Sulfonamides are among the most widely employed antibacterial in veterinary medicine. Because a substantial proportion of sulfonamides are excreted unchanged as parent compounds after administration or are excreted as their metabolites through urine and feces, their presence in soils is a matter of concern. Adsorption and desorption are important processes that influence the transport, transformation and bioavailability of antimicrobials in soils, and data related to sorption capacity are therefore needed for environmental risk assessments. The sorption potential of sulfachloropyridazine (SCP) was assessed in four Brazilians soils using batch equilibrium experiments. The adsorption/desorption data fit well Freundlich isotherms. The sorption coefficients (KD) ranged from 1.00 to 4.48 cm3 g-1, and the Freundlich adsorption coefficient (KF) ranged from 1.89 to 5.63 µg1-1/n (cm3)1/n g-1 showing that SCP adsorption is generally low in the studied soils. The results were compared with previously published data obtained for the sorption of other sulfonamides in the same four soils.

A desidratação osmótica é uma etapa essencial na elaboração de produtos de fruta através da Tecnologia dos Métodos Combinados ou de Obstáculos ("Hurdle Technology"), pois reduz a atividade de água para níveis que, combinando um ou mais obstáculos, aumentam a estabilidade do produto. Neste processo há uma perda de água da fruta para a solução e incorporação de sólidos solúveis pelo produto. Este último fluxo é considerado uma desvantagem do processo pois pode alterar o sabor do produto. Neste trabalho estudou-se a ação de revestimentos comestíveis a base de alginato e gelatina aplicados em abacaxis, previamente à desidratação osmótica, como barreira à incorporação de sólidos solúveis. Os abacaxis com e sem revestimento (controle) foram desidratados em solução de sacarose sob condições isotérmicas. Foram determinadas as isotermas de dessorção de abacaxis revestidos com gelatina, alginato e sem revestimento e os parâmetros cinéticos do processo de desidratação osmótica. Abacaxis revestidos com alginato apresentaram menor velocidade de ganho de sólidos, sem alterar a velocidade de perda de água, quando comparado ao controle.

The osmotic dehydration is an essential stage to manufacture fruit products by Hurdle Technology because it reduces the water activity to levels that, combined with one or more obstacles, increase the stability of the product. This process causes a loss of water from the fruit to solution and soluble solid incorporation by the product. This last flow is considered a disadvantage of the process because it can modify the product flavor. In this work, the action of alginate and gelatin edible coatings as a barrier to soluble solid incorporation during osmotic dehydration was studied. Pineapples with and without coating (control) were dehydrated in sucrose solution under isothermal conditions. The desorption isotherms of pineapples coated with gelatin, sodium alginate and without coating, as well as the kinetic parameters of the osmotic dehydration process were determined. Alginate coated pineapples presented minor solid incorporation without modifying the water loss flow when compared with the control.