Edmar das Mercês Penha

Suco de maracujá orgânico processado por microfiltração

The objective of this work was to evaluate the use of microfiltration to obtain clarified organic passion fruit juice and analyse its sensory acceptability. Passion fruit was cultivated under organic system in Rio de Janeiro State. The juice was submitted to an enzymatic treatment before microfiltration, in order to decrease its viscosity and pulp content, and to improve permeate flux. Microfiltration had been accomplished with a tubular 0.3 µm pore size membrane with 0.05 m2 of filtration area. The process promoted complete removal of the suspended pulp in permeated juice, which resulted in a limpid and clarified juice. Concerning the sensorial analysis, passion fruit refreshment obtained from clarified juice was approved by 75% of the consumers. The microfiltered passion fruit juice was conserved in plastic package for 28 days under refrigeration temperature (7oC). Results confirm the efficiency of microfiltration as an alternative method for conservation of passion fruit juice, and point out the importance of this technology for the processing of organic juices.

COMPARAÇÃO DA ESPECIFICIDADE DE LIPASES DE DUAS CEPAS DE Aspergillus niger NA HIDRÓLISE ENZIMÁTICA DO ÓLEO DE GIRASSOL

Diversas pesquisas tem estudado a tecnologia de modificacao dos oleos e gorduras e a obtencao de concentrados de acidos graxos poli-insaturados que beneficiem a saude do ser humano. As lipases sao enzimas que catalisam a hidrolise parcial ou total destes triacilglicerois (TAGs) produzindo acidos graxos livres (AGLs), diacilglicerol (DAG), monoacilglicerol (MAG) e glicerol. Neste trabalho, as enzimas produzidas pela cepa mutante Aspergillus niger 11T53A14 e pela cepa selvagem Aspergillus niger C foram utilizadas para a hidrolise do oleo de girassol. As lipases foram caracterizadas quanto a sua espeficidade em relacao a diferentes p-nitrofenil esteres e aplicadas na hidrolise de oleo de girassol. As condicoes da hidrolise enzimatica do oleo de girassol foram: proporcao molar de agua:oleo (8:1); carga da lipase de 5 U/g de oleo; 50°C e agitacao orbital de 150 rpm. Os acidos graxos livres foram quantificados em titulador automatico com NaOH 0,05 N. Os melhores resultados de hidrolise foram obtidos com extrato bruto de A. niger C, que apresentaram 228 mM de acidos graxos livres em 5,5 horas de reacao.