RESUMO
Sementes de maracujá foram submetidas à prensagem sob diferentes taxas de alimentação (1,2 a 3,0kgh-1) com o objetivo de avaliar o impacto desta variação no rendimento do processo de extração, nas características de qualidade e na composição em ácidos graxos do óleo de semente de maracujá. O rendimento de extração de óleo variou entre 24 e 25%, com eficiência de 84 a 86% e teor residual de óleo na torta parcialmente desengordurada em torno de 5%, indicando que o processo utilizado foi adequado à matéria-prima. O menor valor de temperatura de saída do óleo da prensa foi observado na taxa de alimentação de 2,4kgh-1. Não houve diferença significativa (P>0,05) para a composição em ácidos graxos, estabilidade oxidativa, densidade e para os índices de iodo, saponificação, refração e de peróxidos. No entanto, houve diferença (P<0,05) quanto ao teor de ácidos graxos livres, que foi menor para o óleo obtido na maior taxa de alimentação, e para umidade do óleo, que foi maior para a menor taxa de alimentação. A taxa de alimentação na prensagem de sementes de maracujá promoveu diferenças quanto à qualidade do óleo.
Passion fruit seeds were subjected to pressing under different feed rates (1.2 to 3.0kgh-1) in order to assess the impact of this variation in the yield of the extraction process, the quality characteristics and fatty acid composition of the passion fruit seed oil obtained. The yield of the process ranged between 24 and 25% and presented 84 to 86% of efficiency and residual oil in partially defatted cake around 5%, indicating that the procedure was adequate to the raw material. The lowest press oil outlet temperature was observed at the feed rate of 2.4kgh-1. No significant difference (P>0.05) were observed for fatty acid composition, oxidative stability, density and iodine, saponification, refraction and peroxide values. However, significant differences (P<0.05) was observed on free fatty acids content, which was lower for the highest feed rate, and oil moisture, which was higher for the lowest feed rate. The feed rate in pressing of passion fruit seeds promoted differences in oil quality.
RESUMO
The aim of this study was to investigate the effect of thickness (between 80 and 120 µm) on apparent opacity, water vapor permeability and mechanical properties (tensile and puncture) of oat starch films plasticized with glycerol, sorbitol, glycerol:sorbitol mixture, urea and sucrose. Films were stored under 11, 57, 76 and 90% relative humidity (RH) to study the mechanical properties. It was observed that the higher the thickness, the higher was the opacity values. Films without the plasticizer were more opaque in comparison with the plasticized ones. Glycerol:sorbitol films presented increased elongation with increasing thickness at all RH. Puncture force showed a strong dependence on the film thickness, except for the films plasticized with sucrose. In general, thickness did not affect the water permeability.