Arthur Claudio Rodrigues de Souza

Estudo das variáveis de processo sobre a cinética de desidratação osmótica de melão

Osmotic dehydration represents a technological alternative to reduce post-harvest losses of fruits. The purpose of this work was to evaluate the influence of the osmotic solution concentration, fruit to osmotic solution ratio and system pressure on kinetics of the osmotic dehydration of melon. It was used 45o, 55o and 65oBrix sucrose solutions at 65oC, and 1:2 and 1:4 fruit to osmotic solution ratios. The osmotic treatments were carried out under atmospheric pressure and vacuum, for five hours. The use of vacuum in the osmotic dehydration of melon intensified the mass transport flows in the system when compared with the ones under atmospheric pressure, in the same conditions of concentration and fruit to osmotic solution ratio. The osmotic treatment under vacuum, which used 65oBrix sucrose solution and 1:4 fruit to osmotic solution ratio, showed be efficient for speeding up the water loss of the product, making possible to reach high degree of dehydration with a relatively small solids gain, in a shorter period of time when compared with the others treatments studied. The kinetics of the osmotic dehydration of melon is influenced by the process conditions, specially by the system pressure and osmotic solution concentration.

Efeito da aplicação de enzimas pectinolíticas no rendimento da extração de polpa de cupuaçu

Brazil displays an richness fruits varieties, many of which occur in the warmer north and northeastern regions of the country. The exotic ¾flavored cupuassu is of particular interest for its importance on the markets in southeastern Brazil and Europe. The pul and the pits constitute industrial raw material of significant potential. As object of studies in the area of nectar production, the pulp of the cupuassu is more commonly used for manufacturing ice cream, jam, mash and canned pulp. However, the pulp and the pit adheres very tighty to each other, their separation is done manually with the aid of domestic utensils such as spoons , scissors and knives, yielding rather small amounts of pulp for further processing. In order to increase the yield during the extraction process, two commercial pectinolitic enzymes (Citrozym L and Rohament PL) in concentrations of 100, 300, 500 and 750 ppm were added to the total pulp. The final yield was compared to that obtained with the control pulp (without enzymes). The experiment was carried out at the food technology laboratories at the Embrapa Tropical Agro-Industry. With the addition of the Citrozim L, tthe yield was over 60% at concentrations of 300, 500 and 750 ppm, while with the addition of Rohament PL the yield attained values between 43 and 57% at these same concentrations. The yield of the control sample was 44% for Citrozym L and 41% for Rohament PL. In conclusion, the use of enzymes with the purpose of increasing the yield of cupuacu pulp during extraction is a viable alternative, and at 300 ppm or more the yield obtained is approximately 60%.