Evaluation of reverse osmosis and osmotic evaporation to concentrate camu-camu juice (Myrciaria dubia)

This study presents a first evaluation of the potential of two membrane processes for the production of concentrated camu-camu juice with high vitamin C content. A clarified camu-camu juice at around 64 g kg(-1) of total soluble solids (TSS) with an average ascorbic acid content of 11 g kg(-1) was subsequently concentrated by reverse osmosis and osmotic evaporation at low temperature (20-35 degreesC). Reverse osmosis trials were carried out in a pilot scale equipment, using a composite film membrane with 95% NaCl rejection. The average permeate flux obtained were between 18 and 50 kg h(-1) m(-2) depending on the transmembrane pressure used. The maximum total soluble solids content reached was 255 g kg(-1) at 60 bar and the ascorbic acid losses were between 8% and 18%. Osmotic evaporation trials were carried out using a laboratory unit with a PTFE flat sheet membrane with an average pore diameter of 0.2 mum. In that case, the juice was concentrated in two steps, the first concentrating the juice up to 250 g kg(-1) TSS, and the second from 250 to 640 g kg(-1) TSS. The difference in temperature between the juice and the brine had a great influence on the evaporation rate. The higher average evaporating flux obtained was 12 kg h(-1) m(-2). For all experiments, the ascorbic acid losses were about 3% that indicated the efficiency of the process in maintaining the nutritional quality of the juice regarding vitamin C content. These two membrane concentration processes are very interesting for the concentration of camu-camu juice. The low concentration level that can be reached is the major drawback of reverse osmosis. Osmotic evaporation allows to produce a concentrate with more than 10% of ascorbic acid. (C) 2003 Elsevier Ltd. All rights reserved.6319710

Estresse percebido em profissionais da Estratégia Saúde da Família

Objective: To evaluate the perceived stress (PS) of professionals in Primary Health Care and its association with the characteristics of the teams in the Family Health Program (FHP). The association between PS and self-referred morbidity was also investigated. Methods: This is a cross-sectional study conducted with 450 employees from 60 teams in 12 Basic Health Units (BHUs) in a region of São Paulo. The differences in the total score in the Perceived Stress Scale were evaluated through multiple linear regression models. Results: Higher levels of PS were observed in those who had been working for one year or more in the same team, in the categories of doctors, nurses and community health workers, females, non-religious, and in BHU professionals in incomplete teams (absence of a physician). Lower perceived stress was found in widowers. It was observed that individuals with higher levels of PS have higher chances of reporting chronic health problems. Conclusion: It can be concluded that the perception of stress in this population is associated with individual, professional factors, and the composition of teams in healthcare units. Objetivo: Avaliar o estresse percebido (EP) de profissionais da Estratégia de Saúde da Família (ESF) e a associação com características das equipes. Também foi investigada a ocorrência de associação entre EP e morbidade autorreferida. Métodos: Trata-se de estudo transversal com 450 trabalhadores de 60 equipes em 12 Unidades Básicas de Saúde (UBS), em uma região de São Paulo. As diferenças entre o escore total da Escala de Estresse Percebido e suas associações com as características individuais e das equipes foram avaliadas por meio de modelos múltiplos de regressão linear. Resultados: Observaram-se níveis mais elevados de EP naqueles com tempo de trabalho igual ou superior a um ano na mesma equipe, nas categorias de médicos, enfermeiros e agentes comunitários de saúde, gênero feminino, em não praticantes de credos religiosos, e em profissionais de UBS com equipes incompletas (ausência do médico). Menor estresse percebido foi encontrado em viúvos. Observou-se que indivíduos com níveis mais elevados de EP têm mais chance de relatar problemas crônicos de saúde. Conclusão: Conclui-se que a percepção de estresse na população estudada está associada a fatores individuais, profissionais, e à composição das equipes nas unidades básicas de saúde