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”).

The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5ºC and light intensities from 15 to 69 µmol photons m-2 s-1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation performed with both sources of nitrogen, it was possible to obtain satisfactory adjustments to relate the dependent variables to the independent variables. The best results were achieved at temperature of 30ºC, at light intensity of 60 µmol photons m-2s-1, for cell growth, with cell productivity of approximately 95 mg L-1 d-1 in cultivations with urea. For the chlorophyll biomass content, the most adequate light intensity was 24 µmol photons m-2 s-1.