores de atividade de água em equilíbrio com as amostras em relação ao tempo de imersão foram avaliadas com o intuito de quantificar o tempo crítico e a atividade de água correspondente em que os cereais matinais comerciais perdem a crocância.

Breakfast cereals are products extrudate, starch-based, which traditionally are consumed with milk. The crispness of these products has been associated to the freshness and quality and their loss has been one of the causes of rejection by consumers. Undesirable textural changes may occur when these cereals are exposed to the atmospheric environment or are soaked in liquid medium. The physical structure of these cereals has a great influence in the moisture diffusion, therefore their high porosity and hygroscopic behavior imply in increase of the diffusivity of the milk and increase of the water activity, gaining moisture quickly and loosing their desirable brittle texture, becoming soggy. This behavior could be related to a transition from the glassy solid state to rubbery liquid state. In this work the behavior of three commercial breakfast cereals were analyzed, the mass diffusion coefficients were determined, besides the texture change of these products, using mechanical properties, which were related to the time of immersion in milk. The variation of water activity values, at equilibrium, of cereal samples immersed in milk was determined to quantify the critical time and the water activity value in that the commercial breakfast cereals became soggy.