The mechanical performance of lightweight glass packages produced by the NNPB (narrow neck press and blow) process was evaluated by comparison with the same glass packages (regular weight) produced by the conventional process (blow and blow). The temper number (annealing process evaluation), thickness distribution behaviour and mechanical performance (impact, vertical load and thermal shock strength) were analysed before and after line simulation, applied in optimized conditions in the laboratory. The performance of lightweight glass packages under transport simulation (truck envelope) in relation to the regular weight bottles was also evaluated. Both bottles presented residual stress values within the speci®ed limits. The lightweight glass bottles had a more homogenous thickness distribution in comparison with the regular weight bottles and a better performance (about 33% improvement) in relation to the impact strength, especially in the heel, even when evaluated after line simulation. As to the vertical load strength, the lightweight glass bottle also indicated a superior performance to the regular weight bottle, both before and after line simulation. Both bottles withstood the temperature difference of 42°C that such packages are supposed to resist according to thermal shock speci®cation. Due to the better thickness distribution of lightweight glass packages, they withstood a maximum temperature difference (progressive thermal shock) of 5±10°C higher than the regular weight bottles. No restrictions of the lightweight glass packages submitted to the transport simulation were found.
ABSTRACT:The vibration during transportation is one of the main causes of fruit damage. The actual methodologies used for damage evaluation in fruits seem to be subjective, since most of them are based on visual evaluation. In this study the effect of vibration, for one and two hours, on polyphenoloxidase (PPO) activity in peach pulp was investigated. The relation among PPO activity variation, postharvest time and resting time were also considered. Results showed that vibration affects PPO activity. However, it was not possible to correlate PPO activity variation and vibration.KEYWORDS: polyphenoloxidase, vibration, damage, peach.
ATIVIDADE DE POLIFENOLOXIDASE EM PÊSSEGOS APÓS VIBRAÇÃO RESUMO:A vibração durante o transporte é uma das principais causas de dano em frutas. As metodologias atuais utilizadas na avaliação de danos em frutas parecem ser subjetivas, visto que a maioria delas é baseada em avaliações visuais. Neste trabalho, investigou-se o efeito da vibração em dois níveis, uma e duas horas, sobre a atividade de polifenoloxidase (PPO) em pêssegos. A relação entre a variação da atividade de PPO, tempo pós-colheita e tempo de repouso também foi considerada. Os resultados mostraram que a vibração afeta a atividade de PPO. Entretanto, não foi possível correlacionar a variação da atividade de PPO e a vibração.
PALAVRAS-CHAVE:polifenoloxidase, vibração, dano, pêssego.
In spite of being a raw material of virtually unlimited availability due to the massive consumption of the highly popular coconut water, fiber produced from green coconut is much less used than the dried coconut fiber. The objective of this study was to investigate the performance of green (white) coconut fiber as a cushioning material for use in packaging systems. The mechanical performance of both green coconut fibers in their natural state as well as those molded into the shape of cushioning pads were evaluated by shock absorption tests. The results showed that the fibers without agglutination agents exhibited the best performance when submitted to increasing static loads by presenting the greatest capacity to reduce impact acceleration. In addition, green coconut fiber presented behavior similar to that of cellulosic cushioning materials and in certain situations can be considered effective in protecting products that are considered fragile.
For the purpose to explore more ecologically sound alternatives as cushioning materials to protect fruits against injury during transport, the objective of the research was to evaluate the performance of coconut fiber and wood straw during the simulated transport of papayas and mangoes. Tests were carried out to simulate the transport of fruits in corrugated paperboard boxes in three different packaging systems: (1) with no cushioning, (2) with coconut fiber and (3) with wood straw. Physical and physiological behaviors of papaya and mango throughout transport and storage period were studied, and the rate of injuries, weight loss, skin color and respiration rate were quantified. The results showed that the coconut fiber was more efficient than wood straw in the prevention of pulp injuries, but not in prevention of abrasions on papaya surface. In mangoes, no significant differences were found between the two cushioning materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.