The aim of this study was the production of amylolytic enzymes by solid state or submerged fermentations (SSF or SF, respectively), followed by purification using chemical process or microfiltration and immobilization of purified enzymes in a polyurethane support. The free and immobilized enzymes obtained were used to evaluate enzymatic hydrolysis of the polysaccharides of Spirulina. Microfiltration of the crude extracts resulted in an increase in their specific activity and thermal stability at 40°C and 50°C for 24h, as compared to extracts obtained by SSF and SF. Immobilization of polyurethane purified enzyme produced yields of 332% and 205% for the enzymes obtained by SF and SSF, respectively. Free or immobilized enzymes favor the generation of fermentable sugar, being the application of the purified and immobilized enzymes in the hydrolysis of microalgal polysaccharides considered a promising alternative towards development of the bioethanol production process from microalgal biomass.

Purpose The phycocyanin is a pigment present in the microalga Spirulina that has been studied due to its applicability as food coloring; however, it can be used due to the ability to act as an emulsifier or stabilizer in function of its protein characteristic. The purpose of this paper is to use aqueous extracts of Spirulina containing phycocyanin (EP) as a substitute of additives in the production of ice creams. Design/methodology/approach The study was divided in two sections: first, the influence of addition of EP in ice cream bases (that represent the ice cream preparation before air incorporation step) and second, the influence of addition of EP in five ice cream formulations, in which the differences were the addition of EP in substitution of stabilizer, Chantilly or emulsifier, one at a time or in substitution of all additives together, by the EP. Findings The different ice creams developed presented centesimal composition according to Brazilian legislation in relation to the chemical parameters. The EP presented emulsifying and stabilizing activity in the ice creams formulations acting in substitution of emulsifier and stabilizer presented in the standard formulation, not influencing the overall acceptability of consumers. Originality/value The authors demonstrate that the aqueous extract of Spirulina containing phycocyanin can be used as a natural additive in ice cream in substitution of emulsifiers and stabilizers normally used in this product, contributing to produce more healthy foods, once phycocyanin is an protein of high nutritional value.

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Os fertilizantes são intencionalmente adicionados no solo ou na superfície da planta com o objetivo de fornecer os nutrientes necessários durante sua vida e assim aumentar a produtividade. Os principais nutrientes utilizados na agricultura são nitrogênio, fósforo e potássio, sendo o conjunto destes macronutrientes chamados de N-P-K. O uso indiscriminado e de longo prazo de fertilizantes tem se tornado uma fonte relevante de poluição do solo, ar e água. O desequilíbrio entre as taxas de liberação dos nutrientes oriundos dos fertilizantes e as taxas de absorção pelas plantas, tornam o processo de fertilização do solo menos eficientes. Para resolver este problema, pode-se usar fertilizantes que tem em sua composição mecanismos que fazem com que os nutrientes adequados para as plantas sejam liberados de maneira compatível com suas demandas. Estes materiais são chamados de fertilizantes de liberação lenta. Uma revisão da literatura é realizada neste trabalho com o objetivo de avaliar as principais características dos fertilizantes de liberação lenta a base de materiais zeolíticos. As zeólitas são aluminosilicatos hidratados de metais alcalinos ou alcalinos terrosos e tem como principais aplicações o uso em tratamento de água e efluentes. As principais características das zeólitas são também abordadas buscando compreender suas propriedades potenciais para a aplicação proposta. Os benefícios em relação ao uso destes materiais na agricultura referem-se principalmente a sua notável seletividade catiônica e microporosidade. O uso de fertilizantes de liberação lenta a base de zeólitas se mostra uma possibilidade factível de utilização na agricultura, aumentando a eficiência e melhorando a sustentabilidade econômica, social e ambiental dos processos de produção agrícola.

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